<button open-type="contact">轉在線客服</button>

  /*
   * https://developers.weixin.qq.com/miniprogram/dev/framework/server-ability/message-push.html
   * 驗證消息的確來自微信服務器
   * 開發(fā)者通過檢驗 signature 對請求進行校驗（下面有校驗方式）。
   * 若確認此次 GET 請求來自微信服務器，請原樣返回 echostr 參數內容，
   * 則接入生效，成為開發(fā)者成功，否則接入失敗。加密/校驗流程如下：
   * 將token、timestamp、nonce三個參數進行字典序排序
   * 將三個參數字符串拼接成一個字符串進行sha1加密
   * 開發(fā)者獲得加密后的字符串可與signature對比，標識該請求來源于微信
   */
   const crypto = require('crypto');
   async wxCallbackAction(){
    const ctx = this.ctx;
    const method = ctx.method;
    //微信服務器簽名驗證，確認請求來自微信
    if(method === 'GET') {
      // 1.獲取微信服務器Get請求的參數 signature、timestamp、nonce、echostr
      const {
        signature,
        timestamp,
        nonce,
        echostr
      } = ctx.query;
      
      // 2.將token、timestamp、nonce三個參數進行字典序排序
      let array = ['yourToken', timestamp, nonce];
      array.sort();
      
      // 3.將三個參數字符串拼接成一個字符串進行sha1加密
      const tempStr = array.join('');
      const hashCode = crypto.createHash('sha1'); //創(chuàng)建加密類型
      const resultCode = hashCode.update(tempStr, 'utf8').digest('hex');
      
      // 4.開發(fā)者獲得加密后的字符串可與signature對比，標識該請求來源于微信
      if (resultCode === signature) {
        console.log('驗證成功，消息是從微信服務器轉發(fā)過來');
        return this.json(echostr);
      }else {
        console.log('驗證失?。。?！');
        return this.json({
          status: -1,
          message: "驗證失敗"
        });
      }
      
    }
   }

  const WXDecryptContact = require('./WXDecryptContact');
  async wxCallbackAction(){
    const ctx = this.ctx;
    const method = ctx.method;
    //接收信息時 為POST請求；(完整代碼自行與上面驗證時的合并即可)
    if(method === 'POST'){
      const { Encrypt } = ctx.request.body;
      //配置時選的安全模式 因此需要解密
      if(!Encrypt){
        return this.json('success');
      }
      const decryptData = WXDecryptContact(Encrypt);
      await this._handleWxMsg(decryptData);
      return this.json('success');
    }else{
      return this.json('success');
    }
  }
  
  //處理微信回調消息的總入口 (只處理了文本類型，其他類型自行添加)
  async _handleWxMsg(msgJson){
    if(!msgJson){
      return this.json('success');
    }

    const { MsgType } = msgJson;
    if(MsgType === 'text'){
      await this._sendTextMessage(msgJson);
    }
  }
  
  //微信文本信息關鍵字自動回復
  async _sendTextMessage(msgJson){
    //獲取CMS客服關鍵詞回復配置
    const result = await this.callService('cms.getDataByName', 'wxApplet.contact');
    
    let keyWordObj = result.data || {};
  
    //默認回復default
    let options = keyWordObj.default;
    for(let key in keyWordObj){
      //查看是否命中配置的關鍵詞
      if(msgJson.Content === key){
        //CMS配置項
        options = keyWordObj[key];
        }
      }
    }
    
    //獲取access_token
    const accessToken = await this._getAccessToken();
    
    /*
    * 先判斷配置回復的消息類型是不是image類型
    * 如果是 則需要先通過 新增素材接口 上傳圖片文件獲得 media_id
    */
    
    let media_id = '';
    if(options.type === 'image'){
      //獲取圖片地址(相對路徑)
      let url = options.url;
      const file = fs.createReadStream(url);
      
      //調用微信 uploadTempMedia接口 具體實現(xiàn)見 service.js
      const mediaResult = await this.callService('wxApplet.uploadTempMedia',
        {
          access_token: accessToken,
          type: 'image'
        },
        {
          media: file
        }
      );
      
      if(mediaResult.status === 0){
        media_id = mediaResult.data.media_id;
      }else {
        //如果圖片id獲取失敗 則按默認處理
        options = keyWordObj.default;
      }
    }
    
