/* jshint -W079 */

 /* jshint -W020 */

 "use strict";

 var _ = require("lodash");

 var sha1 = require('sha1');

 var urlencode = require('urlencode');

 var wurl = require('wurl');

 var request = require('request');

 var express = require('express');

 var router = express.Router();

 module.exports = function(app, domain) {

   var appid="wx75340481908402a8";

   var appsecret = "2b6ee0cbeec0114eb539e68ba356329b";

   /* 微信中继接口 */

   router.get('/wechat/ticket', function (req, res) {

     var page = req.query.page;

     if (page && page.indexOf('from=singlemessage') > 0 && page.indexOf('&isappinstalled=0') < 0) page = page + "&isappinstalled=0";

     WeChatTicket.findOne({appid: appid}).exec(function (err, ticket) {

       if (_.isEmpty(ticket)) { refreshTicket(appid, appsecret, page, null, res); return; }

       var difference = parseInt(new Date().getTime() / 1000) - ticket.at;

       // 如果超时

       if (difference > 7100) refreshTicket(appid, appsecret, page, ticket, res);

       else {

         var json = ticket.toJSON();

         var timestamp = parseInt(new Date().getTime() / 1000);

         json.at = timestamp;

         json.signature = wechatSignature(ticket, page, timestamp);

         res.json({ticket: json});

       }

     });

   });

 // 微信 access_token 接口

 //  3、通过路由获取token，并返回json格式数据;

   router.get('/wechat/access_token', function (req, res) {

     getToken(appid, appsecret, function(token, error) {

       if(error) console.error(error);

       res.json(token);

     });

   });

   //第二步获取token，在数据库中拿出token，如果时间过期重新获取token，如果不过期，使用此token

   function getToken(appid, appsecret, cb) {

     WeChatAccessToken.findOne({appid: appid}, function (err, token) {

       if(token) {

         var difference = parseInt(new Date().getTime() / 1000) - token.at;

         if (difference > 7100) refreshToken(appid, appsecret, function(data, err) { cb(data, err); });

         else cb(token, null);

       } else refreshToken(appid, appsecret, function(data, err) { cb(data, err); });

     });

   }

   //第一步刷新token，此步骤是第一步，通过appid和appsecret就可获得accesstoken;此步骤的作用

   //生成token，此处有个技巧，有token替换，无token，直接生成；

   function refreshToken(appid, appsecret, cb) {

     var access_token_api = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET";

     var url = access_token_api.replace('APPID', appid).replace('APPSECRET', appsecret);

     // 参考请求： http://localhost:7000/wechat/ticket?appid=wx8160a61c2d53fb74&appsecret=aa2c953465334823e20090156527a957

     request.get(url, function (error, response, body) {

       if(body) {

         WeChatAccessToken.findOne({appid: appid}, function (err, token) {

           if (!token) token = new WeChatAccessToken();

           var data = JSON.parse(body);

           token.appid = appid;

           token.access_token = data.access_token;

           token.expires_in = data.expires_in;

           token.at = parseInt(new Date().getTime() / 1000);

           token.save(function (err) { cb(token, err); });

         });

       } else cb(null, error);

     });

   }

   //获取ticket第一步;此处用到了getToken的方法；传入appid,appsecrect,

   //首先得到token,拼接获取ticket的url，求情该url得到ticket；将获得的ticket格式化，即body

   //存储到数据库,此处用到了签名的函数wechatSignature();

   function refreshTicket(appid, appsecret, page, ticket, res) {

     getToken(appid, appsecret, function (token, err) {

       if(err !== null) { res.json({error: err}); return; }

       if(_.isEmpty(token.access_token)) { res.json({error: err}); return; }

       // 获取 jsapi_ticket

       var ticket_url = 'https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token=' + token.access_token + '&type=jsapi';

       request.get(ticket_url, function (error, response, body) {

         var t = ticket === null ? new WeChatTicket() : ticket;

         var data = JSON.parse(body);

         if(!data.ticket) { res.json({error: response}); return; }

         var timestamp = parseInt(new Date().getTime() / 1000);

         t.appid = appid;

         t.ticket = data.ticket;

         t.noncestr = sha1(new Date());

         t.expires_in = data.expires_in;

         t.at = timestamp;

         var signature = wechatSignature(t, page, timestamp);

         t.save(function (err) {

           var json = t.toJSON();

           json.at = timestamp;

           json.signature = signature;

           res.json({ticket: json, error: err});

         });

       });

     });

   }

   /* 微信签名实现 */

   function wechatSignature(t, page, timestamp) {

     var string = "jsapi_ticket=" + t.ticket + "&noncestr=" + t.noncestr + "&timestamp=" + timestamp + "&url=" + page;

     return sha1(string);

   }

   return router;

 };