/**
 * Hash Plugin
 * @version 2.0.0-beta.3
 * @author Artus Kolanowski
 * @license The MIT License (MIT)
 */
;(function($, window, document, undefined) {
	'use strict';

	/**
	 * Creates the hash plugin.
	 * @class The Hash Plugin
	 * @param {Owl} carousel - The Owl Carousel
	 */
	var Hash = function(carousel) {
		/**
		 * Reference to the core.
		 * @protected
		 * @type {Owl}
		 */
		this._core = carousel;

		/**
		 * Hash index for the items.
		 * @protected
		 * @type {Object}
		 */
		this._hashes = {};

		/**
		 * The carousel element.
		 * @type {jQuery}
		 */
		this.$element = this._core.$element;

		/**
		 * All event handlers.
		 * @protected
		 * @type {Object}
		 */
		this._handlers = {
			'initialized.owl.carousel': $.proxy(function(e) {
				if (e.namespace && this._core.settings.startPosition === 'URLHash') {
					$(window).trigger('hashchange.owl.navigation');
				}
			}, this),
			'prepared.owl.carousel': $.proxy(function(e) {
				if (e.namespace) {
					var hash = $(e.content).find('[data-hash]').andSelf('[data-hash]').attr('data-hash');

					if (!hash) {
						return;
					}

					this._hashes[hash] = e.content;
				}
			}, this),
			'changed.owl.carousel': $.proxy(function(e) {
				if (e.namespace && e.property.name === 'position') {
					var current = this._core.items(this._core.relative(this._core.current())),
						hash = $.map(this._hashes, function(item, hash) {
							return item === current ? hash : null;
						}).join();

					if (!hash || window.location.hash.slice(1) === hash) {
						return;
					}

					window.location.hash = hash;
				}
			}, this)
		};

		// set default options
		this._core.options = $.extend({}, Hash.Defaults, this._core.options);

		// register the event handlers
		this.$element.on(this._handlers);

		// register event listener for hash navigation
		$(window).on('hashchange.owl.navigation', $.proxy(function(e) {
			var hash = window.location.hash.substring(1),
				items = this._core.$stage.children(),
				position = this._hashes[hash] && items.index(this._hashes[hash]);

			if (position === undefined || position === this._core.current()) {
				return;
			}

			this._core.to(this._core.relative(position), false, true);
		}, this));
	};

	/**
	 * Default options.
	 * @public
	 */
	Hash.Defaults = {
		URLhashListener: false
	};

	/**
	 * Destroys the plugin.
	 * @public
	 */
	Hash.prototype.destroy = function() {
		var handler, property;

		$(window).off('hashchange.owl.navigation');

		for (handler in this._handlers) {
			this._core.$element.off(handler, this._handlers[handler]);
		}
		for (property in Object.getOwnPropertyNames(this)) {
			typeof this[property] != 'function' && (this[property] = null);
		}
	};

	$.fn.owlCarousel.Constructor.Plugins.Hash = Hash;

})(window.Zepto || window.jQuery, window, document);