    //回復信息給用戶
    const sendMsgResult = await this.callService('wxApplet.sendMessageToCustomer',
      {
        access_token: accessToken,
        touser: msgJson.FromUserName,
        msgtype: options.type || 'text',
        text: {
          content: options.description || '',
        },
        link: options.type === "link" ? 
          {
            title: options.title,
            description: options.description,
            url: options.url,
            thumb_url: options.thumb_url
          }
          :
          {},
        image: {
          media_id
        }
      }
    );    
  }

const request = require('request');
/*
* 獲取CMS客服關鍵詞回復配置
* 這個接口只是為了回去CMS配置的字段回復關鍵字配置 返回的data數據結構如下
*/
async contact(){
  return {
    data: {
      "1": {
        "type": "link",
        "title": "點擊下載[****]APP",
        "description": "注冊領取領***元注冊紅包禮",
        "url": "https://m.renrendai.com/mo/***.html",
        "thumb_url": "https://m.we.com/***/test.png"
       },
       "2": {
        "url": "http://m.renrendai.com/cms/****/test.jpg",
        "type": "image"
       },
       "3": {
        "url": "/cms/***/test02.png",
        "type": "image"
       },
       "default": {
        "type": "text",
        "description": "再見"
       }
    }
  }
}

/*
 * 把媒體文件上傳到微信服務器。目前僅支持圖片。用于發(fā)送客服消息或被動回復用戶消息。
 * https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/customer-message/customerServiceMessage.uploadTempMedia.html
 */
 
 async uploadTempMedia(data,formData){
  const url = `https://api.weixin.qq.com/cgi-bin/media/upload?access_token=${data.access_token}&type=${data.type}`;
  return new Promise((resolve, reject) => {
    request.post({url, formData: formData}, (err, response, body) => {
      try{
        const out = JSON.parse(body);
        let result = {
          data: out,
          status: 0,
          message: "ok"
        }
        
        return resolve(result);
      
      }catch(err){
        return reject({
          status: -1,
          message: err.message
        });
      }
    });
  }
 }
 
 /*
 * 發(fā)送客服消息給用戶
 * https://developers.weixin.qq.com/miniprogram/dev/api-backend/open-api/customer-message/customerServiceMessage.send.html
 */
 
 async sendMessageToCustomer(data){
  const url = `https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token=${data.access_token}`;
  return new Promise((resolve, reject) => {
    request.post({url, data}, (err, response, body) => {
      ...
    });
  }
 }

const crypto = require('crypto'); // 加密模塊

const decodePKCS7 = function (buff) {
  let pad = buff[buff.length - 1];
  if (pad < 1 || pad > 32) {
    pad = 0;
  }
  return buff.slice(0, buff.length - pad);
};

// 微信轉發(fā)客服消息解密
const decryptContact = (key, iv, crypted) => {
  const aesCipher = crypto.createDecipheriv('aes-256-cbc', key, iv);
  aesCipher.setAutoPadding(false);
  let decipheredBuff = Buffer.concat([aesCipher.update(crypted, 'base64'), aesCipher.final()]);
  decipheredBuff = decodePKCS7(decipheredBuff);
  const lenNetOrderCorpid = decipheredBuff.slice(16);
  const msgLen = lenNetOrderCorpid.slice(0, 4).readUInt32BE(0);
  const result = lenNetOrderCorpid.slice(4, msgLen + 4).toString();
  return result;
};

// 解密微信返回給配置的消息服務器的信息
const decryptWXContact = (wechatData) => {
  if(!wechatData){
    wechatData = '';
  }
  //EncodingAESKey 為后臺配置時隨機生成的
  const key = Buffer.from(EncodingAESKey + '=', 'base64');
  const iv = key.slice(0, 16);
  const result = decryptContact(key, iv, wechatData);
  const decryptedResult = JSON.parse(result);
  console.log(decryptedResult);
  return decryptedResult;
};
module.exports = decryptWXContact;