spotify-web-api-js/src/spotify-web-api.js

A client-side JS wrapper for the Spotify Web API

/* global module */
'use strict';

/**
 * Class representing the API
 */
var SpotifyWebApi = (function () {
  var _baseUri = 'https://api.spotify.com/v1';
  var _accessToken = null;
  var _promiseImplementation = null;

  var WrapPromiseWithAbort = function (promise, onAbort) {
    promise.abort = onAbort;
    return promise;
  };

  var _promiseProvider = function (promiseFunction, onAbort) {
    var returnedPromise;
    if (_promiseImplementation !== null) {
      var deferred = _promiseImplementation.defer();
      promiseFunction(
        function (resolvedResult) {
          deferred.resolve(resolvedResult);
        },
        function (rejectedResult) {
          deferred.reject(rejectedResult);
        }
      );
      returnedPromise = deferred.promise;
    } else {
      if (window.Promise) {
        returnedPromise = new window.Promise(promiseFunction);
      }
    }

    if (returnedPromise) {
      return new WrapPromiseWithAbort(returnedPromise, onAbort);
    } else {
      return null;
    }
  };

  var _extend = function () {
    var args = Array.prototype.slice.call(arguments);
    var target = args[0];
    var objects = args.slice(1);
    target = target || {};
    objects.forEach(function (object) {
      for (var j in object) {
        if (object.hasOwnProperty(j)) {
          target[j] = object[j];
        }
      }
    });
    return target;
  };

  var _buildUrl = function (url, parameters) {
    var qs = '';
    for (var key in parameters) {
      if (parameters.hasOwnProperty(key)) {
        var value = parameters[key];
        qs += encodeURIComponent(key) + '=' + encodeURIComponent(value) + '&';
      }
    }
    if (qs.length > 0) {
      // chop off last '&'
      qs = qs.substring(0, qs.length - 1);
      url = url + '?' + qs;
    }
    return url;
  };

  var _performRequest = function (requestData, callback) {
    var req = new XMLHttpRequest();

    var promiseFunction = function (resolve, reject) {
      function success(data) {
        if (resolve) {
          resolve(data);
        }
        if (callback) {
          callback(null, data);
        }
      }

      function failure() {
        if (reject) {
          reject(req);
        }
        if (callback) {
          callback(req, null);
        }
      }

      var type = requestData.type || 'GET';
      req.open(type, _buildUrl(requestData.url, requestData.params));
      if (_accessToken) {
        req.setRequestHeader('Authorization', 'Bearer ' + _accessToken);
      }

      req.onreadystatechange = function () {
        if (req.readyState === 4) {
          var data = null;
          try {
            data = req.responseText ? JSON.parse(req.responseText) : '';
          } catch (e) {
            console.error(e);
          }

          if (req.status >= 200 && req.status < 300) {
            success(data);
          } else {
            failure();
          }
        }
      };

      if (type === 'GET') {
        req.send(null);
      } else {
        var postData = null;
        if (requestData.postData) {
          if (requestData.contentType === 'image/jpeg') {
            postData = requestData.postData;
            req.setRequestHeader('Content-Type', requestData.contentType);
          } else {
            postData = JSON.stringify(requestData.postData);
            req.setRequestHeader('Content-Type', 'application/json');
          }
        }
        req.send(postData);
      }
    };

    if (callback) {
      promiseFunction();
      return null;
    } else {
      return _promiseProvider(promiseFunction, function () {
        req.abort();
      });
    }
  };

  var _checkParamsAndPerformRequest = function (
    requestData,
    options,
    callback,
    optionsAlwaysExtendParams
  ) {
    var opt = {};
    var cb = null;

    if (typeof options === 'object') {
      opt = options;
      cb = callback;
    } else if (typeof options === 'function') {
      cb = options;
    }

    // options extend postData, if any. Otherwise they extend parameters sent in the url
    var type = requestData.type || 'GET';
    if (type !== 'GET' && requestData.postData && !optionsAlwaysExtendParams) {
      requestData.postData = _extend(requestData.postData, opt);
    } else {
      requestData.params = _extend(requestData.params, opt);
    }
    return _performRequest(requestData, cb);
  };

