Fixing Manually cascade delete M2M models when related model is deleted

care/facility/models/asset.py

@@ -2,6 +2,7 @@
 import uuid
 
 from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models import JSONField, Q
 
@@ -54,6 +55,15 @@ class RoomType(enum.Enum):
         null=True, blank=True, default=None, max_length=200
     )
 
+    def delete(self, *args):
+        if UserDefaultAssetLocation.objects.filter(location=self).exists():
+            error = f"Cannot delete AssetLocation {self} because they are referenced as `location` in UserDefaultAssetLocation records."
+            raise ValidationError(error)
+        if FacilityDefaultAssetLocation.objects.filter(location=self).exists():
+            error = f"Cannot delete AssetLocation {self} because they are referenced as `location` in FacilityDefaultAssetLocation records."
+            raise ValidationError(error)
+        return super().delete(*args)
+
 
 class AssetType(enum.Enum):
     INTERNAL = 50

care/facility/models/bed.py

@@ -59,6 +59,10 @@ def save(self, *args, **kwargs) -> None:
         return super().save(*args, **kwargs)
 
     def delete(self, *args, **kwargs) -> None:
+        if ConsultationBed.objects.filter(bed=self).exists():
+            error = f"Cannot delete Bed {self} because they are referenced as `bed` in ConsultationBed records."
+            raise ValidationError(error)
+
         AssetBed.objects.filter(bed=self).update(deleted=True)
         super().delete(*args, **kwargs)
 

care/facility/models/facility.py

@@ -1,6 +1,7 @@
 from django.conf import settings
 from django.contrib.auth import get_user_model
 from django.contrib.postgres.fields import ArrayField
+from django.core.exceptions import ValidationError
 from django.core.validators import MinValueValidator
 from django.db import models, transaction
 from django.db.models import IntegerChoices
@@ -302,14 +303,26 @@ def save(self, *args, **kwargs) -> None:
 
     @transaction.atomic
     def delete(self, *args):
-        from care.facility.models.asset import Asset, AssetLocation
+        from care.facility.models.asset import (
+            Asset,
+            AssetLocation,
+            FacilityDefaultAssetLocation,
+        )
+        from care.facility.models.patient_sample import PatientSample
 
+        if FacilityDefaultAssetLocation.objects.filter(facility=self).exists():
+            error = f"Cannot delete Facility {self} because they are referenced as `facility` in FacilityDefaultAssetLocation records."
+            raise ValidationError(error)
         AssetLocation.objects.filter(facility_id=self.id).update(deleted=True)
         Asset.objects.filter(
             current_location_id__in=AssetLocation._base_manager.filter(  # noqa: SLF001
                 facility_id=self.id
             ).values_list("id", flat=True)
         ).update(deleted=True)
+        FacilityUser.objects.filter(facility=self).delete()
+        PatientSample.objects.filter(testing_facility=self).update(
+            testing_facility=None
+        )
         return super().delete(*args)
 
     @property

care/facility/models/patient.py

@@ -3,6 +3,7 @@
 
 from dateutil.relativedelta import relativedelta
 from django.contrib.postgres.aggregates import ArrayAgg
+from django.core.exceptions import ValidationError
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
 from django.db.models import Case, F, Func, JSONField, Value, When
@@ -474,6 +475,14 @@ def save(self, *args, **kwargs) -> None:
         self._alias_recovery_to_recovered()
         super().save(*args, **kwargs)
 
+    def delete(self, *args):
+        from care.facility.models.patient_sample import PatientSample
+
+        if PatientSample.objects.filter(patient=self).exists():
+            error = f"Cannot delete PatientRegistration {self} because they are referenced as `patient` in PatientSample records."
+            raise ValidationError(error)
+        return super().delete(*args)
+
     def get_age(self) -> str:
         start = self.date_of_birth or date(self.year_of_birth, 1, 1)
         end = (self.death_datetime or timezone.now()).date()

care/facility/models/patient_consultation.py

@@ -1,4 +1,5 @@
 from django.contrib.postgres.fields import ArrayField
+from django.core.exceptions import ValidationError
 from django.core.validators import MinValueValidator
 from django.db import models
 from django.db.models import JSONField
@@ -264,6 +265,25 @@ def save(self, *args, **kwargs):
             self.patient.save(update_fields=["death_datetime"])
         super().save(*args, **kwargs)
 
+    def delete(self, *args):
+        from care.facility.models.bed import ConsultationBed
+        from care.facility.models.patient_investigation import InvestigationValue
+        from care.facility.models.patient_sample import PatientSample
+
+        if InvestigationValue.objects.filter(consultation=self).exists():
+            error = f"Cannot delete PatientConsultation {self.external_id} because they are referenced as `consultation` in InvestigationValue records."
+            raise ValidationError(error)
+
+        if PatientSample.objects.filter(consultation=self).exists():
+            error = f"Cannot delete PatientConsultation {self} because they are referenced as `consultation` in PatientSample records."
+            raise ValidationError(error)
+
+        if ConsultationBed.objects.filter(consultation=self).exists():
+            error = f"Cannot delete PatientConsultation {self} because they are referenced as `consultation` in ConsultationBed records."
+            raise ValidationError(error)
+
+        return super().delete(*args)
+
     class Meta:
         constraints = [
             models.CheckConstraint(

care/facility/models/patient_investigation.py

@@ -1,5 +1,6 @@
 from uuid import uuid4
 
+from django.core.exceptions import ValidationError
 from django.db import models
 
 from care.facility.models.patient_consultation import PatientConsultation
@@ -15,6 +16,12 @@ class PatientInvestigationGroup(BaseModel):
     def __str__(self) -> str:
         return self.name
 
+    def delete(self, *args):
+        if InvestigationValue.objects.filter(group=self).exists():
+            error = f"Cannot delete PatientInvestigationGroup {self.name} because they are referenced as `group` in InvestigationValue records."
+            raise ValidationError(error)
+        super().delete(*args)
+
 
 class PatientInvestigation(BaseModel):
     name = models.CharField(max_length=500, blank=False, null=False, unique=True)
@@ -32,6 +39,13 @@ def __str__(self) -> str:
         unit_part = f" in {self.unit}" if self.unit else ""
         return f"{self.name}{unit_part} as {self.investigation_type}"
 
+    def delete(self, *args):
+        if InvestigationValue.objects.filter(investigation=self).exists():
+            error = f"Cannot delete PatientInvestigation {self} because they are referenced as `investigation` in InvestigationValue records."
+
+            raise ValidationError(error)
+        return super().delete(*args)
+
 
 class InvestigationSession(BaseModel):
     external_id = models.UUIDField(
@@ -41,6 +55,12 @@ class InvestigationSession(BaseModel):
         User, null=False, blank=False, on_delete=models.PROTECT
     )
 
+    def delete(self, *args):
+        if InvestigationValue.objects.filter(session=self).exists():
+            error = f"Cannot delete InvestigationSession {self.external_id} because they are referenced as `session` in InvestigationValue records."
+            raise ValidationError(error)
+        return super().delete(*args)
+
     class Meta:
         indexes = [
             models.Index(