v0.0.7 | 블로그 기능 개선

- Post 모델 개선 (author_id, updated_at, view_count 등)
- Tag 모델 및 태그 기능 추가
- 댓글 기능 추가
- API 확장

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

blog/serializers.py

@@ -1,10 +1,110 @@
 # blog/serializers.py
 
 from rest_framework import serializers
-from .models import Post
+from .models import Post, Comment, Tag
+
+
+class TagSerializer(serializers.ModelSerializer):
+    """태그 시리얼라이저"""
+    post_count = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Tag
+        fields = ['id', 'name', 'post_count']
+        read_only_fields = ['id']
+
+    def get_post_count(self, obj):
+        return obj.posts.count()
+
+
+class CommentSerializer(serializers.ModelSerializer):
+    """댓글/대댓글 시리얼라이저"""
+    replies = serializers.SerializerMethodField()
+    reply_count = serializers.SerializerMethodField()
+
+    class Meta:
+        model = Comment
+        fields = [
+            'id', 'post', 'parent', 'content',
+            'author_id', 'author_name',
+            'created_at', 'updated_at',
+            'reply_count', 'replies'
+        ]
+        read_only_fields = ['author_id', 'author_name', 'post', 'created_at', 'updated_at']
+
+    def get_replies(self, obj):
+        # 최상위 댓글의 대댓글만 반환
+        if obj.parent is None:
+            replies = obj.replies.all()
+            return CommentSerializer(replies, many=True, context=self.context).data
+        return []
+
+    def get_reply_count(self, obj):
+        if obj.parent is None:
+            return obj.replies.count()
+        return 0
+
 
 class PostSerializer(serializers.ModelSerializer):
+    comment_count = serializers.SerializerMethodField()
+    tags = TagSerializer(many=True, read_only=True)
+    tag_names = serializers.ListField(
+        child=serializers.CharField(max_length=50),
+        write_only=True,
+        required=False
+    )
+
     class Meta:
         model = Post
-        fields = ['id', 'title', 'content', 'author_name', 'created_at']
-        read_only_fields = ['author_name', 'created_at']
+        fields = [
+            'id', 'title', 'content',
+            'author_id', 'author_name',
+            'created_at', 'updated_at',
+            'comment_count', 'tags', 'tag_names'
+        ]
+        read_only_fields = ['author_id', 'author_name', 'created_at', 'updated_at']
+
+    def get_comment_count(self, obj):
+        return obj.comments.count()
+
+    def create(self, validated_data):
+        tag_names = validated_data.pop('tag_names', [])
+        post = Post.objects.create(**validated_data)
+        self._set_tags(post, tag_names)
+        return post
+
+    def update(self, instance, validated_data):
+        tag_names = validated_data.pop('tag_names', None)
+        for attr, value in validated_data.items():
+            setattr(instance, attr, value)
+        instance.save()
+        if tag_names is not None:
+            self._set_tags(instance, tag_names)
+        return instance
+
+    def _set_tags(self, post, tag_names):
+        """태그 설정 (없으면 생성)"""
+        tags = []
+        for name in tag_names:
+            name = name.strip().lower()
+            if name:
+                tag, _ = Tag.objects.get_or_create(name=name)
+                tags.append(tag)
+        post.tags.set(tags)
+
+
+class PostListSerializer(serializers.ModelSerializer):
+    """목록 조회용 간소화된 시리얼라이저"""
+    comment_count = serializers.SerializerMethodField()
+    tags = TagSerializer(many=True, read_only=True)
+
+    class Meta:
+        model = Post
+        fields = [
+            'id', 'title',
+            'author_name', 'created_at', 'updated_at',
+            'comment_count', 'tags'
+        ]
+
+    def get_comment_count(self, obj):
+        return obj.comments.count()