/**
 * jQuery.LocalScroll
 * Copyright (c) 2007-2008 Ariel Flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com
 * Dual licensed under MIT and GPL.
 * Date: 3/10/2008
 *
 * @projectDescription Animated scrolling navigation, using anchors.
 * http://flesler.blogspot.com/2007/10/jquerylocalscroll-10.html
 * @author Ariel Flesler
 * @version 1.2.5
 *
 * @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.
 *  - The setting 'speed' is deprecated, use 'duration' instead.
 *    - 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://www.freewebs.com/flesler/jQuery.ScrollTo/
    $localScroll.defaults = {//the defaults are public and can be overriden.
        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 
        /*
        lock:false,//ignore events if already animating
        lazy:false,//if true, links can be added later, and will still work.
        target:null, //what to scroll (selector or element). Keep it null if want to scroll the whole window.
        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 ){
        settings = $.extend( {}, $localScroll.defaults, settings );
        settings.hash = false;//can't be true
        if( location.hash )
            setTimeout(function(){ scroll( 0, location, settings ); }, 0 );//better wrapped with a setTimeout
    };

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

        return ( settings.persistent || settings.lazy ) 
                ? this.bind( settings.event, function( e ){//use event delegation, more links can be added later.
                    var a = $([e.target, e.target.parentNode]).filter(filter)[0];//if a valid link was clicked.
                    a && scroll( e, a, settings );//do scroll.
                })
                : this.find('a')//bind concretely, to each matching link
                        .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 ){
            e && e.preventDefault();
            var $target = $( settings.target || $.scrollTo.window() );//if none specified, then the window.

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

            if( settings.stop )
                $target.queue('fx',[]).stop();//remove all its animations
            $target
                .scrollTo( elem, settings )//do scroll
                .trigger('notify.serialScroll',[elem]);//notify serialScroll about this change
            if( settings.hash )
                $target.queue(function(){
                    location = link.hash;
                });
        }
    };

})( jQuery );