Advanced to version 0.6.0.

.gitignore

@@ -38,3 +38,4 @@ excludes
 *.mo
 zh_Hans
 test_temp.py
+dummy.js

MANIFEST.in

@@ -15,6 +15,7 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 
+exclude src/accounting/static/js/dummy.js
 include src/accounting/translations/*
 include src/accounting/translations/*/LC_MESSAGES/*
 include docs/*
@@ -22,6 +23,7 @@ include docs/source/*
 include docs/source/_static/*
 include docs/source/_templates/*
 include tests/*
+exclude tests/test_temp.py
 include tests/test_site/*
 include tests/test_site/templates/*
 include tests/test_site/translations/*

docs/source/accounting.transaction.forms.rst

@@ -0,0 +1,45 @@
+accounting.transaction.forms package
+====================================
+
+Submodules
+----------
+
+accounting.transaction.forms.currency module
+--------------------------------------------
+
+.. automodule:: accounting.transaction.forms.currency
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.forms.journal\_entry module
+--------------------------------------------------
+
+.. automodule:: accounting.transaction.forms.journal_entry
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.forms.reorder module
+-------------------------------------------
+
+.. automodule:: accounting.transaction.forms.reorder
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.forms.transaction module
+-----------------------------------------------
+
+.. automodule:: accounting.transaction.forms.transaction
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+Module contents
+---------------
+
+.. automodule:: accounting.transaction.forms
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/source/accounting.transaction.rst

@@ -1,6 +1,15 @@
 accounting.transaction package
 ==============================
 
+Subpackages
+-----------
+
+.. toctree::
+   :maxdepth: 4
+
+   accounting.transaction.forms
+   accounting.transaction.utils
+
 Submodules
 ----------
 
@@ -12,30 +21,6 @@ accounting.transaction.converters module
    :undoc-members:
    :show-inheritance:
 
-accounting.transaction.forms module
------------------------------------
-
-.. automodule:: accounting.transaction.forms
-   :members:
-   :undoc-members:
-   :show-inheritance:
-
-accounting.transaction.operators module
----------------------------------------
-
-.. automodule:: accounting.transaction.operators
-   :members:
-   :undoc-members:
-   :show-inheritance:
-
-accounting.transaction.summary\_editor module
----------------------------------------------
-
-.. automodule:: accounting.transaction.summary_editor
-   :members:
-   :undoc-members:
-   :show-inheritance:
-
 accounting.transaction.template\_filters module
 -----------------------------------------------
 

docs/source/accounting.transaction.utils.rst

@@ -0,0 +1,53 @@
+accounting.transaction.utils package
+====================================
+
+Submodules
+----------
+
+accounting.transaction.utils.account\_option module
+---------------------------------------------------
+
+.. automodule:: accounting.transaction.utils.account_option
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.utils.offset\_alias module
+-------------------------------------------------
+
+.. automodule:: accounting.transaction.utils.offset_alias
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.utils.operators module
+---------------------------------------------
+
+.. automodule:: accounting.transaction.utils.operators
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.utils.original\_entries module
+-----------------------------------------------------
+
+.. automodule:: accounting.transaction.utils.original_entries
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+accounting.transaction.utils.summary\_editor module
+---------------------------------------------------
+
+.. automodule:: accounting.transaction.utils.summary_editor
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+Module contents
+---------------
+
+.. automodule:: accounting.transaction.utils
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/source/accounting.utils.rst

@@ -4,6 +4,14 @@ accounting.utils package
 Submodules
 ----------
 
+accounting.utils.cast module
+----------------------------
+
+.. automodule:: accounting.utils.cast
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
 accounting.utils.flash\_errors module
 -------------------------------------
 

setup.cfg

@@ -17,7 +17,7 @@
 
 [metadata]
 name = mia-accounting-flask
-version = 0.5.0
+version = 0.6.0
 author = imacat
 author_email = imacat@mail.imacat.idv.tw
 description = The Mia! Accounting Flask project.

src/accounting/__init__.py

@@ -17,13 +17,12 @@
 """The accounting application.
 
 """
-import typing as t
 from pathlib import Path
 
 from flask import Flask, Blueprint
 from flask_sqlalchemy import SQLAlchemy
 
-from accounting.utils.user import AbstractUserUtils
+from accounting.utils.user import UserUtilityInterface
 
 db: SQLAlchemy = SQLAlchemy()
 """The database instance."""
@@ -31,19 +30,13 @@ data_dir: Path = Path(__file__).parent / "data"
 """The data directory."""
 
 
-def init_app(app: Flask, user_utils: AbstractUserUtils,
-             url_prefix: str = "/accounting",
-             can_view_func: t.Callable[[], bool] | None = None,
-             can_edit_func: t.Callable[[], bool] | None = None) -> None:
+def init_app(app: Flask, user_utils: UserUtilityInterface,
+             url_prefix: str = "/accounting") -> None:
     """Initialize the application.
 
     :param app: The Flask application.
     :param user_utils: The user utilities.
     :param url_prefix: The URL prefix of the accounting application.
-    :param can_view_func: A callback that returns whether the current user can
-        view the accounting data.
-    :param can_edit_func: A callback that returns whether the current user can
-        edit the accounting data.
     :return: None.
     """
     # The database instance must be set before loading everything
@@ -73,7 +66,7 @@ def init_app(app: Flask, user_utils: AbstractUserUtils,
     locale.init_app(app, bp)
 
     from .utils import permission
-    permission.init_app(bp, can_view_func, can_edit_func)
+    permission.init_app(bp, user_utils)
 
     from .utils import next_uri
     next_uri.init_app(bp)

src/accounting/account/commands.py

@@ -18,7 +18,6 @@
 
 """
 import os
-import re
 from secrets import randbelow
 
 import click
@@ -30,7 +29,7 @@ from accounting.utils.user import has_user, get_user_pk
 
 AccountData = tuple[int, str, int, str, str, str, bool]
 """The format of the account data, as a list of (ID, base account code, number,
-English, Traditional Chinese, Simplified Chinese, is-offset-needed) tuples."""
+English, Traditional Chinese, Simplified Chinese, is-need-offset) tuples."""
 
 
 def __validate_username(ctx: click.core.Context, param: click.core.Option,
@@ -93,14 +92,36 @@ def init_accounts_command(username: str) -> None:
     data: list[AccountData] = []
     for base in bases_to_add:
         l10n: dict[str, str] = {x.locale: x.title for x in base.l10n}
-        is_offset_needed: bool = True if re.match("^[12]1[34]", base.code) \
-            else False
+        is_need_offset: bool = __is_need_offset(base.code)
         data.append((get_new_id(), base.code, 1, base.title_l10n,
-                     l10n["zh_Hant"], l10n["zh_Hans"], is_offset_needed))
+                     l10n["zh_Hant"], l10n["zh_Hans"], is_need_offset))
     __add_accounting_accounts(data, creator_pk)
     click.echo(F"{len(data)} added.  Accounting accounts initialized.")
 
 
+def __is_need_offset(base_code: str) -> bool:
+    """Checks that whether entries in the account need offset.
+
+    :param base_code: The code of the base account.
+    :return: True if entries in the account need offset, or False otherwise.
+    """
+    # Assets
+    if base_code[0] == "1":
+        if base_code[:3] in {"113", "114", "118", "184"}:
+            return True
+        if base_code in {"1411", "1421", "1431", "1441", "1511", "1521",
+                         "1581", "1611", "1851", ""}:
+            return True
+        return False
+    # Liabilities
+    if base_code[0] == "2":
+        if base_code in {"2111", "2114", "2284", "2293"}:
+            return False
+        return True
+    # Only assets and liabilities need offset
+    return False
+
+
 def __add_accounting_accounts(data: list[AccountData], creator_pk: int)\
         -> None:
     """Adds the accounts.
@@ -113,7 +134,7 @@ def __add_accounting_accounts(data: list[AccountData], creator_pk: int)\
                                        base_code=x[1],
                                        no=x[2],
                                        title_l10n=x[3],
-                                       is_offset_needed=x[6],
+                                       is_need_offset=x[6],
                                        created_by_id=creator_pk,
                                        updated_by_id=creator_pk)
                                for x in data]

src/accounting/account/forms.py

@@ -53,6 +53,20 @@ class BaseAccountAvailable:
                 "The base account is not available."))
 
 
+class NoOffsetNominalAccount:
+    """The validator to check nominal account is not to be offset."""
+
+    def __call__(self, form: FlaskForm, field: BooleanField) -> None:
+        assert isinstance(form, AccountForm)
+        if not field.data:
+            return
+        if form.base_code.data is None:
+            return
+        if form.base_code.data[0] not in {"1", "2", "3"}:
+            raise ValidationError(lazy_gettext(
+                "A nominal account does not need offset."))
+
+
 class AccountForm(FlaskForm):
     """The form to create or edit an account."""
     base_code = StringField(
@@ -66,7 +80,8 @@ class AccountForm(FlaskForm):
         filters=[strip_text],
         validators=[DataRequired(lazy_gettext("Please fill in the title"))])
     """The title."""
-    is_offset_needed = BooleanField()
+    is_need_offset = BooleanField(
+        validators=[NoOffsetNominalAccount()])
     """Whether the the entries of this account need offset."""
 
     def populate_obj(self, obj: Account) -> None:
@@ -87,7 +102,10 @@ class AccountForm(FlaskForm):
             obj.base_code = self.base_code.data
             obj.no = count + 1
         obj.title = self.title.data
-        obj.is_offset_needed = self.is_offset_needed.data
+        if self.base_code.data[0] in {"1", "2", "3"}:
+            obj.is_need_offset = self.is_need_offset.data
+        else:
+            obj.is_need_offset = False
         if is_new:
             current_user_pk: int = get_current_user_pk()
             obj.created_by_id = current_user_pk

src/accounting/account/queries.py

@@ -48,7 +48,7 @@ def get_account_query() -> list[Account]:
                code.contains(k),
                Account.id.in_(l10n_matches)]
         if k in gettext("Need offset"):
-            sub_conditions.append(Account.is_offset_needed)
+            sub_conditions.append(Account.is_need_offset)
         conditions.append(sa.or_(*sub_conditions))
 
     return Account.query.filter(*conditions)\

src/accounting/account/views.py

@@ -27,6 +27,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Account, BaseAccount
+from accounting.utils.cast import s
 from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.pagination import Pagination
@@ -86,7 +87,7 @@ def add_account() -> redirect:
     form.populate_obj(account)
     db.session.add(account)
     db.session.commit()
-    flash(lazy_gettext("The account is added successfully"), "success")
+    flash(s(lazy_gettext("The account is added successfully")), "success")
     return redirect(inherit_next(__get_detail_uri(account)))
 
 
@@ -138,12 +139,12 @@ def update_account(account: Account) -> redirect:
     with db.session.no_autoflush:
         form.populate_obj(account)
     if not account.is_modified:
-        flash(lazy_gettext("The account was not modified."), "success")
+        flash(s(lazy_gettext("The account was not modified.")), "success")
         return redirect(inherit_next(__get_detail_uri(account)))
     account.updated_by_id = get_current_user_pk()
     account.updated_at = sa.func.now()
     db.session.commit()
-    flash(lazy_gettext("The account is updated successfully."), "success")
+    flash(s(lazy_gettext("The account is updated successfully.")), "success")
     return redirect(inherit_next(__get_detail_uri(account)))
 
 
@@ -159,7 +160,7 @@ def delete_account(account: Account) -> redirect:
     account.delete()
     sort_accounts_in(account.base_code, account.id)
     db.session.commit()
-    flash(lazy_gettext("The account is deleted successfully."), "success")
+    flash(s(lazy_gettext("The account is deleted successfully.")), "success")
     return redirect(or_next(__get_list_uri()))
 
 
@@ -186,10 +187,10 @@ def sort_accounts(base: BaseAccount) -> redirect:
     form: AccountReorderForm = AccountReorderForm(base)
     form.save_order()
     if not form.is_modified:
-        flash(lazy_gettext("The order was not modified."), "success")
+        flash(s(lazy_gettext("The order was not modified.")), "success")
         return redirect(or_next(__get_list_uri()))
     db.session.commit()
-    flash(lazy_gettext("The order is updated successfully."), "success")
+    flash(s(lazy_gettext("The order is updated successfully.")), "success")
     return redirect(or_next(__get_list_uri()))
 
 

src/accounting/currency/forms.py

@@ -17,8 +17,6 @@
 """The forms for the currency management.
 
 """
-from __future__ import annotations
-
 from flask_wtf import FlaskForm
 from wtforms import StringField, ValidationError
 from wtforms.validators import DataRequired, Regexp, NoneOf
@@ -30,22 +28,24 @@ from accounting.utils.strip_text import strip_text
 from accounting.utils.user import get_current_user_pk
 
 
+class CodeUnique:
+    """The validator to check if the code is unique."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, CurrencyForm)
+        if field.data == "":
+            return
+        if form.obj_code is not None and form.obj_code == field.data:
+            return
+        if db.session.get(Currency, field.data) is not None:
+            raise ValidationError(lazy_gettext(
+                "Code conflicts with another currency."))
+
+
 class CurrencyForm(FlaskForm):
     """The form to create or edit a currency."""
     CODE_BLOCKLIST: list[str] = ["create", "store", "exists-code"]
     """The reserved codes that are not available."""
-
-    class CodeUnique:
-        """The validator to check if the code is unique."""
-        def __call__(self, form: CurrencyForm, field: StringField) -> None:
-            if field.data == "":
-                return
-            if form.obj_code is not None and form.obj_code == field.data:
-                return
-            if db.session.get(Currency, field.data) is not None:
-                raise ValidationError(lazy_gettext(
-                    "Code conflicts with another currency."))
-
     code = StringField(
         filters=[strip_text],
         validators=[DataRequired(lazy_gettext("Please fill in the code.")),

src/accounting/currency/views.py

@@ -27,6 +27,7 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Currency
+from accounting.utils.cast import s
 from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.pagination import Pagination
@@ -88,7 +89,7 @@ def add_currency() -> redirect:
     form.populate_obj(currency)
     db.session.add(currency)
     db.session.commit()
-    flash(lazy_gettext("The currency is added successfully"), "success")
+    flash(s(lazy_gettext("The currency is added successfully")), "success")
     return redirect(inherit_next(__get_detail_uri(currency)))
 
 
@@ -141,12 +142,12 @@ def update_currency(currency: Currency) -> redirect:
     with db.session.no_autoflush:
         form.populate_obj(currency)
     if not currency.is_modified:
-        flash(lazy_gettext("The currency was not modified."), "success")
+        flash(s(lazy_gettext("The currency was not modified.")), "success")
         return redirect(inherit_next(__get_detail_uri(currency)))
     currency.updated_by_id = get_current_user_pk()
     currency.updated_at = sa.func.now()
     db.session.commit()
-    flash(lazy_gettext("The currency is updated successfully."), "success")
+    flash(s(lazy_gettext("The currency is updated successfully.")), "success")
     return redirect(inherit_next(__get_detail_uri(currency)))
 
 
@@ -161,7 +162,7 @@ def delete_currency(currency: Currency) -> redirect:
     """
     currency.delete()
     db.session.commit()
-    flash(lazy_gettext("The currency is deleted successfully."), "success")
+    flash(s(lazy_gettext("The currency is deleted successfully.")), "success")
     return redirect(or_next(url_for("accounting.currency.list")))
 
 
@@ -182,4 +183,3 @@ def __get_detail_uri(currency: Currency) -> str:
     :return: The detail URI of the currency.
     """
     return url_for("accounting.currency.detail", currency=currency)
-

src/accounting/models.py

@@ -21,6 +21,7 @@ from __future__ import annotations
 
 import re
 import typing as t
+from datetime import date
 from decimal import Decimal
 
 import sqlalchemy as sa
@@ -113,7 +114,7 @@ class Account(db.Model):
     """The account number under the base account."""
     title_l10n = db.Column("title", db.String, nullable=False)
     """The title."""
-    is_offset_needed = db.Column(db.Boolean, nullable=False, default=False)
+    is_need_offset = db.Column(db.Boolean, nullable=False, default=False)
     """Whether the entries of this account need offset."""
     created_at = db.Column(db.DateTime(timezone=True), nullable=False,
                            server_default=db.func.now())
@@ -197,6 +198,52 @@ class Account(db.Model):
                 return
         self.l10n.append(AccountL10n(locale=current_locale, title=value))
 
+    @property
+    def is_real(self) -> bool:
+        """Returns whether the account is a real account.
+
+        :return: True if the account is a real account, or False otherwise.
+        """
+        return self.base_code[0] in {"1", "2", "3"}
+
+    @property
+    def is_nominal(self) -> bool:
+        """Returns whether the account is a nominal account.
+
+        :return: True if the account is a nominal account, or False otherwise.
+        """
+        return not self.is_real
+
+    @property
+    def query_values(self) -> list[str]:
+        """Returns the values to be queried.
+
+        :return: The values to be queried.
+        """
+        return [self.code, self.title_l10n] + [x.title for x in self.l10n]
+
+    @property
+    def is_modified(self) -> bool:
+        """Returns whether a product account was modified.
+
+        :return: True if modified, or False otherwise.
+        """
+        if db.session.is_modified(self):
+            return True
+        for l10n in self.l10n:
+            if db.session.is_modified(l10n):
+                return True
+        return False
+
+    def delete(self) -> None:
+        """Deletes this account.
+
+        :return: None.
+        """
+        AccountL10n.query.filter(AccountL10n.account == self).delete()
+        cls: t.Type[t.Self] = self.__class__
+        cls.query.filter(cls.id == self.id).delete()
+
     @classmethod
     def find_by_code(cls, code: str) -> t.Self | None:
         """Finds an account by its code.
@@ -251,14 +298,6 @@ class Account(db.Model):
                                 cls.base_code != "3353")\
             .order_by(cls.base_code, cls.no).all()
 
-    @property
-    def query_values(self) -> list[str]:
-        """Returns the values to be queried.
-
-        :return: The values to be queried.
-        """
-        return [self.code, self.title_l10n] + [x.title for x in self.l10n]
-
     @classmethod
     def cash(cls) -> t.Self:
         """Returns the cash account.
@@ -275,28 +314,6 @@ class Account(db.Model):
         """
         return cls.find_by_code(cls.ACCUMULATED_CHANGE_CODE)
 
-    @property
-    def is_modified(self) -> bool:
-        """Returns whether a product account was modified.
-
-        :return: True if modified, or False otherwise.
-        """
-        if db.session.is_modified(self):
-            return True
-        for l10n in self.l10n:
-            if db.session.is_modified(l10n):
-                return True
-        return False
-
-    def delete(self) -> None:
-        """Deletes this account.
-
-        :return: None.
-        """
-        AccountL10n.query.filter(AccountL10n.account == self).delete()
-        cls: t.Type[t.Self] = self.__class__
-        cls.query.filter(cls.id == self.id).delete()
-
 
 class AccountL10n(db.Model):
     """A localized account title."""
@@ -568,6 +585,21 @@ class Transaction(db.Model):
                 return False
         return True
 
+    @property
+    def can_delete(self) -> bool:
+        """Returns whether the transaction can be deleted.
+
+        :return: True if the transaction can be deleted, or False otherwise.
+        """
+        if not hasattr(self, "__can_delete"):
+            def has_offset() -> bool:
+                for entry in self.entries:
+                    if len(entry.offsets) > 0:
+                        return True
+                return False
+            setattr(self, "__can_delete", not has_offset())
+        return getattr(self, "__can_delete")
+
     def delete(self) -> None:
         """Deletes the transaction.
 
@@ -597,14 +629,14 @@ class JournalEntry(db.Model):
     """True for a debit entry, or False for a credit entry."""
     no = db.Column(db.Integer, nullable=False)
     """The entry number under the transaction and debit or credit."""
-    offset_original_id = db.Column(db.Integer,
-                                   db.ForeignKey(id, onupdate="CASCADE"),
-                                   nullable=True)
-    """The ID of the original entry to offset."""
-    offset_original = db.relationship("JournalEntry", back_populates="offsets",
-                                      remote_side=id, passive_deletes=True)
-    """The original entry to offset."""
-    offsets = db.relationship("JournalEntry", back_populates="offset_original")
+    original_entry_id = db.Column(db.Integer,
+                                  db.ForeignKey(id, onupdate="CASCADE"),
+                                  nullable=True)
+    """The ID of the original entry."""
+    original_entry = db.relationship("JournalEntry", back_populates="offsets",
+                                     remote_side=id, passive_deletes=True)
+    """The original entry."""
+    offsets = db.relationship("JournalEntry", back_populates="original_entry")
     """The offset entries."""
     currency_code = db.Column(db.String,
                               db.ForeignKey(Currency.code, onupdate="CASCADE"),
@@ -624,6 +656,21 @@ class JournalEntry(db.Model):
     amount = db.Column(db.Numeric(14, 2), nullable=False)
     """The amount."""
 
+    def __str__(self) -> str:
+        """Returns the string representation of the journal entry.
+
+        :return: The string representation of the journal entry.
+        """
+        if not hasattr(self, "__str"):
+            from accounting.template_filters import format_date, format_amount
+            setattr(self, "__str",
+                    gettext("%(date)s %(summary)s %(amount)s",
+                            date=format_date(self.transaction.date),
+                            summary="" if self.summary is None
+                            else self.summary,
+                            amount=format_amount(self.amount)))
+        return getattr(self, "__str")
+
     @property
     def eid(self) -> int | None:
         """Returns the journal entry ID.  This is the alternative name of the
@@ -649,6 +696,20 @@ class JournalEntry(db.Model):
         """
         return self.amount if self.is_debit else None
 
+    @property
+    def is_need_offset(self) -> bool:
+        """Returns whether the entry needs offset.
+
+        :return: True if the entry needs offset, or False otherwise.
+        """
+        if not self.account.is_need_offset:
+            return False
+        if self.account.base_code[0] == "1" and not self.is_debit:
+            return False
+        if self.account.base_code[0] == "2" and self.is_debit:
+            return False
+        return True
+
     @property
     def credit(self) -> Decimal | None:
         """Returns the credit amount.
@@ -656,3 +717,45 @@ class JournalEntry(db.Model):
         :return: The credit amount, or None if this is not a credit entry.
         """
         return None if self.is_debit else self.amount
+
+    @property
+    def net_balance(self) -> Decimal:
+        """Returns the net balance.
+
+        :return: The net balance.
+        """
+        if not hasattr(self, "__net_balance"):
+            setattr(self, "__net_balance", self.amount + sum(
+                [x.amount if x.is_debit == self.is_debit else -x.amount
+                 for x in self.offsets]))
+        return getattr(self, "__net_balance")
+
+    @net_balance.setter
+    def net_balance(self, net_balance: Decimal) -> None:
+        """Sets the net balance.
+
+        :param net_balance: The net balance.
+        :return: None.
+        """
+        setattr(self, "__net_balance", net_balance)
+
+    @property
+    def query_values(self) -> tuple[list[str], list[str]]:
+        """Returns the values to be queried.
+
+        :return: The values to be queried.
+        """
+        def format_amount(value: Decimal) -> str:
+            whole: int = int(value)
+            frac: Decimal = (value - whole).normalize()
+            return str(whole) + str(abs(frac))[1:]
+
+        txn_day: date = self.transaction.date
+        summary: str = "" if self.summary is None else self.summary
+        return ([summary],
+                [str(txn_day.year),
+                 "{}/{}".format(txn_day.year, txn_day.month),
+                 "{}/{}".format(txn_day.month, txn_day.day),
+                 "{}/{}/{}".format(txn_day.year, txn_day.month, txn_day.day),
+                 format_amount(self.amount),
+                 format_amount(self.net_balance)])

src/accounting/report/reports/balance_sheet.py

@@ -188,10 +188,10 @@ class AccountCollector:
         :return: None.
         """
         self.__add_owner_s_equity(Account.NET_CHANGE_CODE,
-                                  self.__query_currency_period(),
+                                  self.__query_current_period(),
                                   self.__period)
 
-    def __query_currency_period(self) -> Decimal | None:
+    def __query_current_period(self) -> Decimal | None:
         """Queries and returns the net income or loss for current period.
 
         :return: The net income or loss for current period.
@@ -213,7 +213,7 @@ class AccountCollector:
         :return: The balance.
         """
         conditions.extend([sa.not_(Account.base_code.startswith(x))
-                           for x in {"1", "2"}])
+                           for x in {"1", "2", "3"}])
         balance_func: sa.Function = sa.func.sum(sa.case(
             (JournalEntry.is_debit, JournalEntry.amount),
             else_=-JournalEntry.amount))

src/accounting/report/reports/income_expenses.py

@@ -37,6 +37,7 @@ from accounting.report.utils.option_link import OptionLink
 from accounting.report.utils.report_chooser import ReportChooser
 from accounting.report.utils.report_type import ReportType
 from accounting.report.utils.urls import income_expenses_url
+from accounting.utils.cast import be
 from accounting.utils.pagination import Pagination
 
 
@@ -120,7 +121,7 @@ class EntryCollector:
             else_=-JournalEntry.amount))
         select: sa.Select = sa.Select(balance_func)\
             .join(Transaction).join(Account)\
-            .filter(JournalEntry.currency_code == self.__currency.code,
+            .filter(be(JournalEntry.currency_code == self.__currency.code),
                     self.__account_condition,
                     Transaction.date < self.__period.start)
         balance: int | None = db.session.scalar(select)
@@ -159,6 +160,7 @@ class EntryCollector:
                         JournalEntry.currency_code == self.__currency.code,
                         sa.not_(self.__account_condition))
                 .order_by(Transaction.date,
+                          Transaction.no,
                           JournalEntry.is_debit,
                           JournalEntry.no)
                 .options(selectinload(JournalEntry.account),
@@ -342,7 +344,7 @@ class PageParams(BasePageParams):
                           self.account.id == 0)]
         in_use: sa.Select = sa.Select(JournalEntry.account_id)\
             .join(Account)\
-            .filter(JournalEntry.currency_code == self.currency.code,
+            .filter(be(JournalEntry.currency_code == self.currency.code),
                     sa.or_(Account.base_code.startswith("11"),
                            Account.base_code.startswith("12"),
                            Account.base_code.startswith("21"),
@@ -433,7 +435,7 @@ class IncomeExpenses(BaseReport):
         if self.__total is not None:
             all_entries.append(self.__total)
         pagination: Pagination[ReportEntry] \
-            = Pagination[ReportEntry](all_entries)
+            = Pagination[ReportEntry](all_entries, is_reversed=True)
         page_entries: list[ReportEntry] = pagination.list
         has_data: bool = len(page_entries) > 0
         brought_forward: ReportEntry | None = None

src/accounting/report/reports/journal.py

@@ -188,6 +188,7 @@ class Journal(BaseReport):
         return JournalEntry.query.join(Transaction)\
             .filter(*conditions)\
             .order_by(Transaction.date,
+                      Transaction.no,
                       JournalEntry.is_debit.desc(),
                       JournalEntry.no)\
             .options(selectinload(JournalEntry.account),
@@ -208,7 +209,7 @@ class Journal(BaseReport):
         :return: The report as HTML.
         """
         pagination: Pagination[JournalEntry] \
-            = Pagination[JournalEntry](self.__entries)
+            = Pagination[JournalEntry](self.__entries, is_reversed=True)
         params: PageParams = PageParams(period=self.__period,
                                         pagination=pagination,
                                         entries=pagination.list)

src/accounting/report/reports/ledger.py

@@ -36,6 +36,7 @@ from accounting.report.utils.option_link import OptionLink
 from accounting.report.utils.report_chooser import ReportChooser
 from accounting.report.utils.report_type import ReportType
 from accounting.report.utils.urls import ledger_url
+from accounting.utils.cast import be
 from accounting.utils.pagination import Pagination
 
 
@@ -110,14 +111,14 @@ class EntryCollector:
         """
         if self.__period.start is None:
             return None
-        if self.__account.base_code[0] not in {"1", "2", "3"}:
+        if self.__account.is_nominal:
             return None
         balance_func: sa.Function = sa.func.sum(sa.case(
             (JournalEntry.is_debit, JournalEntry.amount),
             else_=-JournalEntry.amount))
         select: sa.Select = sa.Select(balance_func).join(Transaction)\
-            .filter(JournalEntry.currency_code == self.__currency.code,
-                    JournalEntry.account_id == self.__account.id,
+            .filter(be(JournalEntry.currency_code == self.__currency.code),
+                    be(JournalEntry.account_id == self.__account.id),
                     Transaction.date < self.__period.start)
         balance: int | None = db.session.scalar(select)
         if balance is None:
@@ -148,6 +149,7 @@ class EntryCollector:
         return [ReportEntry(x) for x in JournalEntry.query.join(Transaction)
                 .filter(*conditions)
                 .order_by(Transaction.date,
+                          Transaction.no,
                           JournalEntry.is_debit.desc(),
                           JournalEntry.no)
                 .options(selectinload(JournalEntry.transaction)).all()]
@@ -176,6 +178,8 @@ class EntryCollector:
 
         :return: None.
         """
+        if self.__account.is_nominal:
+            return None
         balance: Decimal = 0 if self.brought_forward is None \
             else self.brought_forward.balance
         for entry in self.entries:
@@ -303,7 +307,7 @@ class PageParams(BasePageParams):
         :return: The account options.
         """
         in_use: sa.Select = sa.Select(JournalEntry.account_id)\
-            .filter(JournalEntry.currency_code == self.currency.code)\
+            .filter(be(JournalEntry.currency_code == self.currency.code))\
             .group_by(JournalEntry.account_id)
         return [OptionLink(str(x), ledger_url(self.currency, x, self.period),
                            x.id == self.account.id)
@@ -382,7 +386,7 @@ class Ledger(BaseReport):
         if self.__total is not None:
             all_entries.append(self.__total)
         pagination: Pagination[ReportEntry] \
-            = Pagination[ReportEntry](all_entries)
+            = Pagination[ReportEntry](all_entries, is_reversed=True)
         page_entries: list[ReportEntry] = pagination.list
         has_data: bool = len(page_entries) > 0
         brought_forward: ReportEntry | None = None

src/accounting/report/reports/search.py

@@ -32,6 +32,7 @@ from accounting.report.utils.base_report import BaseReport
 from accounting.report.utils.csv_export import csv_download
 from accounting.report.utils.report_chooser import ReportChooser
 from accounting.report.utils.report_type import ReportType
+from accounting.utils.cast import be
 from accounting.utils.pagination import Pagination
 from accounting.utils.query import parse_query_keywords
 from .journal import get_csv_rows
@@ -68,7 +69,11 @@ class EntryCollector:
             except ArithmeticError:
                 pass
             conditions.append(sa.or_(*sub_conditions))
-        return JournalEntry.query.filter(*conditions)\
+        return JournalEntry.query.join(Transaction).filter(*conditions)\
+            .order_by(Transaction.date,
+                      Transaction.no,
+                      JournalEntry.is_debit,
+                      JournalEntry.no)\
             .options(selectinload(JournalEntry.account),
                      selectinload(JournalEntry.currency),
                      selectinload(JournalEntry.transaction)).all()
@@ -92,7 +97,7 @@ class EntryCollector:
                code.contains(k),
                Account.id.in_(select_l10n)]
         if k in gettext("Need offset"):
-            conditions.append(Account.is_offset_needed)
+            conditions.append(Account.is_need_offset)
         return sa.select(Account.id).filter(sa.or_(*conditions))
 
     @staticmethod
@@ -121,7 +126,7 @@ class EntryCollector:
         try:
             txn_date = datetime.strptime(k, "%Y")
             conditions.append(
-                sa.extract("year", Transaction.date) == txn_date.year)
+                be(sa.extract("year", Transaction.date) == txn_date.year))
         except ValueError:
             pass
         try:
@@ -194,7 +199,7 @@ class Search(BaseReport):
         :return: The report as HTML.
         """
         pagination: Pagination[JournalEntry] \
-            = Pagination[JournalEntry](self.__entries)
+            = Pagination[JournalEntry](self.__entries, is_reversed=True)
         params: PageParams = PageParams(pagination=pagination,
                                         entries=pagination.list)
         return render_template("accounting/report/search.html",

src/accounting/report/utils/option_link.py

@@ -27,10 +27,15 @@ class OptionLink:
         """Constructs an option link.
 
