const Koa = require('koa');
var router = require("koa-router");
const moment = require('moment');
const crypto = require('crypto');

const app = new Koa();
const _ = new router()

_.get('/qingting/', manageRedirect)
_.get('/qingting/:channel_id', manageRedirect)

async function manageRedirect(ctx) {
  let channel_id = ctx.params.channel_id || 388
  let url = getUrl(channel_id)
  console.log(url)
  ctx.response.redirect(url);
}

function getUrl(channel_id) {
  const channel_path = `/live/${channel_id}/64k.mp3`
  const encode_channel_path = encodeURIComponent(channel_path)
  const time = encodeURIComponent(moment().add(1, "hours").unix().toString(16))
  const app_id = encodeURIComponent('web')
  var sign_path = "app_id=".concat(app_id, "&path=").concat(encode_channel_path, "&ts=").concat(time)
  var sign = crypto.createHmac("md5", "Lwrpu$K5oP").update(sign_path).digest("hex").toString();
  var path = `https://lhttp.qingting.fm${channel_path}?app_id=${app_id}&ts=${time}&sign=${sign}`
  return path
}

app.use(_.routes())
app.listen(80);