/**
 * jQuery.ScrollTo
 * Copyright (c) 2007-2008 Ariel Flesler - aflesler(at)gmail(dot)com | http://flesler.blogspot.com
 * Dual licensed under MIT and GPL.
 * Date: 9/11/2008
 *
 * @projectDescription Easy element scrolling using jQuery.
 * http://flesler.blogspot.com/2007/10/jqueryscrollto.html
 * Tested with jQuery 1.2.6. On FF 2/3, IE 6/7, Opera 9.2/5 and Safari 3. on Windows.
 *
 * @author Ariel Flesler
 * @version 1.4
 *
 * @id jQuery.scrollTo
 * @id jQuery.fn.scrollTo
 * @param {String, Number, DOMElement, jQuery, Object} target Where to scroll the matched elements.
 *    The different options for target are:
 *    - A number position (will be applied to all axes).
 *    - A string position ('44', '100px', '+=90', etc ) will be applied to all axes
 *    - A jQuery/DOM element ( logically, child of the element to scroll )
 *    - A string selector, that will be relative to the element to scroll ( 'li:eq(2)', etc )
 *    - A hash { top:x, left:y }, x and y can be any kind of number/string like above.
 * @param {Number} duration The OVERALL length of the animation, this argument can be the settings object instead.
 * @param {Object,Function} settings Optional set of settings or the onAfter callback.
 *   @option {String} axis Which axis must be scrolled, use 'x', 'y', 'xy' or 'yx'.
 *   @option {Number} duration The OVERALL length of the animation.
 *   @option {String} easing The easing method for the animation.
 *   @option {Boolean} margin If true, the margin of the target element will be deducted from the final position.
 *   @option {Object, Number} offset Add/deduct from the end position. One number for both axes or { top:x, left:y }.
 *   @option {Object, Number} over Add/deduct the height/width multiplied by 'over', can be { top:x, left:y } when using both axes.
 *   @option {Boolean} queue If true, and both axis are given, the 2nd axis will only be animated after the first one ends.
 *   @option {Function} onAfter Function to be called after the scrolling ends.
 *   @option {Function} onAfterFirst If queuing is activated, this function will be called after the first scrolling ends.
 * @return {jQuery} Returns the same jQuery object, for chaining.
 *
 * @desc Scroll to a fixed position
 * @example $('div').scrollTo( 340 );
 *
 * @desc Scroll relatively to the actual position
 * @example $('div').scrollTo( '+=340px', { axis:'y' } );
 *
 * @dec Scroll using a selector (relative to the scrolled element)
 * @example $('div').scrollTo( 'p.paragraph:eq(2)', 500, { easing:'swing', queue:true, axis:'xy' } );
 *
 * @ Scroll to a DOM element (same for jQuery object)
 * @example var second_child = document.getElementById('container').firstChild.nextSibling;
 *      $('#container').scrollTo( second_child, { duration:500, axis:'x', onAfter:function(){
 *        alert('scrolled!!');
 *      }});
 *
 * @desc Scroll on both axes, to different values
 * @example $('div').scrollTo( { top: 300, left:'+=200' }, { axis:'xy', offset:-20 } );
 */
;(function( $ ){

  var $scrollTo = $.scrollTo = function( target, duration, settings ){
    $(window).scrollTo( target, duration, settings );
  };

  $scrollTo.defaults = {
    axis:'y',
    duration:1
  };

  // Returns the element that needs to be animated to scroll the window.
  // Kept for backwards compatibility (specially for localScroll & serialScroll)
  $scrollTo.window = function( scope ){
    return $(window).scrollable();
  };

  // Hack, hack, hack... stay away!
  // Returns the real elements to scroll (supports window/iframes, documents and regular nodes)
  $.fn.scrollable = function(){
    console.log(this);
    return this.map(function(){
      // Just store it, we might need it
      var win = this.parentWindow || this.defaultView,
        // If it's a document, get its iframe or the window if it's THE document
        elem = this.nodeName == '#document' ? win.frameElement || win : this,
        // Get the corresponding document
        doc = elem.contentDocument || (elem.contentWindow || elem).document,
        isWin = elem.setInterval;

      return elem.nodeName == 'IFRAME' || isWin && $.browser.safari ? doc.body
        : isWin ? doc.documentElement
        : this;
    });
  };

  $.fn.scrollTo = function( target, duration, settings ){
    if( typeof duration == 'object' ){
      settings = duration;
      duration = 0;
    }
    if( typeof settings == 'function' )
      settings = { onAfter:settings };

    settings = $.extend( {}, $scrollTo.defaults, settings );
    // Speed is still recognized for backwards compatibility
    duration = duration || settings.speed || settings.duration;
    // Make sure the settings are given right
    settings.queue = settings.queue && settings.axis.length > 1;

    if( settings.queue )
      // Let's keep the overall duration
      duration /= 2;
    settings.offset = both( settings.offset );
    settings.over = both( settings.over );

    return this.scrollable().each(function(){
      var elem = this,
        $elem = $(elem),
        targ = target, toff, attr = {},
        win = $elem.is('html,body');

      switch( typeof targ ){
        // A number will pass the regex
        case 'number':
        case 'string':
          if( /^([+-]=)?\d+(px)?$/.test(targ) ){
            targ = both( targ );
            // We are done
            break;
          }
          // Relative selector, no break!
          targ = $(targ,this);
        case 'object':
          // DOMElement / jQuery
          if( targ.is || targ.style )
            // Get the real position of the target
            toff = (targ = $(targ)).offset();
      }
      $.each( settings.axis.split(''), function( i, axis ){
        var Pos = axis == 'x' ? 'Left' : 'Top',
          pos = Pos.toLowerCase(),
          key = 'scroll' + Pos,
          old = elem[key],
          Dim = axis == 'x' ? 'Width' : 'Height',
          dim = Dim.toLowerCase();

        if( toff ){// jQuery / DOMElement
          attr[key] = toff[pos] + ( win ? 0 : old - $elem.offset()[pos] );

          // If it's a dom element, reduce the margin
          if( settings.margin ){
            attr[key] -= parseInt(targ.css('margin'+Pos)) || 0;
            attr[key] -= parseInt(targ.css('border'+Pos+'Width')) || 0;
          }

          attr[key] += settings.offset[pos] || 0;

          if( settings.over[pos] )
            // Scroll to a fraction of its width/height
            attr[key] += targ[dim]() * settings.over[pos];
        }else
          attr[key] = targ[pos];

        // Number or 'number'
        if( /^\d+$/.test(attr[key]) )
          // Check the limits
          attr[key] = attr[key] <= 0 ? 0 : Math.min( attr[key], max(Dim) );

        // Queueing axes
        if( !i && settings.queue ){
          // Don't waste time animating, if there's no need.
          if( old != attr[key] )
            // Intermediate animation
            animate( settings.onAfterFirst );
          // Don't animate this axis again in the next iteration.
          delete attr[key];
        }
      });
      animate( settings.onAfter );

      function animate( callback ){
        $elem.animate( attr, duration, settings.easing, callback && function(){
          callback.call(this, target, settings);
        });
      };
      function max( Dim ){
        var attr ='scroll'+Dim,
          doc = elem.ownerDocument;

        return win
            ? Math.max( doc.documentElement[attr], doc.body[attr]  )
            : elem[attr];
      };
    }).end();
  };

  function both( val ){
    return typeof val == 'object' ? val : { top:val, left:val };
  };

})( jQuery );