Implemented the find_existing_equipments() utility, and applied it in the ledger in the accounting application.

accounting/models.py

@@ -326,6 +326,7 @@ class Record(DirtyFieldsMixin, models.Model):
         self._is_payable = None
         self._is_existing_equipment = None
         self.is_payable = False
+        self.is_existing_equipment = False
 
     def __str__(self):
         """Returns the string representation of this accounting
@@ -383,14 +384,3 @@ class Record(DirtyFieldsMixin, models.Model):
     @has_order_hole.setter
     def has_order_hole(self, value):
         self._has_order_hole = value
-
-    @property
-    def is_existing_equipment(self):
-        # TODO: To be done
-        if self._is_existing_equipment is None:
-            self._is_existing_equipment = False
-        return self._is_existing_equipment
-
-    @is_existing_equipment.setter
-    def is_existing_equipment(self, value):
-        self._is_existing_equipment = value

accounting/utils.py

@@ -352,6 +352,35 @@ def find_payable_records(account, records):
         x.is_payable = True
 
 
+def find_existing_equipments(account, records):
+    """Finds and sets the equipments that still exist.
+
+    Args:
+        account (Account): The current ledger account.
+        records (list[Record]): The accounting records.
+    """
+    if "EQUIPMENT_ACCOUNTS" not in settings.ACCOUNTING:
+        return
+    if not isinstance(settings.ACCOUNTING["EQUIPMENT_ACCOUNTS"], list):
+        return
+    if account.code not in settings.ACCOUNTING["EQUIPMENT_ACCOUNTS"]:
+        return
+    rows = Record.objects\
+        .filter(
+            account__code__in=settings.ACCOUNTING["EQUIPMENT_ACCOUNTS"],
+            summary__isnull=False)\
+        .values("account__code", "summary")\
+        .annotate(
+            balance=Sum(Case(When(is_credit=True, then=1), default=-1)
+                        * F("amount")))\
+        .filter(~Q(balance=0))
+    keys = ["%s-%s" % (x["account__code"], x["summary"]) for x in rows]
+    for x in [x for x in records
+              if x.pk is not None
+                 and F"{x.account.code}-{x.summary}" in keys]:
+        x.is_existing_equipment = True
+
+
 def get_summary_categories():
     """Finds and returns the summary categories and their corresponding account
     hints.

accounting/views.py

@@ -45,7 +45,7 @@ from .utils import ReportUrl, get_cash_accounts, get_ledger_accounts, \
     find_imbalanced, find_order_holes, fill_txn_from_post, \
     sort_post_txn_records, make_txn_form_from_status, \
     make_txn_form_from_model, make_txn_form_from_post, MonthlySummary, \
-    get_summary_categories, find_payable_records
+    get_summary_categories, find_payable_records, find_existing_equipments
 
 
 @method_decorator(require_GET, name="dispatch")
@@ -341,6 +341,7 @@ def ledger(request, account, period):
     find_imbalanced(records)
     find_order_holes(records)
     find_payable_records(account, records)
+    find_existing_equipments(account, records)
     return render(request, "accounting/ledger.html", {
         "item_list": records,
         "pagination": pagination,