import time
import base64
import hmac
def get_token(key, expire=3600):
  '''
  :param key: str (用户给定的key，需要用户保存以便之后验证token,每次产生token时的key 都可以是同一个key)
  :param expire: int(最大有效时间，单位为s)
  :return: token
  '''
  ts_str = str(time.time() + expire)
  ts_byte = ts_str.encode("utf-8")
  sha1_tshexstr = hmac.new(key.encode("utf-8"),ts_byte,'sha1').hexdigest()
  token = ts_str+':'+sha1_tshexstr
  b64_token = base64.urlsafe_b64encode(token.encode("utf-8"))
  return b64_token.decode("utf-8")

def out_token(key, token):
  '''
  :param key: 服务器给的固定key
  :param token: 前端传过来的token
  :return: true,false
  '''
  # token是前端传过来的token字符串
  try:
    token_str = base64.urlsafe_b64decode(token).decode('utf-8')
    token_list = token_str.split(':')
    if len(token_list) != 2:
      return False
    ts_str = token_list[0]
    if float(ts_str) < time.time():
      # token expired
      return False
    known_sha1_tsstr = token_list[1]
    sha1 = hmac.new(key.encode("utf-8"),ts_str.encode('utf-8'),'sha1')
    calc_sha1_tsstr = sha1.hexdigest()
    if calc_sha1_tsstr != known_sha1_tsstr:
      # token certification failed
      return False
    # token certification success
    return True
  except Exception as e:
    print(e)

from rest_framework.response import Response
from rest_framework.views import APIView
from app01 import models
# get_token生成加密token,out_token解密token
from app01.token_module import get_token,out_token
class AuthLogin(APIView):
  def post(self,request):
    response={"status":100,"msg":None}
    name=request.data.get("name")
    pwd=request.data.get("pwd")
    print(name,pwd)
    user=models.User.objects.filter(username=name,password=pwd).first()
    if user:
      # token=get_random(name)
      # 将name进行加密,3600设定超时时间
      token=get_token(name,60)
      models.UserToken.objects.update_or_create(user=user,defaults={"token":token})
      response["msg"]="登入成功"
      response["token"]=token
      response["name"]=user.username
    else:
      response["msg"]="用户名或密码错误"
    return Response(response)

from rest_framework.views import APIView
from app01 import models
from app01.serialize_module import BookSerialize
from app01.authentication_module import TokenAuth1,TokenAuth2
class Books(APIView):
  authentication_classes = [TokenAuth2]
  def get(self,request):
    response = {"status": 100, "msg": None}
    book_list=models.Book.objects.all()
    book_ser = BookSerialize(book_list, many=True)
    response["books"]=book_ser.data
    return Response(response)

from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
  url(r'^admin/', admin.site.urls),
  url(r'^books/$', views.Books.as_view()),
  url(r'^login/$', views.AuthLogin.as_view()),
]

from rest_framework.authentication import BaseAuthentication
from app01 import models
from rest_framework.exceptions import NotAuthenticated
# get_token生成加密token,out_token解密token
from app01.token_module import get_token,out_token
# 存储在前端的token解密比对
class TokenAuth2(BaseAuthentication):
  def authenticate(self,request):
    token=request.GET.get("token")
    name=request.GET.get("name")
    token_obj=out_token(name,token)
    if token_obj:
      return
    else:
      raise NotAuthenticated("你没有登入")