         :param title: The title.
-        :param url: The URI.
+        :param url: The URL.
         :param is_active: True if active, or False otherwise
+        :param fa_icon: The font-awesome icon, if any.
         """
         self.title: str = title
+        """The title."""
         self.url: str = url
+        """The URL."""
         self.is_active: bool = is_active
+        """True if active, or False otherwise."""
         self.fa_icon: str | None = fa_icon
+        """The font-awesome icon, if any."""

src/accounting/static/css/style.css

@@ -31,6 +31,9 @@
     color: #141619;
     background-color: #D3D3D4;
 }
+.form-control.accounting-disabled {
+    background-color: #e9ecef;
+}
 
 /** The toolbar */
 .accounting-toolbar {
@@ -113,6 +116,33 @@
     border-bottom: thick double slategray;
 }
 
+/* Links between objects */
+.accounting-original-entry {
+    border-top: thin solid darkslategray;
+    padding: 0.2rem 0.5rem;
+}
+.accounting-original-entry a {
+    color: inherit;
+    text-decoration: none;
+}
+.accounting-original-entry a:hover {
+    color: inherit;
+}
+.accounting-offset-entries {
+    border-top: thin solid darkslategray;
+    padding: 0.2rem 0.5rem;
+}
+.accounting-offset-entries ul li {
+    list-style: none;
+}
+.accounting-offset-entries ul li a {
+    color: inherit;
+    text-decoration: none;
+}
+.accounting-offset-entries ul li a:hover {
+    color: inherit;
+}
+
 /** The option selector */
 .accounting-selector-list {
     height: 20rem;
@@ -136,9 +166,6 @@
 .accounting-list-group-stripped .list-group-item:nth-child(2n+1) {
     background-color: #f2f2f2;
 }
-.accounting-list-group-stripped .list-group-item-success:nth-child(2n+1) {
-    background-color: #c7dbd2;
-}
 .accounting-list-group-hover .list-group-item:hover {
     background-color: #ececec;
 }
@@ -153,6 +180,9 @@
     font-weight: bolder;
     border-top: thick double slategray;
 }
+.accounting-entry-editor-original-entry-content {
+    width: calc(100% - 3rem);
+}
 
 /* The report table */
 .accounting-report-table-header, .accounting-report-table-footer {
@@ -191,12 +221,18 @@ a.accounting-report-table-row {
 .accounting-journal-table .accounting-report-table-row {
     grid-template-columns: 1fr 1fr 2fr 4fr 1fr 1fr;
 }
-.accounting-ledger-table .accounting-report-table-row {
+.accounting-ledger-real-table .accounting-report-table-row {
     grid-template-columns: 1fr 4fr 1fr 1fr 1fr;
 }
-.accounting-ledger-table .accounting-report-table-footer .accounting-report-table-row {
+.accounting-ledger-real-table .accounting-report-table-footer .accounting-report-table-row {
     grid-template-columns: 5fr 1fr 1fr 1fr;
 }
+.accounting-ledger-nominal-table .accounting-report-table-row {
+    grid-template-columns: 1fr 4fr 1fr 1fr;
+}
+.accounting-ledger-nominal-table .accounting-report-table-footer .accounting-report-table-row {
+    grid-template-columns: 5fr 1fr 1fr;
+}
 .accounting-income-expenses-table .accounting-report-table-row {
     grid-template-columns: 1fr 2fr 4fr 1fr 1fr 1fr;
 }

src/accounting/static/js/account-form.js

@@ -24,161 +24,335 @@
 
 // Initializes the page JavaScript.
 document.addEventListener("DOMContentLoaded", () => {
-    initializeBaseAccountSelector();
-    document.getElementById("accounting-base-code")
-        .onchange = validateBase;
-    document.getElementById("accounting-title")
-        .onchange = validateTitle;
-    document.getElementById("accounting-form")
-        .onsubmit = validateForm;
+    AccountForm.initialize();
 });
 
 /**
- * Initializes the base account selector.
+ * The account form.
  *
  * @private
  */
-function initializeBaseAccountSelector() {
-    const selector = document.getElementById("accounting-base-selector-modal");
-    const base = document.getElementById("accounting-base");
-    const baseCode = document.getElementById("accounting-base-code");
-    const baseContent = document.getElementById("accounting-base-content");
-    const options = Array.from(document.getElementsByClassName("accounting-base-option"));
-    const btnClear = document.getElementById("accounting-btn-clear-base");
-    selector.addEventListener("show.bs.modal", () => {
-        base.classList.add("accounting-not-empty");
-        for (const option of options) {
-            option.classList.remove("active");
-        }
-        const selected = document.getElementById("accounting-base-option-" + baseCode.value);
-        if (selected !== null) {
-            selected.classList.add("active");
-        }
-    });
-    selector.addEventListener("hidden.bs.modal", () => {
-        if (baseCode.value === "") {
-            base.classList.remove("accounting-not-empty");
-        }
-    });
-    for (const option of options) {
-        option.onclick = () => {
-            baseCode.value = option.dataset.code;
-            baseContent.innerText = option.dataset.content;
-            btnClear.classList.add("btn-danger");
-            btnClear.classList.remove("btn-secondary")
-            btnClear.disabled = false;
-            validateBase();
-            bootstrap.Modal.getInstance(selector).hide();
+class AccountForm {
+
+    /**
+     * The base account selector
+     * @type {BaseAccountSelector}
+     */
+    #baseAccountSelector;
+
+    /**
+     * The form element
+     * @type {HTMLFormElement}
+     */
+    #formElement;
+
+    /**
+     * The control of the base account
+     * @type {HTMLDivElement}
+     */
+    #baseControl;
+
+    /**
+     * The input of the base account
+     * @type {HTMLInputElement}
+     */
+    #baseCode;
+
+    /**
+     * The base account
+     * @type {HTMLDivElement}
+     */
+    #base;
+
+    /**
+     * The error message for the base account
+     * @type {HTMLDivElement}
+     */
+    #baseError;
+
+    /**
+     * The title
+     * @type {HTMLInputElement}
+     */
+    #title;
+
+    /**
+     * The error message of the title
+     * @type {HTMLDivElement}
+     */
+    #titleError;
+
+    /**
+     * The control of the is-need-offset option
+     * @type {HTMLDivElement}
+     */
+    #isNeedOffsetControl;
+
+    /**
+     * The is-need-offset option
+     * @type {HTMLInputElement}
+     */
+    #isNeedOffset;
+
+    /**
+     * Constructs the account form.
+     *
+     */
+    constructor() {
+        this.#baseAccountSelector = new BaseAccountSelector(this);
+        this.#formElement = document.getElementById("accounting-form");
+        this.#baseControl = document.getElementById("accounting-base-control");
+        this.#baseCode = document.getElementById("accounting-base-code");
+        this.#base = document.getElementById("accounting-base");
+        this.#baseError = document.getElementById("accounting-base-error");
+        this.#title = document.getElementById("accounting-title");
+        this.#titleError = document.getElementById("accounting-title-error");
+        this.#isNeedOffsetControl = document.getElementById("accounting-is-need-offset-control");
+        this.#isNeedOffset = document.getElementById("accounting-is-need-offset");
+        this.#formElement.onsubmit = () => {
+            return this.#validateForm();
+        };
+        this.#baseControl.onclick = () => {
+            this.#baseControl.classList.add("accounting-not-empty");
+            this.#baseAccountSelector.onOpen(this.#baseCode.value);
         };
     }
-    btnClear.onclick = () => {
-        baseCode.value = "";
-        baseContent.innerText = "";
-        btnClear.classList.add("btn-secondary")
-        btnClear.classList.remove("btn-danger");
-        btnClear.disabled = true;
-        validateBase();
-        bootstrap.Modal.getInstance(selector).hide();
+
+    /**
+     * The callback when the base account selector is closed.
+     *
+     */
+    onBaseAccountSelectorClosed() {
+        if (this.#baseCode.value === "") {
+            this.#baseControl.classList.remove("accounting-not-empty");
+        }
+    }
+
+    /**
+     * Sets the base account.
+     *
+     * @param code {string} the base account code
+     * @param text {string} the text for the base account
+     */
+    setBaseAccount(code, text) {
+        this.#baseCode.value = code;
+        this.#base.innerText = text;
+        if (["1", "2", "3"].includes(code.substring(0, 1))) {
+            this.#isNeedOffsetControl.classList.remove("d-none");
+            this.#isNeedOffset.disabled = false;
+        } else {
+            this.#isNeedOffsetControl.classList.add("d-none");
+            this.#isNeedOffset.disabled = true;
+            this.#isNeedOffset.checked = false;
+        }
+        this.#validateBase();
+    }
+
+    /**
+     * Clears the base account.
+     *
+     */
+    clearBaseAccount() {
+        this.#baseCode.value = "";
+        this.#base.innerText = "";
+        this.#validateBase();
+    }
+
+    /**
+     * Validates the form.
+     *
+     * @returns {boolean} true if valid, or false otherwise
+     */
+    #validateForm() {
+        let isValid = true;
+        isValid = this.#validateBase() && isValid;
+        isValid = this.#validateTitle() && isValid;
+        return isValid;
+    }
+
+    /**
+     * Validates the base account.
+     *
+     * @returns {boolean} true if valid, or false otherwise
+     */
+    #validateBase() {
+        if (this.#baseCode.value === "") {
+            this.#baseControl.classList.add("is-invalid");
+            this.#baseError.innerText = A_("Please select the base account.");
+            return false;
+        }
+        this.#baseControl.classList.remove("is-invalid");
+        this.#baseError.innerText = "";
+        return true;
+    }
+
+    /**
+     * Validates the title.
+     *
+     * @returns {boolean} true if valid, or false otherwise
+     */
+    #validateTitle() {
+        this.#title.value = this.#title.value.trim();
+        if (this.#title.value === "") {
+            this.#title.classList.add("is-invalid");
+            this.#titleError.innerText = A_("Please fill in the title.");
+            return false;
+        }
+        this.#title.classList.remove("is-invalid");
+        this.#titleError.innerText = "";
+        return true;
+    }
+
+    /**
+     * The account form
+     * @type {AccountForm} the form
+     */
+    static #form;
+
+    static initialize() {
+        this.#form = new AccountForm();
     }
-    initializeBaseAccountQuery();
 }
 
 /**
- * Initializes the query on the base account options.
+ * The base account selector.
  *
  * @private
  */
-function initializeBaseAccountQuery() {
-    const query = document.getElementById("accounting-base-selector-query");
-    const optionList = document.getElementById("accounting-base-option-list");
-    const options = Array.from(document.getElementsByClassName("accounting-base-option"));
-    const queryNoResult = document.getElementById("accounting-base-option-no-result");
-    query.addEventListener("input", () => {
-        if (query.value === "") {
-            for (const option of options) {
-                option.classList.remove("d-none");
-            }
-            optionList.classList.remove("d-none");
-            queryNoResult.classList.add("d-none");
-            return
+class BaseAccountSelector {
+
+    /**
+     * The account form
+     * @type {AccountForm}
+     */
+    #form;
+
+    /**
+     * The selector modal
+     * @type {HTMLDivElement}
+     */
+    #modal;
+
+    /**
+     * The query input
+     * @type {HTMLInputElement}
+     */
+    #query;
+
+    /**
+     * The error message when the query has no result
+     * @type {HTMLParagraphElement}
+     */
+    #queryNoResult;
+
+    /**
+     * The option list
+     * @type {HTMLUListElement}
+     */
+    #optionList;
+
+    /**
+     * The options
+     * @type {HTMLLIElement[]}
+     */
+    #options;
+
+    /**
+     * The button to clear the base account value
+     * @type {HTMLButtonElement}
+     */
+    #clearButton;
+
+    /**
+     * Constructs the base account selector.
+     *
+     * @param form {AccountForm} the form
+     */
+    constructor(form) {
+        this.#form = form;
+        this.#modal = document.getElementById("accounting-base-selector-modal");
+        this.#query = document.getElementById("accounting-base-selector-query");
+        this.#optionList = document.getElementById("accounting-base-selector-option-list");
+        // noinspection JSValidateTypes
+        this.#options = Array.from(document.getElementsByClassName("accounting-base-selector-option"));
+        this.#clearButton = document.getElementById("accounting-base-selector-clear");
+        this.#queryNoResult = document.getElementById("accounting-base-selector-option-no-result");
+        this.#modal.addEventListener("hidden.bs.modal", () => {
+            this.#form.onBaseAccountSelectorClosed();
+        });
+        for (const option of this.#options) {
+            option.onclick = () => {
+                this.#form.setBaseAccount(option.dataset.code, option.dataset.content);
+            };
         }
-        let hasAnyMatched = false;
-        for (const option of options) {
-            const queryValues = JSON.parse(option.dataset.queryValues);
-            let isMatched = false;
-            for (const queryValue of queryValues) {
-                if (queryValue.includes(query.value)) {
-                    isMatched = true;
-                    break;
+        this.#clearButton.onclick = () => {
+            this.#form.clearBaseAccount();
+        };
+        this.#initializeBaseAccountQuery();
+    }
+
+    /**
+     * Initializes the query.
+     *
+     */
+    #initializeBaseAccountQuery() {
+        this.#query.addEventListener("input", () => {
+            if (this.#query.value === "") {
+                for (const option of this.#options) {
+                    option.classList.remove("d-none");
+                }
+                this.#optionList.classList.remove("d-none");
+                this.#queryNoResult.classList.add("d-none");
+                return
+            }
+            let hasAnyMatched = false;
+            for (const option of this.#options) {
+                const queryValues = JSON.parse(option.dataset.queryValues);
+                let isMatched = false;
+                for (const queryValue of queryValues) {
+                    if (queryValue.includes(this.#query.value)) {
+                        isMatched = true;
+                        break;
+                    }
+                }
+                if (isMatched) {
+                    option.classList.remove("d-none");
+                    hasAnyMatched = true;
+                } else {
+                    option.classList.add("d-none");
                 }
             }
-            if (isMatched) {
-                option.classList.remove("d-none");
-                hasAnyMatched = true;
+            if (!hasAnyMatched) {
+                this.#optionList.classList.add("d-none");
+                this.#queryNoResult.classList.remove("d-none");
             } else {
-                option.classList.add("d-none");
+                this.#optionList.classList.remove("d-none");
+                this.#queryNoResult.classList.add("d-none");
+            }
+        });
+    }
+
+    /**
+     * The callback when the base account selector is shown.
+     *
+     * @param baseCode {string} the active base code
+     */
+    onOpen(baseCode) {
+        for (const option of this.#options) {
+            if (option.dataset.code === baseCode) {
+                option.classList.add("active");
+            } else {
+                option.classList.remove("active");
             }
         }
-        if (!hasAnyMatched) {
-            optionList.classList.add("d-none");
-            queryNoResult.classList.remove("d-none");
+        if (baseCode === "") {
+            this.#clearButton.classList.add("btn-secondary")
+            this.#clearButton.classList.remove("btn-danger");
+            this.#clearButton.disabled = true;
         } else {
-            optionList.classList.remove("d-none");
-            queryNoResult.classList.add("d-none");
+            this.#clearButton.classList.add("btn-danger");
+            this.#clearButton.classList.remove("btn-secondary")
+            this.#clearButton.disabled = false;
         }
-    });
-}
-
-/**
- * Validates the form.
- *
- * @returns {boolean} true if valid, or false otherwise
- * @private
- */
-function validateForm() {
-    let isValid = true;
-    isValid = validateBase() && isValid;
-    isValid = validateTitle() && isValid;
-    return isValid;
-}
-
-/**
- * Validates the base account.
- *
- * @returns {boolean} true if valid, or false otherwise
- * @private
- */
-function validateBase() {
-    const field = document.getElementById("accounting-base-code");
-    const error = document.getElementById("accounting-base-code-error");
-    const displayField = document.getElementById("accounting-base");
-    field.value = field.value.trim();
-    if (field.value === "") {
-        displayField.classList.add("is-invalid");
-        error.innerText = A_("Please select the base account.");
-        return false;
     }
-    displayField.classList.remove("is-invalid");
-    error.innerText = "";
-    return true;
-}
-
-/**
- * Validates the title.
- *
- * @returns {boolean} true if valid, or false otherwise
- * @private
- */
-function validateTitle() {
-    const field = document.getElementById("accounting-title");
-    const error = document.getElementById("accounting-title-error");
-    field.value = field.value.trim();
-    if (field.value === "") {
-        field.classList.add("is-invalid");
-        error.innerText = A_("Please fill in the title.");
-        return false;
-    }
-    field.classList.remove("is-invalid");
-    error.innerText = "";
-    return true;
 }

src/accounting/static/js/account-selector.js

@@ -22,22 +22,23 @@
  */
 "use strict";
 
-// Initializes the page JavaScript.
-document.addEventListener("DOMContentLoaded", () => {
-    AccountSelector.initialize();
-});
-
 /**
  * The account selector.
  *
  */
 class AccountSelector {
 
+    /**
+     * The journal entry editor
+     * @type {JournalEntryEditor}
+     */
+    #entryEditor;
+
     /**
      * The entry type
      * @type {string}
      */
-    #entryType;
+    entryType;
 
     /**
      * The prefix of the HTML ID and class
@@ -45,78 +46,81 @@ class AccountSelector {
      */
     #prefix;
 
+    /**
+     * The button to clear the account
+     * @type {HTMLButtonElement}
+     */
+    #clearButton
+
+    /**
+     * The query input
+     * @type {HTMLInputElement}
+     */
+    #query;
+
+    /**
+     * The error message when the query has no result
+     * @type {HTMLParagraphElement}
+     */
+    #queryNoResult;
+
+    /**
+     * The option list
+     * @type {HTMLUListElement}
+     */
+    #optionList;
+
+    /**
+     * The options
+     * @type {HTMLLIElement[]}
+     */
+    #options;
+
+    /**
+     * The more item to show all accounts
+     * @type {HTMLLIElement}
+     */
+    #more;
+
     /**
      * Constructs an account selector.
      *
-     * @param modal {HTMLFormElement} the account selector modal
+     * @param entryEditor {JournalEntryEditor} the journal entry editor
+     * @param entryType {string} the entry type, either "debit" or "credit"
      */
-    constructor(modal) {
-        this.#entryType = modal.dataset.entryType;
-        this.#prefix = "accounting-account-selector-" + modal.dataset.entryType;
-        this.#init();
-    }
-
-    /**
-     * Initializes the account selector.
-     *
-     */
-    #init() {
-        const formAccountControl = document.getElementById("accounting-entry-form-account-control");
-        const formAccount = document.getElementById("accounting-entry-form-account");
-        const more = document.getElementById(this.#prefix + "-more");
-        const btnClear = document.getElementById(this.#prefix + "-btn-clear");
-        const options = Array.from(document.getElementsByClassName(this.#prefix + "-option"));
-        more.onclick = () => {
-            more.classList.add("d-none");
-            this.#filterAccountOptions();
+    constructor(entryEditor, entryType) {
+        this.#entryEditor = entryEditor
+        this.entryType = entryType;
+        this.#prefix = "accounting-account-selector-" + entryType;
+        this.#query = document.getElementById(this.#prefix + "-query");
+        this.#queryNoResult = document.getElementById(this.#prefix + "-option-no-result");
+        this.#optionList = document.getElementById(this.#prefix + "-option-list");
+        // noinspection JSValidateTypes
+        this.#options = Array.from(document.getElementsByClassName(this.#prefix + "-option"));
+        this.#more = document.getElementById(this.#prefix + "-more");
+        this.#clearButton = document.getElementById(this.#prefix + "-btn-clear");
+        this.#more.onclick = () => {
+            this.#more.classList.add("d-none");
+            this.#filterOptions();
         };
-        this.#initializeAccountQuery();
-        btnClear.onclick = () => {
-            formAccountControl.classList.remove("accounting-not-empty");
-            formAccount.innerText = "";
-            formAccount.dataset.code = "";
-            formAccount.dataset.text = "";
-            validateJournalEntryAccount();
-        };
-        for (const option of options) {
-            option.onclick = () => {
-                formAccountControl.classList.add("accounting-not-empty");
-                formAccount.innerText = option.dataset.content;
-                formAccount.dataset.code = option.dataset.code;
-                formAccount.dataset.text = option.dataset.content;
-                validateJournalEntryAccount();
-            };
+        this.#clearButton.onclick = () => this.#entryEditor.clearAccount();
+        for (const option of this.#options) {
+            option.onclick = () => this.#entryEditor.saveAccount(option.dataset.code, option.dataset.content, option.classList.contains("accounting-account-is-need-offset"));
         }
-    }
-
-    /**
-     * Initializes the query on the account options.
-     *
-     */
-    #initializeAccountQuery() {
-        const query = document.getElementById(this.#prefix + "-query");
-        query.addEventListener("input", () => {
-            this.#filterAccountOptions();
+        this.#query.addEventListener("input", () => {
+            this.#filterOptions();
         });
     }
 
     /**
-     * Filters the account options.
+     * Filters the options.
      *
      */
-    #filterAccountOptions() {
-        const query = document.getElementById(this.#prefix + "-query");
-        const optionList = document.getElementById(this.#prefix + "-option-list");
-        if (optionList === null) {
-            console.log(this.#prefix + "-option-list");
-        }
-        const options = Array.from(document.getElementsByClassName(this.#prefix + "-option"));
-        const more = document.getElementById(this.#prefix + "-more");
-        const queryNoResult = document.getElementById(this.#prefix + "-option-no-result");
-        const codesInUse = this.#getAccountCodeUsedInForm();
+    #filterOptions() {
+        const codesInUse = this.#getCodesUsedInForm();
         let shouldAnyShow = false;
-        for (const option of options) {
-            const shouldShow = this.#shouldAccountOptionShow(option, more, codesInUse, query);
+        for (const option of this.#options) {
+            const shouldShow = this.#shouldOptionShow(option, this.#more, codesInUse, this.#query);
             if (shouldShow) {
                 option.classList.remove("d-none");
                 shouldAnyShow = true;
@@ -124,12 +128,12 @@ class AccountSelector {
                 option.classList.add("d-none");
             }
         }
-        if (!shouldAnyShow && more.classList.contains("d-none")) {
-            optionList.classList.add("d-none");
-            queryNoResult.classList.remove("d-none");
+        if (!shouldAnyShow && this.#more.classList.contains("d-none")) {
+            this.#optionList.classList.add("d-none");
+            this.#queryNoResult.classList.remove("d-none");
         } else {
-            optionList.classList.remove("d-none");
-            queryNoResult.classList.add("d-none");
+            this.#optionList.classList.remove("d-none");
+            this.#queryNoResult.classList.add("d-none");
         }
     }
 
@@ -138,26 +142,24 @@ class AccountSelector {
      *
      * @return {string[]} the account codes that are used in the form
      */
-    #getAccountCodeUsedInForm() {
-        const accountCodes = Array.from(document.getElementsByClassName("accounting-" + this.#prefix + "-account-code"));
-        const formAccount = document.getElementById("accounting-entry-form-account");
-        const inUse = [formAccount.dataset.code];
-        for (const accountCode of accountCodes) {
-            inUse.push(accountCode.value);
+    #getCodesUsedInForm() {
+        const inUse = this.#entryEditor.form.getAccountCodesUsed(this.entryType);
+        if (this.#entryEditor.accountCode !== null) {
+            inUse.push(this.#entryEditor.accountCode);
         }
         return inUse
     }
 
     /**
-     * Returns whether an account option should show.
+     * Returns whether an option should show.
      *
-     * @param option {HTMLLIElement} the account option
-     * @param more {HTMLLIElement} the more account element
+     * @param option {HTMLLIElement} the option
+     * @param more {HTMLLIElement} the more element
      * @param inUse {string[]} the account codes that are used in the form
      * @param query {HTMLInputElement} the query element, if any
-     * @return {boolean} true if the account option should show, or false otherwise
+     * @return {boolean} true if the option should show, or false otherwise
      */
-    #shouldAccountOptionShow(option, more, inUse, query) {
+    #shouldOptionShow(option, more, inUse, query) {
         const isQueryMatched = () => {
             if (query.value === "") {
                 return true;
@@ -180,71 +182,43 @@ class AccountSelector {
     }
 
     /**
-     * Initializes the account selector when it is shown.
+     * The callback when the account selector is shown.
      *
      */
-    initShow() {
-        const formAccount = document.getElementById("accounting-entry-form-account");
-        const query = document.getElementById(this.#prefix + "-query")
-        const more = document.getElementById(this.#prefix + "-more");
-        const options = Array.from(document.getElementsByClassName(this.#prefix + "-option"));
-        const btnClear = document.getElementById(this.#prefix + "-btn-clear");
-        query.value = "";
-        more.classList.remove("d-none");
-        this.#filterAccountOptions();
-        for (const option of options) {
-            if (option.dataset.code === formAccount.dataset.code) {
+    onOpen() {
+        this.#query.value = "";
+        this.#more.classList.remove("d-none");
+        this.#filterOptions();
+        for (const option of this.#options) {
+            if (option.dataset.code === this.#entryEditor.accountCode) {
                 option.classList.add("active");
             } else {
                 option.classList.remove("active");
             }
         }
-        if (formAccount.dataset.code === "") {
-            btnClear.classList.add("btn-secondary");
-            btnClear.classList.remove("btn-danger");
-            btnClear.disabled = true;
+        if (this.#entryEditor.accountCode === null) {
+            this.#clearButton.classList.add("btn-secondary");
+            this.#clearButton.classList.remove("btn-danger");
+            this.#clearButton.disabled = true;
         } else {
-            btnClear.classList.add("btn-danger");
-            btnClear.classList.remove("btn-secondary");
-            btnClear.disabled = false;
+            this.#clearButton.classList.add("btn-danger");
+            this.#clearButton.classList.remove("btn-secondary");
+            this.#clearButton.disabled = false;
         }
     }
 
     /**
-     * The account selectors.
-     * @type {{debit: AccountSelector, credit: AccountSelector}}
-     */
-    static #selectors = {}
-
-    /**
-     * Initializes the account selectors.
+     * Returns the account selector instances.
      *
+     * @param entryEditor {JournalEntryEditor} the journal entry editor
+     * @return {{debit: AccountSelector, credit: AccountSelector}}
      */
-    static initialize() {
-        const modals = Array.from(document.getElementsByClassName("accounting-account-selector-modal"));
+    static getInstances(entryEditor) {
+        const selectors = {}
+        const modals = Array.from(document.getElementsByClassName("accounting-account-selector"));
         for (const modal of modals) {
-            const selector = new AccountSelector(modal);
-            this.#selectors[selector.#entryType] = selector;
+            selectors[modal.dataset.entryType] = new AccountSelector(entryEditor, modal.dataset.entryType);
         }
-        this.#initializeTransactionForm();
-    }
-
-    /**
-     * Initializes the transaction form.
-     *
-     */
-    static #initializeTransactionForm() {
-        const entryForm = document.getElementById("accounting-entry-form");
-        const formAccountControl = document.getElementById("accounting-entry-form-account-control");
-        formAccountControl.onclick = () => this.#selectors[entryForm.dataset.entryType].initShow();
-    }
-    /**
-     * Initializes the account selector for the journal entry form.
-     *x
-     */
-    static initializeJournalEntryForm() {
-        const entryForm = document.getElementById("accounting-entry-form");
-        const formAccountControl = document.getElementById("accounting-entry-form-account-control");
-        formAccountControl.dataset.bsTarget = "#accounting-account-selector-" + entryForm.dataset.entryType + "-modal";
+        return selectors;
     }
 }

src/accounting/static/js/currency-form.js

@@ -24,152 +24,151 @@
 
 // Initializes the page JavaScript.
 document.addEventListener("DOMContentLoaded", () => {
-    document.getElementById("accounting-code")
-        .onchange = validateCode;
-    document.getElementById("accounting-name")
-        .onchange = validateName;
-    document.getElementById("accounting-form")
-        .onsubmit = validateForm;
+    CurrencyForm.initialize();
 });
 
 /**
- * The asynchronous validation result
- * @type {object}
- * @private
- */
-let isAsyncValid = {};
-
-/**
- * Validates the form.
- *
- * @returns {boolean} true if valid, or false otherwise
- * @private
- */
-function validateForm() {
-    isAsyncValid = {
-        "code": false,
-        "_sync": false,
-    };
-    let isValid = true;
-    isValid = validateCode() && isValid;
-    isValid = validateName() && isValid;
-    isAsyncValid["_sync"] = isValid;
-    submitFormIfAllAsyncValid();
-    return false;
-}
-
-/**
- * Submits the form if the whole form passed the asynchronous
- * validations.
+ * The currency form.
  *
  * @private
  */
-function submitFormIfAllAsyncValid() {
-    let isValid = true;
-    for (const key of Object.keys(isAsyncValid)) {
-        isValid = isAsyncValid[key] && isValid;
-    }
-    if (isValid) {
-        document.getElementById("accounting-form").submit()
-    }
-}
+class CurrencyForm {
 
-/**
- * Validates the code.
- *
- * @param changeEvent {Event} the change event, if invoked from onchange
- * @returns {boolean} true if valid, or false otherwise
- * @private
- */
-function validateCode(changeEvent = null) {
-    const key = "code";
-    const isSubmission = changeEvent === null;
-    let hasAsyncValidation = false;
-    const field = document.getElementById("accounting-code");
-    const error = document.getElementById("accounting-code-error");
-    field.value = field.value.trim();
-    if (field.value === "") {
-        field.classList.add("is-invalid");
-        error.innerText = A_("Please fill in the code.");
-        return false;
-    }
-    const blocklist = JSON.parse(field.dataset.blocklist);
-    if (blocklist.includes(field.value)) {
-        field.classList.add("is-invalid");
-        error.innerText = A_("This code is not available.");
-        return false;
-    }
-    if (!field.value.match(/^[A-Z]{3}$/)) {
-        field.classList.add("is-invalid");
-        error.innerText = A_("Code can only be composed of 3 upper-cased letters.");
-        return false;
-    }
-    const original = field.dataset.original;
-    if (original === "" || field.value !== original) {
-        hasAsyncValidation = true;
-        validateAsyncCodeIsDuplicated(isSubmission, key);
-    }
-    if (!hasAsyncValidation) {
-        isAsyncValid[key] = true;
-        field.classList.remove("is-invalid");
-        error.innerText = "";
-    }
-    return true;
-}
+    /**
+     * The form.
+     * @type {HTMLFormElement}
+     */
+    #formElement;
 
-/**
- * Validates asynchronously whether the code is duplicated.
- * The boolean validation result is stored in isAsyncValid[key].
- *
- * @param isSubmission {boolean} whether this is invoked from a form submission
- * @param key {string} the key to store the result in isAsyncValid
- * @private
- */
-function validateAsyncCodeIsDuplicated(isSubmission, key) {
-    const field = document.getElementById("accounting-code");
-    const error = document.getElementById("accounting-code-error");
-    const url = field.dataset.existsUrl;
-    const onLoad = function () {
-        if (this.status === 200) {
-            const result = JSON.parse(this.responseText);
-            if (result["exists"]) {
-                field.classList.add("is-invalid");
-                error.innerText = A_("Code conflicts with another currency.");
-                if (isSubmission) {
-                    isAsyncValid[key] = false;
+    /**
+     * The code
+     * @type {HTMLInputElement}
+     */
+    #code;
+
+    /**
+     * The error message of the code
+     * @type {HTMLDivElement}
+     */
+    #codeError;
+
+    /**
+     * The name
+     * @type {HTMLInputElement}
+     */
+    #name;
+
+    /**
+     * The error message of the name
+     * @type {HTMLDivElement}
+     */
+    #nameError;
+
+    /**
+     * Constructs the currency form.
+     *
+     */
+    constructor() {
+        this.#formElement = document.getElementById("accounting-form");
+        this.#code = document.getElementById("accounting-code");
+        this.#codeError = document.getElementById("accounting-code-error");
+        this.#name = document.getElementById("accounting-name");
+        this.#nameError = document.getElementById("accounting-name-error");
+        this.#code.onchange = () => {
+            this.#validateCode().then();
+        };
+        this.#name.onchange = () => {
+            this.#validateName();
+        };
+        this.#formElement.onsubmit = () => {
+            this.#validateForm().then((isValid) => {
+                if (isValid) {
+                    this.#formElement.submit();
                 }
-                return;
-            }
-            field.classList.remove("is-invalid");
-            error.innerText = "";
-            if (isSubmission) {
-                isAsyncValid[key] = true;
-                submitFormIfAllAsyncValid();
+            });
+            return false;
+        };
+    }
+
+    /**
+     * Validates the form.
+     *
+     * @returns {Promise<boolean>} true if valid, or false otherwise
+     */
+    async #validateForm() {
+        let isValid = true;
+        isValid = await this.#validateCode() && isValid;
+        isValid = this.#validateName() && isValid;
+        return isValid;
+    }
+
+    /**
+     * Validates the code.
+     *
+     * @param changeEvent {Event} the change event, if invoked from onchange
+     * @returns {Promise<boolean>} true if valid, or false otherwise
+     */
+    async #validateCode(changeEvent = null) {
+        this.#code.value = this.#code.value.trim();
+        if (this.#code.value === "") {
+            this.#code.classList.add("is-invalid");
+            this.#codeError.innerText = A_("Please fill in the code.");
+            return false;
+        }
+        const blocklist = JSON.parse(this.#code.dataset.blocklist);
+        if (blocklist.includes(this.#code.value)) {
+            this.#code.classList.add("is-invalid");
+            this.#codeError.innerText = A_("This code is not available.");
+            return false;
+        }
+        if (!this.#code.value.match(/^[A-Z]{3}$/)) {
+            this.#code.classList.add("is-invalid");
+            this.#codeError.innerText = A_("Code can only be composed of 3 upper-cased letters.");
+            return false;
+        }
+        const original = this.#code.dataset.original;
+        if (original === "" || this.#code.value !== original) {
+            const response = await fetch(this.#code.dataset.existsUrl + "?q=" + encodeURIComponent(this.#code.value));
+            const data = await response.json();
+            if (data["exists"]) {
+                this.#code.classList.add("is-invalid");
+                this.#codeError.innerText = A_("Code conflicts with another currency.");
+                return false;
             }
         }
-    };
-    const request = new XMLHttpRequest();
-    request.onload = onLoad;
-    request.open("GET", url + "?q=" + encodeURIComponent(field.value));
-    request.send();
-}
-
-/**
- * Validates the name.
- *
- * @returns {boolean} true if valid, or false otherwise
- * @private
- */
-function validateName() {
-    const field = document.getElementById("accounting-name");
-    const error = document.getElementById("accounting-name-error");
-    field.value = field.value.trim();
-    if (field.value === "") {
-        field.classList.add("is-invalid");
-        error.innerText = A_("Please fill in the name.");
-        return false;
+        this.#code.classList.remove("is-invalid");
+        this.#codeError.innerText = "";
+        return true;
+    }
+
+    /**
+     * Validates the name.
+     *
+     * @returns {boolean} true if valid, or false otherwise
+     */
+    #validateName() {
+        this.#name.value = this.#name.value.trim();
+        if (this.#name.value === "") {
+            this.#name.classList.add("is-invalid");
+            this.#nameError.innerText = A_("Please fill in the name.");
+            return false;
+        }
+        this.#name.classList.remove("is-invalid");
+        this.#nameError.innerText = "";
+        return true;
+    }
+
+    /**
+     * The form
+     * @type {CurrencyForm}
+     */
+    static #form;
+
+    /**
+     * Initializes the currency form.
+     *
+     */
+    static initialize() {
+        this.#form = new CurrencyForm();
     }
-    field.classList.remove("is-invalid");
-    error.innerText = "";
-    return true;
 }

