from rest_framework import generics, status
from rest_framework.decorators import api_view, permission_classes
from rest_framework.permissions import AllowAny, IsAuthenticated
from rest_framework.response import Response
from rest_framework_simplejwt.views import TokenObtainPairView
from .models import User
from .serializers import UserSerializer, UserCreateSerializer, CustomTokenObtainPairSerializer


class CustomTokenObtainPairView(TokenObtainPairView):
    """
    自定义JWT令牌获取视图
    """
    serializer_class = CustomTokenObtainPairSerializer


class UserListView(generics.ListCreateAPIView):
    """
    用户列表和创建视图
    """
    queryset = User.objects.all()
    serializer_class = UserSerializer
    permission_classes = [IsAuthenticated]

    def get_serializer_class(self):
        if self.request.method == 'POST':
            return UserCreateSerializer
        return UserSerializer

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


class UserDetailView(generics.RetrieveUpdateDestroyAPIView):
    """
    用户详情视图
    """
    queryset = User.objects.all()
    serializer_class = UserSerializer
    permission_classes = [IsAuthenticated]

    def perform_update(self, serializer):
        # 普通用户只能修改自己的信息
        if self.request.user.role != 'admin' and self.request.user.id != self.get_object().id:
            raise PermissionError("无权修改其他用户信息")
        serializer.save()

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


@api_view(['GET'])
@permission_classes([IsAuthenticated])
def current_user(request):
    """
    获取当前用户信息
    """
    serializer = UserSerializer(request.user)
    return Response(serializer.data)