# blog/views.py

from rest_framework import generics, viewsets, permissions, status
from rest_framework.exceptions import PermissionDenied
from rest_framework.response import Response
from django.shortcuts import get_object_or_404
from .models import Post, Comment, Tag
from .serializers import PostSerializer, PostListSerializer, CommentSerializer, TagSerializer
import logging

logger = logging.getLogger(__name__)


class TagListView(generics.ListAPIView):
    """태그 목록 조회"""
    queryset = Tag.objects.all()
    serializer_class = TagSerializer
    permission_classes = [permissions.AllowAny]


class PostListView(generics.ListAPIView):
    """공개 포스트 목록 조회"""
    queryset = Post.objects.all()
    serializer_class = PostListSerializer
    permission_classes = [permissions.AllowAny]

    def get_queryset(self):
        queryset = Post.objects.all()
        tag = self.request.query_params.get('tag')
        if tag:
            queryset = queryset.filter(tags__name=tag)
        return queryset


class PostListCreateView(generics.ListCreateAPIView):
    """인증 사용자용 포스트 목록/생성"""
    queryset = Post.objects.all()
    serializer_class = PostSerializer
    permission_classes = [permissions.IsAuthenticated]

    def perform_create(self, serializer):
        user = self.request.user
        author_id = getattr(user, 'id', '') or getattr(user, 'email', '')
        author_name = getattr(user, 'username', '') or getattr(user, 'email', '')
        instance = serializer.save(author_id=str(author_id), author_name=author_name)
        logger.info(f"Post titled '{instance.title}' has been created by {author_name}.")


class PostDetailView(generics.RetrieveUpdateDestroyAPIView):
    """포스트 상세 조회/수정/삭제"""
    queryset = Post.objects.all()
    serializer_class = PostSerializer

    def get_permissions(self):
        if self.request.method in ["PUT", "PATCH", "DELETE"]:
            return [permissions.IsAuthenticated()]
        return [permissions.AllowAny()]

    def perform_update(self, serializer):
        instance = serializer.instance
        user = self.request.user
        user_id = str(getattr(user, 'id', '') or getattr(user, 'email', ''))
        username = getattr(user, 'username', '') or getattr(user, 'email', '')

        # 작성자 확인
        if instance.author_id != user_id and instance.author_name != username:
            raise PermissionDenied("작성자만 수정할 수 있습니다.")

        serializer.save()
        logger.info(f"Post titled '{instance.title}' has been updated by {username}.")

    def perform_destroy(self, instance):
        user = self.request.user
        user_id = str(getattr(user, 'id', '') or getattr(user, 'email', ''))
        username = getattr(user, 'username', '') or getattr(user, 'email', '')

        # 작성자 확인
        if instance.author_id != user_id and instance.author_name != username:
            raise PermissionDenied("작성자만 삭제할 수 있습니다.")

        title = instance.title
        instance.delete()
        logger.info(f"Post titled '{title}' has been deleted by {username}.")


class CommentViewSet(viewsets.ModelViewSet):
    """댓글/대댓글 CRUD ViewSet"""
    serializer_class = CommentSerializer

    def get_permissions(self):
        if self.action in ['list', 'retrieve']:
            return [permissions.AllowAny()]
        return [permissions.IsAuthenticated()]

    def get_post(self):
        """현재 포스트 가져오기"""
        post_pk = self.kwargs.get('post_pk')
        return get_object_or_404(Post, pk=post_pk)

    def get_queryset(self):
        post_pk = self.kwargs.get('post_pk')
        if post_pk:
            # list 액션에서만 최상위 댓글 반환, 나머지는 모든 댓글 접근 가능
            if self.action == 'list':
                return Comment.objects.filter(post_id=post_pk, parent__isnull=True)
            return Comment.objects.filter(post_id=post_pk)
        return Comment.objects.none()

    def perform_create(self, serializer):
        post = self.get_post()
        user = self.request.user
        author_id = str(getattr(user, 'id', '') or getattr(user, 'email', ''))
        author_name = getattr(user, 'username', '') or getattr(user, 'email', '')

        # parent 검증 (대댓글인 경우)
        parent_id = self.request.data.get('parent')
        parent = None
        if parent_id:
            parent = get_object_or_404(Comment, pk=parent_id, post=post)

        instance = serializer.save(
            post=post,
            parent=parent,
            author_id=author_id,
            author_name=author_name
        )
        logger.info(f"Comment created on post '{post.title}' by {author_name}.")

    def perform_update(self, serializer):
        instance = serializer.instance
        user = self.request.user
        user_id = str(getattr(user, 'id', '') or getattr(user, 'email', ''))
        username = getattr(user, 'username', '') or getattr(user, 'email', '')

        # 작성자 확인
        if instance.author_id != user_id and instance.author_name != username:
            raise PermissionDenied("작성자만 수정할 수 있습니다.")

        serializer.save()
        logger.info(f"Comment {instance.id} updated by {username}.")

    def perform_destroy(self, instance):
        user = self.request.user
        user_id = str(getattr(user, 'id', '') or getattr(user, 'email', ''))
        username = getattr(user, 'username', '') or getattr(user, 'email', '')

        # 작성자 확인
        if instance.author_id != user_id and instance.author_name != username:
            raise PermissionDenied("작성자만 삭제할 수 있습니다.")

        comment_id = instance.id
        instance.delete()
        logger.info(f"Comment {comment_id} deleted by {username}.")