src/accounting/static/js/journal-entry-editor.js

@@ -0,0 +1,596 @@
+/* The Mia! Accounting Flask Project
+ * journal-entry-editor.js: The JavaScript for the journal entry editor
+ */
+
+/*  Copyright (c) 2023 imacat.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/* Author: imacat@mail.imacat.idv.tw (imacat)
+ * First written: 2023/2/25
+ */
+"use strict";
+
+/**
+ * The journal entry editor.
+ *
+ */
+class JournalEntryEditor {
+
+    /**
+     * The transaction form
+     * @type {TransactionForm}
+     */
+    form;
+
+    /**
+     * The journal entry editor
+     * @type {HTMLFormElement}
+     */
+    #element;
+
+    /**
+     * The bootstrap modal
+     * @type {HTMLDivElement}
+     */
+    #modal;
+
+    /**
+     * The entry type, either "debit" or "credit"
+     * @type {string}
+     */
+    entryType;
+
+    /**
+     * The prefix of the HTML ID and class
+     * @type {string}
+     */
+    #prefix = "accounting-entry-editor"
+
+    /**
+     * The container of the original entry
+     * @type {HTMLDivElement}
+     */
+    #originalEntryContainer;
+
+    /**
+     * The control of the original entry
+     * @type {HTMLDivElement}
+     */
+    #originalEntryControl;
+
+    /**
+     * The original entry
+     * @type {HTMLDivElement}
+     */
+    #originalEntry;
+
+    /**
+     * The error message of the original entry
+     * @type {HTMLDivElement}
+     */
+    #originalEntryError;
+
+    /**
+     * The delete button of the original entry
+     * @type {HTMLButtonElement}
+     */
+    #originalEntryDelete;
+
+    /**
+     * The control of the summary
+     * @type {HTMLDivElement}
+     */
+    #summaryControl;
+
+    /**
+     * The summary
+     * @type {HTMLDivElement}
+     */
+    #summary;
+
+    /**
+     * The error message of the summary
+     * @type {HTMLDivElement}
+     */
+    #summaryError;
+
+    /**
+     * The control of the account
+     * @type {HTMLDivElement}
+     */
+    #accountControl;
+
+    /**
+     * The account
+     * @type {HTMLDivElement}
+     */
+    #account;
+
+    /**
+     * The error message of the account
+     * @type {HTMLDivElement}
+     */
+    #accountError;
+
+    /**
+     * The amount
+     * @type {HTMLInputElement}
+     */
+    #amount;
+
+    /**
+     * The error message of the amount
+     * @type {HTMLDivElement}
+     */
+    #amountError;
+
+    /**
+     * The journal entry to edit
+     * @type {JournalEntrySubForm|null}
+     */
+    entry;
+
+    /**
+     * The debit or credit entry side sub-form
+     * @type {DebitCreditSideSubForm}
+     */
+    #side;
+
+    /**
+     * Whether the journal entry needs offset
+     * @type {boolean}
+     */
+    isNeedOffset = false;
+
+    /**
+     * The ID of the original entry
+     * @type {string|null}
+     */
+    originalEntryId = null;
+
+    /**
+     * The date of the original entry
+     * @type {string|null}
+     */
+    originalEntryDate = null;
+
+    /**
+     * The text of the original entry
+     * @type {string|null}
+     */
+    originalEntryText = null;
+
+    /**
+     * The account code
+     * @type {string|null}
+     */
+    accountCode = null;
+
+    /**
+     * The account text
+     * @type {string|null}
+     */
+    accountText = null;
+
+    /**
+     * The summary
+     * @type {string|null}
+     */
+    summary = null;
+
+    /**
+     * The amount
+     * @type {string}
+     */
+    amount = "";
+
+    /**
+     * The summary editors
+     * @type {{debit: SummaryEditor, credit: SummaryEditor}}
+     */
+    #summaryEditors;
+
+    /**
+     * The account selectors
+     * @type {{debit: AccountSelector, credit: AccountSelector}}
+     */
+    #accountSelectors;
+
+    /**
+     * The original entry selector
+     * @type {OriginalEntrySelector}
+     */
+    originalEntrySelector;
+
+    /**
+     * Constructs a new journal entry editor.
+     *
+     * @param form {TransactionForm} the transaction form
+     */
+    constructor(form) {
+        this.form = form;
+        this.#element = document.getElementById(this.#prefix);
+        this.#modal = document.getElementById(this.#prefix + "-modal");
+        this.#originalEntryContainer = document.getElementById(this.#prefix + "-original-entry-container");
+        this.#originalEntryControl = document.getElementById(this.#prefix + "-original-entry-control");
+        this.#originalEntry = document.getElementById(this.#prefix + "-original-entry");
+        this.#originalEntryError = document.getElementById(this.#prefix + "-original-entry-error");
+        this.#originalEntryDelete = document.getElementById(this.#prefix + "-original-entry-delete");
+        this.#summaryControl = document.getElementById(this.#prefix + "-summary-control");
+        this.#summary = document.getElementById(this.#prefix + "-summary");
+        this.#summaryError = document.getElementById(this.#prefix + "-summary-error");
+        this.#accountControl = document.getElementById(this.#prefix + "-account-control");
+        this.#account = document.getElementById(this.#prefix + "-account");
+        this.#accountError = document.getElementById(this.#prefix + "-account-error")
+        this.#amount = document.getElementById(this.#prefix + "-amount");
+        this.#amountError = document.getElementById(this.#prefix + "-amount-error");
+        this.#summaryEditors = SummaryEditor.getInstances(this);
+        this.#accountSelectors = AccountSelector.getInstances(this);
+        this.originalEntrySelector = new OriginalEntrySelector();
+        this.#originalEntryControl.onclick = () => this.originalEntrySelector.onOpen(this, this.originalEntryId)
+        this.#originalEntryDelete.onclick = () => this.clearOriginalEntry();
+        this.#summaryControl.onclick = () => this.#summaryEditors[this.entryType].onOpen();
+        this.#accountControl.onclick = () => this.#accountSelectors[this.entryType].onOpen();
+        this.#amount.onchange = () => this.#validateAmount();
+        this.#element.onsubmit = () => {
+            if (this.#validate()) {
+                if (this.entry === null) {
+                    this.entry = this.#side.addJournalEntry();
+                }
+                this.amount = this.#amount.value;
+                this.entry.save(this);
+                bootstrap.Modal.getInstance(this.#modal).hide();
+            }
+            return false;
+        };
+    }
+
+    /**
+     * Saves the original entry from the original entry selector.
+     *
+     * @param originalEntry {OriginalEntry} the original entry
+     */
+    saveOriginalEntry(originalEntry) {
+        this.isNeedOffset = false;
+        this.#originalEntryContainer.classList.remove("d-none");
+        this.#originalEntryControl.classList.add("accounting-not-empty");
+        this.originalEntryId = originalEntry.id;
+        this.originalEntryDate = originalEntry.date;
+        this.originalEntryText = originalEntry.text;
+        this.#originalEntry.innerText = originalEntry.text;
+        this.#setEnableSummaryAccount(false);
+        if (originalEntry.summary === "") {
+            this.#summaryControl.classList.remove("accounting-not-empty");
+        } else {
+            this.#summaryControl.classList.add("accounting-not-empty");
+        }
+        this.summary = originalEntry.summary === ""? null: originalEntry.summary;
+        this.#summary.innerText = originalEntry.summary;
+        this.#accountControl.classList.add("accounting-not-empty");
+        this.accountCode = originalEntry.accountCode;
+        this.accountText = originalEntry.accountText;
+        this.#account.innerText = originalEntry.accountText;
+        this.#amount.value = String(originalEntry.netBalance);
+        this.#amount.max = String(originalEntry.netBalance);
+        this.#amount.min = "0";
+        this.#validate();
+    }
+
+    /**
+     * Clears the original entry.
+     *
+     */
+    clearOriginalEntry() {
+        this.isNeedOffset = false;
+        this.#originalEntryContainer.classList.add("d-none");
+        this.#originalEntryControl.classList.remove("accounting-not-empty");
+        this.originalEntryId = null;
+        this.originalEntryDate = null;
+        this.originalEntryText = null;
+        this.#originalEntry.innerText = "";
+        this.#setEnableSummaryAccount(true);
+        this.#accountControl.classList.remove("accounting-not-empty");
+        this.accountCode = null;
+        this.accountText = null;
+        this.#account.innerText = "";
+        this.#amount.max = "";
+    }
+
+    /**
+     * Returns the currency code.
+     *
+     * @return {string} the currency code
+     */
+    getCurrencyCode() {
+        return this.#side.currency.getCurrencyCode();
+    }
+
+    /**
+     * Saves the summary from the summary editor.
+     *
+     * @param summary {string} the summary
+     */
+    saveSummary(summary) {
+        if (summary === "") {
+            this.#summaryControl.classList.remove("accounting-not-empty");
+        } else {
+            this.#summaryControl.classList.add("accounting-not-empty");
+        }
+        this.summary = summary === ""? null: summary;
+        this.#summary.innerText = summary;
+        this.#validateSummary();
+        bootstrap.Modal.getOrCreateInstance(this.#modal).show();
+    }
+
+    /**
+     * Saves the summary with the suggested account from the summary editor.
+     *
+     * @param summary {string} the summary
+     * @param accountCode {string} the account code
+     * @param accountText {string} the account text
+     * @param isAccountNeedOffset {boolean} true if the journal entries in the account need offset, or false otherwise
+     */
+    saveSummaryWithAccount(summary, accountCode, accountText, isAccountNeedOffset) {
+        this.isNeedOffset = isAccountNeedOffset;
+        this.#accountControl.classList.add("accounting-not-empty");
+        this.accountCode = accountCode;
+        this.accountText = accountText;
+        this.#account.innerText = accountText;
+        this.#validateAccount();
+        this.saveSummary(summary)
+    }
+
+    /**
+     * Clears the account.
+     *
+     */
+    clearAccount() {
+        this.isNeedOffset = false;
+        this.#accountControl.classList.remove("accounting-not-empty");
+        this.accountCode = null;
+        this.accountText = null;
+        this.#account.innerText = "";
+        this.#validateAccount();
+    }
+
+    /**
+     * Sets the account.
+     *
+     * @param code {string} the account code
+     * @param text {string} the account text
+     * @param isNeedOffset {boolean} true if the journal entries in the account need offset or false otherwise
+     */
+    saveAccount(code, text, isNeedOffset) {
+        this.isNeedOffset = isNeedOffset;
+        this.#accountControl.classList.add("accounting-not-empty");
+        this.accountCode = code;
+        this.accountText = text;
+        this.#account.innerText = text;
+        this.#validateAccount();
+    }
+
+    /**
+     * Validates the form.
+     *
+     * @returns {boolean} true if valid, or false otherwise
+     */
+    #validate() {
+        let isValid = true;
+        isValid = this.#validateOriginalEntry() && isValid;
+        isValid = this.#validateSummary() && isValid;
+        isValid = this.#validateAccount() && isValid;
+        isValid = this.#validateAmount() && isValid
+        return isValid;
+    }
+
+    /**
+     * Validates the original entry.
+     *
+     * @return {boolean} true if valid, or false otherwise
+     * @private
+     */
+    #validateOriginalEntry() {
+        this.#originalEntryControl.classList.remove("is-invalid");
+        this.#originalEntryError.innerText = "";
+        return true;
+    }
+
+    /**
+     * Validates the summary.
+     *
+     * @return {boolean} true if valid, or false otherwise
+     * @private
+     */
+    #validateSummary() {
+        this.#summary.classList.remove("is-invalid");
+        this.#summaryError.innerText = "";
+        return true;
+    }
+
+    /**
+     * Validates the account.
+     *
+     * @return {boolean} true if valid, or false otherwise
+     */
+    #validateAccount() {
+        if (this.accountCode === null) {
+            this.#accountControl.classList.add("is-invalid");
+            this.#accountError.innerText = A_("Please select the account.");
+            return false;
+        }
+        this.#accountControl.classList.remove("is-invalid");
+        this.#accountError.innerText = "";
+        return true;
+    }
+
+    /**
+     * Validates the amount.
+     *
+     * @return {boolean} true if valid, or false otherwise
+     * @private
+     */
+    #validateAmount() {
+        this.#amount.value = this.#amount.value.trim();
+        this.#amount.classList.remove("is-invalid");
+        if (this.#amount.value === "") {
+            this.#amount.classList.add("is-invalid");
+            this.#amountError.innerText = A_("Please fill in the amount.");
+            return false;
+        }
+        const amount =new Decimal(this.#amount.value);
+        if (amount.lessThanOrEqualTo(0)) {
+            this.#amount.classList.add("is-invalid");
+            this.#amountError.innerText = A_("Please fill in a positive amount.");
+            return false;
+        }
+        if (this.#amount.max !== "") {
+            if (amount.greaterThan(new Decimal(this.#amount.max))) {
+                this.#amount.classList.add("is-invalid");
+                this.#amountError.innerText = A_("The amount must not exceed the net balance %(balance)s of the original entry.", {balance: new Decimal(this.#amount.max)});
+                return false;
+            }
+        }
+        if (this.#amount.min !== "") {
+            const min = new Decimal(this.#amount.min);
+            if (amount.lessThan(min)) {
+                this.#amount.classList.add("is-invalid");
+                this.#amountError.innerText = A_("The amount must not be less than the offset total %(total)s.", {total: formatDecimal(min)});
+                return false;
+            }
+        }
+        this.#amount.classList.remove("is-invalid");
+        this.#amountError.innerText = "";
+        return true;
+    }
+
+    /**
+     * The callback when adding a new journal entry.
+     *
+     * @param side {DebitCreditSideSubForm} the debit or credit side sub-form
+     */
+    onAddNew(side) {
+        this.entry = null;
+        this.#side = side;
+        this.entryType = this.#side.entryType;
+        this.isNeedOffset = false;
+        this.#originalEntryContainer.classList.add("d-none");
+        this.#originalEntryControl.classList.remove("accounting-not-empty");
+        this.#originalEntryControl.classList.remove("is-invalid");
+        this.originalEntryId = null;
+        this.originalEntryDate = null;
+        this.originalEntryText = null;
+        this.#originalEntry.innerText = "";
+        this.#setEnableSummaryAccount(true);
+        this.#summaryControl.classList.remove("accounting-not-empty");
+        this.#summaryControl.classList.remove("is-invalid");
+        this.summary = null;
+        this.#summary.innerText = ""
+        this.#summaryError.innerText = ""
+        this.#accountControl.classList.remove("accounting-not-empty");
+        this.#accountControl.classList.remove("is-invalid");
+        this.accountCode = null;
+        this.accountText = null;
+        this.#account.innerText = "";
+        this.#accountError.innerText = "";
+        this.#amount.value = "";
+        this.#amount.max = "";
+        this.#amount.min = "0";
+        this.#amount.classList.remove("is-invalid");
+        this.#amountError.innerText = "";
+    }
+
+    /**
+     * The callback when editing a journal entry.
+     *
+     * @param entry {JournalEntrySubForm} the journal entry sub-form
+     */
+    onEdit(entry) {
+        this.entry = entry;
+        this.#side = entry.side;
+        this.entryType = this.#side.entryType;
+        this.isNeedOffset = entry.isNeedOffset();
+        this.originalEntryId = entry.getOriginalEntryId();
+        this.originalEntryDate = entry.getOriginalEntryDate();
+        this.originalEntryText = entry.getOriginalEntryText();
+        this.#originalEntry.innerText = this.originalEntryText;
+        if (this.originalEntryId === null) {
+            this.#originalEntryContainer.classList.add("d-none");
+            this.#originalEntryControl.classList.remove("accounting-not-empty");
+        } else {
+            this.#originalEntryContainer.classList.remove("d-none");
+            this.#originalEntryControl.classList.add("accounting-not-empty");
+        }
+        this.#setEnableSummaryAccount(!entry.isMatched && this.originalEntryId === null);
+        this.summary = entry.getSummary();
+        if (this.summary === null) {
+            this.#summaryControl.classList.remove("accounting-not-empty");
+        } else {
+            this.#summaryControl.classList.add("accounting-not-empty");
+        }
+        this.#summary.innerText = this.summary === null? "": this.summary;
+        if (entry.getAccountCode() === null) {
+            this.#accountControl.classList.remove("accounting-not-empty");
+        } else {
+            this.#accountControl.classList.add("accounting-not-empty");
+        }
+        this.accountCode = entry.getAccountCode();
+        this.accountText = entry.getAccountText();
+        this.#account.innerText = this.accountText;
+        this.#amount.value = entry.getAmount() === null? "": String(entry.getAmount());
+        const maxAmount = this.#getMaxAmount();
+        this.#amount.max = maxAmount === null? "": maxAmount;
+        this.#amount.min = entry.getAmountMin() === null? "": String(entry.getAmountMin());
+        this.#validate();
+    }
+
+    /**
+     * Finds out the max amount.
+     *
+     * @return {Decimal|null} the max amount
+     */
+    #getMaxAmount() {
+        if (this.originalEntryId === null) {
+            return null;
+        }
+        return this.originalEntrySelector.getNetBalance(this.entry, this.form, this.originalEntryId);
+    }
+
+    /**
+     * Sets the enable status of the summary and account.
+     *
+     * @param isEnabled {boolean} true to enable, or false otherwise
+     */
+    #setEnableSummaryAccount(isEnabled) {
+        if (isEnabled) {
+            this.#summaryControl.dataset.bsToggle = "modal";
+            this.#summaryControl.dataset.bsTarget = "#accounting-summary-editor-" + this.#side.entryType + "-modal";
+            this.#summaryControl.classList.remove("accounting-disabled");
+            this.#summaryControl.classList.add("accounting-clickable");
+            this.#accountControl.dataset.bsToggle = "modal";
+            this.#accountControl.dataset.bsTarget = "#accounting-account-selector-" + this.#side.entryType + "-modal";
+            this.#accountControl.classList.remove("accounting-disabled");
+            this.#accountControl.classList.add("accounting-clickable");
+        } else {
+            this.#summaryControl.dataset.bsToggle = "";
+            this.#summaryControl.dataset.bsTarget = "";
+            this.#summaryControl.classList.add("accounting-disabled");
+            this.#summaryControl.classList.remove("accounting-clickable");
+            this.#accountControl.dataset.bsToggle = "";
+            this.#accountControl.dataset.bsTarget = "";
+            this.#accountControl.classList.add("accounting-disabled");
+            this.#accountControl.classList.remove("accounting-clickable");
+        }
+    }
+}

src/accounting/static/js/original-entry-selector.js

@@ -0,0 +1,417 @@
+/* The Mia! Accounting Flask Project
+ * original-entry-selector.js: The JavaScript for the original entry selector
+ */
+
+/*  Copyright (c) 2023 imacat.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+/* Author: imacat@mail.imacat.idv.tw (imacat)
+ * First written: 2023/3/10
+ */
+"use strict";
+
+/**
+ * The original entry selector.
+ *
+ */
+class OriginalEntrySelector {
+
+    /**
+     * The prefix of the HTML ID and class
+     * @type {string}
+     */
+    #prefix = "accounting-original-entry-selector";
+
+    /**
+     * The modal of the original entry editor
+     * @type {HTMLDivElement}
+     */
+    #modal;
+
+    /**
+     * The query input
+     * @type {HTMLInputElement}
+     */
+    #query;
+
+    /**
+     * The error message when the query has no result
+     * @type {HTMLParagraphElement}
+     */
+    #queryNoResult;
+
+    /**
+     * The option list
+     * @type {HTMLUListElement}
+     */
+    #optionList;
+
+    /**
+     * The options
+     * @type {OriginalEntry[]}
+     */
+    #options;
+
+    /**
+     * The options by their ID
+     * @type {Object.<string, OriginalEntry>}
+     */
+    #optionById;
+
+    /**
+     * The journal entry editor
+     * @type {JournalEntryEditor}
+     */
+    entryEditor;
+
+    /**
+     * The currency code
+     * @type {string}
+     */
+    #currencyCode;
+
+    /**
+     * The entry
+     */
+    #entryType;
+
+    /**
+     * Constructs an original entry selector.
+     *
+     */
+    constructor() {
+        this.#modal = document.getElementById(this.#prefix + "-modal");
+        this.#query = document.getElementById(this.#prefix + "-query");
+        this.#queryNoResult = document.getElementById(this.#prefix + "-option-no-result");
+        this.#optionList = document.getElementById(this.#prefix + "-option-list");
+        this.#options = Array.from(document.getElementsByClassName(this.#prefix + "-option")).map((element) => new OriginalEntry(this, element));
+        this.#optionById = {};
+        for (const option of this.#options) {
+            this.#optionById[option.id] = option;
+        }
+        this.#query.addEventListener("input", () => {
+            this.#filterOptions();
+        });
+    }
+
+    /**
+     * Returns the net balance for an original entry.
+     *
+     * @param currentEntry {JournalEntrySubForm} the journal entry sub-form that is currently editing
+     * @param form {TransactionForm} the transaction form
+     * @param originalEntryId {string} the ID of the original entry
+     * @return {Decimal} the net balance of the original entry
+     */
+    getNetBalance(currentEntry, form, originalEntryId) {
+        const otherEntries = form.getEntries().filter((entry) => entry !== currentEntry);
+        let otherOffset = new Decimal(0);
+        for (const otherEntry of otherEntries) {
+            if (otherEntry.getOriginalEntryId() === originalEntryId) {
+                const amount = otherEntry.getAmount();
+                if (amount !== null) {
+                    otherOffset = otherOffset.plus(amount);
+                }
+            }
+        }
+        return this.#optionById[originalEntryId].bareNetBalance.minus(otherOffset);
+    }
+
+    /**
+     * Updates the net balances, subtracting the offset amounts on the form but the currently editing journal entry
+     *
+     */
+    #updateNetBalances() {
+        const otherEntries = this.entryEditor.form.getEntries().filter((entry) => entry !== this.entryEditor.entry);
+        const otherOffsets = {}
+        for (const otherEntry of otherEntries) {
+            const otherOriginalEntryId = otherEntry.getOriginalEntryId();
+            const amount = otherEntry.getAmount();
+            if (otherOriginalEntryId === null || amount === null) {
+                continue;
+            }
+            if (!(otherOriginalEntryId in otherOffsets)) {
+                otherOffsets[otherOriginalEntryId] = new Decimal("0");
+            }
+            otherOffsets[otherOriginalEntryId] = otherOffsets[otherOriginalEntryId].plus(amount);
+        }
+        for (const option of this.#options) {
+            if (option.id in otherOffsets) {
+                option.updateNetBalance(otherOffsets[option.id]);
+            } else {
+                option.resetNetBalance();
+            }
+        }
+    }
+
+    /**
+     * Filters the options.
+     *
+     */
+    #filterOptions() {
+        let hasAnyMatched = false;
+        for (const option of this.#options) {
+            if (option.isMatched(this.#entryType, this.#currencyCode, this.#query.value)) {
+                option.setShown(true);
+                hasAnyMatched = true;
+            } else {
+                option.setShown(false);
+            }
+        }
+        if (!hasAnyMatched) {
+            this.#optionList.classList.add("d-none");
+            this.#queryNoResult.classList.remove("d-none");
+        } else {
+            this.#optionList.classList.remove("d-none");
+            this.#queryNoResult.classList.add("d-none");
+        }
+    }
+
+    /**
+     * The callback when the original entry selector is shown.
+     *
+     * @param entryEditor {JournalEntryEditor} the journal entry editor
+     * @param originalEntryId {string|null} the ID of the original entry
+     */
+    onOpen(entryEditor, originalEntryId = null) {
+        this.entryEditor = entryEditor
+        this.#currencyCode = entryEditor.getCurrencyCode();
+        this.#entryType = entryEditor.entryType;
+        for (const option of this.#options) {
+            option.setActive(option.id === originalEntryId);
+        }
+        this.#query.value = "";
+        this.#updateNetBalances();
+        this.#filterOptions();
+    }
+}
+
+/**
+ * An original entry.
+ *
+ */
+class OriginalEntry {
+
+    /**
+     * The original entry selector
+     * @type {OriginalEntrySelector}
+     */
+    #selector;
+
+    /**
+     * The element
+     * @type {HTMLLIElement}
+     */
+    #element;
+
+    /**
+     * The ID
+     * @type {string}
+     */
+    id;
+
+    /**
+     * The date
+     * @type {string}
+     */
+    date;
+
+    /**
+     * The entry type, either "debit" or "credit"
+     * @type {string}
+     */
+    #entryType;
+
+    /**
+     * The currency code
+     * @type {string}
+     */
+    #currencyCode;
+
+    /**
+     * The account code
+     * @type {string}
+     */
+    accountCode;
+
+    /**
+     * The account text
+     * @type {string}
+     */
+    accountText;
+
+    /**
+     * The summary
+     * @type {string}
+     */
+    summary;
+
+    /**
+     * The net balance, without the offset amounts on the form
+     * @type {Decimal}
+     */
+    bareNetBalance;
+
+    /**
+     * The net balance
+     * @type {Decimal}
+     */
+    netBalance;
+
+    /**
+     * The text of the net balance
+     * @type {HTMLSpanElement}
+     */
+    netBalanceText;
+
+    /**
+     * The text representation of the original entry
+     * @type {string}
+     */
+    text;
+
+    /**
+     * The values to query against
+     * @type {string[][]}
+     */
+    #queryValues;
+
+    /**
+     * Constructs an original entry.
+     *
+     * @param selector {OriginalEntrySelector} the original entry selector
+     * @param element {HTMLLIElement} the element
+     */
+    constructor(selector, element) {
+        this.#selector = selector;
+        this.#element = element;
+        this.id = element.dataset.id;
+        this.date = element.dataset.date;
+        this.#entryType = element.dataset.entryType;
+        this.#currencyCode = element.dataset.currencyCode;
+        this.accountCode = element.dataset.accountCode;
+        this.accountText = element.dataset.accountText;
+        this.summary = element.dataset.summary;
+        this.bareNetBalance = new Decimal(element.dataset.netBalance);
+        this.netBalance = this.bareNetBalance;
+        this.netBalanceText = document.getElementById("accounting-original-entry-selector-option-" + this.id + "-net-balance");
+        this.text = element.dataset.text;
+        this.#queryValues = JSON.parse(element.dataset.queryValues);
+        this.#element.onclick = () => this.#selector.entryEditor.saveOriginalEntry(this);
+    }
+
+    /**
+     * Resets the net balance to its initial value, without the offset amounts on the form.
+     *
+     */
+    resetNetBalance() {
+        if (this.netBalance !== this.bareNetBalance) {
+            this.netBalance = this.bareNetBalance;
+            this.#updateNetBalanceText();
+        }
+    }
+
+    /**
+     * Updates the net balance with an offset.
+     *
+     * @param offset {Decimal} the offset to be added to the net balance
+     */
+    updateNetBalance(offset) {
+        this.netBalance = this.bareNetBalance.minus(offset);
+        this.#updateNetBalanceText();
+    }
+
+    /**
+     * Updates the text display of the net balance.
+     *
+     */
+    #updateNetBalanceText() {
+        this.netBalanceText.innerText = formatDecimal(this.netBalance);
+    }
+
+    /**
+     * Returns whether the original matches.
+     *
+     * @param entryType {string} the entry type, either "debit" or "credit"
+     * @param currencyCode {string} the currency code
+     * @param query {string|null} the query term
+     */
+    isMatched(entryType, currencyCode, query = null) {
+        return this.netBalance.greaterThan(0)
+            && this.date <= this.#selector.entryEditor.form.getDate()
+            && this.#isEntryTypeMatches(entryType)
+            && this.#currencyCode === currencyCode
+            && this.#isQueryMatches(query);
+    }
+
+    /**
+     * Returns whether the original entry matches the entry type.
+     *
+     * @param entryType {string} the entry type, either "debit" or credit
+     * @return {boolean} true if the option matches, or false otherwise
+     */
+    #isEntryTypeMatches(entryType) {
+        return (entryType === "debit" && this.#entryType === "credit")
+            || (entryType === "credit" && this.#entryType === "debit");
+    }
+
+    /**
+     * Returns whether the original entry matches the query.
+     *
+     * @param query {string|null} the query term
+     * @return {boolean} true if the option matches, or false otherwise
+     */
+    #isQueryMatches(query) {
+        if (query === "") {
+            return true;
+        }
+        for (const queryValue of this.#queryValues[0]) {
+            if (queryValue.toLowerCase().includes(query.toLowerCase())) {
+                return true;
+            }
+        }
+        for (const queryValue of this.#queryValues[1]) {
+            if (queryValue === query) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Sets whether the option is shown.
+     *
+     * @param isShown {boolean} true to show, or false otherwise
+     */
+    setShown(isShown) {
+        if (isShown) {
+            this.#element.classList.remove("d-none");
+        } else {
+            this.#element.classList.add("d-none");
+        }
+    }
+
+    /**
+     * Sets whether the option is active.
+     *
+     * @param isActive {boolean} true if active, or false otherwise
+     */
+    setActive(isActive) {
+        if (isActive) {
+            this.#element.classList.add("active");
+        } else {
+            this.#element.classList.remove("active");
+        }
+    }
+}

src/accounting/static/js/summary-editor.js

@@ -22,17 +22,18 @@
  */
 "use strict";
 
-// Initializes the page JavaScript.
-document.addEventListener("DOMContentLoaded", () => {
-    SummaryEditor.initialize();
-});
-
 /**
  * A summary editor.
  *
  */
 class SummaryEditor {
 
+    /**
+     * The journal entry editor
+     * @type {JournalEntryEditor}
+     */
+    #entryEditor;
+
     /**
      * The summary editor form
      * @type {HTMLFormElement}
@@ -55,28 +56,34 @@ class SummaryEditor {
      * The entry type, either "debit" or "credit"
      * @type {string}
      */
-    #entryType;
+    entryType;
 
     /**
-     * The current tab.
+     * The current tab
      * @type {TabPlane}
      */
     currentTab;
 
     /**
-     * The summary input.
+     * The summary input
      * @type {HTMLInputElement}
      */
     summary;
 
     /**
-     * The number input.
+     * The button to the original entry selector
+     * @type {HTMLButtonElement}
+     */
+    #offsetButton;
+
+    /**
+     * The number input
      * @type {HTMLInputElement}
      */
     number;
 
     /**
-     * The note.
+     * The note
      * @type {HTMLInputElement}
      */
     note;
@@ -93,36 +100,6 @@ class SummaryEditor {
      */
     #selectedAccount = null;
 
-    /**
-     * The modal of the journal entry form
-     * @type {HTMLDivElement}
-     */
-    #entryFormModal;
-
-    /**
-     * The control of the account on the journal entry form
-     * @type {HTMLDivElement}
-     */
-    #formAccountControl;
-
-    /**
-     * The account on the journal entry form
-     * @type {HTMLDivElement}
-     */
-    #formAccount;
-
-    /**
-     * The control of the summary on the journal entry form
-     * @type {HTMLDivElement}
-     */
-    #formSummaryControl;
-
-    /**
-     * The summary on the journal entry form
-     * @type {HTMLDivElement}
-     */
-    #formSummary;
-
     /**
      * The tab planes
      * @type {{general: GeneralTagTab, travel: GeneralTripTab, bus: BusTripTab, regular: RegularPaymentTab, annotation: AnnotationTab}}
@@ -132,26 +109,22 @@ class SummaryEditor {
     /**
      * Constructs a summary editor.
      *
-     * @param form {HTMLFormElement} the summary editor form
+     * @param entryEditor {JournalEntryEditor} the journal entry editor
+     * @param entryType {string} the entry type, either "debit" or "credit"
      */
-    constructor(form) {
-        this.#form = form;
-        this.#entryType = form.dataset.entryType;
-        this.prefix = "accounting-summary-editor-" + form.dataset.entryType;
+    constructor(entryEditor, entryType) {
+        this.#entryEditor = entryEditor;
+        this.entryType = entryType;
+        this.prefix = "accounting-summary-editor-" + entryType;
+        this.#form = document.getElementById(this.prefix);
         this.#modal = document.getElementById(this.prefix + "-modal");
         this.summary = document.getElementById(this.prefix + "-summary");
+        this.#offsetButton = document.getElementById(this.prefix + "-offset");
         this.number = document.getElementById(this.prefix + "-annotation-number");
         this.note = document.getElementById(this.prefix + "-annotation-note");
         // noinspection JSValidateTypes
         this.#accountButtons = Array.from(document.getElementsByClassName(this.prefix + "-account"));
 
-        // Things from the entry form
-        this.#entryFormModal = document.getElementById("accounting-entry-form-modal");
-        this.#formAccountControl = document.getElementById("accounting-entry-form-account-control");
-        this.#formAccount = document.getElementById("accounting-entry-form-account");
-        this.#formSummaryControl = document.getElementById("accounting-entry-form-summary-control");
-        this.#formSummary = document.getElementById("accounting-entry-form-summary");
-
         for (const cls of [GeneralTagTab, GeneralTripTab, BusTripTab, RegularPaymentTab, AnnotationTab]) {
             const tab = new cls(this);
             this.tabPlanes[tab.tabId()] = tab;
@@ -159,6 +132,7 @@ class SummaryEditor {
         this.currentTab = this.tabPlanes.general;
         this.#initializeSuggestedAccounts();
         this.summary.onchange = () => this.#onSummaryChange();
+        this.#offsetButton.onclick = () => this.#entryEditor.originalEntrySelector.onOpen(this.#entryEditor);
         this.#form.onsubmit = () => {
             if (this.currentTab.validate()) {
                 this.#submit();
@@ -239,30 +213,21 @@ class SummaryEditor {
      *
      */
     #submit() {
-        if (this.summary.value === "") {
-            this.#formSummaryControl.classList.remove("accounting-not-empty");
-        } else {
-            this.#formSummaryControl.classList.add("accounting-not-empty");
-        }
-        if (this.#selectedAccount !== null) {
-            this.#formAccountControl.classList.add("accounting-not-empty");
-            this.#formAccount.dataset.code = this.#selectedAccount.dataset.code;
-            this.#formAccount.dataset.text = this.#selectedAccount.dataset.text;
-            this.#formAccount.innerText = this.#selectedAccount.dataset.text;
-        }
-        this.#formSummary.dataset.value = this.summary.value;
-        this.#formSummary.innerText = this.summary.value;
         bootstrap.Modal.getOrCreateInstance(this.#modal).hide();
-        bootstrap.Modal.getOrCreateInstance(this.#entryFormModal).show();
+        if (this.#selectedAccount !== null) {
+            this.#entryEditor.saveSummaryWithAccount(this.summary.value, this.#selectedAccount.dataset.code, this.#selectedAccount.dataset.text, this.#selectedAccount.classList.contains("accounting-account-is-need-offset"));
+        } else {
+            this.#entryEditor.saveSummary(this.summary.value);
+        }
     }
 
     /**
      * The callback when the summary editor is shown.
      *
      */
-    #onOpen() {
+    onOpen() {
         this.#reset();
-        this.summary.value = this.#formSummary.dataset.value;
+        this.summary.value = this.#entryEditor.summary === null? "": this.#entryEditor.summary;
         this.#onSummaryChange();
     }
 
