from rest_framework import serializers, status
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.views import APIView

from basic_info import models as basic_models


class CustomerEmployeeBindingSerializer(serializers.Serializer):
    """客户员工绑定序列化器"""
    customer_name = serializers.CharField(max_length=100, help_text='客户名称')
    employee_name = serializers.CharField(max_length=100, help_text='员工姓名')


class CustomerEmployeeBindingView(APIView):
    """
    客户员工可见性绑定 API
    
    将指定员工添加到指定客户的可见员工列表中。
    
    POST /api/v2/customers/bind-employee/
    """
    
    permission_classes = [IsAuthenticated]
    
    def post(self, request):
        serializer = CustomerEmployeeBindingSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        
        employee_name = serializer.validated_data['employee_name']
        customer_name = serializer.validated_data['customer_name']
        
        # 查询员工
        employees = basic_models.Employee.objects.filter(name=employee_name)
        if employees.count() == 0:
            return Response(
                {'error': f'未找到名为 "{employee_name}" 的员工'},
                status=status.HTTP_400_BAD_REQUEST
            )
        if employees.count() > 1:
            return Response(
                {'error': f'找到多个名为 "{employee_name}" 的员工（{employees.count()} 个），请使用更精确的标识'},
                status=status.HTTP_403_FORBIDDEN
            )
        
        # 查询客户
        customers = basic_models.Customer.objects.filter(name=customer_name)
        if customers.count() == 0:
            return Response(
                {'error': f'未找到名为 "{customer_name}" 的客户'},
                status=status.HTTP_400_BAD_REQUEST
            )
        if customers.count() > 1:
            return Response(
                {'error': f'找到多个名为 "{customer_name}" 的客户（{customers.count()} 个），请使用更精确的标识'},
                status=status.HTTP_403_FORBIDDEN
            )
        
        # 建立绑定关系
        employee = employees.first()
        customer = customers.first()
        
        # 检查是否已经绑定
        if customer.visible_employees.filter(id=employee.id).exists():
            return Response(
                {
                    'message': f'员工 "{employee_name}" 已在客户 "{customer_name}" 的可见列表中',
                    'customer_id': customer.id,
                    'employee_id': employee.id,
                },
                status=status.HTTP_200_OK
            )
        
        # 添加绑定
        customer.visible_employees.add(employee)
        
        return Response(
            {
                'message': f'成功将员工 "{employee_name}" 添加到客户 "{customer_name}" 的可见列表',
                'customer_id': customer.id,
                'customer_name': customer.name,
                'employee_id': employee.id,
                'employee_name': employee.name,
            },
            status=status.HTTP_201_CREATED
        )