from rest_framework import generics
from rest_framework.decorators import api_view, permission_classes
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.exceptions import PermissionDenied
from .models import Factory
from .serializers import FactorySerializer, FactoryListSerializer


class FactoryListView(generics.ListCreateAPIView):
    """
    工厂列表和创建视图
    """
    queryset = Factory.objects.all()
    permission_classes = [IsAuthenticated]

    def get_serializer_class(self):
        if self.request.method == 'GET':
            return FactoryListSerializer
        return FactorySerializer

    def perform_create(self, serializer):
        # 只有管理员可以创建工厂
        if self.request.user.role != 'admin':
            raise PermissionDenied("只有管理员可以创建工厂")
        serializer.save()


class FactoryDetailView(generics.RetrieveUpdateDestroyAPIView):
    """
    工厂详情视图
    """
    queryset = Factory.objects.all()
    serializer_class = FactorySerializer
    permission_classes = [IsAuthenticated]

    def perform_update(self, serializer):
        # 普通用户只能修改自己所属工厂的信息
        if (self.request.user.role != 'admin' and 
            self.request.user.factory_id != self.get_object().id):
            raise PermissionDenied("无权修改其他工厂信息")
        serializer.save()

    def perform_destroy(self, instance):
        # 只有管理员可以删除工厂
        if self.request.user.role != 'admin':
            raise PermissionDenied("只有管理员可以删除工厂")
        instance.delete()


@api_view(['GET'])
@permission_classes([IsAuthenticated])
def factory_list_simple(request):
    """
    简化的工厂列表，用于下拉选择
    """
    factories = Factory.objects.all()
    serializer = FactoryListSerializer(factories, many=True)
    return Response(serializer.data)