from django.db.models import F
from rest_framework import status
from rest_framework.response import Response
from rest_framework.views import APIView

from workTtree.models import SchoolDept


class SchoolDeptViews(APIView):
    def get(self, request):
        reqData = request.GET
        # 前端可以传0值也可没没有parent键
        parent = reqData.get('parent', '0')
        # 处理获取祖节点时数据库值为null的时候问题
        parentId = None if parent == '0' else parent
        if not parent.isdigit():
            return Response(data={}, status=status.HTTP_400_BAD_REQUEST)
        # annotate(has_childred=ExpressionWrapper(rl=1,output_field=BooleanField())).可以通过这个用sql生成避免for
        resData = SchoolDept.objects.filter(parent_id=parentId).annotate(childer=F('rght') - F('lft') - 1).values('id',
                                                                                                                  'name',
                                                                                                                  'remark',
                                                                                                                  'childer','parent_id').all()
        for res in resData:
            res['childer'] = res['childer'] // 2 != 0
        return Response(data=resData, status=status.HTTP_200_OK)

    def post(self, request):
        reqData = request.data
        # 获取前端给的父类id获取父类
        parent = SchoolDept.objects.get(id=reqData['id'])
        # 对象类型转换成dict类型
        data = SchoolDept.objects.create(name=reqData['name'], parent=parent).__dict__
        # 不删除该属性会转换json错误
        data.pop('_state')
        return Response(data=data, status=status.HTTP_200_OK)

    def put(self, request):
        data = request.data
        parent = SchoolDept.objects.get(id=data['id'])
        parent.name = data['name']
        parent.save()
        d = parent.__dict__
        d.pop('_state')
        return Response(data=d, status=status.HTTP_200_OK)

    def delete(self, request):
        try:
            # 当传递的id值不存在数据库或没有传id值直接捕获异常
            data = SchoolDept.objects.get(id=request.GET.get('id')).delete()
        except Exception:
            return Response(data={}, status=status.HTTP_400_BAD_REQUEST)
        return Response(data=data, status=status.HTTP_200_OK)