/**
 * 获取 UID
 * @param  {[object]} req
 * @return {[string]}
 */
exports.getUid = (req) => {
    var _uid = 0,
        cookie = req.cookies._UID,
        cookieList;

    if (req.isApp) {
        return req.query.uid || 0;
    }

    if (cookie) {
        cookieList = cookie.split('::');
        if (cookieList[1] && !isNaN(cookieList[1])) {
            _uid = cookieList[1];
        }
    }

    return _uid;
};