translation into coffeescript of code for backbone.js peepcode

backbone_tunes.coffee

window.Album = Backbone.Model.extend
	isFirstTrack: (index)->
		index == 0
	isLastTrack: (index)->
		index >= @get('tracks').length - 1
	trackUrlAtIndex: (index)->
		if @get('tracks').length > index
			@get('tracks')[index].url
		else
			null

window.Albums = Backbone.Collection.extend
	model: Album
	url: "/albums"

window.Playlist = Albums.extend
	isFirstAlbum: (index)-> index is 0
	isLastAlbum: (index)-> index is @models.length - 1


window.Player = Backbone.Model.extend
	defaults: {
		currentAlbumIndex: 0
		currentTrackIndex: 0
		state: 'stop'
	}

	reset: ->
		@set @defaults
	
	initialize: ->
		@playlist = new Playlist()

	play: ->
		@set state:'play'
		@trigger 'change:currentTrackIndex'
		@logCurrentAlbumAndTrack()

	pause: -> @set state:'pause'
		

	isPlaying: -> @get('state') is 'play'
	isStopped: -> !@isPlaying()

	currentAlbum: -> @playlist.at @get('currentAlbumIndex')
	currentTrackUrl: ->
		album = @currentAlbum()
		album?.trackUrlAtIndex(@get 'currentTrackIndex')

	nextTrack: ->
		trackIndex = @get 'currentTrackIndex'
		albumIndex = @get 'currentAlbumIndex'

		if @currentAlbum().isLastTrack(trackIndex)
			if @playlist.isLastAlbum albumIndex
				@set
					currentAlbumIndex: 0
					currentTrackIndex: 0
			else
				@set
					currentAlbumIndex:(albumIndex + 1)
					currentTrackIndex: 0
		else
			@set currentTrackIndex:(trackIndex + 1)
		@logCurrentAlbumAndTrack()

	prevTrack: ->
		trackIndex = @get 'currentTrackIndex'
		albumIndex = @get 'currentAlbumIndex'

		if @currentAlbum().isFirstTrack(trackIndex)
			if @playlist.isFirstAlbum albumIndex
				lastModelIndex = @playlist.models.length - 1
				@set currentAlbumIndex: lastModelIndex
			else
				@set currentAlbumIndex:(albumIndex - 1)
			lastTrackIndex = @currentAlbum().get('tracks').length - 1
			@set currentTrackIndex:lastTrackIndex
		
		else
			@set currentTrackIndex:(trackIndex - 1)

		@logCurrentAlbumAndTrack()

	logCurrentAlbumAndTrack: ->
		console.log "Player " +
				"#{@get('currentAlbumIndex')}:#{@get('currentTrackIndex')}", @


window.library = new Albums()
window.player = new Player()

$ ->

	window.AlbumView = Backbone.View.extend
		tag: 'li'
		className: 'album'

		template: _.template $("#album-template").html()

		initialize: ->
			_.bindAll(this, 'render')
	
		render: ->
			model = @model.toJSON()
			renderedContent = @template(model)
			$(this.el).html(renderedContent)
			@

	window.PlaylistAlbumView = AlbumView.extend
		events: {
			'click .queue.remove': 'removeFromPlaylist'
		}

		initialize: ->
			_.bindAll(@, 'render', 'updateState', 'updateTrack', 'remove')
			@player = @options.player
			@player.bind 'change:state', @updateState
			@player.bind 'change:currentTrackIndex', @updateTrack
			@model.bind 'remove', @remove

		render: ->
			$(@el).html @template(@model.toJSON())
			@updateTrack()
			@

		updateState: ->
			isAlbumCurrent = @player.currentAlbum() is @model
			$(@el).toggleClass 'current', isAlbumCurrent

		updateTrack: ->
			isAlbumCurrent = @player.currentAlbum() is @model
			if isAlbumCurrent
				currentTrackIndex = @player.get 'currentTrackIndex'
				this.$('li').each (index, el)->
					$(el).toggleClass 'current', (index is currentTrackIndex)
			@updateState()

		removeFromPlaylist: ->
			@options.playlist.remove(@model)
			@player.reset()


	window.LibraryAlbumView = AlbumView.extend
		events: {
			'click .queue.add': 'select'
		}
		select: ->
			@collection.trigger('select', @model)

	window.PlaylistView = Backbone.View.extend
		tagName: 'section'
		className: 'playlist'
		template: _.template $("#playlist-template").html()

		events: {
			'click .play': 'play'
			'click .pause': 'pause'
			'click .next': 'nextTrack'
			'click .prev': 'prevTrack'
		}

		initialize: ->
			_.bindAll(this, 'render', 'renderAlbum', 'queueAlbum', 'updateState', 'updateTrack')
			@collection.bind 'reset', @render
			@collection.bind 'add', @renderAlbum

			@player = @options.player
			@player.bind 'change:state', @updateState
			@player.bind 'change:currentTrackIndex', @updateTrack

			@createAudio()
	
			@library = @options.library
			@library.bind 'select', @queueAlbum

		createAudio: ->
			@audio = new Audio()

		render: ->
			$(@el).html(@template(@player.toJSON()))
			@collection.each @renderAlbum
			@updateState()
			@

		renderAlbum: (album)->
			view = new PlaylistAlbumView
				model:album
				player:@player
				playlist:@collection
			this.$('ul').append(view.render().el)

		updateState: ->
			@updateTrack()
			this.$('button.play').toggle(@player.isStopped())
			this.$('button.pause').toggle(@player.isPlaying())

		updateTrack: ->
			@audio.src = @player.currentTrackUrl()
			if @player.get('state') == 'play'
				@audio.play()
			else
				@audio.pause()

		queueAlbum: (album)->
			@collection.add(album)

		play: -> @player.play()
		pause: -> @player.pause()
		nextTrack: -> @player.nextTrack()
		prevTrack: -> @player.prevTrack()


	window.LibraryView = Backbone.View.extend
		tagName: 'section'
		className: 'library'
		template: _.template $('#library-template').html()

		initialize: ->
			_.bindAll @, 'render'
			@collection.bind 'reset', @render

		render: ->
			$(@el).html @template({})
			$albums = this.$('.albums')
			@collection.each (album)=>
				view = new LibraryAlbumView
					model:album
					collection:@collection

				$albums.append view.render().el
			@

	window.BackboneTunes = Backbone.Router.extend
		routes: {
			'': 'home'
			'blank': 'blank'
		}
		initialize: ->
			@playlistView = new PlaylistView
				collection: window.player.playlist
				player: window.player
				library: window.library

			@libraryView = new LibraryView
				collection: window.library

		home: ->
			$container = $('#inner-container')
			$container.empty()
			$container.append(@playlistView.render().el)
			$container.append(@libraryView.render().el)
		blank: ->
			$('#inner-container').empty()
			$('#inner-container').text('blank')

	window.App = new BackboneTunes()
	Backbone.history.start()
	window.library.fetch()