Add SimilarArticleSerializer and enhance ArticleDetailSerializer with similar articles feature

- Introduced `SimilarArticleSerializer` to provide a structured representation of similar articles, including categories and thumbnail.
- Updated `ArticleDetailSerializer` to include a new `similar_articles` field, which fetches articles from the same categories, excluding the current article.
- Implemented a method to retrieve similar articles, improving the article detail view with relevant content suggestions.

apps/article/serializers.py

@@ -72,6 +72,19 @@ class ArticleContentSerializer(serializers.ModelSerializer):
         model = ArticleContent
         fields = ['id', 'title', 'content', 'priority', 'status', 'created_at', 'updated_at', 'parts']
 
+class SimilarArticleSerializer(serializers.ModelSerializer):
+    categories = ArticleCategoryListSerializer(many=True, read_only=True)
+    thumbnail = serializers.SerializerMethodField()
+    share_link = serializers.CharField(read_only=True)
+
+    class Meta:
+        model = Article
+        fields = ['title', 'slug', 'thumbnail', 'categories', 'share_link', 'created_at']
+
+    def get_thumbnail(self, obj):
+        return get_thumbs(obj.thumbnail, self.context.get('request'))
+
+
 class ArticleDetailSerializer(serializers.ModelSerializer):
     categories = ArticleCategoryListSerializer(many=True, read_only=True)
     thumbnail = serializers.SerializerMethodField()
@@ -80,12 +93,14 @@ class ArticleDetailSerializer(serializers.ModelSerializer):
     average_rate = serializers.SerializerMethodField()
     article_content = serializers.SerializerMethodField()
     share_link = serializers.CharField(read_only=True)
+    similar_articles = serializers.SerializerMethodField()
     
     class Meta:
         model = Article
         fields = ['id', 'title', 'slug', 'thumbnail', 'description', 
                   'article_file', 'view_count', 'download_count',
-                  'categories', 'created_at', 'user_rate', 'average_rate', 'bookmark', 'article_content', 'share_link']
+                  'categories', 'created_at', 'user_rate', 'average_rate', 'bookmark', 'article_content', 'share_link',
+                  'similar_articles']
 
     def get_thumbnail(self, obj):
         return get_thumbs(obj.thumbnail, self.context.get('request'))
@@ -141,6 +156,17 @@ class ArticleDetailSerializer(serializers.ModelSerializer):
             content_id=obj.id
         )
 
+    def get_similar_articles(self, obj):
+        category_ids = obj.categories.values_list('id', flat=True)
+        similar = (
+            Article.objects
+            .filter(categories__id__in=category_ids, status=True)
+            .exclude(id=obj.id)
+            .distinct()
+            .order_by('-created_at')[:3]
+        )
+        return SimilarArticleSerializer(similar, many=True, context=self.context).data
+
     def get_article_content(self, obj):
         """
         Get the content of the article.