control one permission with same name for each page

apps/authorization/api/v1/api.py

@@ -1,5 +1,6 @@
 from rest_framework_simplejwt.authentication import JWTAuthentication
 from rest_framework.permissions import AllowAny, IsAuthenticated
+from apps.core.exceptions import ConflictException
 from rest_framework.exceptions import APIException
 from apps.authorization.api.v1.serializers import (
     RoleSerializer,
@@ -64,6 +65,16 @@ class PermissionViewSet(viewsets.ModelViewSet):
     filter_backends = [filters.SearchFilter]
     search_fields = ['page__name', ]
 
+    def create(self, request, *args, **kwargs):
+        if self.queryset.filter(name=request.data['name'], page_id=request.data['page']).exists():
+            raise ConflictException('a permission with this page exists.')
+        serializer = self.serializer_class(data=request.data)
+        if serializer.is_valid():
+            serializer.save()
+            return Response(serializer.data, status=status.HTTP_200_OK)
+        else:
+            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
+
 
 class UserRelationViewSet(viewsets.ModelViewSet):
     """ Crud Operations for User Relations """

apps/authorization/migrations/0017_alter_permissions_name.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.0 on 2025-06-08 11:10
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('authorization', '0016_alter_permissions_name'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='permissions',
+            name='name',
+            field=models.CharField(max_length=50),
+        ),
+    ]

apps/authorization/models.py

@@ -21,7 +21,7 @@ class Page(BaseModel):
 class Permissions(BaseModel):
     """ permission level of users """
 
-    name = models.CharField(max_length=50, unique=True)
+    name = models.CharField(max_length=50)
     description = models.TextField(max_length=500)
     category_choices = (
         ('api', 'Api'),

apps/core/exceptions.py

@@ -4,3 +4,12 @@
     you can check out the Django Rest Framework documentation at:
     https://www.django-rest-framework.org/api-guide/exceptions/#custom-exception-handling
 """
+
+from rest_framework.exceptions import APIException
+from rest_framework import status
+
+
+class ConflictException(APIException):
+    status_code = status.HTTP_409_CONFLICT
+    default_detail = "Object already exists."
+    default_code = "conflict"