refactor: Combine promo list and create endpoints

Replaced separate views for listing and creating company promos
with a single CompanyPromoListCreateView based on ListCreateAPIView.

This simplifies the API by handling GET and POST requests for promos
at a single URL endpoint (`api/business/promo`).

- Uses get_serializer_class for appropriate request methods.
- Moved query param validation into the list method.
- Updated urls.py to point to the new combined view.
- Remove redundant imports in serializers.

Author: RandomProgramm3r

promo_code/business/serializers.py

@@ -12,7 +12,6 @@
 
 import business.constants
 import business.models
-import business.models as business_models
 import business.utils.auth
 import business.utils.tokens
 import business.validators
@@ -46,12 +45,12 @@ class CompanySignUpSerializer(rest_framework.serializers.ModelSerializer):
     )
 
     class Meta:
-        model = business_models.Company
+        model = business.models.Company
         fields = ('id', 'name', 'email', 'password')
 
     @django.db.transaction.atomic
     def create(self, validated_data):
-        company = business_models.Company.objects.create_company(
+        company = business.models.Company.objects.create_company(
             **validated_data,
         )
 
@@ -76,8 +75,8 @@ def validate(self, attrs):
             )
 
         try:
-            company = business_models.Company.objects.get(email=email)
-        except business_models.Company.DoesNotExist:
+            company = business.models.Company.objects.get(email=email)
+        except business.models.Company.DoesNotExist:
             raise rest_framework.serializers.ValidationError(
                 'Invalid credentials.',
             )
@@ -227,7 +226,7 @@ class PromoCreateSerializer(rest_framework.serializers.ModelSerializer):
     )
 
     class Meta:
-        model = business_models.Promo
+        model = business.models.Promo
         fields = (
             'url',
             'description',
@@ -251,7 +250,7 @@ def create(self, validated_data):
         promo_common = validated_data.pop('promo_common', None)
         promo_unique = validated_data.pop('promo_unique', None)
 
-        return business_models.Promo.objects.create_promo(
+        return business.models.Promo.objects.create_promo(
             user=self.context['request'].user,
             target_data=target_data,
             promo_common=promo_common,
@@ -418,7 +417,7 @@ class PromoReadOnlySerializer(rest_framework.serializers.ModelSerializer):
     )
 
     class Meta:
-        model = business_models.Promo
+        model = business.models.Promo
         fields = (
             'promo_id',
             'company_id',
@@ -484,7 +483,7 @@ class PromoDetailSerializer(rest_framework.serializers.ModelSerializer):
     )
 
     class Meta:
-        model = business_models.Promo
+        model = business.models.Promo
         fields = (
             'promo_id',
             'description',

promo_code/business/urls.py

@@ -22,14 +22,9 @@
         name='company-token-refresh',
     ),
     django.urls.path(
-        'promo/create',
-        business.views.PromoCreateView.as_view(),
-        name='promo-create',
-    ),
-    django.urls.path(
-        'promo/list',
-        business.views.CompanyPromoListView.as_view(),
-        name='company-promo-list',
+        'promo',
+        business.views.CompanyPromoListCreateView.as_view(),
+        name='promo-list-create',
     ),
     django.urls.path(
         'promo/<uuid:id>',

promo_code/business/views.py

@@ -62,73 +62,75 @@ class CompanyTokenRefreshView(rest_framework_simplejwt.views.TokenRefreshView):
     serializer_class = business.serializers.CompanyTokenRefreshSerializer
 
 
-class PromoCreateView(rest_framework.generics.CreateAPIView):
+class CompanyPromoListCreateView(rest_framework.generics.ListCreateAPIView):
     """
-    View for creating a new promo (POST).
+    View for listing (GET) and creating (POST) company promos.
     """
 
     permission_classes = [
         rest_framework.permissions.IsAuthenticated,
         business.permissions.IsCompanyUser,
     ]
-    serializer_class = business.serializers.PromoCreateSerializer
-
-    def perform_create(self, serializer):
-        return serializer.save()
-
-    def create(self, request, *args, **kwargs):
-        serializer = self.get_serializer(data=request.data)
-
-        serializer.is_valid(raise_exception=True)
-
-        instance = self.perform_create(serializer)
-
-        headers = self.get_success_headers(serializer.data)
-
-        response_data = {'id': str(instance.id)}
-
-        return rest_framework.response.Response(
-            response_data,
-            status=rest_framework.status.HTTP_201_CREATED,
-            headers=headers,
-        )
+    # Pagination is only needed for GET (listing)
+    pagination_class = business.pagination.CustomLimitOffsetPagination
 
+    _validated_query_params = {}
 
-class CompanyPromoListView(rest_framework.generics.ListAPIView):
-    permission_classes = [
-        rest_framework.permissions.IsAuthenticated,
-        business.permissions.IsCompanyUser,
-    ]
-    serializer_class = business.serializers.PromoReadOnlySerializer
-    pagination_class = business.pagination.CustomLimitOffsetPagination
+    def get_serializer_class(self):
+        if self.request.method == 'POST':
+            return business.serializers.PromoCreateSerializer
 
-    def initial(self, request, *args, **kwargs):
-        super().initial(request, *args, **kwargs)
+        return business.serializers.PromoReadOnlySerializer
 
-        serializer = business.serializers.PromoListQuerySerializer(
+    def list(self, request, *args, **kwargs):
+        query_serializer = business.serializers.PromoListQuerySerializer(
             data=request.query_params,
         )
-        serializer.is_valid(raise_exception=True)
-        request.validated_query_params = serializer.validated_data
+        query_serializer.is_valid(raise_exception=True)
+        self._validated_query_params = query_serializer.validated_data
+
+        return super().list(request, *args, **kwargs)
 
     def get_queryset(self):
-        params = self.request.validated_query_params
+        params = self._validated_query_params
         countries = [c.upper() for c in params.get('countries', [])]
         sort_by = params.get('sort_by')
 
         queryset = business.models.Promo.objects.for_company(self.request.user)
 
         if countries:
+            # Using a regular expression for case-insensitive searching
             regex_pattern = r'(' + '|'.join(map(re.escape, countries)) + ')'
+            country_filter = django.db.models.Q(
+                target__country__iregex=regex_pattern,
+            )
+
+            # Include promos where the country is not specified
             queryset = queryset.filter(
-                django.db.models.Q(target__country__iregex=regex_pattern)
+                country_filter
                 | django.db.models.Q(target__country__isnull=True),
             )
 
         ordering = f'-{sort_by}' if sort_by else '-created_at'
 
         return queryset.order_by(ordering)
 
+    def perform_create(self, serializer):
+        return serializer.save()
+
+    def create(self, request, *args, **kwargs):
+        serializer = self.get_serializer(data=request.data)
+        serializer.is_valid(raise_exception=True)
+        instance = self.perform_create(serializer)
+        headers = self.get_success_headers(serializer.data)
+        response_data = {'id': str(instance.id)}
+
+        return rest_framework.response.Response(
+            response_data,
+            status=rest_framework.status.HTTP_201_CREATED,
+            headers=headers,
+        )
+
 
 class CompanyPromoDetailView(rest_framework.generics.RetrieveUpdateAPIView):
     """