Added the account management.

src/accounting/account/forms.py

@@ -0,0 +1,130 @@
+# The Mia! Accounting Flask Project.
+# Author: imacat@mail.imacat.idv.tw (imacat), 2023/2/1
+
+#  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 account management.
+
+"""
+import sqlalchemy as sa
+from flask_wtf import FlaskForm
+from wtforms import StringField, BooleanField
+from wtforms.validators import DataRequired, ValidationError
+
+from accounting.base_account import BaseAccount
+from accounting.database import db, user_utils
+from accounting.locale import lazy_gettext
+from accounting.utils.random_id import new_id
+from accounting.utils.strip_text import strip_text
+from .models import Account
+
+
+class BaseAccountExists:
+    """The validator to check if the base account code exists."""
+
+    def __call__(self, form: FlaskForm, field: StringField) -> None:
+        if field.data == "":
+            return
+        if db.session.get(BaseAccount, field.data) is None:
+            raise ValidationError(lazy_gettext(
+                "The base account does not exist."))
+
+
+class AccountForm(FlaskForm):
+    """The form to create or edit an account."""
+    base_code = StringField(
+        filters=[strip_text],
+        validators=[
+            DataRequired(lazy_gettext("Please select the base account.")),
+            BaseAccountExists()])
+    """The code of the base account."""
+    title = StringField(
+        filters=[strip_text],
+        validators=[DataRequired(lazy_gettext("Please fill in the title"))])
+    """The title."""
+    is_offset_needed = BooleanField()
+    """Whether the the entries of this account need offsets."""
+
+    def populate_obj(self, obj: Account) -> None:
+        """Populates the form data into an account object.
+
+        :param obj: The account object.
+        :return: None.
+        """
+        is_new: bool = obj.id is None
+        prev_base_code: str | None = obj.base_code
+        if is_new:
+            obj.id = new_id(Account)
+        obj.base_code = self.base_code.data
+        if prev_base_code != self.base_code.data:
+            last_same_base: Account = Account.query\
+                .filter(Account.base_code == self.base_code.data)\
+                .order_by(Account.base_code.desc()).first()
+            obj.no = 1 if last_same_base is None else last_same_base.no + 1
+        obj.title = self.title.data
+        obj.is_offset_needed = self.is_offset_needed.data
+        if is_new:
+            current_user_pk: int = user_utils.get_pk(user_utils.current_user)
+            obj.created_by_id = current_user_pk
+            obj.updated_by_id = current_user_pk
+        if prev_base_code is not None \
+                and prev_base_code != self.base_code.data:
+            setattr(self, "__post_update",
+                    lambda: sort_accounts_in(prev_base_code, obj.id))
+
+    def post_update(self, obj) -> None:
+        """The post-processing after the update.
+
+        :return: None
+        """
+        current_user_pk: int = user_utils.get_pk(user_utils.current_user)
+        obj.updated_by_id = current_user_pk
+        obj.updated_at = sa.func.now()
+        if hasattr(self, "__post_update"):
+            getattr(self, "__post_update")()
+
+    @property
+    def selected_base(self) -> BaseAccount | None:
+        """The selected base account in the form.
+
+        :return: The selected base account in the form.
+        """
+        return db.session.get(BaseAccount, self.base_code.data)
+
+    @property
+    def base_options(self) -> list[BaseAccount]:
+        """The selectable base accounts.
+
+        :return: The selectable base accounts.
+        """
+        return BaseAccount.query\
+            .filter(sa.func.char_length(BaseAccount.code) == 4)\
+            .order_by(BaseAccount.code).all()
+
+
+def sort_accounts_in(base_code: str, exclude: int) -> None:
+    """Sorts the accounts under a base account after changing the base
+    account or deleting an account.
+
+    :param base_code: The code of the base account.
+    :param exclude: The account ID to exclude.
+    :return: None.
+    """
+    accounts: list[Account] = Account.query\
+        .filter(Account.base_code == base_code,
+                Account.id != exclude)\
+        .order_by(Account.no).all()
+    for i in range(len(accounts)):
+        if accounts[i].no != i + 1:
+            accounts[i].no = i + 1