from article.models import Article
from article.serializers import ArticleListSerializer, ArticleDetailSerializer
from rest_framework.decorators import api_view
from rest_framework.response import Response
from rest_framework.views import APIView
from django.http import Http404
from rest_framework import mixins
from rest_framework import generics
from rest_framework import status
from article.permissions import IsAdminUserOrReadOnly


@api_view(['GET', 'POST'])
def article_list(request):
    # 获取所有文章列表
    if request.method == 'GET':
        articles = Article.objects.all()
        serializer = ArticleListSerializer(articles, many=True)
        return Response(serializer.data)
    # 创建新的文章
    elif request.method == 'POST':
        serializer = ArticleListSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


# 和article_list()功能相同
class ArticleList(generics.ListCreateAPIView):
    # 添加用户权限
    permission_classes = [IsAdminUserOrReadOnly]
    queryset = Article.objects.all()
    serializer_class = ArticleListSerializer

    def perform_create(self, serializer):
        # 在序列化数据真正保存之前调用
        serializer.save(author=self.request.user)


# 第一种版本

# class ArticleDetail(APIView):
#     """文章详情视图"""
#     def get_object(self, pk):
#         """获取单个文章对象"""
#         try:
#             # pk代表主键
#             return Article.objects.get(pk=pk)
#         except:
#             raise Http404
#
#     def get(self, request, pk):
#         article = self.get_object(pk)
#         serializer = ArticleDetailSerializer(article)
#         # 返回Json数据
#         return Response(serializer.data)
#
#     def put(self, request, pk):
#         article = self.get_object(pk)
#         serializer = ArticleDetailSerializer(article, data=request.data)
#         # 验证提交的数据是否合法
#         # 不合法就返回400
#         if serializer.is_valid():
#             # 序列化器将持有的数据反序列化后
#             # 保存到数据库
#             serializer.save()
#             return Response(serializer.data)
#         return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
#
#     def delete(self, request, pk):
#         article = self.get_object(pk=pk)
#         article.delete()
#         # 删除成功后返回204
#         return Response(status=status.HTTP_204_NO_CONTENT)

# 第二种版本

# class ArticleDetail(mixins.RetrieveModelMixin,
#                     mixins.UpdateModelMixin,
#                     mixins.DestroyModelMixin,
#                     generics.GenericAPIView):
#     """文章详情视图"""
#     queryset = Article.objects.all()
#     # 序列化类
#     serializer_class = ArticleDetailSerializer
#
#     def get(self, request, *args, **kwargs):
#         return self.retrieve(request, *args, **kwargs)
#
#     def put(self, request, *args, **kwargs):
#         return self.update(request, *args, **kwargs)
#
#     def delete(self, request, *args, **kwargs):
#         return self.destroy(request, *args, **kwargs)

# ArticleDetail类还可以简化为下面的代码
class ArticleDetail(generics.RetrieveUpdateDestroyAPIView):
    permission_classes = [IsAdminUserOrReadOnly]
    queryset = Article.objects.all()
    serializer_class = ArticleDetailSerializer