@@ -279,33 +244,18 @@ class SummaryEditor {
     }
 
     /**
-     * The summary editors.
-     * @type {{debit: SummaryEditor, credit: SummaryEditor}}
-     */
-    static #editors = {}
-
-    /**
-     * Initializes the summary editors.
+     * Returns the summary editor instances.
      *
+     * @param entryEditor {JournalEntryEditor} the journal entry editor
+     * @return {{debit: SummaryEditor, credit: SummaryEditor}}
      */
-    static initialize() {
+    static getInstances(entryEditor) {
+        const editors = {}
         const forms = Array.from(document.getElementsByClassName("accounting-summary-editor"));
-        const entryForm = document.getElementById("accounting-entry-form");
-        const formSummaryControl = document.getElementById("accounting-entry-form-summary-control");
         for (const form of forms) {
-            const editor = new SummaryEditor(form);
-            this.#editors[editor.#entryType] = editor;
+            editors[form.dataset.entryType] = new SummaryEditor(entryEditor, form.dataset.entryType);
         }
-        formSummaryControl.onclick = () => this.#editors[entryForm.dataset.entryType].#onOpen()
-    }
-
-    /**
-     * Initializes the summary editor for a new journal entry.
-     *
-     * @param entryType {string} the entry type, either "debit" or "credit"
-     */
-    static initializeNewJournalEntry(entryType) {
-        this.#editors[entryType].#onOpen();
+        return editors;
     }
 }
 

src/accounting/templates/accounting/account/detail.html

@@ -85,7 +85,7 @@ First written: 2023/1/31
 <div class="accounting-card col-sm-6">
   <div class="accounting-card-title">{{ obj.title }}</div>
   <div class="accounting-card-code">{{ obj.code }}</div>
-  {% if obj.is_offset_needed %}
+  {% if obj.is_need_offset %}
     <div>
       <span class="badge rounded-pill bg-info">{{ A_("Need offset") }}</span>
     </div>

src/accounting/templates/accounting/account/include/form.html

@@ -41,9 +41,9 @@ First written: 2023/2/1
   {% endif %}
   <div class="form-floating mb-3">
     <input id="accounting-base-code" type="hidden" name="base_code" value="{{ form.base_code.data|accounting_default }}">
-    <div id="accounting-base" class="form-control accounting-clickable accounting-material-text-field {% if form.base_code.data %} accounting-not-empty {% endif %} {% if form.base_code.errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-base-selector-modal">
+    <div id="accounting-base-control" class="form-control accounting-clickable accounting-material-text-field {% if form.base_code.data %} accounting-not-empty {% endif %} {% if form.base_code.errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-base-selector-modal">
       <label class="form-label" for="accounting-base">{{ A_("Base account") }}</label>
-      <div id="accounting-base-content">
+      <div id="accounting-base">
         {% if form.base_code.data %}
           {% if form.base_code.errors %}
             {{ A_("(Unknown)") }}
@@ -53,7 +53,7 @@ First written: 2023/2/1
         {% endif %}
       </div>
     </div>
-    <div id="accounting-base-code-error" class="invalid-feedback">{% if form.base_code.errors %}{{ form.base_code.errors[0] }}{% endif %}</div>
+    <div id="accounting-base-error" class="invalid-feedback">{% if form.base_code.errors %}{{ form.base_code.errors[0] }}{% endif %}</div>
   </div>
 
   <div class="form-floating mb-3">
@@ -62,9 +62,9 @@ First written: 2023/2/1
     <div id="accounting-title-error" class="invalid-feedback">{% if form.title.errors %}{{ form.title.errors[0] }}{% endif %}</div>
   </div>
 
-  <div class="form-check form-switch mb-3">
-    <input id="accounting-is-offset-needed" class="form-check-input" type="checkbox" name="is_offset_needed" value="1" {% if form.is_offset_needed.data %} checked="checked" {% endif %}>
-    <label class="form-check-label" for="accounting-is-offset-needed">
+  <div id="accounting-is-need-offset-control" class="form-check form-switch mb-3 {% if form.base_code.data[0] not in ["1", "2", "3"] %} d-none {% endif %}">
+    <input id="accounting-is-need-offset" class="form-check-input" type="checkbox" name="is_need_offset" value="1" {% if form.is_need_offset.data %} checked="checked" {% endif %}>
+    <label class="form-check-label" for="accounting-is-need-offset">
       {{ A_("The entries in the account need offset.") }}
     </label>
   </div>
@@ -99,21 +99,21 @@ First written: 2023/2/1
           </label>
         </div>
 
-        <ul id="accounting-base-option-list" class="list-group accounting-selector-list">
+        <ul id="accounting-base-selector-option-list" class="list-group accounting-selector-list">
           {% for base in form.base_options %}
-          <li id="accounting-base-option-{{ base.code }}" class="list-group-item accounting-base-option accounting-clickable" data-code="{{ base.code }}" data-content="{{ base }}" data-query-values="{{ base.query_values|tojson|forceescape }}">
-            {{ base }}
-          </li>
+            <li class="list-group-item accounting-clickable accounting-base-selector-option" data-code="{{ base.code }}" data-content="{{ base }}" data-query-values="{{ base.query_values|tojson|forceescape }}" data-bs-dismiss="modal">
+              {{ base }}
+            </li>
           {% endfor %}
         </ul>
-        <p id="accounting-base-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
+        <p id="accounting-base-selector-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
       </div>
       <div class="modal-footer">
         <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">{{ A_("Cancel") }}</button>
         {% if form.base_code.data %}
-          <button id="accounting-btn-clear-base" type="button" class="btn btn-danger">{{ A_("Clear") }}</button>
+          <button id="accounting-base-selector-clear" type="button" class="btn btn-danger" data-bs-dismiss="modal">{{ A_("Clear") }}</button>
         {% else %}
-          <button id="accounting-btn-clear-base" type="button" class="btn btn-secondary" disabled="disabled">{{ A_("Clear") }}</button>
+          <button id="accounting-base-selector-clear" type="button" class="btn btn-secondary" disabled="disabled" data-bs-dismiss="modal">{{ A_("Clear") }}</button>
         {% endif %}
       </div>
     </div>

src/accounting/templates/accounting/account/list.html

@@ -58,7 +58,7 @@ First written: 2023/1/30
   {% for item in list %}
     <a class="list-group-item list-group-item-action" href="{{ url_for("accounting.account.detail", account=item)|accounting_append_next }}">
       {{ item }}
-      {% if item.is_offset_needed %}
+      {% if item.is_need_offset %}
         <span class="badge rounded-pill bg-info">{{ A_("Need offset") }}</span>
       {% endif %}
     </a>

src/accounting/templates/accounting/report/include/ledger-row-desktop.html

@@ -23,4 +23,6 @@ First written: 2023/3/8
 <div>{{ entry.summary|accounting_default }}</div>
 <div class="accounting-amount">{{ entry.debit|accounting_format_amount|accounting_default }}</div>
 <div class="accounting-amount">{{ entry.credit|accounting_format_amount|accounting_default }}</div>
-<div class="accounting-amount {% if entry.balance < 0 %} text-danger {% endif %}">{{ entry.balance|accounting_report_format_amount }}</div>
+{% if report.account.is_real %}
+  <div class="accounting-amount {% if entry.balance < 0 %} text-danger {% endif %}">{{ entry.balance|accounting_report_format_amount }}</div>
+{% endif %}

src/accounting/templates/accounting/report/include/ledger-row-mobile.html

@@ -37,5 +37,7 @@ First written: 2023/3/5
   {% if entry.credit %}
     <span class="badge rounded-pill bg-warning">-{{ entry.credit|accounting_format_amount }}</span>
   {% endif %}
-  <span class="badge rounded-pill bg-primary">{{ entry.balance|accounting_format_amount }}</span>
+  {% if report.account.is_real %}
+    <span class="badge rounded-pill bg-primary">{{ entry.balance|accounting_format_amount }}</span>
+  {% endif %}
 </div>

src/accounting/templates/accounting/report/ledger.html

@@ -49,14 +49,16 @@ First written: 2023/3/5
     {% include "accounting/include/pagination.html" %}
   {% endwith %}
 
-  <div class="d-none d-md-block accounting-report-table accounting-ledger-table">
+  <div class="d-none d-md-block accounting-report-table {% if report.account.is_real %} accounting-ledger-real-table {% else %} accounting-ledger-nominal-table {% endif %}">
     <div class="accounting-report-table-header">
       <div class="accounting-report-table-row">
         <div>{{ A_("Date") }}</div>
         <div>{{ A_("Summary") }}</div>
         <div class="accounting-amount">{{ A_("Debit") }}</div>
         <div class="accounting-amount">{{ A_("Credit") }}</div>
-        <div class="accounting-amount">{{ A_("Balance") }}</div>
+        {% if report.account.is_real %}
+          <div class="accounting-amount">{{ A_("Balance") }}</div>
+        {% endif %}
       </div>
     </div>
     <div class="accounting-report-table-body">
@@ -80,7 +82,9 @@ First written: 2023/3/5
             <div>{{ A_("Total") }}</div>
             <div class="accounting-amount">{{ entry.debit|accounting_format_amount|accounting_default }}</div>
             <div class="accounting-amount">{{ entry.credit|accounting_format_amount|accounting_default }}</div>
-            <div class="accounting-amount {% if entry.balance < 0 %} text-danger {% endif %}">{{ entry.balance|accounting_report_format_amount }}</div>
+            {% if report.account.is_real %}
+              <div class="accounting-amount {% if entry.balance < 0 %} text-danger {% endif %}">{{ entry.balance|accounting_report_format_amount }}</div>
+            {% endif %}
           </div>
         </div>
       {% endwith %}

src/accounting/templates/accounting/transaction/expense/detail.html

@@ -35,19 +35,9 @@ First written: 2023/2/26
 
       <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
         <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Content") }}</li>
-        {% for entry in currency.debit %}
-          <li class="list-group-item accounting-transaction-entry">
-            <div class="d-flex justify-content-between">
-              <div>
-                <div class="small">{{ entry.account }}</div>
-                {% if entry.summary is not none %}
-                  <div>{{ entry.summary }}</div>
-                {% endif %}
-              </div>
-              <div>{{ entry.amount|accounting_format_amount }}</div>
-            </div>
-          </li>
-        {% endfor %}
+        {% with entries = currency.debit %}
+          {% include "accounting/transaction/include/detail-entries.html" %}
+        {% endwith %}
         <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
           <div class="d-flex justify-content-between">
             <div>{{ A_("Total") }}</div>

src/accounting/templates/accounting/transaction/expense/include/form-currency-item.html

@@ -19,22 +19,23 @@ currency-sub-form.html: The currency sub-form in the cash expense transaction fo
 Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
-<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}" data-prefix="accounting-currency-{{ currency_index }}">
+<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}">
   <input id="accounting-currency-{{ currency_index }}-no" type="hidden" name="currency-{{ currency_index }}-no" value="{{ currency_index }}">
+  <input id="accounting-currency-{{ currency_index }}-code" type="hidden" name="currency-{{ currency_index }}-code" value="{{ currency_code_data }}">
   <div id="accounting-currency-{{ currency_index }}-control" class="form-control accounting-currency-control {% if currency_errors %} is-invalid {% endif %}">
     <div class="d-flex justify-content-between mt-2 mb-3">
       <div class="form-floating accounting-currency-content">
-        <select id="accounting-currency-{{ currency_index }}-code" class="form-select" name="currency-{{ currency_index }}-code">
+        <select id="accounting-currency-{{ currency_index }}-code-select" class="form-select {% if currency_code_errors %} is-invalid {% endif %}" name="currency-{{ currency_index }}-code" {% if currency_code_is_locked %} disabled="disabled" {% endif %}>
           {% for currency in accounting_currency_options() %}
             <option value="{{ currency.code }}" {% if currency.code == currency_code_data %} selected="selected" {% endif %}>{{ currency }}</option>
           {% endfor %}
         </select>
-        <label class="form-label" for="accounting-currency-{{ currency_index }}-code">{{ A_("Currency") }}</label>
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-code-select">{{ A_("Currency") }}</label>
         <div id="accounting-currency-{{ currency_index }}-code-error" class="invalid-feedback">{% if currency_code_errors %}{{ currency_code_errors[0] }}{% endif %}</div>
       </div>
 
       <div>
-        <button id="accounting-btn-delete-currency-{{ currency_index }}" class="btn btn-danger rounded-circle accounting-btn-delete-currency {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
+        <button id="accounting-currency-{{ currency_index }}-delete" class="btn btn-danger rounded-circle {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
           <i class="fas fa-minus"></i>
         </button>
       </div>
@@ -55,9 +56,17 @@ First written: 2023/2/25
                     account_text = entry_form.account_text,
                     summary_data = entry_form.summary.data|accounting_default,
                     summary_errors = entry_form.summary.errors,
+                    original_entry_id_data = entry_form.original_entry_id.data|accounting_default,
+                    original_entry_date = entry_form.original_entry_date|accounting_default,
+                    original_entry_text = entry_form.original_entry_text|accounting_default,
+                    is_need_offset = entry_form.is_need_offset,
+                    offset_entries = entry_form.offsets,
+                    offset_total = entry_form.offset_total|accounting_default("0"),
+                    net_balance_data = entry_form.net_balance,
+                    net_balance_text = entry_form.net_balance|accounting_format_amount,
                     amount_data = entry_form.amount.data|accounting_txn_format_amount_input,
                     amount_errors = entry_form.amount.errors,
-                    amount_text = entry_form.amount.data|accounting_format_amount|accounting_default("-"),
+                    amount_text = entry_form.amount.data|accounting_format_amount,
                     entry_errors = entry_form.all_errors %}
               {% include "accounting/transaction/include/form-entry-item.html" %}
             {% endwith %}
@@ -70,7 +79,7 @@ First written: 2023/2/25
         </div>
 
         <div>
-          <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="debit" data-entry-index="new" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+          <button id="accounting-currency-{{ currency_index }}-debit-add-entry" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-entry-type="debit" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
             <i class="fas fa-plus"></i>
             {{ A_("New") }}
           </button>

src/accounting/templates/accounting/transaction/expense/include/form.html

@@ -29,6 +29,7 @@ First written: 2023/2/25
               currency_errors = currency_form.whole_form.errors,
               currency_code_data = currency_form.code.data,
               currency_code_errors = currency_form.code.errors,
+              currency_code_is_locked = currency_form.is_code_locked,
               debit_forms = currency_form.debit,
               debit_errors = currency_form.debit_errors,
               debit_total = currency_form.form.debit_total|accounting_format_amount %}

src/accounting/templates/accounting/transaction/include/account-selector-modal.html

@@ -19,12 +19,12 @@ account-selector-modal.html: The modal for the account selector
 Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
-<div id="accounting-account-selector-{{ entry_type }}-modal" class="modal fade accounting-account-selector-modal" data-entry-type="{{ entry_type }}" tabindex="-1" aria-labelledby="accounting-account-selector-{{ entry_type }}-modal-label" aria-hidden="true">
+<div id="accounting-account-selector-{{ entry_type }}-modal" class="modal fade accounting-account-selector" data-entry-type="{{ entry_type }}" tabindex="-1" aria-labelledby="accounting-account-selector-{{ entry_type }}-modal-label" aria-hidden="true">
   <div class="modal-dialog">
     <div class="modal-content">
       <div class="modal-header">
         <h1 class="modal-title fs-5" id="accounting-account-selector-{{ entry_type }}-modal-label">{{ A_("Select Account") }}</h1>
-        <button type="button" class="btn-close" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal" aria-label="{{ A_("Close") }}"></button>
+        <button type="button" class="btn-close" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal" aria-label="{{ A_("Close") }}"></button>
       </div>
       <div class="modal-body">
         <div class="input-group mb-2">
@@ -37,17 +37,17 @@ First written: 2023/2/25
 
         <ul id="accounting-account-selector-{{ entry_type }}-option-list" class="list-group accounting-selector-list">
           {% for account in account_options %}
-          <li id="accounting-account-selector-{{ entry_type }}-option-{{ account.code }}" class="list-group-item accounting-clickable accounting-account-selector-{{ entry_type }}-option {% if account.is_in_use %} accounting-account-in-use {% endif %}" data-code="{{ account.code }}" data-content="{{ account }}" data-query-values="{{ account.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
-            {{ account }}
-          </li>
+            <li id="accounting-account-selector-{{ entry_type }}-option-{{ account.code }}" class="list-group-item accounting-clickable accounting-account-selector-{{ entry_type }}-option {% if account.is_in_use %} accounting-account-in-use {% endif %} {% if account.is_need_offset %} accounting-account-is-need-offset {% endif %}" data-code="{{ account.code }}" data-content="{{ account }}" data-query-values="{{ account.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
+              {{ account }}
+            </li>
           {% endfor %}
           <li id="accounting-account-selector-{{ entry_type }}-more" class="list-group-item accounting-clickable">{{ A_("More…") }}</li>
         </ul>
         <p id="accounting-account-selector-{{ entry_type }}-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
       </div>
       <div class="modal-footer">
-        <button type="button" class="btn btn-secondary" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Cancel") }}</button>
-        <button id="accounting-account-selector-{{ entry_type }}-btn-clear" type="button" class="btn btn-danger" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Clear") }}</button>
+        <button type="button" class="btn btn-secondary" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">{{ A_("Cancel") }}</button>
+        <button id="accounting-account-selector-{{ entry_type }}-btn-clear" type="button" class="btn btn-danger" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">{{ A_("Clear") }}</button>
       </div>
     </div>
   </div>

src/accounting/templates/accounting/transaction/include/detail-entries.html

@@ -0,0 +1,75 @@
+{#
+The Mia! Accounting Flask Project
+detail-entries-item: The journal entries in the transaction detail
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/3/14
+#}
+{# <ul> For SonarQube not to complain about incorrect HTML #}
+{% for entry in entries %}
+  <li class="list-group-item accounting-transaction-entry">
+    <div class="d-flex justify-content-between">
+      <div>
+        <div class="small">{{ entry.account }}</div>
+        {% if entry.summary is not none %}
+          <div>{{ entry.summary }}</div>
+        {% endif %}
+        {% if entry.original_entry %}
+          <div class="fst-italic small accounting-original-entry">
+            <a href="{{ url_for("accounting.transaction.detail", txn=entry.original_entry.transaction)|accounting_append_next }}">
+              {{ A_("Offset %(entry)s", entry=entry.original_entry) }}
+            </a>
+          </div>
+        {% endif %}
+        {% if entry.is_need_offset %}
+          <div class="fst-italic small accounting-offset-entries">
+            {% if entry.offsets %}
+              <div class="d-flex justify-content-between">
+                <div>{{ A_("Offsets") }}</div>
+                <ul class="ms-2 ps-0">
+                  {% for offset in entry.offsets %}
+                    <li>
+                      <a href="{{ url_for("accounting.transaction.detail", txn=offset.transaction)|accounting_append_next }}">
+                        {{ offset.transaction.date|accounting_format_date }} {{ offset.amount|accounting_format_amount }}
+                      </a>
+                    </li>
+                  {% endfor %}
+                </ul>
+              </div>
+              {% if entry.balance %}
+                <div class="d-flex justify-content-between">
+                  <div>{{ A_("Net balance") }}</div>
+                  <div>{{ entry.balance|accounting_format_amount }}</div>
+                </div>
+              {% else %}
+                <div class="d-flex justify-content-between">
+                  <div>{{ A_("Fully offset") }}</div>
+                </div>
+              {% endif %}
+            {% else %}
+              <div class="d-flex justify-content-between">
+                {{ A_("Unmatched") }}
+              </div>
+            {% endif %}
+          </div>
+        {% endif %}
+      </div>
+      <div>{{ entry.amount|accounting_format_amount }}</div>
+    </div>
+  </li>
+{% endfor %}
+{# </ul> For SonarQube not to complain about incorrect HTML #}

src/accounting/templates/accounting/transaction/include/detail.html

@@ -42,10 +42,17 @@ First written: 2023/2/26
   </a>
   {% if accounting_can_edit() %}
     {% block to_transfer %}{% endblock %}
-    <button class="btn btn-danger" type="button" data-bs-toggle="modal" data-bs-target="#accounting-delete-modal">
-      <i class="fa-solid fa-trash"></i>
-      {{ A_("Delete") }}
-    </button>
+    {% if obj.can_delete %}
+      <button class="btn btn-danger" type="button" data-bs-toggle="modal" data-bs-target="#accounting-delete-modal">
+        <i class="fa-solid fa-trash"></i>
+        {{ A_("Delete") }}
+      </button>
+    {% else %}
+      <button class="btn btn-secondary" type="button" disabled="disabled">
+        <i class="fa-solid fa-trash"></i>
+        {{ A_("Delete") }}
+      </button>
+    {% endif %}
   {% endif %}
 </div>
 
@@ -57,7 +64,7 @@ First written: 2023/2/26
   </div>
 {% endif %}
 
-{% if accounting_can_edit() %}
+{% if accounting_can_edit() and obj.can_delete %}
   <form action="{{ url_for("accounting.transaction.delete", txn=obj) }}" method="post">
     <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
     {% if request.args.next %}

src/accounting/templates/accounting/transaction/include/entry-form-modal.html

@@ -1,60 +0,0 @@
-{#
-The Mia! Accounting Flask Project
-entry-form-modal.html: The modal of the journal entry sub-form
-
- Copyright (c) 2023 imacat.
-
- Licensed under the Apache License, Version 2.0 (the "License");
- you may not use this file except in compliance with the License.
- You may obtain a copy of the License at
-
-     http://www.apache.org/licenses/LICENSE-2.0
-
- Unless required by applicable law or agreed to in writing, software
- distributed under the License is distributed on an "AS IS" BASIS,
- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- See the License for the specific language governing permissions and
- limitations under the License.
-
-Author: imacat@mail.imacat.idv.tw (imacat)
-First written: 2023/2/25
-#}
-<form id="accounting-entry-form" data-currency-index="" data-entry-type="" data-entry-index="">
-  <div id="accounting-entry-form-modal" class="modal fade" tabindex="-1" aria-labelledby="accounting-entry-form-modal-label" aria-hidden="true">
-    <div class="modal-dialog">
-      <div class="modal-content">
-        <div class="modal-header">
-          <h1 class="modal-title fs-5" id="accounting-entry-form-modal-label">{{ A_("Journal Entry Content") }}</h1>
-          <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="{{ A_("Close") }}"></button>
-        </div>
-        <div class="modal-body">
-          <div class="mb-3">
-            <div id="accounting-entry-form-account-control" class="form-control accounting-clickable accounting-material-text-field" data-bs-toggle="modal" data-bs-target="">
-              <label class="form-label" for="accounting-entry-form-account">{{ A_("Account") }}</label>
-              <div id="accounting-entry-form-account" data-code="" data-text=""></div>
-            </div>
-            <div id="accounting-entry-form-account-error" class="invalid-feedback"></div>
-          </div>
-
-          <div class="mb-3">
-            <div id="accounting-entry-form-summary-control" class="form-control accounting-clickable accounting-material-text-field" data-bs-toggle="modal" data-bs-target="">
-              <label class="form-label" for="accounting-entry-form-summary">{{ A_("Summary") }}</label>
-              <div id="accounting-entry-form-summary" data-value=""></div>
-            </div>
-            <div id="accounting-entry-form-summary-error" class="invalid-feedback"></div>
-          </div>
-
-          <div class="form-floating mb-3">
-            <input id="accounting-entry-form-amount" class="form-control" type="number" value="" min="0.01" max="" step="0.01" placeholder=" " required="required">
-            <label for="accounting-entry-form-amount">{{ A_("Amount") }}</label>
-            <div id="accounting-entry-form-amount-error" class="invalid-feedback"></div>
-          </div>
-        </div>
-        <div class="modal-footer">
-          <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">{{ A_("Cancel") }}</button>
-          <button id="accounting-entry-form-btn-save" type="submit" class="btn btn-primary">{{ A_("Save") }}</button>
-        </div>
-      </div>
-    </div>
-  </div>
-</form>

src/accounting/templates/accounting/transaction/include/form-entry-item.html

@@ -20,19 +20,45 @@ Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
 {# <ul> For SonarQube not to complain about incorrect HTML #}
-<li id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}" class="list-group-item list-group-item-action d-flex justify-content-between accounting-entry accounting-currency-{{ currency_index }}-{{ entry_type }}" data-currency-index="{{ currency_index }}" data-entry-type="{{ entry_type }}" data-entry-index="{{ entry_index }}" data-prefix="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}">
+<li id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}" class="list-group-item list-group-item-action d-flex justify-content-between accounting-currency-{{ currency_index }}-{{ entry_type }} {% if offset_entries %} accounting-matched-entry {% endif %}" data-currency-index="{{ currency_index }}" data-entry-type="{{ entry_type }}" data-entry-index="{{ entry_index }}" {% if is_need_offset %} data-is-need-offset="true" {% endif %}>
   {% if entry_id %}
     <input type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-eid" value="{{ entry_id }}">
   {% endif %}
   <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-no" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-no" value="{{ entry_index }}">
-  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account-code" class="accounting-{{ entry_type }}-account-code" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account_code" value="{{ account_code_data }}" data-text="{{ account_text }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-original-entry-id" class="accounting-original-entry-id" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-original_entry_id" value="{{ original_entry_id_data }}" data-date="{{ original_entry_date }}" data-text="{{ original_entry_text }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account-code" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account_code" value="{{ account_code_data }}" data-text="{{ account_text }}">
   <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-summary" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-summary" value="{{ summary_data }}">
-  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount" class="accounting-currency-{{ currency_index }}-{{ entry_type }}-amount" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount" value="{{ amount_data }}">
+  <input id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount" type="hidden" name="currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount" value="{{ amount_data }}" data-min="{{ offset_total }}">
   <div class="accounting-entry-content">
-    <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-control" class="form-control clickable d-flex justify-content-between accounting-entry-control {% if entry_errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+    <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-control" class="form-control clickable d-flex justify-content-between {% if entry_errors %} is-invalid {% endif %}" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
       <div>
         <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-account-text" class="small">{{ account_text }}</div>
         <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-summary-text">{{ summary_data }}</div>
+        <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-original-entry-text" class="fst-italic small accounting-original-entry {% if not original_entry_text %} d-none {% endif %}">
+          {% if original_entry_text %}{{ A_("Offset %(entry)s", entry=original_entry_text) }}{% endif %}
+        </div>
+        <div id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-offsets" class="fst-italic small accounting-offset-entries {% if not is_need_offset %} d-none {% endif %}">
+          {% if offset_entries %}
+            <div class="d-flex justify-content-between {% if not offset_entries %} d-none {% endif %}">
+              <div>{{ A_("Offsets") }}</div>
+              <ul class="ms-2 ps-0">
+                {% for offset in offset_entries %}
+                  <li>{{ offset.transaction.date|accounting_format_date }} {{ offset.amount|accounting_format_amount }}</li>
+                {% endfor %}
+              </ul>
+            </div>
+            {% if net_balance_data == 0 %}
+              <div>{{ A_("Fully offset") }}</div>
+            {% else %}
+              <div class="d-flex justify-content-between">
+                <div>{{ A_("Net balance") }}</div>
+                <div>{{ net_balance_text }}</div>
+              </div>
+            {% endif %}
+          {% else %}
+            {{ A_("Unmatched") }}
+          {% endif %}
+        </div>
       </div>
       <div><span id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-amount-text" class="badge rounded-pill bg-primary">{{ amount_text }}</span></div>
     </div>
@@ -40,7 +66,7 @@ First written: 2023/2/25
   </div>
 
   <div>
-    <button id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-btn-delete" class="btn btn-danger rounded-circle accounting-btn-delete-entry accounting-currency-{{ currency_index }}-{{ entry_type }}-btn-delete-entry {% if only_one_entry_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}" data-same-class="accounting-currency-{{ currency_index }}-{{ entry_type }}-btn-delete-entry">
+    <button id="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}-delete" class="btn btn-danger rounded-circle {% if only_one_entry_form or offset_entries %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}-{{ entry_type }}-{{ entry_index }}">
       <i class="fas fa-minus"></i>
     </button>
   </div>

src/accounting/templates/accounting/transaction/include/form.html

@@ -24,7 +24,9 @@ First written: 2023/2/26
 {% block accounting_scripts %}
   <script src="{{ url_for("accounting.static", filename="js/drag-and-drop-reorder.js") }}"></script>
   <script src="{{ url_for("accounting.static", filename="js/transaction-form.js") }}"></script>
+  <script src="{{ url_for("accounting.static", filename="js/journal-entry-editor.js") }}"></script>
   <script src="{{ url_for("accounting.static", filename="js/account-selector.js") }}"></script>
+  <script src="{{ url_for("accounting.static", filename="js/original-entry-selector.js") }}"></script>
   <script src="{{ url_for("accounting.static", filename="js/summary-editor.js") }}"></script>
 {% endblock %}
 
@@ -44,7 +46,7 @@ First written: 2023/2/26
   {% endif %}
 
   <div class="form-floating mb-3">
-    <input id="accounting-date" class="form-control {% if form.date.errors %} is-invalid {% endif %}" type="date" name="date" value="{{ form.date.data|accounting_default }}" placeholder=" " required="required">
+    <input id="accounting-date" class="form-control {% if form.date.errors %} is-invalid {% endif %}" type="date" name="date" value="{{ form.date.data|accounting_default }}" max="{{ form.max_date|accounting_default }}" min="{{ form.min_date|accounting_default }}" placeholder=" " required="required">
     <label class="form-label" for="accounting-date">{{ A_("Date") }}</label>
     <div id="accounting-date-error" class="invalid-feedback">{% if form.date.errors %}{{ form.date.errors[0] }}{% endif %}</div>
   </div>
@@ -57,7 +59,7 @@ First written: 2023/2/26
       </div>
 
       <div>
-        <button id="accounting-btn-new-currency" class="btn btn-primary" type="button">
+        <button id="accounting-add-currency" class="btn btn-primary" type="button">
           <i class="fas fa-plus"></i>
           {{ A_("New") }}
         </button>
@@ -86,7 +88,8 @@ First written: 2023/2/26
   </div>
 </form>
 
-{% include "accounting/transaction/include/entry-form-modal.html" %}
+{% include "accounting/transaction/include/journal-entry-editor-modal.html" %}
 {% block form_modals %}{% endblock %}
+{% include "accounting/transaction/include/original-entry-selector-modal.html" %}
 
 {% endblock %}

src/accounting/templates/accounting/transaction/include/journal-entry-editor-modal.html

@@ -0,0 +1,76 @@
+{#
+The Mia! Accounting Flask Project
+journal-entry-editor-modal.html: The modal of the journal entry editor
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<form id="accounting-entry-editor">
+  <div id="accounting-entry-editor-modal" class="modal fade" tabindex="-1" aria-labelledby="accounting-entry-editor-modal-label" aria-hidden="true">
+    <div class="modal-dialog">
+      <div class="modal-content">
+        <div class="modal-header">
+          <h1 class="modal-title fs-5" id="accounting-entry-editor-modal-label">{{ A_("Journal Entry Content") }}</h1>
+          <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="{{ A_("Close") }}"></button>
+        </div>
+        <div class="modal-body">
+          <div id="accounting-entry-editor-original-entry-container" class="d-flex justify-content-between mb-3">
+            <div class="accounting-entry-editor-original-entry-content">
+              <div id="accounting-entry-editor-original-entry-control" class="form-control accounting-clickable accounting-material-text-field" data-bs-toggle="modal" data-bs-target="#accounting-original-entry-selector-modal">
+                <label class="form-label" for="accounting-entry-editor-original-entry">{{ A_("Original Entry") }}</label>
+                <div id="accounting-entry-editor-original-entry"></div>
+              </div>
+              <div id="accounting-entry-editor-original-entry-error" class="invalid-feedback"></div>
+            </div>
+
+            <div>
+              <button id="accounting-entry-editor-original-entry-delete" class="btn btn-danger rounded-circle" type="button">
+                <i class="fas fa-minus"></i>
+              </button>
+            </div>
+          </div>
+
+          <div class="mb-3">
+            <div id="accounting-entry-editor-summary-control" class="form-control accounting-clickable accounting-material-text-field" data-bs-toggle="modal" data-bs-target="">
+              <label class="form-label" for="accounting-entry-editor-summary">{{ A_("Summary") }}</label>
+              <div id="accounting-entry-editor-summary"></div>
+            </div>
+            <div id="accounting-entry-editor-summary-error" class="invalid-feedback"></div>
+          </div>
+
+          <div class="mb-3">
+            <div id="accounting-entry-editor-account-control" class="form-control accounting-clickable accounting-material-text-field" data-bs-toggle="modal" data-bs-target="">
+              <label class="form-label" for="accounting-entry-editor-account">{{ A_("Account") }}</label>
+              <div id="accounting-entry-editor-account"></div>
+            </div>
+            <div id="accounting-entry-editor-account-error" class="invalid-feedback"></div>
+          </div>
+
+          <div class="form-floating mb-3">
+            <input id="accounting-entry-editor-amount" class="form-control" type="number" value="" min="0" max="" step="0.01" placeholder=" " required="required">
+            <label for="accounting-entry-editor-amount">{{ A_("Amount") }}</label>
+            <div id="accounting-entry-editor-amount-error" class="invalid-feedback"></div>
+          </div>
+        </div>
+        <div class="modal-footer">
+          <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">{{ A_("Cancel") }}</button>
+          <button type="submit" class="btn btn-primary">{{ A_("Save") }}</button>
+        </div>
+      </div>
+    </div>
+  </div>
+</form>

src/accounting/templates/accounting/transaction/include/original-entry-selector-modal.html

@@ -0,0 +1,56 @@
+{#
+The Mia! Accounting Flask Project
+original-entry-selector-modal.html: The modal of the original entry selector
+
+ Copyright (c) 2023 imacat.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+
+Author: imacat@mail.imacat.idv.tw (imacat)
+First written: 2023/2/25
+#}
+<div id="accounting-original-entry-selector-modal" class="modal fade" tabindex="-1" aria-labelledby="accounting-original-entry-selector-modal-label" aria-hidden="true">
+  <div class="modal-dialog">
+    <div class="modal-content">
+      <div class="modal-header">
+        <h1 class="modal-title fs-5" id="accounting-original-entry-selector-modal-label">{{ A_("Select Original Entry") }}</h1>
+        <button type="button" class="btn-close" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal" aria-label="{{ A_("Close") }}"></button>
+      </div>
+      <div class="modal-body">
+        <div class="input-group mb-2">
+          <input id="accounting-original-entry-selector-query" class="form-control form-control-sm" type="search" placeholder=" " required="required">
+          <label class="input-group-text" for="accounting-original-entry-selector-query">
+            <i class="fa-solid fa-magnifying-glass"></i>
+            {{ A_("Search") }}
+          </label>
+        </div>
+
+        <ul id="accounting-original-entry-selector-option-list" class="list-group accounting-selector-list">
+          {% for entry in form.original_entry_options %}
+            <li id="accounting-original-entry-selector-option-{{ entry.id }}" class="list-group-item d-flex justify-content-between accounting-clickable accounting-original-entry-selector-option" data-id="{{ entry.id }}" data-date="{{ entry.transaction.date }}" data-entry-type="{{ "debit" if entry.is_debit else "credit" }}" data-currency-code="{{ entry.currency.code }}" data-account-code="{{ entry.account_code }}" data-account-text="{{ entry.account }}" data-summary="{{ entry.summary|accounting_default }}" data-net-balance="{{ entry.net_balance|accounting_txn_format_amount_input }}" data-text="{{ entry }}" data-query-values="{{ entry.query_values|tojson|forceescape }}" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
+              <div>{{ entry.transaction.date|accounting_format_date }} {{ entry.summary|accounting_default }}</div>
+              <div>
+                <span class="badge bg-primary rounded-pill">
+                  <span id="accounting-original-entry-selector-option-{{ entry.id }}-net-balance">{{ entry.net_balance|accounting_format_amount }}</span>
+                  / {{ entry.amount|accounting_format_amount }}
+                </span>
+              </div>
+            </li>
+          {% endfor %}
+        </ul>
+        <p id="accounting-original-entry-selector-option-no-result" class="d-none">{{ A_("There is no data.") }}</p>
+      </div>
+    </div>
+  </div>
+</div>
+

src/accounting/templates/accounting/transaction/include/summary-editor-modal.html

