fix: ensure completed lessons count does not exceed total lessons in CourseDetailSerializer

apps/course/serializers/course.py

@@ -234,7 +234,10 @@ class CourseDetailSerializer(serializers.ModelSerializer):
         if student := self._get_authenticated_user():
             if not self._is_participant(student, obj):
                 return None
-            return self._get_completed_lessons_count(student, obj)        
+            completed_count = self._get_completed_lessons_count(student, obj)
+            # Ensure completed count doesn't exceed total lessons count
+            total_lessons = self.get_lessons_count(obj)
+            return min(completed_count, total_lessons)
         return None
         
     def _is_participant(self, student, course):
@@ -296,10 +299,11 @@ class CourseDetailSerializer(serializers.ModelSerializer):
 class MyCourseListSerializer(serializers.ModelSerializer):
     category = CourseCategorySerializer()
     thumbnail = serializers.SerializerMethodField()
+    lessons_count = serializers.SerializerMethodField()
     lessons_complated_count = serializers.SerializerMethodField()
 
     class Meta:
-        model = Course        
+        model = Course
         fields = [
             'id',
             'title',
@@ -314,12 +318,25 @@ class MyCourseListSerializer(serializers.ModelSerializer):
 
     def get_thumbnail(self, obj):
         return get_thumbs(obj.thumbnail, self.context.get('request'))
-    
+
+    def get_lessons_count(self, obj):
+        """Get the actual count of active lessons"""
+        # Use prefetched lessons if available
+        if hasattr(obj, 'lessons') and obj.lessons.all():
+            lessons_count = sum(1 for lesson in obj.lessons.all() if lesson.is_active)
+            return max(lessons_count, obj.lessons_count)
+        # Fallback to direct query
+        lessons_count = obj.lessons.filter(is_active=True).count()
+        return max(lessons_count, obj.lessons_count)
+
     def get_lessons_complated_count(self, obj):
         if student := self._get_authenticated_user():
             if not self._is_participant(student, obj):
                 return None
-            return self._get_completed_lessons_count(student, obj)        
+            completed_count = self._get_completed_lessons_count(student, obj)
+            # Ensure completed count doesn't exceed total lessons count
+            total_lessons = self.get_lessons_count(obj)
+            return min(completed_count, total_lessons)
         return None
         
     def _is_participant(self, student, course):