# encoding:utf-8
import time


class WechatToken(object):
    # Singleton
    _instance = None
    _cache = {}
    
    def __new__(cls, *args, **kw):
        """单例模式"""
        if not cls._instance:
            cls._instance = super(WechatToken, cls).__new__(cls, *args, **kw)
        return cls._instance
    
    def get_token(self, appid):
        data = self._cache.get(appid)
        if data is None:
            return None
        now = round(time.time())
        if data[1] - now < 1200:
            return None
        return data[0]
    
    def update_token(self, appid, token, exptime):
        now = round(time.time()) + exptime
        data = (token, now)
        self._cache[appid] = data