@@ -27,11 +27,14 @@ First written: 2023/2/28
           <h1 class="modal-title fs-5" id="accounting-summary-editor-{{ summary_editor.type }}-modal-label">
             <label for="accounting-summary-editor-{{ summary_editor.type }}-summary">{{ A_("Summary") }}</label>
           </h1>
-          <button class="btn-close" type="button" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal" aria-label="{{ A_("Close") }}"></button>
+          <button class="btn-close" type="button" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal" aria-label="{{ A_("Close") }}"></button>
         </div>
         <div class="modal-body">
-          <div class="mb-3">
+          <div class="d-flex justify-content-between mb-3">
             <input id="accounting-summary-editor-{{ summary_editor.type }}-summary" class="form-control" type="text" aria-labelledby="accounting-summary-editor-{{ summary_editor.type }}-modal-label">
+            <button id="accounting-summary-editor-{{ summary_editor.type }}-offset" class="btn btn-primary text-nowrap ms-2" type="button" data-bs-toggle="modal" data-bs-target="#accounting-original-entry-selector-modal">
+              {{ A_("Offset...") }}
+            </button>
           </div>
 
           {# Tab navigation #}
@@ -174,14 +177,14 @@ First written: 2023/2/28
           {# The suggested accounts #}
           <div class="mt-3">
             {% for account in summary_editor.accounts %}
-              <button class="btn btn-outline-primary d-none accounting-summary-editor-{{ summary_editor.type }}-account" type="button" data-code="{{ account.code }}" data-text="{{ account }}">
+              <button class="btn btn-outline-primary d-none accounting-summary-editor-{{ summary_editor.type }}-account {% if account.is_need_offset %} accounting-account-is-need-offset {% endif %}" type="button" data-code="{{ account.code }}" data-text="{{ account }}">
                 {{ account }}
               </button>
             {% endfor %}
           </div>
         </div>
         <div class="modal-footer">
-          <button class="btn btn-secondary" type="button" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">{{ A_("Cancel") }}</button>
+          <button class="btn btn-secondary" type="button" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">{{ A_("Cancel") }}</button>
           <button id="accounting-summary-editor-{{ summary_editor.type }}-btn-save" type="submit" class="btn btn-primary">{{ A_("Save") }}</button>
         </div>
       </div>

src/accounting/templates/accounting/transaction/income/detail.html

@@ -35,19 +35,9 @@ First written: 2023/2/26
 
       <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
         <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Content") }}</li>
-        {% for entry in currency.credit %}
-          <li class="list-group-item accounting-transaction-entry">
-            <div class="d-flex justify-content-between">
-              <div>
-                <div class="small">{{ entry.account }}</div>
-                {% if entry.summary is not none %}
-                  <div>{{ entry.summary }}</div>
-                {% endif %}
-              </div>
-              <div>{{ entry.amount|accounting_format_amount }}</div>
-            </div>
-          </li>
-        {% endfor %}
+        {% with entries = currency.credit %}
+          {% include "accounting/transaction/include/detail-entries.html" %}
+        {% endwith %}
         <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
           <div class="d-flex justify-content-between">
             <div>{{ A_("Total") }}</div>

src/accounting/templates/accounting/transaction/income/include/form-currency-item.html

@@ -19,22 +19,23 @@ currency-sub-form.html: The currency sub-form in the cash income transaction for
 Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
-<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}" data-prefix="accounting-currency-{{ currency_index }}">
+<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}">
   <input id="accounting-currency-{{ currency_index }}-no" type="hidden" name="currency-{{ currency_index }}-no" value="{{ currency_index }}">
+  <input id="accounting-currency-{{ currency_index }}-code" type="hidden" name="currency-{{ currency_index }}-code" value="{{ currency_code_data }}">
   <div id="accounting-currency-{{ currency_index }}-control" class="form-control accounting-currency-control {% if currency_errors %} is-invalid {% endif %}">
     <div class="d-flex justify-content-between mt-2 mb-3">
       <div class="form-floating accounting-currency-content">
-        <select id="accounting-currency-{{ currency_index }}-code" class="form-select" name="currency-{{ currency_index }}-code">
+        <select id="accounting-currency-{{ currency_index }}-code-select" class="form-select {% if currency_code_errors %} is-invalid {% endif %}" name="currency-{{ currency_index }}-code" {% if currency_code_is_locked %} disabled="disabled" {% endif %}>
           {% for currency in accounting_currency_options() %}
             <option value="{{ currency.code }}" {% if currency.code == currency_code_data %} selected="selected" {% endif %}>{{ currency }}</option>
           {% endfor %}
         </select>
-        <label class="form-label" for="accounting-currency-{{ currency_index }}-code">{{ A_("Currency") }}</label>
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-code-select">{{ A_("Currency") }}</label>
         <div id="accounting-currency-{{ currency_index }}-code-error" class="invalid-feedback">{% if currency_code_errors %}{{ currency_code_errors[0] }}{% endif %}</div>
       </div>
 
       <div>
-        <button id="accounting-btn-delete-currency-{{ currency_index }}" class="btn btn-danger rounded-circle accounting-btn-delete-currency {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
+        <button id="accounting-currency-{{ currency_index }}-delete" class="btn btn-danger rounded-circle {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
           <i class="fas fa-minus"></i>
         </button>
       </div>
@@ -55,9 +56,17 @@ First written: 2023/2/25
                     account_text = entry_form.account_text,
                     summary_data = entry_form.summary.data|accounting_default,
                     summary_errors = entry_form.summary.errors,
+                    original_entry_id_data = entry_form.original_entry_id.data|accounting_default,
+                    original_entry_date = entry_form.original_entry_date|accounting_default,
+                    original_entry_text = entry_form.original_entry_text|accounting_default,
+                    is_need_offset = entry_form.is_need_offset,
+                    offset_entries = entry_form.offsets,
+                    offset_total = entry_form.offset_total|accounting_default("0"),
+                    net_balance_data = entry_form.net_balance,
+                    net_balance_text = entry_form.net_balance|accounting_format_amount,
                     amount_data = entry_form.amount.data|accounting_txn_format_amount_input,
                     amount_errors = entry_form.amount.errors,
-                    amount_text = entry_form.amount.data|accounting_format_amount|accounting_default("-"),
+                    amount_text = entry_form.amount.data|accounting_format_amount,
                     entry_errors = entry_form.all_errors %}
               {% include "accounting/transaction/include/form-entry-item.html" %}
             {% endwith %}
@@ -70,7 +79,7 @@ First written: 2023/2/25
         </div>
 
         <div>
-          <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="credit" data-entry-index="new" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+          <button id="accounting-currency-{{ currency_index }}-credit-add-entry" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-entry-type="credit" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
             <i class="fas fa-plus"></i>
             {{ A_("New") }}
           </button>

src/accounting/templates/accounting/transaction/income/include/form.html

@@ -29,6 +29,7 @@ First written: 2023/2/25
               currency_errors = currency_form.whole_form.errors,
               currency_code_data = currency_form.code.data,
               currency_code_errors = currency_form.code.errors,
+              currency_code_is_locked = currency_form.is_code_locked,
               credit_forms = currency_form.credit,
               credit_errors = currency_form.credit_errors,
               credit_total = currency_form.form.credit_total|accounting_format_amount %}

src/accounting/templates/accounting/transaction/transfer/detail.html

@@ -31,19 +31,9 @@ First written: 2023/2/26
         <div class="col-sm-6 mb-2">
           <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
             <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Debit") }}</li>
-            {% for entry in currency.debit %}
-              <li class="list-group-item accounting-transaction-entry">
-                <div class="d-flex justify-content-between">
-                  <div>
-                    <div class="small">{{ entry.account }}</div>
-                    {% if entry.summary is not none %}
-                      <div>{{ entry.summary }}</div>
-                    {% endif %}
-                  </div>
-                  <div>{{ entry.amount|accounting_format_amount }}</div>
-                </div>
-              </li>
-            {% endfor %}
+            {% with entries = currency.debit %}
+              {% include "accounting/transaction/include/detail-entries.html" %}
+            {% endwith %}
             <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
               <div class="d-flex justify-content-between">
                 <div>{{ A_("Total") }}</div>
@@ -57,19 +47,9 @@ First written: 2023/2/26
         <div class="col-sm-6 mb-2">
           <ul class="list-group accounting-list-group-stripped accounting-list-group-hover">
             <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-header">{{ A_("Credit") }}</li>
-            {% for entry in currency.credit %}
-              <li class="list-group-item accounting-transaction-entry">
-                <div class="d-flex justify-content-between">
-                  <div>
-                    <div class="small">{{ entry.account }}</div>
-                    {% if entry.summary is not none %}
-                      <div>{{ entry.summary }}</div>
-                    {% endif %}
-                  </div>
-                  <div>{{ entry.amount|accounting_format_amount }}</div>
-                </div>
-              </li>
-            {% endfor %}
+            {% with entries = currency.credit %}
+              {% include "accounting/transaction/include/detail-entries.html" %}
+            {% endwith %}
             <li class="list-group-item accounting-transaction-entry accounting-transaction-entry-total">
               <div class="d-flex justify-content-between">
                 <div>{{ A_("Total") }}</div>

src/accounting/templates/accounting/transaction/transfer/include/form-currency-item.html

@@ -19,22 +19,23 @@ currency-sub-form.html: The currency sub-form in the transfer transaction form
 Author: imacat@mail.imacat.idv.tw (imacat)
 First written: 2023/2/25
 #}
-<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}" data-prefix="accounting-currency-{{ currency_index }}">
+<div id="accounting-currency-{{ currency_index }}" class="mb-3 accounting-currency" data-index="{{ currency_index }}">
   <input id="accounting-currency-{{ currency_index }}-no" type="hidden" name="currency-{{ currency_index }}-no" value="{{ currency_index }}">
+  <input id="accounting-currency-{{ currency_index }}-code" type="hidden" name="currency-{{ currency_index }}-code" value="{{ currency_code_data }}">
   <div id="accounting-currency-{{ currency_index }}-control" class="form-control accounting-currency-control {% if currency_errors %} is-invalid {% endif %}">
     <div class="d-flex justify-content-between mt-2 mb-3">
       <div class="form-floating accounting-currency-content">
-        <select id="accounting-currency-{{ currency_index }}-code" class="form-select" name="currency-{{ currency_index }}-code">
+        <select id="accounting-currency-{{ currency_index }}-code-select" class="form-select {% if currency_code_errors %} is-invalid {% endif %}" {% if currency_code_is_locked %} disabled="disabled" {% endif %}>
           {% for currency in accounting_currency_options() %}
             <option value="{{ currency.code }}" {% if currency.code == currency_code_data %} selected="selected" {% endif %}>{{ currency }}</option>
           {% endfor %}
         </select>
-        <label class="form-label" for="accounting-currency-{{ currency_index }}-code">{{ A_("Currency") }}</label>
+        <label class="form-label" for="accounting-currency-{{ currency_index }}-code-select">{{ A_("Currency") }}</label>
         <div id="accounting-currency-{{ currency_index }}-code-error" class="invalid-feedback">{% if currency_code_errors %}{{ currency_code_errors[0] }}{% endif %}</div>
       </div>
 
       <div>
-        <button id="accounting-btn-delete-currency-{{ currency_index }}" class="btn btn-danger rounded-circle accounting-btn-delete-currency {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
+        <button id="accounting-currency-{{ currency_index }}-delete" class="btn btn-danger rounded-circle {% if only_one_currency_form %} d-none {% endif %}" type="button" data-target="accounting-currency-{{ currency_index }}">
           <i class="fas fa-minus"></i>
         </button>
       </div>
@@ -57,9 +58,17 @@ First written: 2023/2/25
                       account_text = entry_form.account_text,
                       summary_data = entry_form.summary.data|accounting_default,
                       summary_errors = entry_form.summary.errors,
+                      original_entry_id_data = entry_form.original_entry_id.data|accounting_default,
+                      original_entry_date = entry_form.original_entry_date|accounting_default,
+                      original_entry_text = entry_form.original_entry_text|accounting_default,
+                      is_need_offset = entry_form.is_need_offset,
+                      offset_entries = entry_form.offsets,
+                      offset_total = entry_form.offset_total|accounting_default,
+                      net_balance_data = entry_form.net_balance,
+                      net_balance_text = entry_form.net_balance|accounting_format_amount,
                       amount_data = entry_form.amount.data|accounting_txn_format_amount_input,
                       amount_errors = entry_form.amount.errors,
-                      amount_text = entry_form.amount.data|accounting_format_amount|accounting_default("-"),
+                      amount_text = entry_form.amount.data|accounting_format_amount,
                       entry_errors = entry_form.all_errors %}
                 {% include "accounting/transaction/include/form-entry-item.html" %}
               {% endwith %}
@@ -72,7 +81,7 @@ First written: 2023/2/25
           </div>
 
           <div>
-            <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="debit" data-entry-index="new" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+            <button id="accounting-currency-{{ currency_index }}-debit-add-entry" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-entry-type="debit" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
               <i class="fas fa-plus"></i>
               {{ A_("New") }}
             </button>
@@ -88,18 +97,26 @@ First written: 2023/2/25
           <ul id="accounting-currency-{{ currency_index }}-credit-list" class="list-group accounting-entry-list">
             {% for entry_form in credit_forms %}
               {% with currency_index = currency_index,
-                      entry_id = entry_form.eid.data,
                       entry_type = "credit",
                       entry_index = loop.index,
                       only_one_entry_form = debit_forms|length == 1,
+                      entry_id = entry_form.eid.data,
                       account_code_data = entry_form.account_code.data|accounting_default,
                       account_code_error = entry_form.account_code.errors,
                       account_text = entry_form.account_text,
                       summary_data = entry_form.summary.data|accounting_default,
                       summary_errors = entry_form.summary.errors,
+                      original_entry_id_data = entry_form.original_entry_id.data|accounting_default,
+                      original_entry_date = entry_form.original_entry_date|accounting_default,
+                      original_entry_text = entry_form.original_entry_text|accounting_default,
+                      is_need_offset = entry_form.is_need_offset,
+                      offset_entries = entry_form.offsets,
+                      offset_total = entry_form.offset_total|accounting_default("0"),
+                      net_balance_data = entry_form.net_balance,
+                      net_balance_text = entry_form.net_balance|accounting_format_amount,
                       amount_data = entry_form.amount.data|accounting_txn_format_amount_input,
                       amount_errors = entry_form.amount.errors,
-                      amount_text = entry_form.amount.data|accounting_format_amount|accounting_default("-"),
+                      amount_text = entry_form.amount.data|accounting_format_amount,
                       entry_errors = entry_form.all_errors %}
                 {% include "accounting/transaction/include/form-entry-item.html" %}
               {% endwith %}
@@ -112,7 +129,7 @@ First written: 2023/2/25
           </div>
 
           <div>
-            <button class="btn btn-primary accounting-btn-new-entry accounting-currency-{{ currency_index }}-btn-new-entry" type="button" data-currency-index="{{ currency_index }}" data-entry-type="credit" data-entry-index="new" data-bs-toggle="modal" data-bs-target="#accounting-entry-form-modal">
+            <button id="accounting-currency-{{ currency_index }}-credit-add-entry" class="btn btn-primary" type="button" data-currency-index="{{ currency_index }}" data-entry-type="credit" data-bs-toggle="modal" data-bs-target="#accounting-entry-editor-modal">
               <i class="fas fa-plus"></i>
               {{ A_("New") }}
             </button>

src/accounting/templates/accounting/transaction/transfer/include/form.html

@@ -29,6 +29,7 @@ First written: 2023/2/25
               currency_errors = currency_form.whole_form.errors,
               currency_code_data = currency_form.code.data,
               currency_code_errors = currency_form.code.errors,
+              currency_code_is_locked = currency_form.is_code_locked,
               debit_forms = currency_form.debit,
               debit_errors = currency_form.debit_errors,
               debit_total = currency_form.form.debit_total|accounting_format_amount,

src/accounting/transaction/converters.py

@@ -20,10 +20,10 @@
 from datetime import date
 
 from flask import abort
+from sqlalchemy.orm import selectinload
 from werkzeug.routing import BaseConverter
 
-from accounting import db
-from accounting.models import Transaction
+from accounting.models import Transaction, JournalEntry
 from accounting.utils.txn_types import TransactionType
 
 
@@ -37,7 +37,13 @@ class TransactionConverter(BaseConverter):
         :param value: The transaction ID.
         :return: The corresponding transaction.
         """
-        transaction: Transaction | None = db.session.get(Transaction, value)
+        transaction: Transaction | None = Transaction.query\
+            .join(JournalEntry)\
+            .filter(Transaction.id == value)\
+            .options(selectinload(Transaction.entries)
+                     .selectinload(JournalEntry.offsets)
+                     .selectinload(JournalEntry.transaction))\
+            .first()
         if transaction is None:
             abort(404)
         return transaction

src/accounting/transaction/forms/__init__.py

@@ -0,0 +1,22 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The forms for the transaction management.
+
+"""
+from .reorder import sort_transactions_in, TransactionReorderForm
+from .transaction import TransactionForm, IncomeTransactionForm, \
+    ExpenseTransactionForm, TransferTransactionForm

src/accounting/transaction/forms/currency.py

@@ -0,0 +1,294 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The currency sub-forms for the transaction management.
+
+"""
+from decimal import Decimal
+
+import sqlalchemy as sa
+from flask_babel import LazyString
+from flask_wtf import FlaskForm
+from wtforms import StringField, ValidationError, FieldList, IntegerField, \
+    BooleanField, FormField
+from wtforms.validators import DataRequired
+
+from accounting import db
+from accounting.locale import lazy_gettext
+from accounting.models import Currency, JournalEntry
+from accounting.transaction.utils.offset_alias import offset_alias
+from accounting.utils.cast import be
+from accounting.utils.strip_text import strip_text
+from .journal_entry import JournalEntryForm, CreditEntryForm, DebitEntryForm
+
+CURRENCY_REQUIRED: DataRequired = DataRequired(
+    lazy_gettext("Please select the currency."))
+"""The validator to check if the currency code is empty."""
+
+
+class CurrencyExists:
+    """The validator to check if the account exists."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if db.session.get(Currency, field.data) is None:
+            raise ValidationError(lazy_gettext(
+                "The currency does not exist."))
+
+
+class SameCurrencyAsOriginalEntries:
+    """The validator to check if the currency is the same as the original
+    entries."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, CurrencyForm)
+        if field.data is None:
+            return
+        original_entry_id: set[int] = {x.original_entry_id.data
+                                       for x in form.entries
+                                       if x.original_entry_id.data is not None}
+        if len(original_entry_id) == 0:
+            return
+        original_entry_currency_codes: set[str] = set(db.session.scalars(
+            sa.select(JournalEntry.currency_code)
+            .filter(JournalEntry.id.in_(original_entry_id))).all())
+        for currency_code in original_entry_currency_codes:
+            if field.data != currency_code:
+                raise ValidationError(lazy_gettext(
+                    "The currency must be the same as the original entry."))
+
+
+class KeepCurrencyWhenHavingOffset:
+    """The validator to check if the currency is the same when there is
+    offset."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, CurrencyForm)
+        if field.data is None:
+            return
+        offset: sa.Alias = offset_alias()
+        original_entries: list[JournalEntry] = JournalEntry.query\
+            .join(offset, be(JournalEntry.id == offset.c.original_entry_id),
+                  isouter=True)\
+            .filter(JournalEntry.id.in_({x.eid.data for x in form.entries
+                                         if x.eid.data is not None}))\
+            .group_by(JournalEntry.id, JournalEntry.currency_code)\
+            .having(sa.func.count(offset.c.id) > 0).all()
+        for original_entry in original_entries:
+            if original_entry.currency_code != field.data:
+                raise ValidationError(lazy_gettext(
+                    "The currency must not be changed when there is offset."))
+
+
+class NeedSomeJournalEntries:
+    """The validator to check if there is any journal entry sub-form."""
+
+    def __call__(self, form: FlaskForm, field: FieldList) -> None:
+        if len(field) == 0:
+            raise ValidationError(lazy_gettext(
+                "Please add some journal entries."))
+
+
+class IsBalanced:
+    """The validator to check that the total amount of the debit and credit
+    entries are equal."""
+
+    def __call__(self, form: FlaskForm, field: BooleanField) -> None:
+        assert isinstance(form, TransferCurrencyForm)
+        if len(form.debit) == 0 or len(form.credit) == 0:
+            return
+        if form.debit_total != form.credit_total:
+            raise ValidationError(lazy_gettext(
+                "The totals of the debit and credit amounts do not match."))
+
+
+class CurrencyForm(FlaskForm):
+    """The form to create or edit a currency in a transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField()
+    """The currency code."""
+    whole_form = BooleanField()
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def entries(self) -> list[JournalEntryForm]:
+        """Returns the journal entry sub-forms.
+
+        :return: The journal entry sub-forms.
+        """
+        entry_forms: list[JournalEntryForm] = []
+        if isinstance(self, IncomeCurrencyForm):
+            entry_forms.extend([x.form for x in self.credit])
+        elif isinstance(self, ExpenseCurrencyForm):
+            entry_forms.extend([x.form for x in self.debit])
+        elif isinstance(self, TransferCurrencyForm):
+            entry_forms.extend([x.form for x in self.debit])
+            entry_forms.extend([x.form for x in self.credit])
+        return entry_forms
+
+    @property
+    def is_code_locked(self) -> bool:
+        """Returns whether the currency code should not be changed.
+
+        :return: True if the currency code should not be changed, or False
+            otherwise
+        """
+        entry_forms: list[JournalEntryForm] = self.entries
+        original_entry_id: set[int] \
+            = {x.original_entry_id.data for x in entry_forms
+               if x.original_entry_id.data is not None}
+        if len(original_entry_id) > 0:
+            return True
+        entry_id: set[int] = {x.eid.data for x in entry_forms
+                              if x.eid.data is not None}
+        select: sa.Select = sa.select(sa.func.count(JournalEntry.id))\
+            .filter(JournalEntry.original_entry_id.in_(entry_id))
+        return db.session.scalar(select) > 0
+
+
+class IncomeCurrencyForm(CurrencyForm):
+    """The form to create or edit a currency in a cash income transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField(
+        filters=[strip_text],
+        validators=[CURRENCY_REQUIRED,
+                    CurrencyExists(),
+                    SameCurrencyAsOriginalEntries(),
+                    KeepCurrencyWhenHavingOffset()])
+    """The currency code."""
+    credit = FieldList(FormField(CreditEntryForm),
+                       validators=[NeedSomeJournalEntries()])
+    """The credit entries."""
+    whole_form = BooleanField()
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def credit_total(self) -> Decimal:
+        """Returns the total amount of the credit journal entries.
+
+        :return: The total amount of the credit journal entries.
+        """
+        return sum([x.amount.data for x in self.credit
+                    if x.amount.data is not None])
+
+    @property
+    def credit_errors(self) -> list[str | LazyString]:
+        """Returns the credit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.credit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+
+class ExpenseCurrencyForm(CurrencyForm):
+    """The form to create or edit a currency in a cash expense transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField(
+        filters=[strip_text],
+        validators=[CURRENCY_REQUIRED,
+                    CurrencyExists(),
+                    SameCurrencyAsOriginalEntries(),
+                    KeepCurrencyWhenHavingOffset()])
+    """The currency code."""
+    debit = FieldList(FormField(DebitEntryForm),
+                      validators=[NeedSomeJournalEntries()])
+    """The debit entries."""
+    whole_form = BooleanField()
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def debit_total(self) -> Decimal:
+        """Returns the total amount of the debit journal entries.
+
+        :return: The total amount of the debit journal entries.
+        """
+        return sum([x.amount.data for x in self.debit
+                    if x.amount.data is not None])
+
+    @property
+    def debit_errors(self) -> list[str | LazyString]:
+        """Returns the debit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.debit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+
+class TransferCurrencyForm(CurrencyForm):
+    """The form to create or edit a currency in a transfer transaction."""
+    no = IntegerField()
+    """The order in the transaction."""
+    code = StringField(
+        filters=[strip_text],
+        validators=[CURRENCY_REQUIRED,
+                    CurrencyExists(),
+                    SameCurrencyAsOriginalEntries(),
+                    KeepCurrencyWhenHavingOffset()])
+    """The currency code."""
+    debit = FieldList(FormField(DebitEntryForm),
+                      validators=[NeedSomeJournalEntries()])
+    """The debit entries."""
+    credit = FieldList(FormField(CreditEntryForm),
+                       validators=[NeedSomeJournalEntries()])
+    """The credit entries."""
+    whole_form = BooleanField(validators=[IsBalanced()])
+    """The pseudo field for the whole form validators."""
+
+    @property
+    def debit_total(self) -> Decimal:
+        """Returns the total amount of the debit journal entries.
+
+        :return: The total amount of the debit journal entries.
+        """
+        return sum([x.amount.data for x in self.debit
+                    if x.amount.data is not None])
+
+    @property
+    def credit_total(self) -> Decimal:
+        """Returns the total amount of the credit journal entries.
+
+        :return: The total amount of the credit journal entries.
+        """
+        return sum([x.amount.data for x in self.credit
+                    if x.amount.data is not None])
+
+    @property
+    def debit_errors(self) -> list[str | LazyString]:
+        """Returns the debit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.debit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]
+
+    @property
+    def credit_errors(self) -> list[str | LazyString]:
+        """Returns the credit journal entry errors, without the errors in their
+        sub-forms.
+
+        :return:
+        """
+        return [x for x in self.credit.errors
+                if isinstance(x, str) or isinstance(x, LazyString)]

src/accounting/transaction/forms/journal_entry.py

@@ -0,0 +1,524 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The journal entry sub-forms for the transaction management.
+
+"""
+import re
+from datetime import date
+from decimal import Decimal
+
+import sqlalchemy as sa
+from flask_babel import LazyString
+from flask_wtf import FlaskForm
+from sqlalchemy.orm import selectinload
+from wtforms import StringField, ValidationError, DecimalField, IntegerField
+from wtforms.validators import DataRequired, Optional
+
+from accounting import db
+from accounting.locale import lazy_gettext
+from accounting.models import Account, JournalEntry
+from accounting.template_filters import format_amount
+from accounting.utils.cast import be
+from accounting.utils.random_id import new_id
+from accounting.utils.strip_text import strip_text
+from accounting.utils.user import get_current_user_pk
+
+ACCOUNT_REQUIRED: DataRequired = DataRequired(
+    lazy_gettext("Please select the account."))
+"""The validator to check if the account code is empty."""
+
+
+class OriginalEntryExists:
+    """The validator to check if the original entry exists."""
+
+    def __call__(self, form: FlaskForm, field: IntegerField) -> None:
+        if field.data is None:
+            return
+        if db.session.get(JournalEntry, field.data) is None:
+            raise ValidationError(lazy_gettext(
+                "The original entry does not exist."))
+
+
+class OriginalEntryOppositeSide:
+    """The validator to check if the original entry is on the opposite side."""
+
+    def __call__(self, form: FlaskForm, field: IntegerField) -> None:
+        if field.data is None:
+            return
+        original_entry: JournalEntry | None \
+            = db.session.get(JournalEntry, field.data)
+        if original_entry is None:
+            return
+        if isinstance(form, CreditEntryForm) and original_entry.is_debit:
+            return
+        if isinstance(form, DebitEntryForm) and not original_entry.is_debit:
+            return
+        raise ValidationError(lazy_gettext(
+            "The original entry is on the same side."))
+
+
+class OriginalEntryNeedOffset:
+    """The validator to check if the original entry needs offset."""
+
+    def __call__(self, form: FlaskForm, field: IntegerField) -> None:
+        if field.data is None:
+            return
+        original_entry: JournalEntry | None \
+            = db.session.get(JournalEntry, field.data)
+        if original_entry is None:
+            return
+        if not original_entry.account.is_need_offset:
+            raise ValidationError(lazy_gettext(
+                "The original entry does not need offset."))
+
+
+class OriginalEntryNotOffset:
+    """The validator to check if the original entry is not itself an offset
+    entry."""
+
+    def __call__(self, form: FlaskForm, field: IntegerField) -> None:
+        if field.data is None:
+            return
+        original_entry: JournalEntry | None \
+            = db.session.get(JournalEntry, field.data)
+        if original_entry is None:
+            return
+        if original_entry.original_entry_id is not None:
+            raise ValidationError(lazy_gettext(
+                "The original entry cannot be an offset entry."))
+
+
+class AccountExists:
+    """The validator to check if the account exists."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if Account.find_by_code(field.data) is None:
+            raise ValidationError(lazy_gettext(
+                "The account does not exist."))
+
+
+class IsDebitAccount:
+    """The validator to check if the account is for debit journal entries."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if re.match(r"^(?:[1235689]|7[5678])", field.data) \
+                and not field.data.startswith("3351-") \
+                and not field.data.startswith("3353-"):
+            return
+        raise ValidationError(lazy_gettext(
+            "This account is not for debit entries."))
+
+
+class IsCreditAccount:
+    """The validator to check if the account is for credit journal entries."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data is None:
+            return
+        if re.match(r"^(?:[123489]|7[1234])", field.data) \
+                and not field.data.startswith("3351-") \
+                and not field.data.startswith("3353-"):
+            return
+        raise ValidationError(lazy_gettext(
+            "This account is not for credit entries."))
+
+
+class SameAccountAsOriginalEntry:
+    """The validator to check if the account is the same as the original
+    entry."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, JournalEntryForm)
+        if field.data is None or form.original_entry_id.data is None:
+            return
+        original_entry: JournalEntry | None \
+            = db.session.get(JournalEntry, form.original_entry_id.data)
+        if original_entry is None:
+            return
+        if field.data != original_entry.account_code:
+            raise ValidationError(lazy_gettext(
+                "The account must be the same as the original entry."))
+
+
+class KeepAccountWhenHavingOffset:
+    """The validator to check if the account is the same when having offset."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, JournalEntryForm)
+        if field.data is None or form.eid.data is None:
+            return
+        entry: JournalEntry | None = db.session.query(JournalEntry)\
+            .filter(JournalEntry.id == form.eid.data)\
+            .options(selectinload(JournalEntry.offsets)).first()
+        if entry is None or len(entry.offsets) == 0:
+            return
+        if field.data != entry.account_code:
+            raise ValidationError(lazy_gettext(
+                "The account must not be changed when there is offset."))
+
+
+class NotStartPayableFromDebit:
+    """The validator to check that a payable journal entry does not start from
+    the debit side."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, DebitEntryForm)
+        if field.data is None \
+                or field.data[0] != "2" \
+                or form.original_entry_id.data is not None:
+            return
+        account: Account | None = Account.find_by_code(field.data)
+        if account is not None and account.is_need_offset:
+            raise ValidationError(lazy_gettext(
+                "A payable entry cannot start from the debit side."))
+
+
+class NotStartReceivableFromCredit:
+    """The validator to check that a receivable journal entry does not start
+    from the credit side."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        assert isinstance(form, CreditEntryForm)
+        if field.data is None \
+                or field.data[0] != "1" \
+                or form.original_entry_id.data is not None:
+            return
+        account: Account | None = Account.find_by_code(field.data)
+        if account is not None and account.is_need_offset:
+            raise ValidationError(lazy_gettext(
+                "A receivable entry cannot start from the credit side."))
+
+
+class PositiveAmount:
+    """The validator to check if the amount is positive."""
+
+    def __call__(self, form: FlaskForm, field: DecimalField) -> None:
+        if field.data is None:
+            return
+        if field.data <= 0:
+            raise ValidationError(lazy_gettext(
+                "Please fill in a positive amount."))
+
+
+class NotExceedingOriginalEntryNetBalance:
+    """The validator to check if the amount exceeds the net balance of the
+    original entry."""
+
+    def __call__(self, form: FlaskForm, field: DecimalField) -> None:
+        assert isinstance(form, JournalEntryForm)
+        if field.data is None or form.original_entry_id.data is None:
+            return
+        original_entry: JournalEntry | None \
+            = db.session.get(JournalEntry, form.original_entry_id.data)
+        if original_entry is None:
+            return
+        is_debit: bool = isinstance(form, DebitEntryForm)
+        existing_entry_id: set[int] = set()
+        if form.txn_form.obj is not None:
+            existing_entry_id = {x.id for x in form.txn_form.obj.entries}
+        offset_total_func: sa.Function = sa.func.sum(sa.case(
+            (be(JournalEntry.is_debit == is_debit), JournalEntry.amount),
+            else_=-JournalEntry.amount))
+        offset_total_but_form: Decimal | None = db.session.scalar(
+            sa.select(offset_total_func)
+            .filter(be(JournalEntry.original_entry_id == original_entry.id),
+                    JournalEntry.id.not_in(existing_entry_id)))
+        if offset_total_but_form is None:
+            offset_total_but_form = Decimal("0")
+        offset_total_on_form: Decimal = sum(
+            [x.amount.data for x in form.txn_form.entries
+             if x.original_entry_id.data == original_entry.id
+             and x.amount != field and x.amount.data is not None])
+        net_balance: Decimal = original_entry.amount - offset_total_but_form \
+            - offset_total_on_form
+        if field.data > net_balance:
+            raise ValidationError(lazy_gettext(
+                "The amount must not exceed the net balance %(balance)s of the"
+                " original entry.", balance=format_amount(net_balance)))
+
+
+class NotLessThanOffsetTotal:
+    """The validator to check if the amount is less than the offset total."""
+
+    def __call__(self, form: FlaskForm, field: DecimalField) -> None:
+        assert isinstance(form, JournalEntryForm)
+        if field.data is None or form.eid.data is None:
+            return
+        is_debit: bool = isinstance(form, DebitEntryForm)
+        select_offset_total: sa.Select = sa.select(sa.func.sum(sa.case(
+            (JournalEntry.is_debit != is_debit, JournalEntry.amount),
+            else_=-JournalEntry.amount)))\
+            .filter(be(JournalEntry.original_entry_id == form.eid.data))
+        offset_total: Decimal | None = db.session.scalar(select_offset_total)
+        if offset_total is not None and field.data < offset_total:
+            raise ValidationError(lazy_gettext(
+                "The amount must not be less than the offset total %(total)s.",
+                total=format_amount(offset_total)))
+
+
+class JournalEntryForm(FlaskForm):
+    """The base form to create or edit a journal entry."""
+    eid = IntegerField()
+    """The existing journal entry ID."""
+    no = IntegerField()
+    """The order in the currency."""
+    original_entry_id = IntegerField()
+    """The Id of the original entry."""
+    account_code = StringField()
+    """The account code."""
+    amount = DecimalField()
+    """The amount."""
+
+    def __init__(self, *args, **kwargs):
+        """Constructs a base transaction form.
+
+        :param args: The arguments.
+        :param kwargs: The keyword arguments.
+        """
+        super().__init__(*args, **kwargs)
+        from .transaction import TransactionForm
+        self.txn_form: TransactionForm | None = None
+        """The source transaction form."""
+
+    @property
+    def account_text(self) -> str:
+        """Returns the text representation of the account.
+
+        :return: The text representation of the account.
+        """
+        if self.account_code.data is None:
+            return ""
+        account: Account | None = Account.find_by_code(self.account_code.data)
+        if account is None:
+            return ""
+        return str(account)
+
+    @property
+    def __original_entry(self) -> JournalEntry | None:
+        """Returns the original entry.
+
+        :return: The original entry.
+        """
+        if not hasattr(self, "____original_entry"):
+            def get_entry() -> JournalEntry | None:
+                if self.original_entry_id.data is None:
+                    return None
+                return db.session.get(JournalEntry,
+                                      self.original_entry_id.data)
+            setattr(self, "____original_entry", get_entry())
+        return getattr(self, "____original_entry")
+
+    @property
+    def original_entry_date(self) -> date | None:
+        """Returns the text representation of the original entry.
+
+        :return: The text representation of the original entry.
+        """
+        return None if self.__original_entry is None \
+            else self.__original_entry.transaction.date
+
+    @property
+    def original_entry_text(self) -> str | None:
+        """Returns the text representation of the original entry.
+
+        :return: The text representation of the original entry.
+        """
+        return None if self.__original_entry is None \
+            else str(self.__original_entry)
+
+    @property
+    def is_need_offset(self) -> bool:
+        """Returns whether the entry needs offset.
+
+        :return: True if the entry needs offset, or False otherwise.
+        """
+        if self.account_code.data is None:
+            return False
+        if self.account_code.data[0] == "1":
+            if isinstance(self, CreditEntryForm):
+                return False
+        elif self.account_code.data[0] == "2":
+            if isinstance(self, DebitEntryForm):
+                return False
+        else:
+            return False
+        account: Account | None = Account.find_by_code(self.account_code.data)
+        return account is not None and account.is_need_offset
+
+    @property
+    def offsets(self) -> list[JournalEntry]:
+        """Returns the offsets.
+
+        :return: The offsets.
+        """
+        if not hasattr(self, "__offsets"):
+            def get_offsets() -> list[JournalEntry]:
+                if not self.is_need_offset or self.eid.data is None:
+                    return []
+                return JournalEntry.query\
+                    .filter(JournalEntry.original_entry_id == self.eid.data)\
+                    .options(selectinload(JournalEntry.transaction),
+                             selectinload(JournalEntry.account),
+                             selectinload(JournalEntry.offsets)
+                             .selectinload(JournalEntry.transaction)).all()
+            setattr(self, "__offsets", get_offsets())
+        return getattr(self, "__offsets")
+
+    @property
+    def offset_total(self) -> Decimal | None:
+        """Returns the total amount of the offsets.
+
+        :return: The total amount of the offsets.
+        """
+        if not hasattr(self, "__offset_total"):
+            def get_offset_total():
+                if not self.is_need_offset or self.eid.data is None:
+                    return None
+                is_debit: bool = isinstance(self, DebitEntryForm)
+                return sum([x.amount if x.is_debit != is_debit else -x.amount
+                            for x in self.offsets])
+            setattr(self, "__offset_total", get_offset_total())
+        return getattr(self, "__offset_total")
+
+    @property
+    def net_balance(self) -> Decimal | None:
+        """Returns the net balance.
+
+        :return: The net balance.
+        """
+        if not self.is_need_offset or self.eid.data is None \
+                or self.amount.data is None:
+            return None
+        return self.amount.data - self.offset_total
+
+    @property
+    def all_errors(self) -> list[str | LazyString]:
+        """Returns all the errors of the form.
+
+        :return: All the errors of the form.
+        """
+        all_errors: list[str | LazyString] = []
+        for key in self.errors:
+            if key != "csrf_token":
+                all_errors.extend(self.errors[key])
+        return all_errors
+
+
+class DebitEntryForm(JournalEntryForm):
+    """The form to create or edit a debit journal entry."""
+    eid = IntegerField()
+    """The existing journal entry ID."""
+    no = IntegerField()
+    """The order in the currency."""
+    original_entry_id = IntegerField(
+        validators=[Optional(),
+                    OriginalEntryExists(),
+                    OriginalEntryOppositeSide(),
+                    OriginalEntryNeedOffset(),
+                    OriginalEntryNotOffset()])
+    """The Id of the original entry."""
+    account_code = StringField(
+        filters=[strip_text],
+        validators=[ACCOUNT_REQUIRED,
+                    AccountExists(),
+                    IsDebitAccount(),
+                    SameAccountAsOriginalEntry(),
+                    KeepAccountWhenHavingOffset(),
+                    NotStartPayableFromDebit()])
+    """The account code."""
+    offset_original_entry_id = IntegerField()
+    """The Id of the original entry."""
+    summary = StringField(filters=[strip_text])
+    """The summary."""
+    amount = DecimalField(
+        validators=[PositiveAmount(),
+                    NotExceedingOriginalEntryNetBalance(),
+                    NotLessThanOffsetTotal()])
+    """The amount."""
+
+    def populate_obj(self, obj: JournalEntry) -> None:
+        """Populates the form data into a journal entry object.
+
+        :param obj: The journal entry object.
+        :return: None.
+        """
+        is_new: bool = obj.id is None
+        if is_new:
+            obj.id = new_id(JournalEntry)
+        obj.original_entry_id = self.original_entry_id.data
+        obj.account_id = Account.find_by_code(self.account_code.data).id
+        obj.summary = self.summary.data
+        obj.is_debit = True
+        obj.amount = self.amount.data
+        if is_new:
+            current_user_pk: int = get_current_user_pk()
+            obj.created_by_id = current_user_pk
+            obj.updated_by_id = current_user_pk
+
+
+class CreditEntryForm(JournalEntryForm):
+    """The form to create or edit a credit journal entry."""
+    eid = IntegerField()
+    """The existing journal entry ID."""
+    no = IntegerField()
+    """The order in the currency."""
+    original_entry_id = IntegerField(
+        validators=[Optional(),
+                    OriginalEntryExists(),
+                    OriginalEntryOppositeSide(),
+                    OriginalEntryNeedOffset(),
+                    OriginalEntryNotOffset()])
+    """The Id of the original entry."""
+    account_code = StringField(
+        filters=[strip_text],
+        validators=[ACCOUNT_REQUIRED,
+                    AccountExists(),
+                    IsCreditAccount(),
+                    SameAccountAsOriginalEntry(),
+                    KeepAccountWhenHavingOffset(),
+                    NotStartReceivableFromCredit()])
+    """The account code."""
+    summary = StringField(filters=[strip_text])
+    """The summary."""
+    amount = DecimalField(
+        validators=[PositiveAmount(),
+                    NotExceedingOriginalEntryNetBalance(),
+                    NotLessThanOffsetTotal()])
+    """The amount."""
+
+    def populate_obj(self, obj: JournalEntry) -> None:
+        """Populates the form data into a journal entry object.
+
+        :param obj: The journal entry object.
+        :return: None.
+        """
+        is_new: bool = obj.id is None
+        if is_new:
+            obj.id = new_id(JournalEntry)
+        obj.original_entry_id = self.original_entry_id.data
+        obj.account_id = Account.find_by_code(self.account_code.data).id
+        obj.summary = self.summary.data
+        obj.is_debit = False
+        obj.amount = self.amount.data
+        if is_new:
+            current_user_pk: int = get_current_user_pk()
+            obj.created_by_id = current_user_pk
+            obj.updated_by_id = current_user_pk

