from django.db.models import Q
from rest_framework.viewsets import ModelViewSet
from rest_framework.permissions import IsAuthenticated, IsAdminUser
from rest_framework.authentication import TokenAuthentication
from rest_framework.parsers import MultiPartParser, FormParser, JSONParser

from .models import Blog, BlogContent, BlogSeo
from .serializers_admin import (
    AdminBlogListSerializer,
    AdminBlogDetailSerializer,
    AdminBlogContentSerializer,
    AdminBlogSeoSerializer
)

class AdminBlogViewSet(ModelViewSet):
    """
    Admin CRUD ViewSet for Blog management.
    """
    permission_classes = [IsAuthenticated, IsAdminUser]
    authentication_classes = [TokenAuthentication]
    # Allow multipart so admins can upload thumbnail images directly
    parser_classes = (MultiPartParser, FormParser, JSONParser) 

    def get_serializer_class(self):
        if self.action == 'list':
            return AdminBlogListSerializer
        return AdminBlogDetailSerializer

    def get_queryset(self):
        queryset = Blog.objects.all().prefetch_related('contents', 'seos')

        # Custom Search handling for JSON fields
        search_query = self.request.query_params.get('search', None)
        if search_query:
            # Note: Searching inside a JSON array of dicts in Django can be tricky 
            # depending on your DB (PostgreSQL vs SQLite). 
            # This is a safe fallback using text casting for SQLite/PG compatibility.
            queryset = queryset.filter(
                Q(title__icontains=search_query) |
                Q(slogan__icontains=search_query)
            )
            
        return queryset.order_by('-created_at')

class AdminBlogContentViewSet(ModelViewSet):
    """
    Admin CRUD ViewSet for managing the content blocks inside a specific blog.
    """
    serializer_class = AdminBlogContentSerializer
    permission_classes = [IsAuthenticated, IsAdminUser]
    authentication_classes = [TokenAuthentication]
    parser_classes = (MultiPartParser, FormParser, JSONParser)

    def get_queryset(self):
        queryset = BlogContent.objects.all()
        
        # Filter contents by blog_id if provided in the URL query params
        blog_id = self.request.query_params.get('blog_id', None)
        if blog_id:
            queryset = queryset.filter(blog_id=blog_id)
            
        return queryset.order_by('order', 'created_at')

class AdminBlogSeoViewSet(ModelViewSet):
    """
    Admin CRUD ViewSet for managing SEO meta tags for a specific blog.
    """
    serializer_class = AdminBlogSeoSerializer
    permission_classes = [IsAuthenticated, IsAdminUser]
    authentication_classes = [TokenAuthentication]

    def get_queryset(self):
        queryset = BlogSeo.objects.all()
        
        blog_id = self.request.query_params.get('blog_id', None)
        if blog_id:
            queryset = queryset.filter(blog_id=blog_id)
            
        return queryset