Add validation for override receivabletype update

leasing/enums.py

@@ -659,6 +659,16 @@ class Labels:
         KUVA_NUP = "KuVa / Nuorisopalvelut"
 
 
+def is_akv_or_kuva_service_unit_id(service_unit_id: int) -> bool:
+    akv_kuva_service_unit_ids = [
+        ServiceUnitId.AKV,
+        ServiceUnitId.KUVA_LIPA,
+        ServiceUnitId.KUVA_UPA,
+        ServiceUnitId.KUVA_NUP,
+    ]
+    return service_unit_id in akv_kuva_service_unit_ids
+
+
 class SapSalesOfficeNumber(Enum):
     """
     In Finnish: SAP myyntitoimiston numero

leasing/serializers/rent.py

@@ -5,32 +5,39 @@
 from rest_framework.serializers import ListSerializer
 
 from field_permissions.serializers import FieldPermissionsSerializerMixin
-from leasing.enums import DueDatesType, RentAdjustmentAmountType, RentCycle, RentType
-from leasing.models import Index, ReceivableType
-from leasing.models.rent import (
-    EqualizedRent,
-    LeaseBasisOfRentManagementSubvention,
-    LeaseBasisOfRentTemporarySubvention,
-    ManagementSubvention,
-    ManagementSubventionFormOfManagement,
-    TemporarySubvention,
+from leasing.enums import (
+    DueDatesType,
+    RentAdjustmentAmountType,
+    RentCycle,
+    RentType,
+    is_akv_or_kuva_service_unit_id,
 )
-from leasing.serializers.receivable_type import ReceivableTypeSerializer
-from leasing.serializers.utils import validate_seasonal_day_for_month
-from users.serializers import UserSerializer
-
-from ..models import (
+from leasing.models import (
     ContractRent,
     Decision,
     FixedInitialYearRent,
+    Index,
     IndexAdjustedRent,
     LeaseBasisOfRent,
     PayableRent,
+    ReceivableType,
     Rent,
     RentAdjustment,
     RentDueDate,
     RentIntendedUse,
 )
+from leasing.models.rent import (
+    EqualizedRent,
+    LeaseBasisOfRentManagementSubvention,
+    LeaseBasisOfRentTemporarySubvention,
+    ManagementSubvention,
+    ManagementSubventionFormOfManagement,
+    TemporarySubvention,
+)
+from leasing.serializers.receivable_type import ReceivableTypeSerializer
+from leasing.serializers.utils import validate_seasonal_day_for_month
+from users.serializers import UserSerializer
+
 from .decision import DecisionSerializer
 from .utils import (
     DayMonthField,
@@ -538,12 +545,18 @@ class Meta:
             "override_receivable_type",
         )
 
-    def validate(self, data):
+    def validate(self, rent_data: dict):
+        self.validate_seasonal_values(rent_data)
+        self.validate_override_receivable_type_value(rent_data)
+        return rent_data
+
+    def validate_seasonal_values(self, rent_data: dict) -> None:
+        """Raises: serializers.ValidationError"""
         seasonal_values = [
-            data.get("seasonal_start_day"),
-            data.get("seasonal_start_month"),
-            data.get("seasonal_end_day"),
-            data.get("seasonal_end_month"),
+            rent_data.get("seasonal_start_day"),
+            rent_data.get("seasonal_start_month"),
+            rent_data.get("seasonal_end_day"),
+            rent_data.get("seasonal_end_month"),
         ]
 
         if not all(v is None for v in seasonal_values) and any(
@@ -553,7 +566,10 @@ def validate(self, data):
                 _("All seasonal values are required if one is set")
             )
 
-        if all(seasonal_values) and data.get("due_dates_type") != DueDatesType.CUSTOM:
+        if (
+            all(seasonal_values)
+            and rent_data.get("due_dates_type") != DueDatesType.CUSTOM
+        ):
             raise serializers.ValidationError(
                 _("Due dates type must be custom if seasonal dates are set")
             )
@@ -562,7 +578,63 @@ def validate(self, data):
         validate_seasonal_day_for_month(start_day, start_month)
         validate_seasonal_day_for_month(end_day, end_month)
 
