# -*- coding: utf-8 -*-

"""
@Remark: 自定义序列化器
"""
from rest_framework import serializers
from rest_framework.fields import empty
from rest_framework.request import Request
from rest_framework.serializers import ModelSerializer
from django.utils.functional import cached_property
from rest_framework.utils.serializer_helpers import BindingDict

from mysystem.models import Users


class CustomModelSerializer(ModelSerializer):
    """
    增强DRF的ModelSerializer,可自动更新模型的审计字段记录
    (1)self.request能获取到rest_framework.request.Request对象
    """
    # 修改人的审计字段名称, 默认modifier, 继承使用时可自定义覆盖
    modifier_field_id = 'modifier'
    # modifier_name = serializers.SerializerMethodField(read_only=True)

    # def get_modifier_name(self, instance):
    #     if not hasattr(instance,'modifier'):
    #         return None
    #     queryset = Users.objects.filter(id=instance.modifier).values_list('name', flat=True).first()
    #     if queryset:
    #         return queryset
    #     return None

    # 创建人的审计字段名称, 默认creator, 继承使用时可自定义覆盖
    creator_field_id = 'creator'
    # creator_name = serializers.SlugRelatedField(slug_field="name", source="creator", read_only=True)
    # 数据所属部门字段
    dept_belong_id_field_name = 'dept_belong_id'
    # 添加默认时间返回格式
    create_datetime = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S", required=False, read_only=True)
    update_datetime = serializers.DateTimeField(format="%Y-%m-%d %H:%M:%S", required=False)

    def __init__(self, instance=None, data=empty, request=None, **kwargs):
        super().__init__(instance, data, **kwargs)
        self.request: Request = request or self.context.get('request', None)

    def get_all_model_fields(self):
        return [field.name for field in self.Meta.model._meta.fields]

    def save(self, **kwargs):
        return super().save(**kwargs)

    def create(self, validated_data):
        if self.request:
            #优化：采用获取模型所有字段信息替换原self.fields.fields（解决获取序列化后字段，因受exclude影响，如果排除了审计字段则无法正确给审计字段赋值）
            model_fields = self.get_all_model_fields()
            if str(self.request.user) != "AnonymousUser":
                if self.modifier_field_id in model_fields:
                    validated_data[self.modifier_field_id] = self.get_request_user_id()
                if self.creator_field_id in model_fields:
                    validated_data[self.creator_field_id] = self.request.user
                if self.dept_belong_id_field_name in model_fields and not validated_data.get(self.dept_belong_id_field_name, None):
                    validated_data[self.dept_belong_id_field_name] = getattr(self.request.user, 'dept_id', None)
        return super().create(validated_data)

    def update(self, instance, validated_data):
        if self.request:
            model_fields = self.get_all_model_fields()
            if str(self.request.user) != "AnonymousUser":
                if self.modifier_field_id in model_fields:
                    validated_data[self.modifier_field_id] = self.get_request_user_id()
            if hasattr(self.instance, self.modifier_field_id):
                setattr(self.instance, self.modifier_field_id, self.get_request_user_id())
        return super().update(instance, validated_data)

    def get_request_username(self):
        if getattr(self.request, 'user', None):
            return getattr(self.request.user, 'username', None)
        return None

    def get_request_name(self):
        if getattr(self.request, 'user', None):
            return getattr(self.request.user, 'name', None)
        return None

    def get_request_user_id(self):
        if getattr(self.request, 'user', None):
            return getattr(self.request.user, 'id', None)
        return None