gistfile1.js

//Takes a song's UID and returns the index of that song in the playlist if found.
var getSongIndexById = function(songs, id) {
	var songIndex = -1;
	for (var i = 0; i < songs.length; i++) {
		if (songs[i] && songs[i].id === id) {
			songIndex = i;
			break;
		}
	}

	return songIndex;
};


//Takes a song and returns the next song object by index.
getNextSong: function() {
	var nextSong = null;

	var isShuffleEnabled = JSON.parse(localStorage.getItem('isShuffleEnabled')) || false;

	if (isShuffleEnabled === true) {
		nextSong = playlist.shuffledSongs[0];
	} else {
		var currentSong = playlist.songHistory[0];

		if (currentSong) {
			var currentSongIndex = getSongIndexById(playlist.songs, currentSong.id);
			var nextSongIndex = currentSongIndex + 1;

			//Loop back to the front if at end. Should make this togglable in the future.
			if (playlist.songs.length <= nextSongIndex) {
				nextSongIndex = 0;
				nextSong = playlist.songs[nextSongIndex];
			} else {
				nextSong = playlist.songs[nextSongIndex];
			}
		}
	}

	return nextSong;
},