  /**
   * Creates an instance of the wrapper
   * @constructor
   */
  var Constr = function () {};

  Constr.prototype = {
    constructor: SpotifyWebApi
  };

  /**
   * Fetches a resource through a generic GET request.
   *
   * @param {string} url The URL to be fetched
   * @param {function(Object,Object)} callback An optional callback
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getGeneric = function (url, callback) {
    var requestData = {
      url: url
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Fetches information about the current user.
   * See [Get Current User's Profile](https://developer.spotify.com/web-api/get-current-users-profile/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getMe = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches current user's saved tracks.
   * See [Get Current User's Saved Tracks](https://developer.spotify.com/web-api/get-users-saved-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getMySavedTracks = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me/tracks'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Adds a list of tracks to the current user's saved tracks.
   * See [Save Tracks for Current User](https://developer.spotify.com/web-api/save-tracks-user/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} trackIds The ids of the tracks. If you know their Spotify URI it is easy
   * to find their track id (e.g. spotify:track:<here_is_the_track_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.addToMySavedTracks = function (trackIds, options, callback) {
    var requestData = {
      url: _baseUri + '/me/tracks',
      type: 'PUT',
      postData: trackIds
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Remove a list of tracks from the current user's saved tracks.
   * See [Remove Tracks for Current User](https://developer.spotify.com/web-api/remove-tracks-user/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} trackIds The ids of the tracks. If you know their Spotify URI it is easy
   * to find their track id (e.g. spotify:track:<here_is_the_track_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.removeFromMySavedTracks = function (
    trackIds,
    options,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/me/tracks',
      type: 'DELETE',
      postData: trackIds
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Checks if the current user's saved tracks contains a certain list of tracks.
   * See [Check Current User's Saved Tracks](https://developer.spotify.com/web-api/check-users-saved-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} trackIds The ids of the tracks. If you know their Spotify URI it is easy
   * to find their track id (e.g. spotify:track:<here_is_the_track_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.containsMySavedTracks = function (
    trackIds,
    options,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/me/tracks/contains',
      params: { ids: trackIds.join(',') }
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Get a list of the albums saved in the current Spotify user's "Your Music" library.
   * See [Get Current User's Saved Albums](https://developer.spotify.com/web-api/get-users-saved-albums/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getMySavedAlbums = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me/albums'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Save one or more albums to the current user's "Your Music" library.
   * See [Save Albums for Current User](https://developer.spotify.com/web-api/save-albums-user/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} albumIds The ids of the albums. If you know their Spotify URI, it is easy
   * to find their album id (e.g. spotify:album:<here_is_the_album_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.addToMySavedAlbums = function (albumIds, options, callback) {
    var requestData = {
      url: _baseUri + '/me/albums',
      type: 'PUT',
      postData: albumIds
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Remove one or more albums from the current user's "Your Music" library.
   * See [Remove Albums for Current User](https://developer.spotify.com/web-api/remove-albums-user/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} albumIds The ids of the albums. If you know their Spotify URI, it is easy
