From 7eda86bbc33ca424c3d2c9c47c05ead4826c3fde Mon Sep 17 00:00:00 2001
From: mohsentaba <s.hosseintaba98@gmail.com>
Date: Mon, 6 Apr 2026 08:49:28 +0330
Subject: [PATCH] resolve performance issue of book reference hadiths

using pagination for hadiths.
---
 apps/hadis/serializers/reference.py | 33 ++++++++++++++++++++++++++---
 apps/hadis/views/reference.py       | 15 ++++++++-----
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/apps/hadis/serializers/reference.py b/apps/hadis/serializers/reference.py
index ed3c0c3..4e37389 100644
--- a/apps/hadis/serializers/reference.py
+++ b/apps/hadis/serializers/reference.py
@@ -1,4 +1,5 @@
 from rest_framework import serializers
+from rest_framework.pagination import PageNumberPagination
 from django.utils.translation import get_language
 from .category import get_localized_text
 
@@ -115,9 +116,35 @@ class BookDetailSerializer(serializers.ModelSerializer):
         fields = ['id','title','rate','isbn','share_link','language','number_page','publisher','description','volume','slug','attribute','author','image','hadis']
 
     def get_hadis(self,obj):
-        references = obj.hadis_references.all()
-        hadis_list = [ref.hadis for ref in references if ref.hadis]
-        return HadisListSerializer(hadis_list,many=True, context=self.context).data
+        from apps.hadis.models import Hadis
+        # 1. Fetch related hadis QuerySet for better pagination efficiency
+        # We filter by status=True to ensure only visible hadises are returned
+        hadis_ids = obj.hadis_references.values_list('hadis', flat=True)
+        hadis_qs = Hadis.objects.filter(id__in=hadis_ids, status=True).order_by('id')
+
+        # 2. Initialize Pagination
+        paginator = PageNumberPagination()
+        paginator.page_size = 20 # Requirements: 20 per page
+
+        request = self.context.get("request")
+        
+        # 3. Paginate the QuerySet
+        paginated_hadis = paginator.paginate_queryset(hadis_qs, request)
+
+        if paginated_hadis is not None:
+            # 4. Serialize paginated items
+            serializer = HadisListSerializer(paginated_hadis, many=True, context=self.context)
+            
+            # 5. Build paginated response structure
+            return {
+                'count': paginator.page.paginator.count,
+                'next': paginator.get_next_link(),
+                'previous': paginator.get_previous_link(),
+                'results': serializer.data
+            }
+
+        # Fallback
+        return HadisListSerializer(hadis_qs, many=True, context=self.context).data
 
 
 
diff --git a/apps/hadis/views/reference.py b/apps/hadis/views/reference.py
index a0d5912..f5f0ba4 100644
--- a/apps/hadis/views/reference.py
+++ b/apps/hadis/views/reference.py
@@ -69,11 +69,16 @@ class BookDetailView(RetrieveAPIView):
         return super().get(request, *args, **kwargs)
 
     def get_queryset(self):
-        return BookReference.objects.filter(slug = self.kwargs.get('reference_slug'))
-        # .prefetch_related(
-        #     'authors__name',
-        #     'images__image',
-        # )
+        return (
+            BookReference.objects
+            .filter(slug = self.kwargs.get('reference_slug'))
+            .prefetch_related(
+                'attributes',
+                'authors',
+                'images',
+                'hadis_references__hadis'
+            )
+        )
 
 
 from django.db.models import Prefetch