# 认证的实现
    1 写一个类，继承BaseAuthentication，重写authenticate，认证的逻辑写在里面，认证通过，返回两个值，一个值最终给了Requet对象的user，认证失败，抛异常：APIException或者AuthenticationFailed
    2 全局使用，局部使用

from django.db import models


# Create your models here.
class Book(models.Model):
    name = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=8, decimal_places=2)
    publish = models.CharField(max_length=32)

# ===========================认证用到的============================
class User(models.Model):
    username = models.CharField(max_length=32)
    password = models.CharField(max_length=32)
    user_type = models.IntegerField(choices=((1, ‘超级用户‘), (2, ‘普通用户‘), (3, ‘二笔用户‘)))


class UserToken(models.Model):
    token = models.CharField(max_length=64)
    user = models.OneToOneField(to=‘User‘, on_delete=models.CASCADE)   # on_delete=models.CASCADE级联删除

from rest_framework.authentication import BaseAuthentication
from rest_framework.exceptions import AuthenticationFailed
from app01.models import UserToken


class MyAuthentication(BaseAuthentication):
    def authenticate(self, request):
        # 认证逻辑，如果认证通过，返回两个值
        # 如果认证失败，抛出AuthenticationFailed异常
        token = request.GET.get(‘token‘)
        if token:
            user_token = UserToken.objects.filter(token=token).first()
            # 认证通过
            if user_token:
                return user_token.user, token
            else:
                raise AuthenticationFailed(‘认证失败‘)
        else:
            raise AuthenticationFailed(‘请求地址中需要携带token‘)

from rest_framework.viewsets import ModelViewSet
from rest_framework.views import APIView
from app01.models import Book
from app01.serializers import BookSerializer
from rest_framework.decorators import action  # 装饰器
from rest_framework.response import Response
# ===============认证相关===========================
from app01.app_atuh import MyAuthentication
from app01 import models
import uuid

# Create your views here.
class BookViewSet(ModelViewSet):
    authentication_classes = [MyAuthentication, ]     # 局部使用认证
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    @action(methods=[‘GET‘, ‘POST‘], detail=True)
    def get_1(self, request, pk):
        print(pk)
        book = self.get_queryset()[:1]  # 从0开始截取一条
        ser = self.get_serializer(book, many=True)
        return Response(ser.data)

class LoginView(APIView):
    def post(self, request):
        username = request.data.get("username")
        password = request.data.get("password")
        user = models.User.objects.filter(username=username, password=password).first()
        if user:
            # 登录成功，生成随机字符串
            token = uuid.uuid4()
            # 存到UserToken表中
            # models.UserToken.objects.create(token=u_str, user=user)   # 用它每次登录都会记录一条，不好，
            # update_or_create有就更新，没有就新增
            models.UserToken.objects.update_or_create(defaults={‘token‘: token}, user=user)
            return Response({‘status‘: 200, ‘msg‘: ‘登录成功‘, ‘token‘: token})
        else:
            return Response({‘status‘: 101, ‘msg‘: ‘用户名或密码错误‘})

from django.contrib import admin
from django.urls import path, re_path
from app01 import views

urlpatterns = [
    path(‘admin/‘, admin.site.urls),
    path(‘login/‘, views.LoginView.as_view()),
]


from rest_framework import routers
router = routers.SimpleRouter()
router.register(‘books‘, views.BookViewSet)  # 不要加斜杠了

urlpatterns += router.urls

REST_FRAMEWORK={
    "DEFAULT_AUTHENTICATION_CLASSES":["app01.app_auth.MyAuthentication",]
}

#局部使用，只需要在视图类里加入：
authentication_classes = [TokenAuth, ]