src/accounting/transaction/forms/reorder.py

@@ -0,0 +1,92 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The reorder forms for the transaction management.
+
+"""
+from datetime import date
+
+import sqlalchemy as sa
+from flask import request
+
+from accounting import db
+from accounting.models import Transaction
+
+
+def sort_transactions_in(txn_date: date, exclude: int | None = None) -> None:
+    """Sorts the transactions under a date after changing the date or deleting
+    a transaction.
+
+    :param txn_date: The date of the transaction.
+    :param exclude: The transaction ID to exclude.
+    :return: None.
+    """
+    conditions: list[sa.BinaryExpression] = [Transaction.date == txn_date]
+    if exclude is not None:
+        conditions.append(Transaction.id != exclude)
+    transactions: list[Transaction] = Transaction.query\
+        .filter(*conditions)\
+        .order_by(Transaction.no).all()
+    for i in range(len(transactions)):
+        if transactions[i].no != i + 1:
+            transactions[i].no = i + 1
+
+
+class TransactionReorderForm:
+    """The form to reorder the transactions."""
+
+    def __init__(self, txn_date: date):
+        """Constructs the form to reorder the transactions in a day.
+
+        :param txn_date: The date.
+        """
+        self.date: date = txn_date
+        self.is_modified: bool = False
+
+    def save_order(self) -> None:
+        """Saves the order of the account.
+
+        :return:
+        """
+        transactions: list[Transaction] = Transaction.query\
+            .filter(Transaction.date == self.date).all()
+
+        # Collects the specified order.
+        orders: dict[Transaction, int] = {}
+        for txn in transactions:
+            if f"{txn.id}-no" in request.form:
+                try:
+                    orders[txn] = int(request.form[f"{txn.id}-no"])
+                except ValueError:
+                    pass
+
+        # Missing and invalid orders are appended to the end.
+        missing: list[Transaction] \
+            = [x for x in transactions if x not in orders]
+        if len(missing) > 0:
+            next_no: int = 1 if len(orders) == 0 else max(orders.values()) + 1
+            for txn in missing:
+                orders[txn] = next_no
+
+        # Sort by the specified order first, and their original order.
+        transactions.sort(key=lambda x: (orders[x], x.no))
+
+        # Update the orders.
+        with db.session.no_autoflush:
+            for i in range(len(transactions)):
+                if transactions[i].no != i + 1:
+                    transactions[i].no = i + 1
+                    self.is_modified = True

src/accounting/transaction/forms/transaction.py

@@ -14,268 +14,95 @@
 #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
-"""The forms for the transaction management.
+"""The transaction forms for the transaction management.
 
 """
-from __future__ import annotations
-
-import re
+import datetime as dt
 import typing as t
 from abc import ABC, abstractmethod
-from datetime import date
-from decimal import Decimal
 
 import sqlalchemy as sa
-from flask import request
 from flask_babel import LazyString
 from flask_wtf import FlaskForm
-from wtforms import DateField, StringField, FieldList, FormField, \
-    IntegerField, TextAreaField, DecimalField, BooleanField
+from wtforms import DateField, FieldList, FormField, TextAreaField, \
+    BooleanField
 from wtforms.validators import DataRequired, ValidationError
 
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Transaction, Account, JournalEntry, \
-    TransactionCurrency, Currency
-from accounting.transaction.summary_editor import SummaryEditor
+    TransactionCurrency
+from accounting.transaction.utils.account_option import AccountOption
+from accounting.transaction.utils.original_entries import \
+    get_selectable_original_entries
+from accounting.transaction.utils.summary_editor import SummaryEditor
 from accounting.utils.random_id import new_id
-from accounting.utils.strip_text import strip_text, strip_multiline_text
+from accounting.utils.strip_text import strip_multiline_text
 from accounting.utils.user import get_current_user_pk
+from .currency import CurrencyForm, IncomeCurrencyForm, ExpenseCurrencyForm, \
+    TransferCurrencyForm
+from .journal_entry import JournalEntryForm, DebitEntryForm, CreditEntryForm
+from .reorder import sort_transactions_in
 
-MISSING_CURRENCY: LazyString = lazy_gettext("Please select the currency.")
-"""The error message when the currency code is empty."""
-MISSING_ACCOUNT: LazyString = lazy_gettext("Please select the account.")
-"""The error message when the account code is empty."""
 DATE_REQUIRED: DataRequired = DataRequired(
     lazy_gettext("Please fill in the date."))
 """The validator to check if the date is empty."""
 
 
+class NotBeforeOriginalEntries:
+    """The validator to check if the date is not before the original
+    entries."""
+
+    def __call__(self, form: FlaskForm, field: DateField) -> None:
+        assert isinstance(form, TransactionForm)
+        if field.data is None:
+            return
+        min_date: dt.date | None = form.min_date
+        if min_date is None:
+            return
+        if field.data < min_date:
+            raise ValidationError(lazy_gettext(
+                "The date cannot be earlier than the original entries."))
+
+
+class NotAfterOffsetEntries:
+    """The validator to check if the date is not after the offset entries."""
+
+    def __call__(self, form: FlaskForm, field: DateField) -> None:
+        assert isinstance(form, TransactionForm)
+        if field.data is None:
+            return
+        max_date: dt.date | None = form.max_date
+        if max_date is None:
+            return
+        if field.data > max_date:
+            raise ValidationError(lazy_gettext(
+                "The date cannot be later than the offset entries."))
+
+
 class NeedSomeCurrencies:
     """The validator to check if there is any currency sub-form."""
 
-    def __call__(self, form: CurrencyForm, field: FieldList) \
-            -> None:
+    def __call__(self, form: FlaskForm, field: FieldList) -> None:
         if len(field) == 0:
-            raise ValidationError(lazy_gettext(
-                "Please add some currencies."))
+            raise ValidationError(lazy_gettext("Please add some currencies."))
 
 
-class CurrencyExists:
-    """The validator to check if the account exists."""
+class CannotDeleteOriginalEntriesWithOffset:
+    """The validator to check the original entries with offset."""
 
-    def __call__(self, form: FlaskForm, field: StringField) -> None:
-        if field.data is None:
+    def __call__(self, form: FlaskForm, field: FieldList) -> None:
+        assert isinstance(form, TransactionForm)
+        if form.obj is None:
             return
-        if db.session.get(Currency, field.data) is None:
-            raise ValidationError(lazy_gettext(
-                "The currency does not exist."))
-
-
-class NeedSomeJournalEntries:
-    """The validator to check if there is any journal entry sub-form."""
-
-    def __call__(self, form: TransferCurrencyForm, field: FieldList) \
-            -> None:
-        if len(field) == 0:
-            raise ValidationError(lazy_gettext(
-                "Please add some journal entries."))
-
-
-class AccountExists:
-    """The validator to check if the account exists."""
-
-    def __call__(self, form: FlaskForm, field: StringField) -> None:
-        if field.data is None:
-            return
-        if Account.find_by_code(field.data) is None:
-            raise ValidationError(lazy_gettext(
-                "The account does not exist."))
-
-
-class PositiveAmount:
-    """The validator to check if the amount is positive."""
-
-    def __call__(self, form: FlaskForm, field: DecimalField) -> None:
-        if field.data is None:
-            return
-        if field.data <= 0:
-            raise ValidationError(lazy_gettext(
-                "Please fill in a positive amount."))
-
-
-class IsDebitAccount:
-    """The validator to check if the account is for debit journal entries."""
-
-    def __call__(self, form: FlaskForm, field: StringField) -> None:
-        if field.data is None:
-            return
-        if re.match(r"^(?:[1235689]|7[5678])", field.data) \
-                and not field.data.startswith("3351-") \
-                and not field.data.startswith("3353-"):
-            return
-        raise ValidationError(lazy_gettext(
-            "This account is not for debit entries."))
-
-
-class AccountOption:
-    """An account option."""
-
-    def __init__(self, account: Account):
-        """Constructs an account option.
-
-        :param account: The account.
-        """
-        self.id: str = account.id
-        """The account ID."""
-        self.code: str = account.code
-        """The account code."""
-        self.query_values: list[str] = account.query_values
-        """The values to be queried."""
-        self.__str: str = str(account)
-        """The string representation of the account option."""
-        self.is_in_use: bool = False
-        """True if this account is in use, or False otherwise."""
-
-    def __str__(self) -> str:
-        """Returns the string representation of the account option.
-
-        :return: The string representation of the account option.
-        """
-        return self.__str
-
-
-class JournalEntryForm(FlaskForm):
-    """The base form to create or edit a journal entry."""
-    eid = IntegerField()
-    """The existing journal entry ID."""
-    no = IntegerField()
-    """The order in the currency."""
-    account_code = StringField()
-    """The account code."""
-    amount = DecimalField()
-    """The amount."""
-
-    @property
-    def account_text(self) -> str:
-        """Returns the text representation of the account.
-
-        :return: The text representation of the account.
-        """
-        if self.account_code.data is None:
-            return ""
-        account: Account | None = Account.find_by_code(self.account_code.data)
-        if account is None:
-            return ""
-        return str(account)
-
-    @property
-    def all_errors(self) -> list[str | LazyString]:
-        """Returns all the errors of the form.
-
-        :return: All the errors of the form.
-        """
-        all_errors: list[str | LazyString] = []
-        for key in self.errors:
-            if key != "csrf_token":
-                all_errors.extend(self.errors[key])
-        return all_errors
-
-
-class DebitEntryForm(JournalEntryForm):
-    """The form to create or edit a debit journal entry."""
-    eid = IntegerField()
-    """The existing journal entry ID."""
-    no = IntegerField()
-    """The order in the currency."""
-    account_code = StringField(
-        filters=[strip_text],
-        validators=[DataRequired(MISSING_ACCOUNT),
-                    AccountExists(),
-                    IsDebitAccount()])
-    """The account code."""
-    summary = StringField(filters=[strip_text])
-    """The summary."""
-    amount = DecimalField(validators=[PositiveAmount()])
-    """The amount."""
-
-    def populate_obj(self, obj: JournalEntry) -> None:
-        """Populates the form data into a journal entry object.
-
-        :param obj: The journal entry object.
-        :return: None.
-        """
-        is_new: bool = obj.id is None
-        if is_new:
-            obj.id = new_id(JournalEntry)
-        obj.account_id = Account.find_by_code(self.account_code.data).id
-        obj.summary = self.summary.data
-        obj.is_debit = True
-        obj.amount = self.amount.data
-        if is_new:
-            current_user_pk: int = get_current_user_pk()
-            obj.created_by_id = current_user_pk
-            obj.updated_by_id = current_user_pk
-
-
-class IsCreditAccount:
-    """The validator to check if the account is for credit journal entries."""
-
-    def __call__(self, form: FlaskForm, field: StringField) -> None:
-        if field.data is None:
-            return
-        if re.match(r"^(?:[123489]|7[1234])", field.data) \
-                and not field.data.startswith("3351-") \
-                and not field.data.startswith("3353-"):
-            return
-        raise ValidationError(lazy_gettext(
-            "This account is not for credit entries."))
-
-
-class CreditEntryForm(JournalEntryForm):
-    """The form to create or edit a credit journal entry."""
-    eid = IntegerField()
-    """The existing journal entry ID."""
-    no = IntegerField()
-    """The order in the currency."""
-    account_code = StringField(
-        filters=[strip_text],
-        validators=[DataRequired(MISSING_ACCOUNT),
-                    AccountExists(),
-                    IsCreditAccount()])
-    """The account code."""
-    summary = StringField(filters=[strip_text])
-    """The summary."""
-    amount = DecimalField(validators=[PositiveAmount()])
-    """The amount."""
-
-    def populate_obj(self, obj: JournalEntry) -> None:
-        """Populates the form data into a journal entry object.
-
-        :param obj: The journal entry object.
-        :return: None.
-        """
-        is_new: bool = obj.id is None
-        if is_new:
-            obj.id = new_id(JournalEntry)
-        obj.account_id = Account.find_by_code(self.account_code.data).id
-        obj.summary = self.summary.data
-        obj.is_debit = False
-        obj.amount = self.amount.data
-        if is_new:
-            current_user_pk: int = get_current_user_pk()
-            obj.created_by_id = current_user_pk
-            obj.updated_by_id = current_user_pk
-
-
-class CurrencyForm(FlaskForm):
-    """The form to create or edit a currency in a transaction."""
-    no = IntegerField()
-    """The order in the transaction."""
-    code = StringField()
-    """The currency code."""
-    whole_form = BooleanField()
-    """The pseudo field for the whole form validators."""
+        existing_matched_original_entry_id: set[int] \
+            = {x.id for x in form.obj.entries if len(x.offsets) > 0}
+        entry_id_in_form: set[int] \
+            = {x.eid.data for x in form.entries if x.eid.data is not None}
+        for entry_id in existing_matched_original_entry_id:
+            if entry_id not in entry_id_in_form:
+                raise ValidationError(lazy_gettext(
+                    "Journal entries with offset cannot be deleted."))
 
 
 class TransactionForm(FlaskForm):
@@ -300,8 +127,19 @@ class TransactionForm(FlaskForm):
         """The journal entry collector.  The default is the base abstract
         collector only to provide the correct type.  The subclass forms should
         provide their own collectors."""
-        self.__in_use_account_id: set[int] | None = None
-        """The ID of the accounts that are in use."""
+        self.obj: Transaction | None = kwargs.get("obj")
+        """The transaction, when editing an existing one."""
+        self._is_need_payable: bool = False
+        """Whether we need the payable original entries."""
+        self._is_need_receivable: bool = False
+        """Whether we need the receivable original entries."""
+        self.__original_entry_options: list[JournalEntry] | None = None
+        """The options of the original entries."""
+        self.__net_balance_exceeded: dict[int, LazyString] | None = None
+        """The original entries whose net balances were exceeded by the
+        amounts in the journal entry sub-forms."""
+        for entry in self.entries:
+            entry.txn_form = self
 
     def populate_obj(self, obj: Transaction) -> None:
         """Populates the form data into a transaction object.
@@ -312,6 +150,7 @@ class TransactionForm(FlaskForm):
         is_new: bool = obj.id is None
         if is_new:
             obj.id = new_id(Transaction)
+        self.date: DateField
         self.__set_date(obj, self.date.data)
         obj.note = self.note.data
 
@@ -333,8 +172,18 @@ class TransactionForm(FlaskForm):
             obj.created_by_id = current_user_pk
             obj.updated_by_id = current_user_pk
 
-    @staticmethod
-    def __set_date(obj: Transaction, new_date: date) -> None:
+    @property
+    def entries(self) -> list[JournalEntryForm]:
+        """Collects and returns the journal entry sub-forms.
+
+        :return: The journal entry sub-forms.
+        """
+        entries: list[JournalEntryForm] = []
+        for currency in self.currencies:
+            entries.extend(currency.entries)
+        return entries
+
+    def __set_date(self, obj: Transaction, new_date: dt.date) -> None:
         """Sets the transaction date and number.
 
         :param obj: The transaction object.
@@ -344,11 +193,23 @@ class TransactionForm(FlaskForm):
         if obj.date is None or obj.date != new_date:
             if obj.date is not None:
                 sort_transactions_in(obj.date, obj.id)
-            sort_transactions_in(new_date, obj.id)
-            count: int = Transaction.query\
-                .filter(Transaction.date == new_date).count()
-            obj.date = new_date
-            obj.no = count + 1
+            if self.max_date is not None and new_date == self.max_date:
+                db_min_no: int | None = db.session.scalar(
+                    sa.select(sa.func.min(Transaction.no))
+                    .filter(Transaction.date == new_date))
+                if db_min_no is None:
+                    obj.date = new_date
+                    obj.no = 1
+                else:
+                    obj.date = new_date
+                    obj.no = db_min_no - 1
+                    sort_transactions_in(new_date)
+            else:
+                sort_transactions_in(new_date, obj.id)
+                count: int = Transaction.query\
+                    .filter(Transaction.date == new_date).count()
+                obj.date = new_date
+                obj.no = count + 1
 
     @property
     def debit_account_options(self) -> list[AccountOption]:
@@ -357,7 +218,8 @@ class TransactionForm(FlaskForm):
         :return: The selectable debit accounts.
         """
         accounts: list[AccountOption] \
-            = [AccountOption(x) for x in Account.debit()]
+            = [AccountOption(x) for x in Account.debit()
+               if not (x.code[0] == "2" and x.is_need_offset)]
         in_use: set[int] = set(db.session.scalars(
             sa.select(JournalEntry.account_id)
             .filter(JournalEntry.is_debit)
@@ -373,7 +235,8 @@ class TransactionForm(FlaskForm):
         :return: The selectable credit accounts.
         """
         accounts: list[AccountOption] \
-            = [AccountOption(x) for x in Account.credit()]
+            = [AccountOption(x) for x in Account.credit()
+               if not (x.code[0] == "1" and x.is_need_offset)]
         in_use: set[int] = set(db.session.scalars(
             sa.select(JournalEntry.account_id)
             .filter(sa.not_(JournalEntry.is_debit))
@@ -399,6 +262,46 @@ class TransactionForm(FlaskForm):
         """
         return SummaryEditor()
 
+    @property
+    def original_entry_options(self) -> list[JournalEntry]:
+        """Returns the selectable original entries.
+
+        :return: The selectable original entries.
+        """
+        if self.__original_entry_options is None:
+            self.__original_entry_options = get_selectable_original_entries(
+                {x.eid.data for x in self.entries if x.eid.data is not None},
+                self._is_need_payable, self._is_need_receivable)
+        return self.__original_entry_options
+
+    @property
+    def min_date(self) -> dt.date | None:
+        """Returns the minimal available date.
+
+        :return: The minimal available date.
+        """
+        original_entry_id: set[int] \
+            = {x.original_entry_id.data for x in self.entries
+               if x.original_entry_id.data is not None}
+        if len(original_entry_id) == 0:
+            return None
+        select: sa.Select = sa.select(sa.func.max(Transaction.date))\
+            .join(JournalEntry).filter(JournalEntry.id.in_(original_entry_id))
+        return db.session.scalar(select)
+
+    @property
+    def max_date(self) -> dt.date | None:
+        """Returns the maximum available date.
+
+        :return: The maximum available date.
+        """
+        entry_id: set[int] = {x.eid.data for x in self.entries
+                              if x.eid.data is not None}
+        select: sa.Select = sa.select(sa.func.min(Transaction.date))\
+            .join(JournalEntry)\
+            .filter(JournalEntry.original_entry_id.in_(entry_id))
+        return db.session.scalar(select)
+
 
 T = t.TypeVar("T", bound=TransactionForm)
 """A transaction form variant."""
@@ -538,53 +441,25 @@ class JournalEntryCollector(t.Generic[T], ABC):
                                   ord_by_form.get(x)))
 
 
-class IncomeCurrencyForm(CurrencyForm):
-    """The form to create or edit a currency in a cash income transaction."""
-    no = IntegerField()
-    """The order in the transaction."""
-    code = StringField(
-        filters=[strip_text],
-        validators=[DataRequired(MISSING_CURRENCY),
-                    CurrencyExists()])
-    """The currency code."""
-    credit = FieldList(FormField(CreditEntryForm),
-                       validators=[NeedSomeJournalEntries()])
-    """The credit entries."""
-    whole_form = BooleanField()
-    """The pseudo field for the whole form validators."""
-
-    @property
-    def credit_total(self) -> Decimal:
-        """Returns the total amount of the credit journal entries.
-
-        :return: The total amount of the credit journal entries.
-        """
-        return sum([x.amount.data for x in self.credit
-                    if x.amount.data is not None])
-
-    @property
-    def credit_errors(self) -> list[str | LazyString]:
-        """Returns the credit journal entry errors, without the errors in their
-        sub-forms.
-
-        :return:
-        """
-        return [x for x in self.credit.errors
-                if isinstance(x, str) or isinstance(x, LazyString)]
-
-
 class IncomeTransactionForm(TransactionForm):
     """The form to create or edit a cash income transaction."""
-    date = DateField(validators=[DATE_REQUIRED])
+    date = DateField(
+        validators=[DATE_REQUIRED,
+                    NotBeforeOriginalEntries(),
+                    NotAfterOffsetEntries()])
     """The date."""
     currencies = FieldList(FormField(IncomeCurrencyForm), name="currency",
                            validators=[NeedSomeCurrencies()])
     """The journal entries categorized by their currencies."""
     note = TextAreaField(filters=[strip_multiline_text])
     """The note."""
+    whole_form = BooleanField(
+        validators=[CannotDeleteOriginalEntriesWithOffset()])
+    """The pseudo field for the whole form validators."""
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self._is_need_receivable = True
 
         class Collector(JournalEntryCollector[IncomeTransactionForm]):
             """The journal entry collector for the cash income transactions."""
@@ -611,53 +486,25 @@ class IncomeTransactionForm(TransactionForm):
         self.collector = Collector
 
 
-class ExpenseCurrencyForm(CurrencyForm):
-    """The form to create or edit a currency in a cash expense transaction."""
-    no = IntegerField()
-    """The order in the transaction."""
-    code = StringField(
-        filters=[strip_text],
-        validators=[DataRequired(MISSING_CURRENCY),
-                    CurrencyExists()])
-    """The currency code."""
-    debit = FieldList(FormField(DebitEntryForm),
-                      validators=[NeedSomeJournalEntries()])
-    """The debit entries."""
-    whole_form = BooleanField()
-    """The pseudo field for the whole form validators."""
-
-    @property
-    def debit_total(self) -> Decimal:
-        """Returns the total amount of the debit journal entries.
-
-        :return: The total amount of the debit journal entries.
-        """
-        return sum([x.amount.data for x in self.debit
-                    if x.amount.data is not None])
-
-    @property
-    def debit_errors(self) -> list[str | LazyString]:
-        """Returns the debit journal entry errors, without the errors in their
-        sub-forms.
-
-        :return:
-        """
-        return [x for x in self.debit.errors
-                if isinstance(x, str) or isinstance(x, LazyString)]
-
-
 class ExpenseTransactionForm(TransactionForm):
     """The form to create or edit a cash expense transaction."""
-    date = DateField(validators=[DATE_REQUIRED])
+    date = DateField(
+        validators=[DATE_REQUIRED,
+                    NotBeforeOriginalEntries(),
+                    NotAfterOffsetEntries()])
     """The date."""
     currencies = FieldList(FormField(ExpenseCurrencyForm), name="currency",
                            validators=[NeedSomeCurrencies()])
     """The journal entries categorized by their currencies."""
     note = TextAreaField(filters=[strip_multiline_text])
     """The note."""
+    whole_form = BooleanField(
+        validators=[CannotDeleteOriginalEntriesWithOffset()])
+    """The pseudo field for the whole form validators."""
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self._is_need_payable = True
 
         class Collector(JournalEntryCollector[ExpenseTransactionForm]):
             """The journal entry collector for the cash expense
@@ -685,88 +532,26 @@ class ExpenseTransactionForm(TransactionForm):
         self.collector = Collector
 
