from rest_framework import viewsets, permissions, status
from rest_framework.response import Response
from rest_framework.decorators import action
from django.utils import timezone
from .models import Region, ModeratorApplication, ModeratorPermission, ModeratorSupport
from .serializers import RegionSerializer, RegionDetailSerializer, ModeratorApplicationSerializer, ModeratorPermissionSerializer


class RegionViewSet(viewsets.ModelViewSet):
    queryset = Region.objects.filter(is_active=True)
    serializer_class = RegionSerializer
    permission_classes = [permissions.AllowAny]
    
    def get_serializer_class(self):
        if self.action == 'retrieve':
            return RegionDetailSerializer
        return RegionSerializer
    
    @action(detail=False, methods=['get'])
    def provinces(self, request):
        provinces = Region.objects.filter(level='province', is_active=True)
        serializer = self.get_serializer(provinces, many=True)
        return Response(serializer.data)
    
    @action(detail=True, methods=['get'])
    def children(self, request, pk=None):
        region = self.get_object()
        children = region.children.filter(is_active=True)
        serializer = self.get_serializer(children, many=True)
        return Response(serializer.data)


class ModeratorApplicationViewSet(viewsets.ModelViewSet):
    queryset = ModeratorApplication.objects.all()
    serializer_class = ModeratorApplicationSerializer
    permission_classes = [permissions.IsAuthenticatedOrReadOnly]
    
    def perform_create(self, serializer):
        application = serializer.save(applicant=self.request.user)
        # 设置默认截止时间为 7 天后
        application.deadline = timezone.now() + timezone.timedelta(days=7)
        application.save()
    
    @action(detail=True, methods=['post'])
    def support(self, request, pk=None):
        application = self.get_object()
        user = request.user
        
        # 检查是否已经支持过
        if ModeratorSupport.objects.filter(supporter=user, application=application).exists():
            return Response({'detail': '已经支持过该申请'}, status=status.HTTP_400_BAD_REQUEST)
        
        # 创建支持记录
        ModeratorSupport.objects.create(supporter=user, application=application)
        application.support_count += 1
        application.save()
        
        return Response({'support_count': application.support_count})
    
    @action(detail=True, methods=['post'])
    def approve(self, request, pk=None):
        application = self.get_object()
        user = request.user
        
        # 检查权限
        if not user.is_staff:
            return Response({'detail': '没有权限'}, status=status.HTTP_403_FORBIDDEN)
        
        application.status = 'approved'
        application.reviewer = user
        application.reviewed_at = timezone.now()
        application.save()
        
        # 创建版主权限
        ModeratorPermission.objects.create(
            moderator=application.applicant,
            region=application.region,
            rank=self._get_rank_by_level(application.region.level)
        )
        
        return Response({'detail': '申请已批准'})
    
    @action(detail=True, methods=['post'])
    def reject(self, request, pk=None):
        application = self.get_object()
        user = request.user
        
        if not user.is_staff:
            return Response({'detail': '没有权限'}, status=status.HTTP_403_FORBIDDEN)
        
        application.status = 'rejected'
        application.reviewer = user
        application.reviewed_at = timezone.now()
        application.review_comment = request.data.get('comment', '')
        application.save()
        
        return Response({'detail': '申请已拒绝'})
    
    def _get_rank_by_level(self, level):
        rank_map = {
            'province': 'general',
            'city': 'colonel',
            'county': 'lieutenant',
            'town': 'soldier',
            'village': 'soldier',
        }
        return rank_map.get(level, 'soldier')