   * to find their album id (e.g. spotify:album:<here_is_the_album_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.removeFromMySavedAlbums = function (
    albumIds,
    options,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/me/albums',
      type: 'DELETE',
      postData: albumIds
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Check if one or more albums is already saved in the current Spotify user's "Your Music" library.
   * See [Check User's Saved Albums](https://developer.spotify.com/web-api/check-users-saved-albums/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} albumIds The ids of the albums. If you know their Spotify URI, it is easy
   * to find their album id (e.g. spotify:album:<here_is_the_album_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.containsMySavedAlbums = function (
    albumIds,
    options,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/me/albums/contains',
      params: { ids: albumIds.join(',') }
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Get the current user’s top artists based on calculated affinity.
   * See [Get a User’s Top Artists](https://developer.spotify.com/web-api/get-users-top-artists-and-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getMyTopArtists = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me/top/artists'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Get the current user’s top tracks based on calculated affinity.
   * See [Get a User’s Top Tracks](https://developer.spotify.com/web-api/get-users-top-artists-and-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getMyTopTracks = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me/top/tracks'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Get tracks from the current user’s recently played tracks.
   * See [Get Current User’s Recently Played Tracks](https://developer.spotify.com/web-api/web-api-personalization-endpoints/get-recently-played/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getMyRecentlyPlayedTracks = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me/player/recently-played'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Adds the current user as a follower of one or more other Spotify users.
   * See [Follow Artists or Users](https://developer.spotify.com/web-api/follow-artists-users/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} userIds The ids of the users. If you know their Spotify URI it is easy
   * to find their user id (e.g. spotify:user:<here_is_the_user_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an empty value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.followUsers = function (userIds, callback) {
    var requestData = {
      url: _baseUri + '/me/following/',
      type: 'PUT',
      params: {
        ids: userIds.join(','),
        type: 'user'
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Adds the current user as a follower of one or more artists.
   * See [Follow Artists or Users](https://developer.spotify.com/web-api/follow-artists-users/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} artistIds The ids of the artists. If you know their Spotify URI it is easy
   * to find their artist id (e.g. spotify:artist:<here_is_the_artist_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an empty value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.followArtists = function (artistIds, callback) {
    var requestData = {
      url: _baseUri + '/me/following/',
      type: 'PUT',
      params: {
        ids: artistIds.join(','),
        type: 'artist'
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Add the current user as a follower of one playlist.
   * See [Follow a Playlist](https://developer.spotify.com/web-api/follow-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Object} options A JSON object with options that can be passed. For instance,
   * whether you want the playlist to be followed privately ({public: false})
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an empty value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.followPlaylist = function (playlistId, options, callback) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/followers',
      type: 'PUT',
      postData: {}
    };