 
-class TransferCurrencyForm(CurrencyForm):
-    """The form to create or edit a currency in a transfer transaction."""
-
-    class IsBalanced:
-        """The validator to check that the total amount of the debit and credit
-        entries are equal."""
-        def __call__(self, form: TransferCurrencyForm, field: BooleanField)\
-                -> None:
-            if len(form.debit) == 0 or len(form.credit) == 0:
-                return
-            if form.debit_total != form.credit_total:
-                raise ValidationError(lazy_gettext(
-                    "The totals of the debit and credit amounts do not"
-                    " match."))
-
-    no = IntegerField()
-    """The order in the transaction."""
-    code = StringField(
-        filters=[strip_text],
-        validators=[DataRequired(MISSING_CURRENCY),
-                    CurrencyExists()])
-    """The currency code."""
-    debit = FieldList(FormField(DebitEntryForm),
-                      validators=[NeedSomeJournalEntries()])
-    """The debit entries."""
-    credit = FieldList(FormField(CreditEntryForm),
-                       validators=[NeedSomeJournalEntries()])
-    """The credit entries."""
-    whole_form = BooleanField(validators=[IsBalanced()])
-    """The pseudo field for the whole form validators."""
-
-    @property
-    def debit_total(self) -> Decimal:
-        """Returns the total amount of the debit journal entries.
-
-        :return: The total amount of the debit journal entries.
-        """
-        return sum([x.amount.data for x in self.debit
-                    if x.amount.data is not None])
-
-    @property
-    def credit_total(self) -> Decimal:
-        """Returns the total amount of the credit journal entries.
-
-        :return: The total amount of the credit journal entries.
-        """
-        return sum([x.amount.data for x in self.credit
-                    if x.amount.data is not None])
-
-    @property
-    def debit_errors(self) -> list[str | LazyString]:
-        """Returns the debit journal entry errors, without the errors in their
-        sub-forms.
-
-        :return:
-        """
-        return [x for x in self.debit.errors
-                if isinstance(x, str) or isinstance(x, LazyString)]
-
-    @property
-    def credit_errors(self) -> list[str | LazyString]:
-        """Returns the credit journal entry errors, without the errors in their
-        sub-forms.
-
-        :return:
-        """
-        return [x for x in self.credit.errors
-                if isinstance(x, str) or isinstance(x, LazyString)]
-
-
 class TransferTransactionForm(TransactionForm):
     """The form to create or edit a transfer transaction."""
-    date = DateField(validators=[DATE_REQUIRED])
+    date = DateField(
+        validators=[DATE_REQUIRED,
+                    NotBeforeOriginalEntries(),
+                    NotAfterOffsetEntries()])
     """The date."""
     currencies = FieldList(FormField(TransferCurrencyForm), name="currency",
                            validators=[NeedSomeCurrencies()])
     """The journal entries categorized by their currencies."""
     note = TextAreaField(filters=[strip_multiline_text])
     """The note."""
+    whole_form = BooleanField(
+        validators=[CannotDeleteOriginalEntriesWithOffset()])
+    """The pseudo field for the whole form validators."""
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self._is_need_payable = True
+        self._is_need_receivable = True
 
         class Collector(JournalEntryCollector[TransferTransactionForm]):
             """The journal entry collector for the transfer transactions."""
@@ -795,67 +580,3 @@ class TransferTransactionForm(TransactionForm):
                         self._credit_no = self._credit_no + 1
 
         self.collector = Collector
-
-
-def sort_transactions_in(txn_date: date, exclude: int) -> None:
-    """Sorts the transactions under a date after changing the date or deleting
-    a transaction.
-
-    :param txn_date: The date of the transaction.
-    :param exclude: The transaction ID to exclude.
-    :return: None.
-    """
-    transactions: list[Transaction] = Transaction.query\
-        .filter(Transaction.date == txn_date,
-                Transaction.id != exclude)\
-        .order_by(Transaction.no).all()
-    for i in range(len(transactions)):
-        if transactions[i].no != i + 1:
-            transactions[i].no = i + 1
-
-
-class TransactionReorderForm:
-    """The form to reorder the transactions."""
-
-    def __init__(self, txn_date: date):
-        """Constructs the form to reorder the transactions in a day.
-
-        :param txn_date: The date.
-        """
-        self.date: date = txn_date
-        self.is_modified: bool = False
-
-    def save_order(self) -> None:
-        """Saves the order of the account.
-
-        :return:
-        """
-        transactions: list[Transaction] = Transaction.query\
-            .filter(Transaction.date == self.date).all()
-
-        # Collects the specified order.
-        orders: dict[Transaction, int] = {}
-        for txn in transactions:
-            if f"{txn.id}-no" in request.form:
-                try:
-                    orders[txn] = int(request.form[f"{txn.id}-no"])
-                except ValueError:
-                    pass
-
-        # Missing and invalid orders are appended to the end.
-        missing: list[Transaction] \
-            = [x for x in transactions if x not in orders]
-        if len(missing) > 0:
-            next_no: int = 1 if len(orders) == 0 else max(orders.values()) + 1
-            for txn in missing:
-                orders[txn] = next_no
-
-        # Sort by the specified order first, and their original order.
-        transactions.sort(key=lambda x: (orders[x], x.no))
-
-        # Update the orders.
-        with db.session.no_autoflush:
-            for i in range(len(transactions)):
-                if transactions[i].no != i + 1:
-                    transactions[i].no = i + 1
-                    self.is_modified = True

src/accounting/transaction/utils/__init__.py

@@ -0,0 +1,19 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The utilities for the transaction management.
+
+"""

src/accounting/transaction/utils/account_option.py

@@ -0,0 +1,49 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The account option for the transaction management.
+
+"""
+from accounting.models import Account
+
+
+class AccountOption:
+    """An account option."""
+
+    def __init__(self, account: Account):
+        """Constructs an account option.
+
+        :param account: The account.
+        """
+        self.id: str = account.id
+        """The account ID."""
+        self.code: str = account.code
+        """The account code."""
+        self.query_values: list[str] = account.query_values
+        """The values to be queried."""
+        self.__str: str = str(account)
+        """The string representation of the account option."""
+        self.is_in_use: bool = False
+        """True if this account is in use, or False otherwise."""
+        self.is_need_offset: bool = account.is_need_offset
+        """True if this account needs offset, or False otherwise."""
+
+    def __str__(self) -> str:
+        """Returns the string representation of the account option.
+
+        :return: The string representation of the account option.
+        """
+        return self.__str

src/accounting/transaction/utils/offset_alias.py

@@ -0,0 +1,39 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/15
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The SQLAlchemy alias for the offset entries.
+
+"""
+import typing as t
+
+import sqlalchemy as sa
+
+from accounting.models import JournalEntry
+
+
+def offset_alias() -> sa.Alias:
+    """Returns the SQLAlchemy alias for the offset entries.
+
+    :return: The SQLAlchemy alias for the offset entries.
+    """
+
+    def as_from(model_cls: t.Any) -> sa.FromClause:
+        return model_cls
+
+    def as_alias(alias: t.Any) -> sa.Alias:
+        return alias
+
+    return as_alias(sa.alias(as_from(JournalEntry), name="offset"))

src/accounting/transaction/utils/operators.py

@@ -26,8 +26,8 @@ from flask_wtf import FlaskForm
 from accounting.models import Transaction
 from accounting.template_globals import default_currency_code
 from accounting.utils.txn_types import TransactionType
-from .forms import TransactionForm, IncomeTransactionForm, \
-    ExpenseTransactionForm, TransferTransactionForm
+from accounting.transaction.forms import TransactionForm, \
+    IncomeTransactionForm, ExpenseTransactionForm, TransferTransactionForm
 
 
 class TransactionOperator(ABC):

src/accounting/transaction/utils/original_entries.py

@@ -0,0 +1,82 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/10
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The selectable original entries.
+
+"""
+from decimal import Decimal
+
+import sqlalchemy as sa
+from flask_babel import LazyString
+from sqlalchemy.orm import selectinload
+
+from accounting import db
+from accounting.locale import lazy_gettext
+from accounting.models import Account, Transaction, JournalEntry
+from accounting.transaction.forms.journal_entry import JournalEntryForm
+from accounting.utils.cast import be
+from .offset_alias import offset_alias
+
+
+def get_selectable_original_entries(
+        entry_id_on_form: set[int], is_payable: bool, is_receivable: bool) \
+        -> list[JournalEntry]:
+    """Queries and returns the selectable original entries, with their net
+    balances.  The offset amounts of the form is excluded.
+
+    :param entry_id_on_form: The ID of the journal entries on the form.
+    :param is_payable: True to check the payable original entries, or False
+        otherwise.
+    :param is_receivable: True to check the receivable original entries, or
+        False otherwise.
+    :return: The selectable original entries, with their net balances.
+    """
+    assert is_payable or is_receivable
+    offset: sa.Alias = offset_alias()
+    net_balance: sa.Label = (JournalEntry.amount + sa.func.sum(sa.case(
+        (offset.c.id.in_(entry_id_on_form), 0),
+        (be(offset.c.is_debit == JournalEntry.is_debit), offset.c.amount),
+        else_=-offset.c.amount))).label("net_balance")
+    conditions: list[sa.BinaryExpression] = [Account.is_need_offset]
+    sub_conditions: list[sa.BinaryExpression] = []
+    if is_payable:
+        sub_conditions.append(sa.and_(Account.base_code.startswith("2"),
+                                      sa.not_(JournalEntry.is_debit)))
+    if is_receivable:
+        sub_conditions.append(sa.and_(Account.base_code.startswith("1"),
+                                      JournalEntry.is_debit))
+    conditions.append(sa.or_(*sub_conditions))
+    select_net_balances: sa.Select = sa.select(JournalEntry.id, net_balance)\
+        .join(Account)\
+        .join(offset, be(JournalEntry.id == offset.c.original_entry_id),
+              isouter=True)\
+        .filter(*conditions)\
+        .group_by(JournalEntry.id)\
+        .having(sa.or_(sa.func.count(offset.c.id) == 0, net_balance != 0))
+    net_balances: dict[int, Decimal] \
+        = {x.id: x.net_balance
+           for x in db.session.execute(select_net_balances).all()}
+    entries: list[JournalEntry] = JournalEntry.query\
+        .filter(JournalEntry.id.in_({x for x in net_balances}))\
+        .join(Transaction)\
+        .order_by(Transaction.date, JournalEntry.is_debit, JournalEntry.no)\
+        .options(selectinload(JournalEntry.currency),
+                 selectinload(JournalEntry.account),
+                 selectinload(JournalEntry.transaction)).all()
+    for entry in entries:
+        entry.net_balance = entry.amount if net_balances[entry.id] is None \
+            else net_balances[entry.id]
+    return entries

src/accounting/transaction/utils/summary_editor.py

@@ -218,7 +218,8 @@ class SummaryEditor:
                                       JournalEntry.account_id,
                                       sa.func.count().label("freq"))\
             .filter(JournalEntry.summary.is_not(None),
-                    JournalEntry.summary.like("_%—_%"))\
+                    JournalEntry.summary.like("_%—_%"),
+                    JournalEntry.original_entry_id.is_(None))\
             .group_by(entry_type, tag_type, tag, JournalEntry.account_id)
         result: list[sa.Row] = db.session.execute(select).all()
         accounts: dict[int, Account] \

src/accounting/transaction/views.py

@@ -28,15 +28,16 @@ from werkzeug.datastructures import ImmutableMultiDict
 from accounting import db
 from accounting.locale import lazy_gettext
 from accounting.models import Transaction
+from accounting.utils.cast import s
 from accounting.utils.flash_errors import flash_form_errors
 from accounting.utils.next_uri import inherit_next, or_next
 from accounting.utils.permission import has_permission, can_view, can_edit
 from accounting.utils.txn_types import TransactionType
 from accounting.utils.user import get_current_user_pk
 from .forms import sort_transactions_in, TransactionReorderForm
-from .operators import TransactionOperator, TXN_TYPE_TO_OP, get_txn_op
 from .template_filters import with_type, to_transfer, format_amount_input, \
     text2html
+from .utils.operators import TransactionOperator, TXN_TYPE_TO_OP, get_txn_op
 
 bp: Blueprint = Blueprint("transaction", __name__)
 """The view blueprint for the transaction management."""
@@ -87,7 +88,7 @@ def add_transaction(txn_type: TransactionType) -> redirect:
     form.populate_obj(txn)
     db.session.add(txn)
     db.session.commit()
-    flash(lazy_gettext("The transaction is added successfully"), "success")
+    flash(s(lazy_gettext("The transaction is added successfully")), "success")
     return redirect(inherit_next(__get_detail_uri(txn)))
 
 
@@ -116,6 +117,7 @@ def show_transaction_edit_form(txn: Transaction) -> str:
     if "form" in session:
         form = txn_op.form(ImmutableMultiDict(parse_qsl(session["form"])))
         del session["form"]
+        form.obj = txn
         form.validate()
     else:
         form = txn_op.form(obj=txn)
@@ -133,6 +135,7 @@ def update_transaction(txn: Transaction) -> redirect:
     """
     txn_op: TransactionOperator = get_txn_op(txn, is_check_as=True)
     form: txn_op.form = txn_op.form(request.form)
+    form.obj = txn
     if not form.validate():
         flash_form_errors(form)
         session["form"] = urlencode(list(request.form.items()))
@@ -141,12 +144,13 @@ def update_transaction(txn: Transaction) -> redirect:
     with db.session.no_autoflush:
         form.populate_obj(txn)
     if not form.is_modified:
-        flash(lazy_gettext("The transaction was not modified."), "success")
+        flash(s(lazy_gettext("The transaction was not modified.")), "success")
         return redirect(inherit_next(__get_detail_uri(txn)))
     txn.updated_by_id = get_current_user_pk()
     txn.updated_at = sa.func.now()
     db.session.commit()
-    flash(lazy_gettext("The transaction is updated successfully."), "success")
+    flash(s(lazy_gettext("The transaction is updated successfully.")),
+          "success")
     return redirect(inherit_next(__get_detail_uri(txn)))
 
 
@@ -162,7 +166,8 @@ def delete_transaction(txn: Transaction) -> redirect:
     txn.delete()
     sort_transactions_in(txn.date, txn.id)
     db.session.commit()
-    flash(lazy_gettext("The transaction is deleted successfully."), "success")
+    flash(s(lazy_gettext("The transaction is deleted successfully.")),
+          "success")
     return redirect(or_next(__get_default_page_uri()))
 
 
@@ -193,10 +198,10 @@ def sort_transactions(txn_date: date) -> redirect:
     form: TransactionReorderForm = TransactionReorderForm(txn_date)
     form.save_order()
     if not form.is_modified:
-        flash(lazy_gettext("The order was not modified."), "success")
+        flash(s(lazy_gettext("The order was not modified.")), "success")
         return redirect(or_next(__get_default_page_uri()))
     db.session.commit()
-    flash(lazy_gettext("The order is updated successfully."), "success")
+    flash(s(lazy_gettext("The order is updated successfully.")), "success")
     return redirect(or_next(__get_default_page_uri()))
 
 

src/accounting/utils/cast.py

@@ -0,0 +1,44 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/15
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The utility to cast a SQLAlchemy column into the column type, to avoid
+warnings from the IDE.
+
+This module should not import any other module from the application.
+
+"""
+import typing as t
+
+import sqlalchemy as sa
+
+
+def be(expression: t.Any) -> sa.BinaryExpression:
+    """Casts the SQLAlchemy binary expression to the binary expression type.
+
+    :param expression: The binary expression.
+    :return: The binary expression itself.
+    """
+    assert isinstance(expression, sa.BinaryExpression)
+    return expression
+
+
+def s(message: t.Any) -> str:
+    """Casts the LazyString message to the string type.
+
+    :param message: The message.
+    :return: The binary expression itself.
+    """
+    return message

src/accounting/utils/permission.py

@@ -23,7 +23,7 @@ import typing as t
 
 from flask import abort, Blueprint
 
-from accounting.utils.user import get_current_user
+from accounting.utils.user import get_current_user, UserUtilityInterface
 
 
 def has_permission(rule: t.Callable[[], bool]) -> t.Callable:
@@ -87,22 +87,15 @@ def can_edit() -> bool:
     return __can_edit_func()
 
 
-def init_app(bp: Blueprint,
-             can_view_func: t.Callable[[], bool] | None = None,
-             can_edit_func: t.Callable[[], bool] | None = None) -> None:
+def init_app(bp: Blueprint, user_utils: UserUtilityInterface) -> None:
     """Initializes the application.
 
     :param bp: The blueprint of the accounting application.
-    :param can_view_func: A callback that returns whether the current user can
-        view the accounting data.
-    :param can_edit_func: A callback that returns whether the current user can
-        edit the accounting data.
+    :param user_utils: The user utilities.
     :return: None.
     """
     global __can_view_func, __can_edit_func
-    if can_view_func is not None:
-        __can_view_func = can_view_func
-    if can_edit_func is not None:
-        __can_edit_func = can_edit_func
-    bp.add_app_template_global(can_view, "accounting_can_view")
-    bp.add_app_template_global(can_edit, "accounting_can_edit")
+    __can_view_func = user_utils.can_view
+    __can_edit_func = user_utils.can_edit
+    bp.add_app_template_global(user_utils.can_view, "accounting_can_view")
+    bp.add_app_template_global(user_utils.can_edit, "accounting_can_edit")

src/accounting/utils/user.py

@@ -29,15 +29,33 @@ from flask_sqlalchemy.model import Model
 T = t.TypeVar("T", bound=Model)
 
 
-class AbstractUserUtils(t.Generic[T], ABC):
-    """The abstract user utilities."""
+class UserUtilityInterface(t.Generic[T], ABC):
+    """The interface for the user utilities."""
+
+    @abstractmethod
+    def can_view(self) -> bool:
+        """Returns whether the currently logged-in user can view the accounting
+        data.
+
+        :return: True if the currently logged-in user can view the accounting
+            data, or False otherwise.
+        """
+
+    @abstractmethod
+    def can_edit(self) -> bool:
+        """Returns whether the currently logged-in user can edit the accounting
+        data.
+
+        :return: True if the currently logged-in user can edit the accounting
+            data, or False otherwise.
+        """
 
     @property
     @abstractmethod
     def cls(self) -> t.Type[T]:
-        """Returns the user class.
+        """Returns the class of the user data model.
 
-        :return: The user class.
+        :return: The class of the user data model.
         """
 
     @property
@@ -66,13 +84,13 @@ class AbstractUserUtils(t.Generic[T], ABC):
 
     @abstractmethod
     def get_pk(self, user: T) -> int:
-        """Returns the primary key of the user.
+        """Returns the primary key of the user, as an integer.
 
-        :return: The primary key of the user.
+        :return: The primary key of the user, as an integer.
         """
 
 
-__user_utils: AbstractUserUtils
+__user_utils: UserUtilityInterface
 """The user utilities."""
 user_cls: t.Type[Model] = Model
 """The user class."""
@@ -80,7 +98,7 @@ user_pk_column: sa.Column = sa.Column(sa.Integer)
 """The primary key column of the user class."""
 
 
-def init_user_utils(utils: AbstractUserUtils) -> None:
+def init_user_utils(utils: UserUtilityInterface) -> None:
     """Initializes the user utilities.
 
     :param utils: The user utilities.

tests/test_account.py

@@ -26,8 +26,8 @@ from click.testing import Result
 from flask import Flask
 from flask.testing import FlaskCliRunner
 
-from test_site import create_app, db
-from testlib import get_client, set_locale
+from test_site import db
+from testlib import create_test_app, get_client, set_locale
 
 NEXT_URI: str = "/_next"
 """The next URI."""
@@ -74,7 +74,7 @@ class AccountCommandTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -127,7 +127,7 @@ class AccountTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -372,6 +372,15 @@ class AccountTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
+        # A nominal account that needs offset
+        response = self.client.post(store_uri,
+                                    data={"csrf_token": self.csrf_token,
+                                          "base_code": "6172",
+                                          "title": stock.title,
+                                          "is_need_offset": "yes"})
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
         # Success, with spaces to be stripped
         response = self.client.post(store_uri,
                                     data={"csrf_token": self.csrf_token,
@@ -470,6 +479,15 @@ class AccountTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
+        # A nominal account that needs offset
+        response = self.client.post(update_uri,
+                                    data={"csrf_token": self.csrf_token,
+                                          "base_code": "6172",
+                                          "title": stock.title,
+                                          "is_need_offset": "yes"})
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
         # Change the base account
         response = self.client.post(update_uri,
                                     data={"csrf_token": self.csrf_token,

tests/test_base_account.py

@@ -26,8 +26,7 @@ from click.testing import Result
 from flask import Flask
 from flask.testing import FlaskCliRunner
 
-from test_site import create_app
-from testlib import get_client
+from testlib import create_test_app, get_client
 
 LIST_URI: str = "/accounting/base-accounts"
 """The list URI."""
@@ -45,7 +44,7 @@ class BaseAccountCommandTestCase(unittest.TestCase):
         :return: None.
         """
         from accounting.models import BaseAccount, BaseAccountL10n
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -98,7 +97,7 @@ class BaseAccountTestCase(unittest.TestCase):
         :return: None.
         """
         from accounting.models import BaseAccount
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():

tests/test_currency.py

@@ -27,8 +27,8 @@ from click.testing import Result
 from flask import Flask
 from flask.testing import FlaskCliRunner
 
-from test_site import create_app, db
-from testlib import get_client, set_locale
+from test_site import db
+from testlib import create_test_app, get_client, set_locale
 
 
 class CurrencyData:
@@ -67,7 +67,7 @@ class CurrencyCommandTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -123,7 +123,7 @@ class CurrencyTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():

tests/test_offset.py

@@ -0,0 +1,685 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/3/11
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The test for the offset.
+
+"""
+import unittest
+from decimal import Decimal
+
+import httpx
+from click.testing import Result
+from flask import Flask
+from flask.testing import FlaskCliRunner
+
+from test_site import db
+from testlib import create_test_app, get_client
+from testlib_offset import TestData, JournalEntryData, TransactionData, \
+    CurrencyData
+from testlib_txn import Accounts, match_txn_detail
+
+PREFIX: str = "/accounting/transactions"
+"""The URL prefix for the transaction management."""
+
+
+class OffsetTestCase(unittest.TestCase):
+    """The offset test case."""
+
+    def setUp(self) -> None:
+        """Sets up the test.
+        This is run once per test.
+
+        :return: None.
+        """
+        self.app: Flask = create_test_app()
+
+        runner: FlaskCliRunner = self.app.test_cli_runner()
+        with self.app.app_context():
+            from accounting.models import BaseAccount, Transaction, \
+                JournalEntry
+            result: Result
+            result = runner.invoke(args="init-db")
+            self.assertEqual(result.exit_code, 0)
+            if BaseAccount.query.first() is None:
+                result = runner.invoke(args="accounting-init-base")
+                self.assertEqual(result.exit_code, 0)
+            result = runner.invoke(args=["accounting-init-currencies",
+                                         "-u", "editor"])
+            self.assertEqual(result.exit_code, 0)
+            result = runner.invoke(args=["accounting-init-accounts",
+                                         "-u", "editor"])
+            self.assertEqual(result.exit_code, 0)
+            Transaction.query.delete()
+            JournalEntry.query.delete()
+
+        self.client, self.csrf_token = get_client(self.app, "editor")
+        self.data: TestData = TestData(self.app, self.client, self.csrf_token)
+
+    def test_add_receivable_offset(self) -> None:
+        """Tests to add the receivable offset.
+
+        :return: None.
+        """
+        from accounting.models import Account, Transaction
+        create_uri: str = f"{PREFIX}/create/income?next=%2F_next"
+        store_uri: str = f"{PREFIX}/store/income"
+        form: dict[str, str]
+        old_amount: Decimal
+        response: httpx.Response
+
+        txn_data: TransactionData = TransactionData(
+            self.data.e_r_or3d.txn.days, [CurrencyData(
+                "USD",
+                [],
+                [JournalEntryData(Accounts.RECEIVABLE,
+                                  self.data.e_r_or1d.summary, "300",
+                                  original_entry=self.data.e_r_or1d),
+                 JournalEntryData(Accounts.RECEIVABLE,
+                                  self.data.e_r_or1d.summary, "100",
+                                  original_entry=self.data.e_r_or1d),
+                 JournalEntryData(Accounts.RECEIVABLE,
+                                  self.data.e_r_or3d.summary, "100",
+                                  original_entry=self.data.e_r_or3d)])])
+
+        # Non-existing original entry ID
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-credit-1-original_entry_id"] = "9999"
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # The same side
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-credit-1-original_entry_id"] = self.data.e_p_or1c.id
+        form["currency-1-credit-1-account_code"] = self.data.e_p_or1c.account
+        form["currency-1-credit-1-amount"] = "100"
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # The original entry does not need offset
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.RECEIVABLE)
+            account.is_need_offset = False
+            db.session.commit()
+        response = self.client.post(store_uri,
+                                    data=txn_data.new_form(self.csrf_token))
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.RECEIVABLE)
+            account.is_need_offset = True
+            db.session.commit()
+
+        # The original entry is also an offset
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-credit-1-original_entry_id"] = self.data.e_p_of1d.id
+        form["currency-1-credit-1-account_code"] = self.data.e_p_of1d.account
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not the same currency
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-code"] = "EUR"
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not the same account
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-credit-1-account_code"] = Accounts.NOTES_RECEIVABLE
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not exceeding net balance - partially offset
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-credit-1-amount"] \
+            = str(txn_data.currencies[0].credit[0].amount + Decimal("0.01"))
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not exceeding net balance - unmatched
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-credit-3-amount"] \
+            = str(txn_data.currencies[0].credit[2].amount + Decimal("0.01"))
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not before the original entries
+        old_days = txn_data.days
+        txn_data.days = old_days + 1
+        form = txn_data.new_form(self.csrf_token)
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+        txn_data.days = old_days
+
+        # Success
+        form = txn_data.new_form(self.csrf_token)
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        txn_id: int = match_txn_detail(response.headers["Location"])
+        with self.app.app_context():
+            txn = db.session.get(Transaction, txn_id)
+            for offset in txn.currencies[0].credit:
+                self.assertIsNotNone(offset.original_entry_id)
+
+    def test_edit_receivable_offset(self) -> None:
+        """Tests to edit the receivable offset.
+
+        :return: None.
+        """
+        from accounting.models import Account
+        txn_data: TransactionData = self.data.t_r_of2
+        edit_uri: str = f"{PREFIX}/{txn_data.id}/edit?next=%2F_next"
+        update_uri: str = f"{PREFIX}/{txn_data.id}/update"
+        form: dict[str, str]
+        response: httpx.Response
+
+        txn_data.days = self.data.t_r_or2.days
+        txn_data.currencies[0].debit[0].amount = Decimal("600")
+        txn_data.currencies[0].credit[0].amount = Decimal("600")
+        txn_data.currencies[0].debit[2].amount = Decimal("600")
+        txn_data.currencies[0].credit[2].amount = Decimal("600")
+
+        # Non-existing original entry ID
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-credit-1-original_entry_id"] = "9999"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # The same side
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-credit-1-original_entry_id"] = self.data.e_p_or1c.id
+        form["currency-1-credit-1-account_code"] = self.data.e_p_or1c.account
+        form["currency-1-debit-1-amount"] = "100"
+        form["currency-1-credit-1-amount"] = "100"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # The original entry does not need offset
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.RECEIVABLE)
+            account.is_need_offset = False
+            db.session.commit()
+        response = self.client.post(update_uri,
+                                    data=txn_data.update_form(self.csrf_token))
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.RECEIVABLE)
+            account.is_need_offset = True
+            db.session.commit()
+
+        # The original entry is also an offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-credit-1-original_entry_id"] = self.data.e_p_of1d.id
+        form["currency-1-credit-1-account_code"] = self.data.e_p_of1d.account
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not the same currency
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-code"] = "EUR"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not the same account
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-credit-1-account_code"] = Accounts.NOTES_RECEIVABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not exceeding net balance - partially offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-amount"] \
+            = str(txn_data.currencies[0].debit[0].amount + Decimal("0.01"))
+        form["currency-1-credit-1-amount"] \
+            = str(txn_data.currencies[0].credit[0].amount + Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not exceeding net balance - unmatched
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-3-amount"] \
+            = str(txn_data.currencies[0].debit[2].amount + Decimal("0.01"))
+        form["currency-1-credit-3-amount"] \
+            = str(txn_data.currencies[0].credit[2].amount + Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not before the original entries
+        old_days: int = txn_data.days
+        txn_data.days = old_days + 1
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+        txn_data.days = old_days
+
+        # Success
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"],
+                         f"{PREFIX}/{txn_data.id}?next=%2F_next")
+
+    def test_edit_receivable_original_entry(self) -> None:
+        """Tests to edit the receivable original entry.
+
+        :return: None.
+        """
+        from accounting.models import Transaction
+        txn_data: TransactionData = self.data.t_r_or1
+        edit_uri: str = f"{PREFIX}/{txn_data.id}/edit?next=%2F_next"
+        update_uri: str = f"{PREFIX}/{txn_data.id}/update"
+        form: dict[str, str]
+        response: httpx.Response
+
+        txn_data.days = self.data.t_r_of1.days
+        txn_data.currencies[0].debit[0].amount = Decimal("800")
+        txn_data.currencies[0].credit[0].amount = Decimal("800")
+        txn_data.currencies[0].debit[1].amount = Decimal("3.4")
+        txn_data.currencies[0].credit[1].amount = Decimal("3.4")
+
+        # Not the same currency
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-code"] = "EUR"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not the same account
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-account_code"] = Accounts.NOTES_RECEIVABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not less than offset total - partially offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-amount"] \
+            = str(txn_data.currencies[0].debit[0].amount - Decimal("0.01"))
+        form["currency-1-credit-1-amount"] \
+            = str(txn_data.currencies[0].credit[0].amount - Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not less than offset total - fully offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-2-amount"] \
+            = str(txn_data.currencies[0].debit[1].amount - Decimal("0.01"))
+        form["currency-1-credit-2-amount"] \
+            = str(txn_data.currencies[0].credit[1].amount - Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not after the offset entries
+        old_days: int = txn_data.days
+        txn_data.days = old_days - 1
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+        txn_data.days = old_days
+
+        # Not deleting matched original entries
+        form = txn_data.update_form(self.csrf_token)
+        del form["currency-1-debit-1-eid"]
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Success
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"],
+                         f"{PREFIX}/{txn_data.id}?next=%2F_next")
+
+        # The original entry is always before the offset entry, even when they
+        # happen in the same day.
+        with self.app.app_context():
+            txn_or: Transaction | None = db.session.get(
+                Transaction, txn_data.id)
+            self.assertIsNotNone(txn_or)
+            txn_of: Transaction | None = db.session.get(
+                Transaction, self.data.t_r_of1.id)
+            self.assertIsNotNone(txn_of)
+            self.assertEqual(txn_or.date, txn_of.date)
+            self.assertLess(txn_or.no, txn_of.no)
+
+    def test_add_payable_offset(self) -> None:
+        """Tests to add the payable offset.
+
+        :return: None.
+        """
+        from accounting.models import Account, Transaction
+        create_uri: str = f"{PREFIX}/create/expense?next=%2F_next"
+        store_uri: str = f"{PREFIX}/store/expense"
+        form: dict[str, str]
+        response: httpx.Response
+
+        txn_data: TransactionData = TransactionData(
+            self.data.e_p_or3c.txn.days, [CurrencyData(
+                "USD",
+                [JournalEntryData(Accounts.PAYABLE,
+                                  self.data.e_p_or1c.summary, "500",
+                                  original_entry=self.data.e_p_or1c),
+                 JournalEntryData(Accounts.PAYABLE,
+                                  self.data.e_p_or1c.summary, "300",
+                                  original_entry=self.data.e_p_or1c),
+                 JournalEntryData(Accounts.PAYABLE,
+                                  self.data.e_p_or3c.summary, "120",
+                                  original_entry=self.data.e_p_or3c)],
+                [])])
+
+        # Non-existing original entry ID
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-debit-1-original_entry_id"] = "9999"
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # The same side
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-debit-1-original_entry_id"] = self.data.e_r_or1d.id
+        form["currency-1-debit-1-account_code"] = self.data.e_r_or1d.account
+        form["currency-1-debit-1-amount"] = "100"
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # The original entry does not need offset
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.PAYABLE)
+            account.is_need_offset = False
+            db.session.commit()
+        response = self.client.post(store_uri,
+                                    data=txn_data.new_form(self.csrf_token))
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.PAYABLE)
+            account.is_need_offset = True
+            db.session.commit()
+
+        # The original entry is also an offset
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-debit-1-original_entry_id"] = self.data.e_r_of1c.id
+        form["currency-1-debit-1-account_code"] = self.data.e_r_of1c.account
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not the same currency
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-code"] = "EUR"
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not the same account
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-debit-1-account_code"] = Accounts.NOTES_PAYABLE
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not exceeding net balance - partially offset
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-debit-1-amount"] \
+            = str(txn_data.currencies[0].debit[0].amount + Decimal("0.01"))
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not exceeding net balance - unmatched
+        form = txn_data.new_form(self.csrf_token)
+        form["currency-1-debit-3-amount"] \
+            = str(txn_data.currencies[0].debit[2].amount + Decimal("0.01"))
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # Not before the original entries
+        old_days: int = txn_data.days
+        txn_data.days = old_days + 1
+        form = txn_data.new_form(self.csrf_token)
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+        txn_data.days = old_days
+
+        # Success
+        form = txn_data.new_form(self.csrf_token)
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        txn_id: int = match_txn_detail(response.headers["Location"])
+        with self.app.app_context():
+            txn = db.session.get(Transaction, txn_id)
+            for offset in txn.currencies[0].debit:
+                self.assertIsNotNone(offset.original_entry_id)
+
+    def test_edit_payable_offset(self) -> None:
+        """Tests to edit the payable offset.
+
+        :return: None.
+        """
+        from accounting.models import Account, Transaction
+        txn_data: TransactionData = self.data.t_p_of2
+        edit_uri: str = f"{PREFIX}/{txn_data.id}/edit?next=%2F_next"
+        update_uri: str = f"{PREFIX}/{txn_data.id}/update"
+        form: dict[str, str]
+        response: httpx.Response
+
+        txn_data.days = self.data.t_p_or2.days
+        txn_data.currencies[0].debit[0].amount = Decimal("1100")
+        txn_data.currencies[0].credit[0].amount = Decimal("1100")
+        txn_data.currencies[0].debit[2].amount = Decimal("900")
+        txn_data.currencies[0].credit[2].amount = Decimal("900")
+
+        # Non-existing original entry ID
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-original_entry_id"] = "9999"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # The same side
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-original_entry_id"] = self.data.e_r_or1d.id
+        form["currency-1-debit-1-account_code"] = self.data.e_r_or1d.account
+        form["currency-1-debit-1-amount"] = "100"
+        form["currency-1-credit-1-amount"] = "100"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # The original entry does not need offset
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.PAYABLE)
+            account.is_need_offset = False
+            db.session.commit()
+        response = self.client.post(update_uri,
+                                    data=txn_data.update_form(self.csrf_token))
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+        with self.app.app_context():
+            account = Account.find_by_code(Accounts.PAYABLE)
+            account.is_need_offset = True
+            db.session.commit()
+
+        # The original entry is also an offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-original_entry_id"] = self.data.e_r_of1c.id
+        form["currency-1-debit-1-account_code"] = self.data.e_r_of1c.account
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not the same currency
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-code"] = "EUR"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not the same account
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-account_code"] = Accounts.NOTES_PAYABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not exceeding net balance - partially offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-amount"] \
+            = str(txn_data.currencies[0].debit[0].amount + Decimal("0.01"))
+        form["currency-1-credit-1-amount"] \
+            = str(txn_data.currencies[0].credit[0].amount + Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not exceeding net balance - unmatched
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-3-amount"] \
+            = str(txn_data.currencies[0].debit[2].amount + Decimal("0.01"))
+        form["currency-1-credit-3-amount"] \
+            = str(txn_data.currencies[0].credit[2].amount + Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not before the original entries
+        old_days: int = txn_data.days
+        txn_data.days = old_days + 1
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+        txn_data.days = old_days
+
+        # Success
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        txn_id: int = match_txn_detail(response.headers["Location"])
+        with self.app.app_context():
+            txn = db.session.get(Transaction, txn_id)
+            for offset in txn.currencies[0].debit:
+                self.assertIsNotNone(offset.original_entry_id)
+
+    def test_edit_payable_original_entry(self) -> None:
+        """Tests to edit the payable original entry.
+
+        :return: None.
+        """
+        from accounting.models import Transaction
+        txn_data: TransactionData = self.data.t_p_or1
+        edit_uri: str = f"{PREFIX}/{txn_data.id}/edit?next=%2F_next"
+        update_uri: str = f"{PREFIX}/{txn_data.id}/update"
+        form: dict[str, str]
+        response: httpx.Response
+
+        txn_data.days = self.data.t_p_of1.days
+        txn_data.currencies[0].debit[0].amount = Decimal("1200")
+        txn_data.currencies[0].credit[0].amount = Decimal("1200")
+        txn_data.currencies[0].debit[1].amount = Decimal("0.9")
+        txn_data.currencies[0].credit[1].amount = Decimal("0.9")
+
+        # Not the same currency
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-code"] = "EUR"
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not the same account
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-credit-1-account_code"] = Accounts.NOTES_PAYABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not less than offset total - partially offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-1-amount"] \
+            = str(txn_data.currencies[0].debit[0].amount - Decimal("0.01"))
+        form["currency-1-credit-1-amount"] \
+            = str(txn_data.currencies[0].credit[0].amount - Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not less than offset total - fully offset
+        form = txn_data.update_form(self.csrf_token)
+        form["currency-1-debit-2-amount"] \
+            = str(txn_data.currencies[0].debit[1].amount - Decimal("0.01"))
+        form["currency-1-credit-2-amount"] \
+            = str(txn_data.currencies[0].credit[1].amount - Decimal("0.01"))
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Not after the offset entries
+        old_days: int = txn_data.days
+        txn_data.days = old_days - 1
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+        txn_data.days = old_days
+
+        # Not deleting matched original entries
+        form = txn_data.update_form(self.csrf_token)
+        del form["currency-1-credit-1-eid"]
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # Success
+        form = txn_data.update_form(self.csrf_token)
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"],
+                         f"{PREFIX}/{txn_data.id}?next=%2F_next")
+
+        # The original entry is always before the offset entry, even when they
+        # happen in the same day
+        with self.app.app_context():
+            txn_or: Transaction | None = db.session.get(
+                Transaction, txn_data.id)
+            self.assertIsNotNone(txn_or)
+            txn_of: Transaction | None = db.session.get(
+                Transaction, self.data.t_p_of1.id)
+            self.assertIsNotNone(txn_of)
+            self.assertEqual(txn_or.date, txn_of.date)
+            self.assertLess(txn_or.no, txn_of.no)

tests/test_site/__init__.py

@@ -29,8 +29,6 @@ from flask_sqlalchemy import SQLAlchemy
 from flask_wtf import CSRFProtect
 from sqlalchemy import Column
 
