YouTube.js/lib/Player.js

'use strict';

const fs = require('fs');
const Axios = require('axios');
const Utils = require('./Utils');
const Constants = require('./Constants');

class Player {
  constructor(innertube_session) {
    this.session = innertube_session;
    this.player_name = Utils.getStringBetweenStrings(this.session.player_url, '/player/', '/');
    this.tmp_cache_dir = __dirname.slice(0, -3) + 'cache';
  }

  async init() {
    if (fs.existsSync(`${this.tmp_cache_dir}/${this.player_name}.js`)) {
      const player_data = fs.readFileSync(`${this.tmp_cache_dir}/${this.player_name}.js`).toString();
      this.getSigDecipherCode(player_data);
      this.getNEncoder(player_data);
    } else {
      const response = await Axios.get(`${Constants.urls.YT_BASE_URL}${this.session.player_url}`, { path: this.session.playerUrl, headers: { 'content-type': 'text/javascript', 'user-agent': Utils.getRandomUserAgent('desktop').userAgent } }).catch((error) => error);
      if (response instanceof Error) throw new Error('Could not download player script: ' + response.message);

      try {
        // Caches the current player so we don't have to download it all the time
        fs.mkdirSync(this.tmp_cache_dir, { recursive: true });
        fs.writeFileSync(`${this.tmp_cache_dir}/${this.player_name}.js`, response.data);
      } catch (err) {}

      this.getSigDecipherCode(response.data);
      this.getNEncoder(response.data);
    }
  }

  getSigDecipherCode(data) {
    const manipulation_algorithm_code = Utils.getStringBetweenStrings(data, 'this.audioTracks};var', '};');
    const manipulation_sequence_code = Utils.getStringBetweenStrings(data, 'function(a){a=a.split("")', 'return a.join("")}');
    this.sig_decipher_sc = manipulation_algorithm_code + manipulation_sequence_code;
  }

  getNEncoder(data) {
    this.ntoken_sc = `var b=a.split("")${Utils.getStringBetweenStrings(data, 'b=a.split("")', '}return b.join("")}')}} return b.join("");`;
  }
}

module.exports = Player;