    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Removes the current user as a follower of one or more other Spotify users.
   * See [Unfollow Artists or Users](https://developer.spotify.com/web-api/unfollow-artists-users/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} userIds The ids of the users. If you know their Spotify URI it is easy
   * to find their user id (e.g. spotify:user:<here_is_the_user_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an empty value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.unfollowUsers = function (userIds, callback) {
    var requestData = {
      url: _baseUri + '/me/following/',
      type: 'DELETE',
      params: {
        ids: userIds.join(','),
        type: 'user'
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Removes the current user as a follower of one or more artists.
   * See [Unfollow Artists or Users](https://developer.spotify.com/web-api/unfollow-artists-users/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} artistIds The ids of the artists. If you know their Spotify URI it is easy
   * to find their artist id (e.g. spotify:artist:<here_is_the_artist_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an empty value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.unfollowArtists = function (artistIds, callback) {
    var requestData = {
      url: _baseUri + '/me/following/',
      type: 'DELETE',
      params: {
        ids: artistIds.join(','),
        type: 'artist'
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Remove the current user as a follower of one playlist.
   * See [Unfollow a Playlist](https://developer.spotify.com/web-api/unfollow-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an empty value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.unfollowPlaylist = function (playlistId, callback) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/followers',
      type: 'DELETE'
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Checks to see if the current user is following one or more other Spotify users.
   * See [Check if Current User Follows Users or Artists](https://developer.spotify.com/web-api/check-current-user-follows/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} userIds The ids of the users. If you know their Spotify URI it is easy
   * to find their user id (e.g. spotify:user:<here_is_the_user_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an array of boolean values that indicate
   * whether the user is following the users sent in the request.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.isFollowingUsers = function (userIds, callback) {
    var requestData = {
      url: _baseUri + '/me/following/contains',
      type: 'GET',
      params: {
        ids: userIds.join(','),
        type: 'user'
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Checks to see if the current user is following one or more artists.
   * See [Check if Current User Follows](https://developer.spotify.com/web-api/check-current-user-follows/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} artistIds The ids of the artists. If you know their Spotify URI it is easy
   * to find their artist id (e.g. spotify:artist:<here_is_the_artist_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an array of boolean values that indicate
   * whether the user is following the artists sent in the request.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.isFollowingArtists = function (artistIds, callback) {
    var requestData = {
      url: _baseUri + '/me/following/contains',
      type: 'GET',
      params: {
        ids: artistIds.join(','),
        type: 'artist'
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Check to see if one or more Spotify users are following a specified playlist.
   * See [Check if Users Follow a Playlist](https://developer.spotify.com/web-api/check-user-following-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Array<string>} userIds The ids of the users. If you know their Spotify URI it is easy
   * to find their user id (e.g. spotify:user:<here_is_the_user_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an array of boolean values that indicate
   * whether the users are following the playlist sent in the request.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.areFollowingPlaylist = function (
    playlistId,
    userIds,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/followers/contains',
      type: 'GET',
      params: {
        ids: userIds.join(',')
      }
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Get the current user's followed artists.
   * See [Get User's Followed Artists](https://developer.spotify.com/web-api/get-followed-artists/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Object} [options] Options, being after and limit.
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is an object with a paged object containing
   * artists.
   * @returns {Promise|undefined} A promise that if successful, resolves to an object containing a paging object which contains
   * artists objects. Not returned if a callback is given.
   */
  Constr.prototype.getFollowedArtists = function (options, callback) {
    var requestData = {
      url: _baseUri + '/me/following',
      type: 'GET',
      params: {
        type: 'artist'
      }
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches information about a specific user.
   * See [Get a User's Profile](https://developer.spotify.com/web-api/get-users-profile/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} userId The id of the user. If you know the Spotify URI it is easy
   * to find the id (e.g. spotify:user:<here_is_the_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getUser = function (userId, options, callback) {
    var requestData = {
      url: _baseUri + '/users/' + encodeURIComponent(userId)
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches a list of the current user's playlists.
   * See [Get a List of a User's Playlists](https://developer.spotify.com/web-api/get-list-users-playlists/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} userId An optional id of the user. If you know the Spotify URI it is easy
   * to find the id (e.g. spotify:user:<here_is_the_id>). If not provided, the id of the user that granted
   * the permissions will be used.
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getUserPlaylists = function (userId, options, callback) {
    var requestData;
    if (typeof userId === 'string') {
      requestData = {
        url: _baseUri + '/users/' + encodeURIComponent(userId) + '/playlists'
      };
    } else {
      requestData = {
        url: _baseUri + '/me/playlists'
      };
      callback = options;
      options = userId;
    }
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches a specific playlist.
   * See [Get a Playlist](https://developer.spotify.com/web-api/get-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getPlaylist = function (playlistId, options, callback) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches the tracks from a specific playlist.
   * See [Get a Playlist's Tracks](https://developer.spotify.com/web-api/get-playlists-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getPlaylistTracks = function (
    playlistId,
    options,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Gets the current image associated with a specific playlist.
   * See [Get a Playlist Cover Image](https://developer.spotify.com/documentation/web-api/reference/playlists/get-playlist-cover/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:playlist:<here_is_the_playlist_id>)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getPlaylistCoverImage = function (playlistId, callback) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/images'
    };
    return _checkParamsAndPerformRequest(requestData, callback);
  };

