""" 
CreateModelMixin：单增工具类
    create方法
    
ListModelMixin：群查工具类
    list方法

RetrieveModelMixin：单查工具类
    retrieve方法

UpdateModelMixin：单整体局部改工具类
    update方法

DestroyModelMixin：单删工具类
    destory方法
"""

""" generics包下的所有GenericAPIView的子类（就是继承GenericAPIView和不同mixins下的工具类的组合）
1）定义的视图类，继承generics包下已有的特点的GenericAPIView子类，可以在只初始化queryset和serializer_class两个类属性后，就获得特定的功能

2）定义的视图类，自己手动继承GenericAPIView基类，再任意组合mixins包下的一个或多个工具类，可以实现自定义的工具视图类，获得特定的功能或功能们

注：
i）在这些模式下，不能实现单查群查共存（可以加逻辑区分，也可以用视图集知识）
ii）DestroyModelMixin工具类提供的destory方法默认是从数据库中删除数据，所以一般删除数据的需求需要自定义逻辑
"""

# ----------------------------- 过渡写法：了解 -----------------------------

from rest_framework.generics import GenericAPIView
class BookV1APIView(GenericAPIView):
    # 将数据和序列化提升为类属性，所有的请求方法都可以复用
    queryset = models.Book.objects.filter(is_delete=False).all()
    serializer_class = serializers.BookModelSerializer
    lookup_field = ‘pk‘  # 可以省略，默认是pk，与url有名分组对应的

    # 群查
    def get(self, request, *args, **kwargs):
        # queryset = models.Book.objects.filter(is_delete=False).all()  # => 拆分成方法+属性两行代码
        queryset = self.get_queryset()
        # serializer = serializers.BookModelSerializer(instance=queryset, many=True)  # => 拆分成方法+属性两行代码
        serializer = self.get_serializer(instance=queryset, many=True)
        return APIResponse(results=serializer.data)

    # 单查
    # def get(self, request, *args, **kwargs):
    #    obj = self.get_object()
    #    serializer = self.get_serializer(obj)
    #    return APIResponse(results=serializer.data)

    # 单增
    def post(self, request, *args, **kwargs):
        # serializer = serializers.BookModelSerializer(data=request.data)
        serializer = self.get_serializer(data=request.data)  # 同样的步骤多了，好处就来了
        serializer.is_valid(raise_exception=True)
        obj = serializer.save()
        return APIResponse(result=self.get_serializer(obj).data, http_status=201)
    
# ----------------------------- 过渡写法2：了解 -----------------------------

from rest_framework.generics import GenericAPIView
from rest_framework import mixins
class BookV2APIView(GenericAPIView, mixins.RetrieveModelMixin, mixins.CreateModelMixin):
    queryset = models.Book.objects.filter(is_delete=False).all()
    serializer_class = serializers.BookModelSerializer

    # 单查
    def get(self, request, *args, **kwargs):
        # obj = self.get_object()
        # serializer = self.get_serializer(obj)
        # return APIResponse(results=serializer.data)  

        # return self.retrieve(request, *args, **kwargs)   

        response = self.retrieve(request, *args, **kwargs)
        return APIResponse(result=response.data)

    # 单增
    def post(self, request, *args, **kwargs):
        return self.create(request, *args, **kwargs)


# ----------------------------- 开发写法：常用 -----------------------------

from rest_framework.generics import RetrieveAPIView
class BookV3APIView(RetrieveAPIView):
    queryset = models.Book.objects.filter(is_delete=False).all()
    serializer_class = serializers.BookModelSerializer

    # 单查
    pass