-import accounting.utils.user
-
 bp: Blueprint = Blueprint("home", __name__)
 babel_js: BabelJS = BabelJS()
 csrf: CSRFProtect = CSRFProtect()
@@ -69,7 +67,16 @@ def create_app(is_testing: bool = False) -> Flask:
     from . import auth
     auth.init_app(app)
 
-    class UserUtils(accounting.utils.user.AbstractUserUtils[auth.User]):
+    class UserUtilities(accounting.UserUtilityInterface[auth.User]):
+
+        def can_view(self) -> bool:
+            return auth.current_user() is not None \
+                and auth.current_user().username in ["viewer", "editor",
+                                                     "editor2"]
+
+        def can_edit(self) -> bool:
+            return auth.current_user() is not None \
+                and auth.current_user().username in ["editor", "editor2"]
 
         @property
         def cls(self) -> t.Type[auth.User]:
@@ -90,12 +97,7 @@ def create_app(is_testing: bool = False) -> Flask:
         def get_pk(self, user: auth.User) -> int:
             return user.id
 
-    can_view: t.Callable[[], bool] = lambda: auth.current_user() is not None \
-        and auth.current_user().username in ["viewer", "editor", "editor2"]
-    can_edit: t.Callable[[], bool] = lambda: auth.current_user() is not None \
-        and auth.current_user().username in ["editor", "editor2"]
-    accounting.init_app(app, user_utils=UserUtils(),
-                        can_view_func=can_view, can_edit_func=can_edit)
+    accounting.init_app(app, user_utils=UserUtilities())
 
     return app
 

tests/test_summary_editor.py

@@ -24,8 +24,7 @@ from click.testing import Result
 from flask import Flask
 from flask.testing import FlaskCliRunner
 
-from test_site import create_app
-from testlib import get_client
+from testlib import create_test_app, get_client
 from testlib_txn import Accounts, NEXT_URI, add_txn
 
 
@@ -38,7 +37,7 @@ class SummeryEditorTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -66,7 +65,7 @@ class SummeryEditorTestCase(unittest.TestCase):
 
         :return: None.
         """
-        from accounting.transaction.summary_editor import SummaryEditor
+        from accounting.transaction.utils.summary_editor import SummaryEditor
         for form in get_form_data(self.csrf_token):
             add_txn(self.client, form)
         with self.app.app_context():
@@ -79,13 +78,13 @@ class SummeryEditorTestCase(unittest.TestCase):
         self.assertEqual(editor.debit.general.tags[0].accounts[0].code,
                          Accounts.MEAL)
         self.assertEqual(editor.debit.general.tags[0].accounts[1].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
         self.assertEqual(editor.debit.general.tags[1].name, "Dinner")
         self.assertEqual(len(editor.debit.general.tags[1].accounts), 2)
         self.assertEqual(editor.debit.general.tags[1].accounts[0].code,
                          Accounts.MEAL)
         self.assertEqual(editor.debit.general.tags[1].accounts[1].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
 
         # Debit-Travel
         self.assertEqual(len(editor.debit.travel.tags), 3)
@@ -118,7 +117,7 @@ class SummeryEditorTestCase(unittest.TestCase):
         self.assertEqual(editor.credit.general.tags[0].name, "Lunch")
         self.assertEqual(len(editor.credit.general.tags[0].accounts), 3)
         self.assertEqual(editor.credit.general.tags[0].accounts[0].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
         self.assertEqual(editor.credit.general.tags[0].accounts[1].code,
                          Accounts.BANK)
         self.assertEqual(editor.credit.general.tags[0].accounts[2].code,
@@ -128,20 +127,20 @@ class SummeryEditorTestCase(unittest.TestCase):
         self.assertEqual(editor.credit.general.tags[1].accounts[0].code,
                          Accounts.BANK)
         self.assertEqual(editor.credit.general.tags[1].accounts[1].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
 
         # Credit-Travel
         self.assertEqual(len(editor.credit.travel.tags), 2)
         self.assertEqual(editor.credit.travel.tags[0].name, "Bike")
         self.assertEqual(len(editor.credit.travel.tags[0].accounts), 2)
         self.assertEqual(editor.credit.travel.tags[0].accounts[0].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
         self.assertEqual(editor.credit.travel.tags[0].accounts[1].code,
                          Accounts.PREPAID)
         self.assertEqual(editor.credit.travel.tags[1].name, "Taxi")
         self.assertEqual(len(editor.credit.travel.tags[1].accounts), 2)
         self.assertEqual(editor.credit.travel.tags[1].accounts[0].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
         self.assertEqual(editor.credit.travel.tags[1].accounts[1].code,
                          Accounts.CASH)
 
@@ -152,7 +151,7 @@ class SummeryEditorTestCase(unittest.TestCase):
         self.assertEqual(editor.credit.bus.tags[0].accounts[0].code,
                          Accounts.PREPAID)
         self.assertEqual(editor.credit.bus.tags[0].accounts[1].code,
-                         Accounts.PAYABLE)
+                         Accounts.PETTY_CASH)
         self.assertEqual(editor.credit.bus.tags[1].name, "Bus")
         self.assertEqual(len(editor.credit.bus.tags[1].accounts), 1)
         self.assertEqual(editor.credit.bus.tags[1].accounts[0].code,
@@ -186,7 +185,7 @@ def get_form_data(csrf_token: str) -> list[dict[str, str]]:
              "currency-0-debit-1-account_code": Accounts.MEAL,
              "currency-0-debit-1-summary": " Lunch—Fries ",
              "currency-0-debit-1-amount": "2.15",
-             "currency-0-credit-1-account_code": Accounts.PAYABLE,
+             "currency-0-credit-1-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-1-summary": " Lunch—Fries ",
              "currency-0-credit-1-amount": "2.15",
              "currency-0-debit-2-account_code": Accounts.MEAL,
@@ -208,7 +207,7 @@ def get_form_data(csrf_token: str) -> list[dict[str, str]]:
              "currency-0-debit-1-account_code": Accounts.MEAL,
              "currency-0-debit-1-summary": " Dinner—Steak  ",
              "currency-0-debit-1-amount": "8.28",
-             "currency-0-credit-1-account_code": Accounts.PAYABLE,
+             "currency-0-credit-1-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-1-summary": " Dinner—Steak ",
              "currency-0-credit-1-amount": "8.28"},
             {"csrf_token": csrf_token,
@@ -218,13 +217,13 @@ def get_form_data(csrf_token: str) -> list[dict[str, str]]:
              "currency-0-debit-0-account_code": Accounts.MEAL,
              "currency-0-debit-0-summary": " Lunch—Pizza  ",
              "currency-0-debit-0-amount": "5.49",
-             "currency-0-credit-0-account_code": Accounts.PAYABLE,
+             "currency-0-credit-0-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-0-summary": " Lunch—Pizza ",
              "currency-0-credit-0-amount": "5.49",
              "currency-0-debit-1-account_code": Accounts.MEAL,
              "currency-0-debit-1-summary": " Lunch—Noodles ",
              "currency-0-debit-1-amount": "7.47",
-             "currency-0-credit-1-account_code": Accounts.PAYABLE,
+             "currency-0-credit-1-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-1-summary": " Lunch—Noodles ",
              "currency-0-credit-1-amount": "7.47"},
             {"csrf_token": csrf_token,
@@ -259,7 +258,7 @@ def get_form_data(csrf_token: str) -> list[dict[str, str]]:
              "currency-0-debit-3-account_code": Accounts.TRAVEL,
              "currency-0-debit-3-summary": " Train—Red—Mall→Museum ",
              "currency-0-debit-3-amount": "4.4",
-             "currency-0-credit-3-account_code": Accounts.PAYABLE,
+             "currency-0-credit-3-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-3-summary": " Train—Red—Mall→Museum ",
              "currency-0-credit-3-amount": "4.4"},
             {"csrf_token": csrf_token,
@@ -275,31 +274,31 @@ def get_form_data(csrf_token: str) -> list[dict[str, str]]:
              "currency-0-debit-1-account_code": Accounts.TRAVEL,
              "currency-0-debit-1-summary": " Taxi—Office→Restaurant ",
              "currency-0-debit-1-amount": "12",
-             "currency-0-credit-1-account_code": Accounts.PAYABLE,
+             "currency-0-credit-1-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-1-summary": " Taxi—Office→Restaurant ",
              "currency-0-credit-1-amount": "12",
              "currency-0-debit-2-account_code": Accounts.TRAVEL,
              "currency-0-debit-2-summary": " Taxi—Restaurant→City Hall ",
              "currency-0-debit-2-amount": "8",
-             "currency-0-credit-2-account_code": Accounts.PAYABLE,
+             "currency-0-credit-2-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-2-summary": " Taxi—Restaurant→City Hall ",
              "currency-0-credit-2-amount": "8",
              "currency-0-debit-3-account_code": Accounts.TRAVEL,
              "currency-0-debit-3-summary": " Bike—City Hall→Office ",
              "currency-0-debit-3-amount": "3.5",
-             "currency-0-credit-3-account_code": Accounts.PAYABLE,
+             "currency-0-credit-3-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-3-summary": " Bike—City Hall→Office ",
              "currency-0-credit-3-amount": "3.5",
              "currency-0-debit-4-account_code": Accounts.TRAVEL,
              "currency-0-debit-4-summary": " Bike—Restaurant→Office ",
              "currency-0-debit-4-amount": "4",
-             "currency-0-credit-4-account_code": Accounts.PAYABLE,
+             "currency-0-credit-4-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-4-summary": " Bike—Restaurant→Office ",
              "currency-0-credit-4-amount": "4",
              "currency-0-debit-5-account_code": Accounts.TRAVEL,
              "currency-0-debit-5-summary": " Bike—Office→Theatre ",
              "currency-0-debit-5-amount": "1.5",
-             "currency-0-credit-5-account_code": Accounts.PAYABLE,
+             "currency-0-credit-5-account_code": Accounts.PETTY_CASH,
              "currency-0-credit-5-summary": " Bike—Office→Theatre ",
              "currency-0-credit-5-amount": "1.5",
              "currency-0-debit-6-account_code": Accounts.TRAVEL,
@@ -312,13 +311,13 @@ def get_form_data(csrf_token: str) -> list[dict[str, str]]:
              "next": NEXT_URI,
              "date": txn_date,
              "currency-0-code": "USD",
-             "currency-0-debit-0-account_code": Accounts.PAYABLE,
+             "currency-0-debit-0-account_code": Accounts.PETTY_CASH,
              "currency-0-debit-0-summary": " Dinner—Steak  ",
              "currency-0-debit-0-amount": "8.28",
              "currency-0-credit-0-account_code": Accounts.BANK,
              "currency-0-credit-0-summary": " Dinner—Steak ",
              "currency-0-credit-0-amount": "8.28",
-             "currency-0-debit-1-account_code": Accounts.PAYABLE,
+             "currency-0-debit-1-account_code": Accounts.PETTY_CASH,
              "currency-0-debit-1-summary": " Lunch—Pizza ",
              "currency-0-debit-1-amount": "5.49",
              "currency-0-credit-1-account_code": Accounts.BANK,

tests/test_transaction.py

@@ -26,8 +26,8 @@ from click.testing import Result
 from flask import Flask
 from flask.testing import FlaskCliRunner
 
-from test_site import create_app, db
-from testlib import get_client
+from test_site import db
+from testlib import create_test_app, get_client
 from testlib_txn import Accounts, get_add_form, get_unchanged_update_form, \
     get_update_form, match_txn_detail, set_negative_amount, \
     remove_debit_in_a_currency, remove_credit_in_a_currency, NEXT_URI, \
@@ -48,7 +48,7 @@ class CashIncomeTransactionTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -229,6 +229,15 @@ class CashIncomeTransactionTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
+        # A receivable entry cannot start from the credit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-credit-" in x][0]
+        form[key] = Accounts.RECEIVABLE
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
         # Negative amount
         form = self.__get_add_form()
         set_negative_amount(form)
@@ -380,6 +389,15 @@ class CashIncomeTransactionTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
+        # A receivable entry cannot start from the credit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-credit-" in x][0]
+        form[key] = Accounts.RECEIVABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
         # Negative amount
         form: dict[str, str] = form_0.copy()
         set_negative_amount(form)
@@ -600,7 +618,7 @@ class CashExpenseTransactionTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -781,6 +799,15 @@ class CashExpenseTransactionTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
+        # A payable entry cannot start from the debit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-debit-" in x][0]
+        form[key] = Accounts.PAYABLE
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
         # Negative amount
         form = self.__get_add_form()
         set_negative_amount(form)
@@ -935,6 +962,15 @@ class CashExpenseTransactionTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
+        # A payable entry cannot start from the debit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-debit-" in x][0]
+        form[key] = Accounts.PAYABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
         # Negative amount
         form: dict[str, str] = form_0.copy()
         set_negative_amount(form)
@@ -1159,7 +1195,7 @@ class TransferTransactionTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():
@@ -1356,6 +1392,24 @@ class TransferTransactionTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], create_uri)
 
+        # A receivable entry cannot start from the credit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-credit-" in x][0]
+        form[key] = Accounts.RECEIVABLE
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
+        # A payable entry cannot start from the debit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-debit-" in x][0]
+        form[key] = Accounts.PAYABLE
+        response = self.client.post(store_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], create_uri)
+
         # Negative amount
         form = self.__get_add_form()
         set_negative_amount(form)
@@ -1537,6 +1591,24 @@ class TransferTransactionTestCase(unittest.TestCase):
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response.headers["Location"], edit_uri)
 
+        # A receivable entry cannot start from the credit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-credit-" in x][0]
+        form[key] = Accounts.RECEIVABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
+        # A payable entry cannot start from the debit side
+        form = self.__get_add_form()
+        key: str = [x for x in form.keys()
+                    if x.endswith("-account_code") and "-debit-" in x][0]
+        form[key] = Accounts.PAYABLE
+        response = self.client.post(update_uri, data=form)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.headers["Location"], edit_uri)
+
         # Negative amount
         form: dict[str, str] = form_0.copy()
         set_negative_amount(form)
@@ -1973,7 +2045,7 @@ class TransactionReorderTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
 
         runner: FlaskCliRunner = self.app.test_cli_runner()
         with self.app.app_context():

tests/test_utils.py

@@ -21,13 +21,12 @@ import unittest
 from urllib.parse import quote_plus
 
 import httpx
-from flask import Flask, request, render_template_string
+from flask import Flask, request
 
 from accounting.utils.next_uri import append_next, inherit_next, or_next
 from accounting.utils.pagination import Pagination, DEFAULT_PAGE_SIZE
 from accounting.utils.query import parse_query_keywords
-from test_site import create_app
-from testlib import TEST_SERVER
+from testlib import TEST_SERVER, create_test_app, get_csrf_token
 
 
 class NextUriTestCase(unittest.TestCase):
@@ -40,12 +39,7 @@ class NextUriTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
-
-        @self.app.get("/test-csrf")
-        def test_csrf() -> str:
-            """The test view to return the CSRF token."""
-            return render_template_string("{{csrf_token()}}")
+        self.app: Flask = create_test_app()
 
     def test_next_uri(self) -> None:
         """Tests the next URI utilities with the next URI.
@@ -69,7 +63,7 @@ class NextUriTestCase(unittest.TestCase):
                               methods=["GET", "POST"])
         client: httpx.Client = httpx.Client(app=self.app, base_url=TEST_SERVER)
         client.headers["Referer"] = TEST_SERVER
-        csrf_token: str = client.get("/test-csrf").text
+        csrf_token: str = get_csrf_token(client)
         response: httpx.Response
 
         response = client.get("/test-next?next=/next&q=abc&page-no=4")
@@ -98,7 +92,7 @@ class NextUriTestCase(unittest.TestCase):
                               methods=["GET", "POST"])
         client: httpx.Client = httpx.Client(app=self.app, base_url=TEST_SERVER)
         client.headers["Referer"] = TEST_SERVER
-        csrf_token: str = client.get("/test-csrf").text
+        csrf_token: str = get_csrf_token(client)
         response: httpx.Response
 
         response = client.get("/test-no-next?q=abc&page-no=4")
@@ -158,7 +152,7 @@ class PaginationTestCase(unittest.TestCase):
             :param items: All the items in the list.
             :param is_reversed: Whether the default page is the last page.
             :param result: The expected items on the page.
-            :param is_paged: Whether the pagination is needed.
+            :param is_paged: Whether we need pagination.
             """
             self.items: list[int] = items
             self.is_reversed: bool | None = is_reversed
@@ -171,7 +165,7 @@ class PaginationTestCase(unittest.TestCase):
 
         :return: None.
         """
-        self.app: Flask = create_app(is_testing=True)
+        self.app: Flask = create_test_app()
         self.params = self.Params([], None, [], True)
 
         @self.app.get("/test-pagination")
@@ -198,7 +192,7 @@ class PaginationTestCase(unittest.TestCase):
         :param query: The query string.
         :param items: The original items.
         :param result: The expected page content.
-        :param is_paged: Whether the pagination is needed.
+        :param is_paged: Whether we need pagination.
         :param is_reversed: Whether the list is reversed.
         :return: None.
         """
@@ -253,8 +247,8 @@ class PaginationTestCase(unittest.TestCase):
         self.__test_success("page-no=46&page-size=15", range(1, 687),
                             range(676, 687))
 
-    def test_not_needed(self) -> None:
-        """Tests the pagination that is not needed.
+    def test_not_need(self) -> None:
+        """Tests that the data does not need pagination.
 
         :return: None.
         """

tests/testlib.py

@@ -18,15 +18,46 @@
 
 """
 import typing as t
-from html.parser import HTMLParser
 
 import httpx
-from flask import Flask
+from flask import Flask, render_template_string
+
+from test_site import create_app
 
 TEST_SERVER: str = "https://testserver"
 """The test server URI."""
 
 
+def create_test_app() -> Flask:
+    """Creates and returns the testing Flask application.
+
+    :return: The testing Flask application.
+    """
+    app: Flask = create_app(is_testing=True)
+
+    @app.get("/.csrf-token")
+    def get_csrf_token_view() -> str:
+        """The test view to return the CSRF token."""
+        return render_template_string("{{csrf_token()}}")
+
+    @app.get("/.errors")
+    def get_errors_view() -> str:
+        """The test view to return the CSRF token."""
+        return render_template_string("{{get_flashed_messages()|tojson}}")
+
+    return app
+
+
+def get_csrf_token(client: httpx.Client) -> str:
+    """Returns the CSRF token.
+
+    :param client: The httpx client.
+    :return: The CSRF token.
+    """
+    return client.get("/.csrf-token").text
+
+
+
 def get_client(app: Flask, username: str) -> tuple[httpx.Client, str]:
     """Returns a user client.
 
@@ -36,7 +67,7 @@ def get_client(app: Flask, username: str) -> tuple[httpx.Client, str]:
     """
     client: httpx.Client = httpx.Client(app=app, base_url=TEST_SERVER)
     client.headers["Referer"] = TEST_SERVER
-    csrf_token: str = get_csrf_token(client, "/login")
+    csrf_token: str = get_csrf_token(client)
     response: httpx.Response = client.post("/login",
                                            data={"csrf_token": csrf_token,
                                                  "username": username})
@@ -45,38 +76,6 @@ def get_client(app: Flask, username: str) -> tuple[httpx.Client, str]:
     return client, csrf_token
 
 
-def get_csrf_token(client: httpx.Client, uri: str) -> str:
-    """Returns the CSRF token from a form in a URI.
-
-    :param client: The httpx client.
-    :param uri: The URI.
-    :return: The CSRF token.
-    """
-
-    class CsrfParser(HTMLParser):
-        """The CSRF token parser."""
-
-        def __init__(self):
-            """Constructs the CSRF token parser."""
-            super().__init__()
-            self.csrf_token: str | None = None
-            """The CSRF token."""
-
-        def handle_starttag(self, tag: str,
-                            attrs: list[tuple[str, str | None]]) -> None:
-            """Handles when a start tag is found."""
-            attrs_dict: dict[str, str] = dict(attrs)
-            if attrs_dict.get("name") == "csrf_token":
-                self.csrf_token = attrs_dict["value"]
-
-    response: httpx.Response = client.get(uri)
-    assert response.status_code == 200
-    parser: CsrfParser = CsrfParser()
-    parser.feed(response.text)
-    assert parser.csrf_token is not None
-    return parser.csrf_token
-
-
 def set_locale(client: httpx.Client, csrf_token: str,
                locale: t.Literal["en", "zh_Hant", "zh_Hans"]) -> None:
     """Sets the current locale.

tests/testlib_offset.py

@@ -0,0 +1,309 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/27
+
+#  Copyright (c) 2023 imacat.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+"""The common test libraries for the offset test cases.
+
+"""
+from __future__ import annotations
+
+from datetime import date, timedelta
+from decimal import Decimal
+
+import httpx
+from flask import Flask
+
+from test_site import db
+from testlib_txn import Accounts, match_txn_detail, NEXT_URI
+
+
+class JournalEntryData:
+    """The journal entry data."""
+
+    def __init__(self, account: str, summary: str, amount: str,
+                 original_entry: JournalEntryData | None = None):
+        """Constructs the journal entry data.
+
+        :param account: The account code.
+        :param summary: The summary.
+        :param amount: The amount.
+        :param original_entry: The original entry.
+        """
+        self.txn: TransactionData | None = None
+        self.id: int = -1
+        self.no: int = -1
+        self.original_entry: JournalEntryData | None = original_entry
+        self.account: str = account
+        self.summary: str = summary
+        self.amount: Decimal = Decimal(amount)
+
+    def form(self, prefix: str, entry_type: str, index: int, is_update: bool) \
+            -> dict[str, str]:
+        """Returns the journal entry as form data.
+
+        :param prefix: The prefix of the form fields.
+        :param entry_type: The entry type, either "debit" or "credit".
+        :param index: The entry index.
+        :param is_update: True for an update operation, or False otherwise
+        :return: The form data.
+        """
+        prefix = f"{prefix}-{entry_type}-{index}"
+        form: dict[str, str] = {f"{prefix}-account_code": self.account,
+                                f"{prefix}-summary": self.summary,
+                                f"{prefix}-amount": str(self.amount)}
+        if is_update and self.id != -1:
+            form[f"{prefix}-eid"] = str(self.id)
+        form[f"{prefix}-no"] = str(index) if self.no == -1 else str(self.no)
+        if self.original_entry is not None:
+            assert self.original_entry.id != -1
+            form[f"{prefix}-original_entry_id"] = str(self.original_entry.id)
+        return form
+
+
+class CurrencyData:
+    """The transaction currency data."""
+
+    def __init__(self, currency: str, debit: list[JournalEntryData],
+                 credit: list[JournalEntryData]):
+        """Constructs the transaction currency data.
+
+        :param currency: The currency code.
+        :param debit: The debit journal entries.
+        :param credit: The credit journal entries.
+        """
+        self.code: str = currency
+        self.debit: list[JournalEntryData] = debit
+        self.credit: list[JournalEntryData] = credit
+
+    def form(self, index: int, is_update: bool) -> dict[str, str]:
+        """Returns the currency as form data.
+
+        :param index: The currency index.
+        :param is_update: True for an update operation, or False otherwise
+        :return: The form data.
+        """
+        prefix: str = f"currency-{index}"
+        form: dict[str, str] = {f"{prefix}-code": self.code}
+        for i in range(len(self.debit)):
+            form.update(self.debit[i].form(prefix, "debit", i + 1, is_update))
+        for i in range(len(self.credit)):
+            form.update(self.credit[i].form(prefix, "credit", i + 1,
+                                            is_update))
+        return form
+
+
+class TransactionData:
+    """The transaction data."""
+
+    def __init__(self, days: int, currencies: list[CurrencyData]):
+        """Constructs a transaction.
+
+        :param days: The number of days before today.
+        :param currencies: The transaction currency data.
+        """
+        self.id: int = -1
+        self.days: int = days
+        self.currencies: list[CurrencyData] = currencies
+        self.note: str | None = None
+        for currency in self.currencies:
+            for entry in currency.debit:
+                entry.txn = self
+            for entry in currency.credit:
+                entry.txn = self
+
+    def new_form(self, csrf_token: str) -> dict[str, str]:
+        """Returns the transaction as a form.
+
+        :param csrf_token: The CSRF token.
+        :return: The transaction as a form.
+        """
+        return self.__form(csrf_token, is_update=False)
+
+    def update_form(self, csrf_token: str) -> dict[str, str]:
+        """Returns the transaction as a form.
+
+        :param csrf_token: The CSRF token.
+        :return: The transaction as a form.
+        """
+        return self.__form(csrf_token, is_update=True)
+
+    def __form(self, csrf_token: str, is_update: bool = False) \
+            -> dict[str, str]:
+        """Returns the transaction as a form.
+
+        :param csrf_token: The CSRF token.
+        :param is_update: True for an update operation, or False otherwise
+        :return: The transaction as a form.
+        """
+        txn_date: date = date.today() - timedelta(days=self.days)
+        form: dict[str, str] = {"csrf_token": csrf_token,
+                                "next": NEXT_URI,
+                                "date": txn_date.isoformat()}
+        for i in range(len(self.currencies)):
+            form.update(self.currencies[i].form(i + 1, is_update))
+        if self.note is not None:
+            form["note"] = self.note
+        return form
+
+
+class TestData:
+    """The test data."""
+
+    def __init__(self, app: Flask, client: httpx.Client, csrf_token: str):
+        """Constructs the test data.
+
+        :param app: The Flask application.
+        :param client: The client.
+        :param csrf_token: The CSRF token.
+        """
+        self.app: Flask = app
+        self.client: httpx.Client = client
+        self.csrf_token: str = csrf_token
+
+        def couple(summary: str, amount: str, debit: str, credit: str) \
+                -> tuple[JournalEntryData, JournalEntryData]:
+            """Returns a couple of debit-credit journal entries.
+
+            :param summary: The summary.
+            :param amount: The amount.
+            :param debit: The debit account code.
+            :param credit: The credit account code.
+            :return: The debit journal entry and credit journal entry.
+            """
+            return JournalEntryData(debit, summary, amount),\
+                JournalEntryData(credit, summary, amount)
+
+        # Receivable original entries
+        self.e_r_or1d, self.e_r_or1c = couple(
+            "Accountant", "1200", Accounts.RECEIVABLE, Accounts.SERVICE)
+        self.e_r_or2d, self.e_r_or2c = couple(
+            "Toy", "600", Accounts.RECEIVABLE, Accounts.SALES)
+        self.e_r_or3d, self.e_r_or3c = couple(
+            "Noodles", "100", Accounts.RECEIVABLE, Accounts.SALES)
+        self.e_r_or4d, self.e_r_or4c = couple(
+            "Interest", "3.4", Accounts.RECEIVABLE, Accounts.INTEREST)
+
+        # Payable original entries
+        self.e_p_or1d, self.e_p_or1c = couple(
+            "Airplane", "2000", Accounts.TRAVEL, Accounts.PAYABLE)
+        self.e_p_or2d, self.e_p_or2c = couple(
+            "Phone", "900", Accounts.OFFICE, Accounts.PAYABLE)
+        self.e_p_or3d, self.e_p_or3c = couple(
+            "Steak", "120", Accounts.MEAL, Accounts.PAYABLE)
+        self.e_p_or4d, self.e_p_or4c = couple(
+            "Envelop", "0.9", Accounts.OFFICE, Accounts.PAYABLE)
+
+        # Original transactions
+        self.t_r_or1: TransactionData = TransactionData(
+            50, [CurrencyData("USD", [self.e_r_or1d, self.e_r_or4d],
+                              [self.e_r_or1c, self.e_r_or4c])])
+        self.t_r_or2: TransactionData = TransactionData(
+            30, [CurrencyData("USD", [self.e_r_or2d, self.e_r_or3d],
+                              [self.e_r_or2c, self.e_r_or3c])])
+        self.t_p_or1: TransactionData = TransactionData(
+            40, [CurrencyData("USD", [self.e_p_or1d, self.e_p_or4d],
+                              [self.e_p_or1c, self.e_p_or4c])])
+        self.t_p_or2: TransactionData = TransactionData(
+            20, [CurrencyData("USD", [self.e_p_or2d, self.e_p_or3d],
+                              [self.e_p_or2c, self.e_p_or3c])])
+
+        self.__add_txn(self.t_r_or1)
+        self.__add_txn(self.t_r_or2)
+        self.__add_txn(self.t_p_or1)
+        self.__add_txn(self.t_p_or2)
+
+        # Receivable offset entries
+        self.e_r_of1d, self.e_r_of1c = couple(
+            "Accountant", "500", Accounts.CASH, Accounts.RECEIVABLE)
+        self.e_r_of1c.original_entry = self.e_r_or1d
+        self.e_r_of2d, self.e_r_of2c = couple(
+            "Accountant", "200", Accounts.CASH, Accounts.RECEIVABLE)
+        self.e_r_of2c.original_entry = self.e_r_or1d
+        self.e_r_of3d, self.e_r_of3c = couple(
+            "Accountant", "100", Accounts.CASH, Accounts.RECEIVABLE)
+        self.e_r_of3c.original_entry = self.e_r_or1d
+        self.e_r_of4d, self.e_r_of4c = couple(
+            "Toy", "240", Accounts.CASH, Accounts.RECEIVABLE)
+        self.e_r_of4c.original_entry = self.e_r_or2d
+        self.e_r_of5d, self.e_r_of5c = couple(
+            "Interest", "3.4", Accounts.CASH, Accounts.RECEIVABLE)
+        self.e_r_of5c.original_entry = self.e_r_or4d
+
+        # Payable offset entries
+        self.e_p_of1d, self.e_p_of1c = couple(
+            "Airplane", "800", Accounts.PAYABLE, Accounts.CASH)
+        self.e_p_of1d.original_entry = self.e_p_or1c
+        self.e_p_of2d, self.e_p_of2c = couple(
+            "Airplane", "300", Accounts.PAYABLE, Accounts.CASH)
+        self.e_p_of2d.original_entry = self.e_p_or1c
+        self.e_p_of3d, self.e_p_of3c = couple(
+            "Airplane", "100", Accounts.PAYABLE, Accounts.CASH)
+        self.e_p_of3d.original_entry = self.e_p_or1c
+        self.e_p_of4d, self.e_p_of4c = couple(
+            "Phone", "400", Accounts.PAYABLE, Accounts.CASH)
+        self.e_p_of4d.original_entry = self.e_p_or2c
+        self.e_p_of5d, self.e_p_of5c = couple(
+            "Envelop", "0.9", Accounts.PAYABLE, Accounts.CASH)
+        self.e_p_of5d.original_entry = self.e_p_or4c
+
+        # Offset transactions
+        self.t_r_of1: TransactionData = TransactionData(
+            25, [CurrencyData("USD", [self.e_r_of1d], [self.e_r_of1c])])
+        self.t_r_of2: TransactionData = TransactionData(
+            20, [CurrencyData("USD",
+                              [self.e_r_of2d, self.e_r_of3d, self.e_r_of4d],
+                              [self.e_r_of2c, self.e_r_of3c, self.e_r_of4c])])
+        self.t_r_of3: TransactionData = TransactionData(
+            15, [CurrencyData("USD", [self.e_r_of5d], [self.e_r_of5c])])
+        self.t_p_of1: TransactionData = TransactionData(
+            15, [CurrencyData("USD", [self.e_p_of1d], [self.e_p_of1c])])
+        self.t_p_of2: TransactionData = TransactionData(
+            10, [CurrencyData("USD",
+                              [self.e_p_of2d, self.e_p_of3d, self.e_p_of4d],
+                              [self.e_p_of2c, self.e_p_of3c, self.e_p_of4c])])
+        self.t_p_of3: TransactionData = TransactionData(
+            5, [CurrencyData("USD", [self.e_p_of5d], [self.e_p_of5c])])
+
+        self.__add_txn(self.t_r_of1)
+        self.__add_txn(self.t_r_of2)
+        self.__add_txn(self.t_r_of3)
+        self.__add_txn(self.t_p_of1)
+        self.__add_txn(self.t_p_of2)
+        self.__add_txn(self.t_p_of3)
+
+    def __add_txn(self, txn_data: TransactionData) -> None:
+        """Adds a transaction.
+
+        :param txn_data: The transaction data.
+        :return: None.
+        """
+        from accounting.models import Transaction
+        store_uri: str = "/accounting/transactions/store/transfer"
+
+        response: httpx.Response = self.client.post(
+            store_uri, data=txn_data.new_form(self.csrf_token))
+        assert response.status_code == 302
+        txn_id: int = match_txn_detail(response.headers["Location"])
+        txn_data.id = txn_id
+        with self.app.app_context():
+            txn: Transaction | None = db.session.get(Transaction, txn_id)
+            assert txn is not None
+            for i in range(len(txn.currencies)):
+                for j in range(len(txn.currencies[i].debit)):
+                    txn_data.currencies[i].debit[j].id \
+                        = txn.currencies[i].debit[j].id
+                for j in range(len(txn.currencies[i].credit)):
+                    txn_data.currencies[i].credit[j].id \
+                        = txn.currencies[i].credit[j].id

tests/testlib_txn.py

@@ -38,8 +38,12 @@ EMPTY_NOTE: str = " \n\n  "
 class Accounts:
     """The shortcuts to the common accounts."""
     CASH: str = "1111-001"
+    PETTY_CASH: str = "1112-001"
     BANK: str = "1113-001"
+    NOTES_RECEIVABLE: str = "1131-001"
+    RECEIVABLE: str = "1141-001"
     PREPAID: str = "1258-001"
+    NOTES_PAYABLE: str = "2131-001"
     PAYABLE: str = "2141-001"
     SALES: str = "4111-001"
     SERVICE: str = "4611-001"
@@ -47,7 +51,7 @@ class Accounts:
     OFFICE: str = "6153-001"
     TRAVEL: str = "6154-001"
     MEAL: str = "6172-001"
-    INTEREST: str = "4111-001"
+    INTEREST: str = "7111-001"
     DONATION: str = "7481-001"
     RENT: str = "7482-001"