from rest_framework import viewsets, permissions, filters
from rest_framework.decorators import action
from rest_framework.response import Response
from django.shortcuts import get_object_or_404
from .models import Region
from .serializers import (
    RegionSerializer,
    RegionDetailSerializer,
    RegionTreeSerializer
)
from apps.interactions.models import Rating, Favorite


class RegionViewSet(viewsets.ModelViewSet):
    """ViewSet for Region model."""

    queryset = Region.objects.filter(status='active')
    permission_classes = [permissions.IsAuthenticatedOrReadOnly]
    filter_backends = [filters.SearchFilter, filters.OrderingFilter]
    search_fields = ['name']
    ordering_fields = ['name', 'level', 'created_at']
    ordering = ['level', 'name']

    def get_serializer_class(self):
        if self.action == 'retrieve':
            return RegionDetailSerializer
        elif self.action == 'tree':
            return RegionTreeSerializer
        return RegionSerializer

    def perform_create(self, serializer):
        # Only admin can create regions
        if not self.request.user.is_admin():
            from rest_framework.exceptions import PermissionDenied
            raise PermissionDenied("Only admins can create regions")
        serializer.save()

    def perform_update(self, serializer):
        # Only admin can update regions
        if not self.request.user.is_admin():
            from rest_framework.exceptions import PermissionDenied
            raise PermissionDenied("Only admins can update regions")
        serializer.save()

    @action(detail=False, methods=['get'])
    def provinces(self, request):
        """Get all provinces (top-level regions)."""
        provinces = self.queryset.filter(parent__isnull=True)
        serializer = self.get_serializer(provinces, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=['get'])
    def children(self, request, pk=None):
        """Get children of a region."""
        region = self.get_object()
        children = region.get_children()
        serializer = self.get_serializer(children, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=['get'])
    def path(self, request, pk=None):
        """Get full path of a region."""
        region = self.get_object()
        path = []
        current = region
        while current:
            serializer = self.get_serializer(current)
            path.insert(0, serializer.data)
            current = current.parent
        return Response(path)

    @action(detail=False, methods=['get'])
    def tree(self, request):
        """Get region tree structure."""
        root_regions = self.queryset.filter(parent__isnull=True)
        serializer = RegionTreeSerializer(root_regions, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=['get'])
    def articles(self, request, pk=None):
        """Get articles for a region."""
        region = self.get_object()
        articles = region.articles.filter(publish_status='published')
        from apps.articles.serializers import ArticleListSerializer
        serializer = ArticleListSerializer(articles, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=['get'])
    def services(self, request, pk=None):
        """Get featured services for a region."""
        region = self.get_object()
        services = region.featured_services.filter(publish_status='published')
        from apps.featured_services.serializers import FeaturedServiceListSerializer
        serializer = FeaturedServiceListSerializer(services, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=['get'])
    def stats(self, request, pk=None):
        """Get statistics for a region."""
        region = self.get_object()
        return Response({
            'articles_count': region.articles.filter(publish_status='published').count(),
            'services_count': region.featured_services.filter(publish_status='published').count(),
            'children_count': region.children.count(),
        })

    @action(detail=True, methods=['post'])
    def rate(self, request, pk=None):
        """Rate a region."""
        region = self.get_object()
        serializer = RatingCreateSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save(target_type='region', target_id=region.id)
            return Response({'message': 'Rating saved'}, status=201)
        return Response(serializer.errors, status=400)

    @action(detail=True, methods=['get'])
    def my_rating(self, request, pk=None):
        """Get user's rating for a region."""
        region = self.get_object()
        try:
            rating = Rating.objects.get(
                user=request.user,
                target_type='region',
                target_id=region.id
            )
            return Response({'score': rating.score})
        except Rating.DoesNotExist:
            return Response({'score': None})

    @action(detail=True, methods=['post'])
    def favorite(self, request, pk=None):
        """Favorite or unfavorite a region."""
        region = self.get_object()
        serializer = FavoriteCreateSerializer(data=request.data)
        if serializer.is_valid():
            result = serializer.save(target_type='region', target_id=region.id)
            if result is None:
                return Response({'message': 'Unfavorited'}, status=200)
            return Response({'message': 'Favorited'}, status=201)
        return Response(serializer.errors, status=400)