koel/resources/assets/js/services/info/song.js

import { http, albumInfo, artistInfo } from '..';

export const songInfo = {
  /**
   * Get extra song information (lyrics, artist info, album info).
   *
   * @param  {Object}   song
   * @param  {?Function}  cb
   */
  fetch(song, cb = null) {
    // Check if the song's info has been retrieved before.
    if (song.infoRetrieved) {
      cb && cb();

      return;
    }

    http.get(`${song.id}/info`, response => {
      const data = response.data;

      song.lyrics = data.lyrics;

      data.artist_info && artistInfo.merge(song.artist, data.artist_info);
      data.album_info && albumInfo.merge(song.album, data.album_info);

      song.infoRetrieved = true;

      cb && cb();
    });
  },
};