'use strict';

const request = require('request-promise');
const md5 = require('md5'); // 引入md5加密模块
const fs = require('fs');
// const appId = 'wx1c015df104db7030'; // 小程序的appid
const mchId = '1226156302'; // 商户号
const mchKey = 'zaq12wsxcde34rfvbgt56yhnmjuioplk'; // 商户秘钥


// 进行签名的参数
function getSignParam(obj) {
  let keys = Object.keys(obj);
  keys = keys.sort();
  let _str = '';
  const _arr = [];
  keys.forEach(function(key) {
    _arr.push(key + '=' + obj[key]);
  });
  _str = _str + _arr.join('&') + '&key=' + mchKey;
  _str = md5(_str);
  const signValue = _str.toUpperCase();
  return signValue;
}


// 请求时的xml参数
function getXmlParam(obj) {
  let _xml = '<xml>';
  for (const key in obj) {
    _xml += '<' + key + '>' + obj[key] + '</' + key + '>';
  }
  _xml = _xml + '</xml>';
  return _xml;
}

// 微信提现http请求
async function WeApiPromotion(formData) {
  const options = {
    url: 'https://api.mch.weixin.qq.com/mmpaymkttransfers/promotion/transfers', // 微信官方请求接口
    method: 'POST',
    headers: {
      'content-type': 'application/json;charset=utf-8',
    },
    body: formData,
    agentOptions: {
      key: fs.readFileSync('./app/public/uploads/apiclient_key.pem'), // 将微信生成的证书放入 cert目录下
      cert: fs.readFileSync('./app/public/uploads/apiclient_cert.pem'),
      passphrase: mchId,
    },
  };
  const payData = await request(options);
  return payData;
}

// 产生一个随机字符串
function getRandomStr(strLength) {
  let str = '';
  const arr = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' ];
  for (let i = 1; i <= strLength; i++) {
    const random = Math.floor(Math.random() * arr.length);
    str += arr[random];
  }
  return str;
}


// 构造订单号
function getOrderID() {
  const currentDate = new Date();
  const year = currentDate.getFullYear();

  let month = currentDate.getMonth();
  month = month >= 9 ? month + 1 : '0' + (month + 1);

  let day = currentDate.getDate();
  day = this.MgetFixedNumber(day);

  // mch_id 是微信支付分配的商户号
  const orderid = mchId + year + month + day + this.MgetRandomNumber();
  return orderid;
}


// 返回给定宽度的数字字符串
function MgetFixedNumber(number, width) {
  width = width ? width : 2;
  let fixedNumber = number.toString();
  for (; fixedNumber.length < width;) {
    fixedNumber = '0' + fixedNumber;
  }
  return fixedNumber;
}

// 返回随机数字字符串
function MgetRandomNumber(length) {
  const numbers = '0123456789';
  length = length ? length : 10;
  const range = numbers.length;
  let result = '';
  let position = 0;
  for (let i = 0; i < length; i++) {
    position = Math.floor(Math.random() * range);
    result += numbers[position];
  }
  return result;
}


module.exports = {
  getRandomStr,
  getSignParam,
  getXmlParam,
  WeApiPromotion,
  MgetFixedNumber, MgetRandomNumber, getOrderID,
};