from rest_framework import generics, status
from rest_framework.decorators import api_view, permission_classes, action
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.viewsets import ModelViewSet
from .models import Material
from .serializers import MaterialSerializer, MaterialListSerializer


class MaterialViewSet(ModelViewSet):
    """
    材料视图集
    """
    permission_classes = [IsAuthenticated]

    def get_queryset(self):
        """
        根据用户角色过滤材料
        """
        queryset = Material.objects.all()

        # 普通用户只能看到自己工厂的材料
        if self.request.user.role != 'admin':
            queryset = queryset.filter(factory=self.request.user.factory)

        # 支持按状态过滤
        status_filter = self.request.query_params.get('status')
        if status_filter:
            queryset = queryset.filter(status=status_filter)

        # 支持按工厂过滤
        factory_id = self.request.query_params.get('factory_id')
        if factory_id:
            queryset = queryset.filter(factory_id=factory_id)

        # 支持按专业类别过滤
        major_category = self.request.query_params.get('major_category')
        if major_category:
            queryset = queryset.filter(major_category=major_category)

        # 支持按材料子类过滤
        material_subcategory = self.request.query_params.get('material_subcategory')
        if material_subcategory:
            queryset = queryset.filter(material_subcategory=material_subcategory)

        return queryset

    def get_serializer_class(self):
        """
        根据操作类型选择序列化器
        """
        if self.action == 'list':
            return MaterialListSerializer
        return MaterialSerializer

    def perform_create(self, serializer):
        """
        创建材料时自动设置工厂
        """
        # 普通用户只能为自己工厂创建材料
        if self.request.user.role != 'admin':
            serializer.save(factory=self.request.user.factory)
        else:
            serializer.save()

    def perform_update(self, serializer):
        """
        更新材料时的权限控制
        """
        # 普通用户只能更新自己工厂的材料
        if (self.request.user.role != 'admin' and 
            self.request.user.factory_id != self.get_object().factory_id):
            raise PermissionError("无权修改其他工厂的材料")
        serializer.save()

    def perform_destroy(self, instance):
        """
        删除材料时的权限控制
        """
        # 普通用户只能删除自己工厂的材料
        if (self.request.user.role != 'admin' and 
            self.request.user.factory_id != instance.factory_id):
            raise PermissionError("无权删除其他工厂的材料")
        instance.delete()

    @action(detail=True, methods=['post'])
    def submit(self, request, pk=None):
        """
        提交审核
        """
        material = self.get_object()

        # 普通用户只能提交自己工厂的材料
        if (request.user.role != 'admin' and 
            request.user.factory_id != material.factory_id):
            return Response(
                {"detail": "无权提交其他工厂的材料"},
                status=status.HTTP_403_FORBIDDEN
            )

        if material.status != 'draft':
            return Response(
                {"detail": "只有创建中的材料才能提交审核"},
                status=status.HTTP_400_BAD_REQUEST
            )

        material.status = 'pending'
        material.save()
        return Response({"status": "已提交审核"})

    @action(detail=True, methods=['post'])
    def approve(self, request, pk=None):
        """
        审核通过
        """
        # 只有管理员可以审核
        if request.user.role != 'admin':
            return Response(
                {"detail": "只有管理员可以审核材料"},
                status=status.HTTP_403_FORBIDDEN
            )

        material = self.get_object()
        if material.status != 'pending':
            return Response(
                {"detail": "只有待审核的材料才能审核"},
                status=status.HTTP_400_BAD_REQUEST
            )

        material.status = 'approved'
        material.save()
        return Response({"status": "审核通过"})

    @action(detail=True, methods=['post'])
    def reject(self, request, pk=None):
        """
        审核拒绝
        """
        # 只有管理员可以审核
        if request.user.role != 'admin':
            return Response(
                {"detail": "只有管理员可以审核材料"},
                status=status.HTTP_403_FORBIDDEN
            )

        material = self.get_object()
        if material.status != 'pending':
            return Response(
                {"detail": "只有待审核的材料才能审核"},
                status=status.HTTP_400_BAD_REQUEST
            )

        material.status = 'draft'
        material.save()
        return Response({"status": "审核拒绝"})