-        return data
+    def validate_override_receivable_type_value(self, rent_data: dict) -> None:
+        """
+        Override receivabletype is mandatory for AKV and KuVa leases, and not
+        used by MaKe/Tontit.
+
+        It is only used in index rents, fixed rents, and manual rents, because
+        these rent types can generate automatic invoices.
+
+        Raises: serializers.ValidationError
+        """
+        override_receivable_type = rent_data.get("override_receivable_type")
+
+        if not override_receivable_type:
+            # Empty override receivabletype input should be allowed, because it
+            # is always empty for all MaKe rents, and those must be allowed.
+            return
+
+        elif not is_akv_or_kuva_service_unit_id(
+            override_receivable_type.service_unit_id
+        ):
+            # All MaKe receivabletypes should be rejected regardless of rent
+            # type, because MaKe doesn't use the override feature, and if any
+            # other service unit would use MaKe's receivabletypes, it would be
+            # a mistake.
+            raise serializers.ValidationError(
+                _(
+                    f'Override receivabletype "{override_receivable_type.name}" was unexpected. '
+                    "Override receivabletype is not used by MaKe/Tontit."
+                )
+            )
+
+        elif is_akv_or_kuva_service_unit_id(override_receivable_type.service_unit_id):
+            rent_type = rent_data.get("type", {})
+
+            if rent_type in [
+                RentType.INDEX,
+                RentType.INDEX2022,
+                RentType.FIXED,
+                RentType.MANUAL,
+            ]:
+                # These rent types can generate automatic invoices, so they can
+                # utilize the override receivabletype.
+                return
+            else:
+                raise serializers.ValidationError(
+                    _(
+                        f'Override receivabletype "{override_receivable_type.name}" was unexpected. '
+                        f'Rent type "{rent_type.name}" does not generate automatic invoices.'
+                    )
+                )
+
+        else:
+            raise serializers.ValidationError(
+                _(
+                    "Unhandled case in override receivabletype validation. Rejecting just in case."
+                )
+            )
 
 
 class LeaseBasisOfRentManagementSubventionSerializer(serializers.ModelSerializer):

leasing/serializers/utils.py

@@ -308,7 +308,8 @@ def get_file_filename(self, obj):
         return os.path.basename(obj.file.name)
 
 
-def validate_seasonal_day_for_month(day: int | None, month: int | None):
+def validate_seasonal_day_for_month(day: int | None, month: int | None) -> None:
+    """Raises: serializers.ValidationError"""
     if day is None and month is None:
         return
 

leasing/tests/serializers/test_rent.py

@@ -0,0 +1,83 @@
+import pytest
+from rest_framework.exceptions import ValidationError
+
+from leasing.enums import RentType, ServiceUnitId
+from leasing.models import ServiceUnit
+from leasing.serializers.rent import RentCreateUpdateSerializer
+
+
+@pytest.mark.django_db
+def test_is_valid_override_receivable_type(django_db_setup, receivable_type_factory):
+    """
+    Test that the requirements described in the target function docstring hold.
+    """
+    make = ServiceUnit.objects.get(pk=ServiceUnitId.MAKE)
+    akv = ServiceUnit.objects.get(pk=ServiceUnitId.AKV)
+    kuva_lipa = ServiceUnit.objects.get(pk=ServiceUnitId.KUVA_LIPA)
+    kuva_upa = ServiceUnit.objects.get(pk=ServiceUnitId.KUVA_UPA)
+    kuva_nup = ServiceUnit.objects.get(pk=ServiceUnitId.KUVA_NUP)
+
+    serializer = RentCreateUpdateSerializer()
+
+    # Validator should reject all MaKe receivable types regardless of rent type.
+    rent_datas_make = [
+        {
+            "type": rent_type,
+            "override_receivable_type": receivable_type_factory(service_unit=make),
+        }
+        for rent_type in RentType
+    ]
+    for data in rent_datas_make:
+        with pytest.raises(ValidationError):
+            serializer.validate(data)
+
+    # Validator should allow empty override receivable type input.
+    rent_datas_empty = [
+        {
+            "type": rent_type,
+            "override_receivable_type": None,
+        }
+        for rent_type in RentType
+    ]
+    for data in rent_datas_empty:
+        assert serializer.validate(data)
+
+    # Validator should allow AKV and KuVa receivable types, if rent type is valid.
+    rent_datas_akv_and_kuva = [
+        {
+            "type": RentType.INDEX2022,
+            "override_receivable_type": receivable_type_factory(service_unit=unit),
+        }
+        for unit in [akv, kuva_lipa, kuva_upa, kuva_nup]
+    ]
+    for data in rent_datas_akv_and_kuva:
+        assert serializer.validate(data)
+
+    # Validator should allow rent types that can generate automatic invoices.
+    rent_datas_valid_types = [
+        {
+            "type": rent_type,
+            "override_receivable_type": receivable_type_factory(service_unit=akv),
+        }
+        for rent_type in [
+            RentType.FIXED,
+            RentType.INDEX,
+            RentType.INDEX2022,
+            RentType.MANUAL,
+        ]
+    ]
+    for data in rent_datas_valid_types:
+        assert serializer.validate(data)
+
+    # Validator should reject the receivable type input for rent types that
+    # don't generate automatic invoices.
+    rent_datas_invalid_types = [
+        {
+            "type": rent_type,
+            "override_receivable_type": receivable_type_factory(service_unit=akv),
+        }
+        for rent_type in [RentType.FREE, RentType.ONE_TIME]
+    ]
+    for data in rent_datas_invalid_types:
+        with pytest.raises(ValidationError):
+            serializer.validate(data)