  /**
   * Creates a playlist and stores it in the current user's library.
   * See [Create a Playlist](https://developer.spotify.com/web-api/create-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} userId The id of the user. If you know the Spotify URI it is easy
   * to find the id (e.g. spotify:user:<here_is_the_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.createPlaylist = function (userId, options, callback) {
    var requestData = {
      url: _baseUri + '/users/' + encodeURIComponent(userId) + '/playlists',
      type: 'POST',
      postData: options
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Change a playlist's name and public/private state
   * See [Change a Playlist's Details](https://developer.spotify.com/web-api/change-playlist-details/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Object} data A JSON object with the data to update. E.g. {name: 'A new name', public: true}
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.changePlaylistDetails = function (
    playlistId,
    data,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId,
      type: 'PUT',
      postData: data
    };
    return _checkParamsAndPerformRequest(requestData, data, callback);
  };

  /**
   * Add tracks to a playlist.
   * See [Add Tracks to a Playlist](https://developer.spotify.com/web-api/add-tracks-to-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Array<string>} uris An array of Spotify URIs for the tracks
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.addTracksToPlaylist = function (
    playlistId,
    uris,
    options,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks',
      type: 'POST',
      postData: {
        uris: uris
      }
    };
    return _checkParamsAndPerformRequest(requestData, options, callback, true);
  };

  /**
   * Replace the tracks of a playlist
   * See [Replace a Playlist's Tracks](https://developer.spotify.com/web-api/replace-playlists-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Array<string>} uris An array of Spotify URIs for the tracks
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.replaceTracksInPlaylist = function (
    playlistId,
    uris,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks',
      type: 'PUT',
      postData: { uris: uris }
    };
    return _checkParamsAndPerformRequest(requestData, {}, callback);
  };

  /**
   * Reorder tracks in a playlist
   * See [Reorder a Playlist’s Tracks](https://developer.spotify.com/web-api/reorder-playlists-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {number} rangeStart The position of the first track to be reordered.
   * @param {number} insertBefore The position where the tracks should be inserted. To reorder the tracks to
   * the end of the playlist, simply set insert_before to the position after the last track.
   * @param {Object} options An object with optional parameters (range_length, snapshot_id)
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.reorderTracksInPlaylist = function (
    playlistId,
    rangeStart,
    insertBefore,
    options,
    callback
  ) {
    /* eslint-disable camelcase */
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks',
      type: 'PUT',
      postData: {
        range_start: rangeStart,
        insert_before: insertBefore
      }
    };
    /* eslint-enable camelcase */
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Remove tracks from a playlist
   * See [Remove Tracks from a Playlist](https://developer.spotify.com/web-api/remove-tracks-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Array<Object>} uris An array of tracks to be removed. Each element of the array can be either a
   * string, in which case it is treated as a URI, or an object containing the properties `uri` (which is a
   * string) and `positions` (which is an array of integers).
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.removeTracksFromPlaylist = function (
    playlistId,
    uris,
    callback
  ) {
    var dataToBeSent = uris.map(function (uri) {
      if (typeof uri === 'string') {
        return { uri: uri };
      } else {
        return uri;
      }
    });

    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks',
      type: 'DELETE',
      postData: { tracks: dataToBeSent }
    };
    return _checkParamsAndPerformRequest(requestData, {}, callback);
  };

  /**
   * Remove tracks from a playlist, specifying a snapshot id.
   * See [Remove Tracks from a Playlist](https://developer.spotify.com/web-api/remove-tracks-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Array<Object>} uris An array of tracks to be removed. Each element of the array can be either a
   * string, in which case it is treated as a URI, or an object containing the properties `uri` (which is a
   * string) and `positions` (which is an array of integers).
   * @param {string} snapshotId The playlist's snapshot ID against which you want to make the changes
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.removeTracksFromPlaylistWithSnapshotId = function (
    playlistId,
    uris,
    snapshotId,
    callback
  ) {
    var dataToBeSent = uris.map(function (uri) {
      if (typeof uri === 'string') {
        return { uri: uri };
      } else {
        return uri;
      }
    });
    /* eslint-disable camelcase */
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks',
      type: 'DELETE',
      postData: {
        tracks: dataToBeSent,
        snapshot_id: snapshotId
      }
    };
    /* eslint-enable camelcase */
    return _checkParamsAndPerformRequest(requestData, {}, callback);
  };

