feat: Switch total_deposits() implementation to use Ledger function

ENT-9075

enterprise_subsidy/apps/api/v1/serializers.py

@@ -28,7 +28,7 @@ class SubsidySerializer(serializers.ModelSerializer):
     """
     current_balance = serializers.SerializerMethodField(help_text="The current (remaining) balance of this subsidy.")
     is_active = serializers.BooleanField(read_only=True, help_text="Whether this subsidy is currently active.")
-    total_deposits = serializers.SerializerMethodField(
+    total_deposits = serializers.IntegerField(
         help_text="The aggregate of the initial balance plus all adjustments made on the subsidy in usd cents"
     )
 
@@ -68,10 +68,6 @@ class Meta:
     def get_current_balance(self, obj) -> int:
         return obj.current_balance()
 
-    @extend_schema_field(serializers.IntegerField)
-    def get_total_deposits(self, obj) -> int:
-        return obj.total_deposits()
-
 
 class ReversalSerializer(serializers.ModelSerializer):
     """

enterprise_subsidy/apps/api/v1/tests/test_views.py

@@ -274,7 +274,7 @@ def test_get_adjustments_related_subsidy(self):
             "internal_only": False,
             "revenue_category": RevenueCategoryChoices.BULK_ENROLLMENT_PREPAY,
             "is_active": True,
-            "total_deposits": self.subsidy_5.total_deposits(),
+            "total_deposits": self.subsidy_5.total_deposits,
         }
         total_deposits_including_positive_adjustment = sum(
             [self.subsidy_5.starting_balance, APITestBase.adjustment_quantity_1]
@@ -312,7 +312,7 @@ def test_get_adjustments_related_subsidy(self):
             "internal_only": False,
             "revenue_category": RevenueCategoryChoices.BULK_ENROLLMENT_PREPAY,
             "is_active": True,
-            "total_deposits": self.subsidy_5.total_deposits(),
+            "total_deposits": self.subsidy_5.total_deposits,
         }
 
         total_deposits_including_negative_adjustment = sum(

enterprise_subsidy/apps/subsidy/models.py

@@ -21,7 +21,7 @@
 from edx_rbac.utils import ALL_ACCESS_CONTEXT
 from model_utils.models import TimeStampedModel
 from openedx_ledger import api as ledger_api
-from openedx_ledger.models import Adjustment, Ledger, TransactionStateChoices, UnitChoices
+from openedx_ledger.models import Ledger, TransactionStateChoices, UnitChoices
 from openedx_ledger.utils import create_idempotency_key_for_transaction
 from requests.exceptions import HTTPError
 from rest_framework import status
@@ -114,6 +114,8 @@ class Meta:
         Metaclass for Subsidy.
         """
         ordering = ['-created']
+        verbose_name = 'Subsidy'
+        verbose_name_plural = 'Subsidies'
 
     # Please reserve the "subsidy_type" field name for the future when we use it to distinguish between
     # LearnerCreditSubsidy vs. SubscriptionSubsidy.
@@ -349,19 +351,17 @@ def price_for_content(self, content_key):
     def current_balance(self):
         return self.ledger.balance()
 
+    @property
     def total_deposits(self):
         """
-        Returns the sum of all adjustments for the subsidy + the starting balance in USD cents.
+        Returns the sum of all value added to the subsidy.
+
+        At the time of writing, this includes both deposits AND positive adjustments.
 
         Returns:
-            int: Sum of all adjustments and the starting balance in USD cents.
-        """
-        adjustments_for_subsidy = Adjustment.objects.filter(ledger=self.ledger)
-        total_deposits = sum([
-            adjustment.transaction.quantity
-            for adjustment in adjustments_for_subsidy
-        ], self.starting_balance)
-        return total_deposits
+            int: Sum of all value added to the subsidy, in USD cents.
+        """
+        return self.ledger.total_deposits()
 
     def create_transaction(
         self,