/**
 * jquery.localscroll
 * copyright (c) 2007-2009 ariel flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com
 * dual licensed under mit and gpl.
 * date: 3/11/2009
 *
 * @projectdescription animated scrolling navigation, using anchors.
 * http://flesler.blogspot.com/2007/10/jquerylocalscroll-10.html
 * @author ariel flesler
 * @version 1.2.7
 *
 * @id jquery.fn.localscroll
 * @param {object} settings hash of settings, it is passed in to jquery.scrollto, none is required.
 * @return {jquery} returns the same jquery object, for chaining.
 *
 * @example $('ul.links').localscroll();
 *
 * @example $('ul.links').localscroll({ filter:'.animated', duration:400, axis:'x' });
 *
 * @example $.localscroll({ target:'#pane', axis:'xy', queue:true, event:'mouseover' });
 *
 * notes:
 *	- the plugin requires jquery.scrollto.
 *	- the hash of settings, is passed to jquery.scrollto, so the settings are valid for that plugin as well.
 *	- jquery.localscroll can be used if the desired links, are all over the document, it accepts the same settings.
 *  - if the setting 'lazy' is set to true, then the binding will still work for later added anchors.
  *	- if onbefore returns false, the event is ignored.
 **/
;(function( $ ){
	var uri = location.href.replace(/#.*/,''); // local url without hash

	var $localscroll = $.localscroll = function( settings ){
		$('body').localscroll( settings );
	};

	// many of these defaults, belong to jquery.scrollto, check it's demo for an example of each option.
	// @see http://flesler.demos.com/jquery/scrollto/
	// the defaults are public and can be overriden.
	$localscroll.defaults = {
		duration:1000, // how long to animate.
		axis:'y', // which of top and left should be modified.
		event:'click', // on which event to react.
		stop:true, // avoid queuing animations 
		target: window, // what to scroll (selector or element). the whole window by default.
		reset: true // used by $.localscroll.hash. if true, elements' scroll is resetted before actual scrolling
		/*
		lock:false, // ignore events if already animating
		lazy:false, // if true, links can be added later, and will still work.
		filter:null, // filter some anchors out of the matched elements.
		hash: false // if true, the hash of the selected link, will appear on the address bar.
		*/
	};

	// if the url contains a hash, it will scroll to the pointed element
	$localscroll.hash = function( settings ){
		if( location.hash ){
			settings = $.extend( {}, $localscroll.defaults, settings );
			settings.hash = false; // can't be true
			
			if( settings.reset ){
				var d = settings.duration;
				delete settings.duration;
				$(settings.target).scrollto( 0, settings );
				settings.duration = d;
			}
			scroll( 0, location, settings );
		}
	};

	$.fn.localscroll = function( settings ){
		settings = $.extend( {}, $localscroll.defaults, settings );

		return settings.lazy ?
			// use event delegation, more links can be added later.		
			this.bind( settings.event, function( e ){
				// could use closest(), but that would leave out jquery -1.3.x
				var a = $([e.target, e.target.parentnode]).filter(filter)[0];
				// if a valid link was clicked
				if( a )
					scroll( e, a, settings ); // do scroll.
			}) :
			// bind concretely, to each matching link
			this.find('a,area')
				.filter( filter ).bind( settings.event, function(e){
					scroll( e, this, settings );
				}).end()
			.end();

		function filter(){// is this a link that points to an anchor and passes a possible filter ? href is checked to avoid a bug in ff.
			return !!this.href && !!this.hash && this.href.replace(this.hash,'') == uri && (!settings.filter || $(this).is( settings.filter ));
		};
	};

	function scroll( e, link, settings ){
		var id = link.hash.slice(1),
			elem = document.getelementbyid(id) || document.getelementsbyname(id)[0];

		if ( !elem )
			return;

		if( e )
			e.preventdefault();

		var $target = $( settings.target );

		if( settings.lock && $target.is(':animated') ||
			settings.onbefore && settings.onbefore.call(settings, e, elem, $target) === false ) 
			return;

		if( settings.stop )
			$target.stop(true); // remove all its animations

		if( settings.hash ){
			var attr = elem.id == id ? 'id' : 'name',
				$a = $('<a> </a>').attr(attr, id).css({
					position:'absolute',
					top: $(window).scrolltop(),
					left: $(window).scrollleft()
				});

			elem[attr] = '';
			$('body').prepend($a);
			location = link.hash;
			$a.remove();
			elem[attr] = id;
		}
			
		$target
			.scrollto( elem, settings ) // do scroll
			.trigger('notify.serialscroll',[elem]); // notify serialscroll about this change
	};

})( jquery );