/*!
Deck JS - deck.hash - v1.0
Copyright (c) 2011 Caleb Troughton
Dual licensed under the MIT license and GPL license.
https://github.com/imakewebthings/deck.js/blob/master/MIT-license.txt
https://github.com/imakewebthings/deck.js/blob/master/GPL-license.txt
*/

/*
This module adds deep linking to individual slides, enables internal links
to slides within decks, and updates the address bar with the hash as the user
moves through the deck. A permalink anchor is also updated. Standard themes
hide this link in browsers that support the History API, and show it for
those that do not. Slides that do not have an id are assigned one according to
the hashPrefix option.
*/
(function ($, deck, window, undefined) {
	var $d = $(document),
	$window = $(window),
	
	/* Collection of internal fragment links in the deck */
	$internals,
	
	/*
	Internal only function.  Given a string, extracts the id from the hash,
	matches it to the appropriate slide, and navigates there.
	*/
	goByHash = function(str) {
		var id = str.substr(str.indexOf("#") + 1),
		slides = $[deck]('getSlides');
		
		$.each(slides, function(i, $el) {
			if ($el.attr('id') === id) {
				$[deck]('go', i);
				return false;
			}
		});
	};
	
	/*
	Extends defaults/options.
	
	options.selectors.hashLink
		The element matching this selector has its href attribute updated to
		the hash of the current slide as the user navigates through the deck.
		
	options.hashPrefix
		Every slide that does not have an id is assigned one at initialization.
		Assigned ids take the form of hashPrefix + slideIndex, e.g., slide-0,
		slide-12, etc.
	*/
	$.extend(true, $[deck].defaults, {
		selectors: {
			hashLink: '.deck-permalink'
		},
		
		hashPrefix: 'slide-'
	});
	
	
	$d.bind('deck.init', function() {
		$internals = $();
		
		$.each($[deck]('getSlides'), function(i, $el) {
			var hash;
			
			/* Hand out ids to the unfortunate slides born without them */
			if (!$el.attr('id')) {
				$el.attr('id', $[deck]('getOptions').hashPrefix + i);
			}
			
			hash ='#' + $el.attr('id');
			
			/* Deep link to slides on init */
			if (hash === window.location.hash) {
				$[deck]('go', i);
			}
			
			/* Add internal links to this slide */
			$internals = $internals.add('a[href="' + hash + '"]');
		});
		
		if (!Modernizr.hashchange) {
			/* Set up internal links using click for the poor browsers
			without a hashchange event. */
			$internals.bind('click.deck', function(e) {
				goByHash($(this).attr('href'));
			});
		}
	})
	/* Update permalink and address bar on a slide change */
	.bind('deck.change', function(e, from, to) {
		var hash = '#' + $[deck]('getSlide', to).attr('id');
		
		$($[deck]('getOptions').selectors.hashLink).attr('href', hash);
		if (Modernizr.history) {
			window.history.replaceState({}, "", hash);
		}
	});
	
	/* Deals with internal links in modern browsers */
	$window.bind('hashchange.deck', function(e) {
		if (e.originalEvent.newURL) {
			goByHash(e.originalEvent.newURL);
		}
		else {
			goByHash(window.location.hash);
		}
	});
})(jQuery, 'deck', this);