/* global _wpmejsSettings, MediaElementPlayer */

(function ($, _, Backbone) {

	'use strict';

	/** @namespace wp */

	window.wp = window.wp || {};

	var WPPlaylistView = Backbone.View.extend(/** @lends WPPlaylistView.prototype */{

		/**

		 * @constructs

		 *

		 * @param {Object} options          The options to create this playlist view with.

		 * @param {Object} options.metadata The metadata

		 */

		initialize : function (options) {

			this.index = 0;

			this.settings = {};

			this.data = options.metadata || $.parseJSON( this.$('script.wp-playlist-script').html() );

			this.playerNode = this.$( this.data.type );

			this.tracks = new Backbone.Collection( this.data.tracks );

			this.current = this.tracks.first();

			if ( 'audio' === this.data.type ) {

				this.currentTemplate = wp.template( 'wp-playlist-current-item' );

				this.currentNode = this.$( '.wp-playlist-current-item' );

			}

			this.renderCurrent();

			if ( this.data.tracklist ) {

				this.itemTemplate = wp.template( 'wp-playlist-item' );

				this.playingClass = 'wp-playlist-playing';

				this.renderTracks();

			}

			this.playerNode.attr( 'src', this.current.get( 'src' ) );

			_.bindAll( this, 'bindPlayer', 'bindResetPlayer', 'setPlayer', 'ended', 'clickTrack' );

			if ( ! _.isUndefined( window._wpmejsSettings ) ) {

				this.settings = _.clone( _wpmejsSettings );

			}

			this.settings.success = this.bindPlayer;

			this.setPlayer();

		},

		bindPlayer : function (mejs) {

			this.mejs = mejs;

			this.mejs.addEventListener( 'ended', this.ended );

		},

		bindResetPlayer : function (mejs) {

			this.bindPlayer( mejs );

			this.playCurrentSrc();

		},

		setPlayer: function (force) {

			if ( this.player ) {

				this.player.pause();

				this.player.remove();

				this.playerNode = this.$( this.data.type );

			}

			if (force) {

				this.playerNode.attr( 'src', this.current.get( 'src' ) );

				this.settings.success = this.bindResetPlayer;

			}

			// This is also our bridge to the outside world.

			this.player = new MediaElementPlayer( this.playerNode.get(0), this.settings );

		},

		playCurrentSrc : function () {

			this.renderCurrent();

			this.mejs.setSrc( this.playerNode.attr( 'src' ) );

			this.mejs.load();

			this.mejs.play();

		},

		renderCurrent : function () {

			var dimensions, defaultImage = 'wp-includes/images/media/video.svg';

			if ( 'video' === this.data.type ) {

				if ( this.data.images && this.current.get( 'image' ) && -1 === this.current.get( 'image' ).src.indexOf( defaultImage ) ) {

					this.playerNode.attr( 'poster', this.current.get( 'image' ).src );

				}

				dimensions = this.current.get( 'dimensions' );

				if ( dimensions && dimensions.resized ) {

					this.playerNode.attr( dimensions.resized );

				}

			} else {

				if ( ! this.data.images ) {

					this.current.set( 'image', false );

				}

				this.currentNode.html( this.currentTemplate( this.current.toJSON() ) );

			}

		},

		renderTracks : function () {

			var self = this, i = 1, tracklist = $( '<div class="wp-playlist-tracks"></div>' );

			this.tracks.each(function (model) {

				if ( ! self.data.images ) {

					model.set( 'image', false );

				}

				model.set( 'artists', self.data.artists );

				model.set( 'index', self.data.tracknumbers ? i : false );

				tracklist.append( self.itemTemplate( model.toJSON() ) );

				i += 1;

			});

			this.$el.append( tracklist );

			this.$( '.wp-playlist-item' ).eq(0).addClass( this.playingClass );

		},

		events : {

			'click .wp-playlist-item' : 'clickTrack',

			'click .wp-playlist-next' : 'next',

			'click .wp-playlist-prev' : 'prev'

		},

		clickTrack : function (e) {

			e.preventDefault();

			this.index = this.$( '.wp-playlist-item' ).index( e.currentTarget );

			this.setCurrent();

		},

		ended : function () {

			if ( this.index + 1 < this.tracks.length ) {

				this.next();

			} else {

				this.index = 0;

				this.setCurrent();

			}

		},

		next : function () {

			this.index = this.index + 1 >= this.tracks.length ? 0 : this.index + 1;

			this.setCurrent();

		},

		prev : function () {

			this.index = this.index - 1 < 0 ? this.tracks.length - 1 : this.index - 1;

			this.setCurrent();

		},

		loadCurrent : function () {

			var last = this.playerNode.attr( 'src' ) && this.playerNode.attr( 'src' ).split('.').pop(),

				current = this.current.get( 'src' ).split('.').pop();

			this.mejs && this.mejs.pause();

			if ( last !== current ) {

				this.setPlayer( true );

			} else {

				this.playerNode.attr( 'src', this.current.get( 'src' ) );

				this.playCurrentSrc();

			}

		},

		setCurrent : function () {

			this.current = this.tracks.at( this.index );

			if ( this.data.tracklist ) {

				this.$( '.wp-playlist-item' )

					.removeClass( this.playingClass )

					.eq( this.index )

						.addClass( this.playingClass );

			}

			this.loadCurrent();

		}

	});

	/**

	 * Initialize media playlists in the document.

	 *

	 * Only initializes new playlists not previously-initialized.

	 *

	 * @since 4.9.3

	 * @return {void}

	 */

	function initialize() {

		$( '.wp-playlist:not(:has(.mejs-container))' ).each( function() {

			new WPPlaylistView( { el: this } );

		} );

	}

	/**

	 * Expose the API publicly on window.wp.playlist.

	 *

	 * @namespace wp.playlist

	 * @since 4.9.3

	 * @type {object}

	 */

	window.wp.playlist = {

		initialize: initialize

	};

	$( document ).ready( initialize );

	window.WPPlaylistView = WPPlaylistView;

}(jQuery, _, Backbone));