index.js

var http = require('follow-redirects').http;
var test = require('net');
var runnel = require('runnel');
var fs = require('fs');

var downloader = {};

var host = 'www.youtube-mp3.org';

var pushItemLink = null;
var itemInfoLink = null;
var pingLink = 'http://ping.aclst.com/ping.php/12790944/{0}';
var downloadLink = '/get?ab=256&video_id={0}&h={1}&r={2}';

var filename = null;

var _cc = function(a) {
  var __AM = 65521;
  if ("string" != typeof a) throw Error("se");
  var c = 1,
      b = 0,
      d, e;
  for (e = 0; e < a.length; e++) d = a.charCodeAt(e), c = (c + d) % __AM, b = (b + c) % __AM;
  return b << 16 | c
}

/**
 * Push the item to their API
 **/
var pushItem = function(cb) {
  http.get({
      host: host,
      schema: 'http',
      path: pushItemLink
  }, function(res) {
    res.setEncoding('utf8');
    var body = '';

    res.on('data', function(chunk) {
      body += chunk;
    });

    res.on('end', function() {
      return cb(null, body);
    });
  });
}

/**
 * Get the item info link
 **/
var getItemInfo = function(token, cb) {
  http.get({
      host: host,
      schema: 'http',
      path: itemInfoLink.replace('{0}', token)
  }, function(res) {
    res.setEncoding('utf8');
    var body = '';

    res.on('data', function(chunk) {
      body += chunk;
    });

    res.on('end', function() {
      cb(null, token, body);
    });
  });
}

/**
 * Ping the item on the aclst.com service
 **/
var pingItem = function(token, reqBody, cb) {
 if(reqBody.indexOf('info') !== 0) return cb('Fail from api: ' + reqBody);

 eval(reqBody);

 http.get(info.pf, function(res) {
  cb(null, token, info);
 }).on('error', function(e) {
   return cb(e.message);
 });
}

/**
 * Download the file
 **/
var downloadFile = function(token, info, cb) {
  var timestamp = (new Date).getTime();

  var options = {
    path: downloadLink.replace('{0}', token).
      replace('{1}', info.h).
      replace('{2}', timestamp + '.' + _cc(token + timestamp)),
    host: host,
    agent: false
  };

  var req = http.get(options, function(res) {
    var writeFile = fs.createWriteStream(filename, {'flags': 'a'});
    res.on('data', function(chunk) {
      writeFile.write(chunk, encoding='binary');
    });

    res.on('end', function() {
      writeFile.end();
      cb(null);
    });
  }).on('error', function(e) {
    cb(e);
  });
}

var getDownloadLink = function(token, info, cb) {
    var timestamp = (new Date).getTime();
    var url = host + downloadLink.replace('{0}', token).
      replace('{1}', info.h).
      replace('{2}', timestamp + '.' + _cc(token + timestamp));

    cb(null, url);
}

downloader.getDownloadLink = function(youtubeLink, finalCallback) {
    pushItemLink = '/a/pushItem' +
      '/?item=' + encodeURI(youtubeLink) +
      '&el=na&bf=false';
    itemInfoLink = '/a/itemInfo' +
      '/?video_id={0}&ac=www&t=grp';
    runnel(
        pushItem,
        getItemInfo,
        pingItem.bind(this),
        getDownloadLink.bind(this),
        function done(err, url) {
          finalCallback(err, url);
        });
}

downloader.download = function(youtubeLink, file, finalCallback) {
  filename = file;
  pushItemLink = '/a/pushItem' +
    '/?item=' + encodeURI(youtubeLink) +
    '&el=na&bf=false';
  itemInfoLink = '/a/itemInfo' +
    '/?video_id={0}&ac=www&t=grp';
  runnel(
      pushItem,
      getItemInfo,
      pingItem.bind(this),
      downloadFile.bind(this),
      function done(err) {
        finalCallback(err);
      });
}

module.exports = downloader;