/**
 * 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 );