INSTALLED_APPS = [
  'django.contrib.admin',
  'django.contrib.auth',
  'django.contrib.contenttypes',
  'django.contrib.sessions',
  'django.contrib.messages',
  'django.contrib.staticfiles',
  'app.apps.AppConfig',
  'rest_framework', #注册
]

from django.conf.urls import url
from django.contrib import admin
from app import views
urlpatterns = [
  url(r'^admin/', admin.site.urls),
  url(r'^auth/', views.AuthView.as_view()), #验证
  url(r'^index/', views.IndexView.as_view()), #首页
  url(r'^order/', views.OrderView.as_view()), #定单
]

from rest_framework.views import APIView
from rest_framework.request import Request
from django.http import JsonResponse,HttpResponse
from app.utils.commons import gen_token
from app.utils.auth import LuffyAuthentication
from app.utils.throttle import LuffyAnonRateThrottle,LuffyUserRateThrottle
from app.utils.permission import LuffyPermission
from . import models
class AuthView(APIView):
  """
  认证相关视图
  由于继承了APIView,所以csrf就没有了，具体的源代码只是有一个装饰器，
  加上了csrf_exempt装饰器，屏蔽了csrf
  写法是在return的时候csrf_exempt(view) 和@使用装饰器效果是一样的，这种写法还可以写在url路由中。
  """
  def post(self,request,*args,**kwargs):
    """
    用户登录功能
    :param request:
    :param args:
    :param kwargs:
    :return:
    """
    ret = {'code': 1000, 'msg': None}
    # 默认要返回的信息
    user = request.data.get('username')
    # 这里的request已经不是原来的request了
    pwd = request.data.get('password')
    user_obj = models.UserInfo.objects.filter(user=user, pwd=pwd).first()
    if user_obj:
      tk = gen_token(user) #返回一个哈希过得字符串
      #进行token验证
      models.Token.objects.update_or_create(user=user_obj, defaults={'token': tk})
      # 数据库存入一个token信息
      ret['code'] = 1001
      ret['token'] = tk
    else:
      ret['msg'] = "用户名或密码错误"
    return JsonResponse(ret)

def gen_token(username):
  import time
  import hashlib
  ctime = str(time.time())
  hash = hashlib.md5(username.encode('utf-8'))
  hash.update(ctime.encode('utf-8'))
  return hash.hexdigest()

class IndexView(APIView):
  """
  用户认证
    http://127.0.0.1:8001/v1/index/"""
  authentication_classes = [LuffyAuthentication,]
  #认证成功返回一个用户名，一个对象，不成功就是None
  throttle_classes = [LuffyAnonRateThrottle,LuffyUserRateThrottle]
  #访问次数限制，如果合格都为True
  def get(self,request,*args,**kwargs):
    return HttpResponse('首页')

from rest_framework.authentication import BaseAuthentication
from rest_framework import exceptions
from app import models
class LuffyAuthentication(BaseAuthentication):
  def authenticate(self, request):
    tk = request.query_params.get('tk')
    if not tk:
      return (None,None)
      # raise exceptions.AuthenticationFailed('认证失败')
    token_obj = models.Token.objects.filter(token=tk).first()
    if not token_obj:
      return (None,None)
    return (token_obj.user,token_obj)

from rest_framework.throttling import BaseThrottle,SimpleRateThrottle
class LuffyAnonRateThrottle(SimpleRateThrottle):
  scope = "luffy_anon"
  def allow_request(self, request, view):
    """
    Return `True` if the request should be allowed, `False` otherwise.
    """
    if request.user:
      return True
    # 获取当前访问用户的唯一标识
    self.key = self.get_cache_key(request, view)
    # 根据当前用户的唯一标识，获取所有访问记录
    # [1511312683.7824545, 1511312682.7824545, 1511312681.7824545]
    self.history = self.cache.get(self.key, [])
    # 获取当前时间
    self.now = self.timer()
    # Drop any requests from the history which have now passed the
    # throttle duration
    while self.history and self.history[-1] <= self.now - self.duration:
      self.history.pop()
    if len(self.history) >= self.num_requests:  #判断访问次数是否大于限制次数
      return self.throttle_failure()
    return self.throttle_success() #返回True
  def get_cache_key(self, request, view):
    return 'throttle_%(scope)s_%(ident)s' % {
      'scope': self.scope,
      'ident': self.get_ident(request),
      # 判断是否为代理等等
    }
class LuffyUserRateThrottle(SimpleRateThrottle):
  scope = "luffy_user"
  def allow_request(self, request, view):
    """
    Return `True` if the request should be allowed, `False` otherwise.
    """
    if not request.user:  #判断登录直接返回True
      return True
    # 获取当前访问用户的唯一标识
    # 用户对所有页面
    # self.key = request.user.user
    self.key = request.user.user + view.__class__.__name__
    # 用户对单页面的访问限制
    # 根据当前用户的唯一标识，获取所有访问记录
    # [1511312683.7824545, 1511312682.7824545, 1511312681.7824545]
    self.history = self.cache.get(self.key, [])
    # 获取当前时间
    self.now = self.timer()
    # Drop any requests from the history which have now passed the
    # throttle duration
    while self.history and self.history[-1] <= self.now - self.duration:
      self.history.pop()
    if len(self.history) >= self.num_requests:  #访问次数的限制
      return self.throttle_failure()
    return self.throttle_success()  #返回True

from rest_framework.permissions import BasePermission
class LuffyPermission(BasePermission):
  def has_permission(self, request, view):
    """
    Return `True` if permission is granted, `False` otherwise.
    """
    if request.user:
      return True
    return False

class OrderView(APIView):
  """
  订单页面：只有登录成功后才能访问
    - 认证(匿名和用户)
    - 权限(用户)
    - 限制（）
  """
  authentication_classes = [LuffyAuthentication, ]
  permission_classes = [LuffyPermission,] #登录就返回True
  throttle_classes = [LuffyAnonRateThrottle, LuffyUserRateThrottle]
  def get(self,request,*args,**kwargs):
    return HttpResponse('订单')

REST_FRAMEWORK = {
  'UNAUTHENTICATED_USER': None,
  'UNAUTHENTICATED_TOKEN': None,
  "DEFAULT_THROTTLE_RATES": {
    'luffy_anon': '3/m', #匿名用户一分钟访问3次
    'luffy_user': '6/m'　　#登录用户一分钟访问6次
  },
}