from rest_framework.permissions import BasePermission

class VIPPremission(BasePermission):
    message = {'code': 401, 'msg': "只允许SVIP用户访问"}
    def has_permission(self, request, view):
        if request.user.user_type != 3:
            return False
        return True

class UserPremission(BasePermission):
    def has_permission(self, request, view):
        if request.user.user_type == 3:
            return True
        return False

REST_FRAMEWORK = {
    # 认证处理
    'DEFAULT_AUTHENTICATION_CLASSES': ['api.utils.auth.Authentication'],
    # 权限处理
    'DEFAULT_PERMISSION_CLASSES': ['api.utils.premission.VIPPremission'],
}

from django.db import models


# Create your models here.

class Book(models.Model):
    title = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=5, decimal_places=2)
    objects = models.Manager()

    class Meta:
        db_table = "old_boy_book"
        verbose_name = "书籍"
        verbose_name_plural = verbose_name

    def __str__(self):
        return "《%s》" % self.title


class UserInfo(models.Model):
    USER_TYPE = (
        (1, '普通用户'),
        (2, 'VIP'),
        (3, 'SVIP')
    )

    user_type = models.IntegerField(choices=USER_TYPE)
    username = models.CharField(max_length=32)
    password = models.CharField(max_length=64)

    class Meta:
        # db_table = "user_info"
        verbose_name = "用户"
        verbose_name_plural = verbose_name

    def __str__(self):
        return self.username


class UserToken(models.Model):
    user = models.OneToOneField(UserInfo, on_delete=models.CASCADE)
    token = models.CharField(max_length=64)

from rest_framework import status
from rest_framework.response import Response
from rest_framework.views import APIView

from api.utils.premission import UserPremission
from . import models


# Create your views here.

class Book(APIView):
    # 允许具有UserPremission 用户访问
    permission_classes = [UserPremission]
    
    def get(self, request, *args, **kwargs):
        pk = kwargs.get('pk')
        if pk is not None:
            book_obj = models.Book.objects.get(pk=pk)
            return Response({'code': 1000, 'msg': 'ok', 'results': {'title': book_obj.title, 'price': book_obj.price}})
        book_dict = [book for book in models.Book.objects.filter().values()]
        return Response({'code': 1000, 'msg': 'ok', 'results': book_dict})

    def post(self, request, *args, **kwargs):
        try:
            title = request.data['title']
            price = request.data['price']
            book_obj = models.Book.objects.create(title=title, price=price)
            book_obj.save()

            return Response({'code': 1, 'msg': 'ok', 'results': {'title': book_obj.title, 'price': book_obj.price}})
        except Exception as e:

            return Response({'code': 5, 'msg': 'params error'})

    # def delete(self,request,*args,**kwargs):


def md5(user):
    import hashlib
    import time
    # 当前时间，相当于生成一个随机的字符串
    ctime = str(time.time())
    m = hashlib.md5(bytes(user, encoding='utf-8'))
    m.update(bytes(ctime, encoding='utf-8'))
    return m.hexdigest()


class AuthView(APIView):
    authentication_classes = []
    permission_classes = []

    def post(self, request, *args, **kwargs):
        ret = {'code': 1000, 'msg': None}
        try:
            # user = request._request.POST.get('username')
            user = request.data.get('username')
            # pwd = request._request.POST.get('password')
            pwd = request.data.get('password')
            obj = models.UserInfo.objects.filter(username=user, password=pwd).first()
            if not obj:
                ret['code'] = 1001
                ret['msg'] = '用户名或密码错误'
                return Response(ret, status=status.HTTP_401_UNAUTHORIZED)
            # 为用户创建token
            token = md5(user)
            # 存在就更新，不存在就创建
            models.UserToken.objects.update_or_create(user=obj, defaults={'token': token})
            ret['token'] = token
            return Response(ret, status=status.HTTP_200_OK)
        except Exception as e:
            ret['code'] = 1002
            ret['msg'] = '请求异常'
        return Response(ret)


ORDER_DICT = {
    1: {
        'name': 'apple',
        'price': 15
    },
    2: {
        'name': 'dog',
        'price': 100
    }
}


class OrderView(APIView):
    """订单相关业务"""
		# 根据全局配置，只允许具有svip权限的用户访问67945
    def get(self, request, *args, **kwargs):
        # request.user
        # request.auth
        ret = {'code': 1000, 'msg': None, 'data': None}
        try:
            ret['data'] = ORDER_DICT
        except Exception as e:
            print(e)
        return Response(ret)

urlpatterns = [
    re_path(r'book/$', views.Book.as_view()),
    re_path(r'book/(?P<pk>.*)/$', views.Book.as_view()),
    re_path(r'auth/$', views.AuthView.as_view()),
    re_path(r'order/', views.OrderView.as_view())
]

class BasePermission(metaclass=BasePermissionMetaclass):
    """
    A base class from which all permission classes should inherit.
    """

    def has_permission(self, request, view):
        """
        Return `True` if permission is granted, `False` otherwise.
        """
        return True

    def has_object_permission(self, request, view, obj):
        """
        Return `True` if permission is granted, `False` otherwise.
        """
        return True