  /**
   * Remove tracks from a playlist, specifying the positions of the tracks to be removed.
   * See [Remove Tracks from a Playlist](https://developer.spotify.com/web-api/remove-tracks-playlist/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {Array<number>} positions array of integers containing the positions of the tracks to remove
   * from the playlist.
   * @param {string} snapshotId The playlist's snapshot ID against which you want to make the changes
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.removeTracksFromPlaylistInPositions = function (
    playlistId,
    positions,
    snapshotId,
    callback
  ) {
    /* eslint-disable camelcase */
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/tracks',
      type: 'DELETE',
      postData: {
        positions: positions,
        snapshot_id: snapshotId
      }
    };
    /* eslint-enable camelcase */
    return _checkParamsAndPerformRequest(requestData, {}, callback);
  };

  /**
   * Upload a custom playlist cover image.
   * See [Upload A Custom Playlist Cover Image](https://developer.spotify.com/web-api/upload-a-custom-playlist-cover-image/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} playlistId The id of the playlist. If you know the Spotify URI it is easy
   * to find the playlist id (e.g. spotify:user:xxxx:playlist:<here_is_the_playlist_id>)
   * @param {string} imageData Base64 encoded JPEG image data, maximum payload size is 256 KB.
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.uploadCustomPlaylistCoverImage = function (
    playlistId,
    imageData,
    callback
  ) {
    var requestData = {
      url: _baseUri + '/playlists/' + playlistId + '/images',
      type: 'PUT',
      postData: imageData.replace(/^data:image\/jpeg;base64,/, ''),
      contentType: 'image/jpeg'
    };
    return _checkParamsAndPerformRequest(requestData, {}, callback);
  };

  /**
   * Fetches an album from the Spotify catalog.
   * See [Get an Album](https://developer.spotify.com/web-api/get-album/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} albumId The id of the album. If you know the Spotify URI it is easy
   * to find the album id (e.g. spotify:album:<here_is_the_album_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getAlbum = function (albumId, options, callback) {
    var requestData = {
      url: _baseUri + '/albums/' + albumId
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches the tracks of an album from the Spotify catalog.
   * See [Get an Album's Tracks](https://developer.spotify.com/web-api/get-albums-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} albumId The id of the album. If you know the Spotify URI it is easy
   * to find the album id (e.g. spotify:album:<here_is_the_album_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getAlbumTracks = function (albumId, options, callback) {
    var requestData = {
      url: _baseUri + '/albums/' + albumId + '/tracks'
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches multiple albums from the Spotify catalog.
   * See [Get Several Albums](https://developer.spotify.com/web-api/get-several-albums/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} albumIds The ids of the albums. If you know their Spotify URI it is easy
   * to find their album id (e.g. spotify:album:<here_is_the_album_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getAlbums = function (albumIds, options, callback) {
    var requestData = {
      url: _baseUri + '/albums/',
      params: { ids: albumIds.join(',') }
    };
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches a track from the Spotify catalog.
   * See [Get a Track](https://developer.spotify.com/web-api/get-track/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {string} trackId The id of the track. If you know the Spotify URI it is easy
   * to find the track id (e.g. spotify:track:<here_is_the_track_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getTrack = function (trackId, options, callback) {
    var requestData = {};
    requestData.url = _baseUri + '/tracks/' + trackId;
    return _checkParamsAndPerformRequest(requestData, options, callback);
  };

  /**
   * Fetches multiple tracks from the Spotify catalog.
   * See [Get Several Tracks](https://developer.spotify.com/web-api/get-several-tracks/) on
   * the Spotify Developer site for more information about the endpoint.
   *
   * @param {Array<string>} trackIds The ids of the tracks. If you know their Spotify URI it is easy
   * to find their track id (e.g. spotify:track:<here_is_the_track_id>)
   * @param {Object} options A JSON object with options that can be passed
   * @param {function(Object,Object)} callback An optional callback that receives 2 parameters. The first
   * one is the error object (null if no error), and the second is the value if the request succeeded.
   * @return {Object} Null if a callback is provided, a `Promise` object otherwise
   */
  Constr.prototype.getTracks = function (trackIds, options, callback) {
    var requestData = {
      url: _baseUri + '/tracks/',
      params: { ids: trackIds.join(',')