/**
 * @depends jquery
 * @name jquery.scrollto
 * @package jquery-scrollto {@link http://www.balupton/projects/jquery-scrollto}
 */

/**
 * jQuery Aliaser
 */
(function($){
	
	/**
	 * jQuery ScrollTo (balupton edition)
	 * @version 1.0.1
	 * @date August 31, 2010
	 * @since 0.1.0, August 27, 2010
     * @package jquery-scrollto {@link http://www.balupton/projects/jquery-scrollto}
	 * @author Benjamin "balupton" Lupton {@link http://www.balupton.com}
	 * @copyright (c) 2010 Benjamin Arthur Lupton {@link http://www.balupton.com}
	 * @license GNU Affero General Public License version 3 {@link http://www.gnu.org/licenses/agpl-3.0.html}
	 */
	if ( !($.ScrollTo||false) ) {
		$.ScrollTo = {
			/**
			 * The Default Configuration
			 */
			config: {
				duration: 400,
				easing: 'swing',
				callback: undefined,
				durationMode: 'each'
			},
			
			/**
			 * Configure ScrollTo
			 */
			configure: function(options){
				var ScrollTo = $.ScrollTo;
				
				// Apply Options to Config
				$.extend(ScrollTo.config, options||{});
				
				// Chain
				return this;
			},
		
			/**
			 * Perform the Scroll Animation for the Collections
			 * We use $inline here, so we can determine the actual offset start for each overflow:scroll item
			 * Each collection is for each overflow:scroll item
			 */
			scroll: function(collections, config){
				var ScrollTo = $.ScrollTo;
			
				// Determine the Scroll
	    		var	collection = collections.pop(),
					$container = collection.$container,
					$target = collection.$target;
			
				// Prepare the Inline Element of the Container
				var $inline = $('<span/>').css({
					'position': 'absolute',
					'top': '0px',
					'left': '0px'
				});
				var position = $container.css('position');
			
				// Insert the Inline Element of the Container
				$container.css('position','relative');
				$inline.appendTo($container);
			
				// Determine the Offsets
				var	startOffset = $inline.offset().top,
					targetOffset = $target.offset().top,
					offsetDifference = targetOffset - startOffset;
			
				// Reset the Inline Element of the Container
				$inline.remove();
				$container.css('position',position);
				
				// Prepare the callback
				var callback = function(event){
					// Check
					if ( collections.length === 0 ) {
						// Callback
						if ( typeof config.callback === 'function' ) {
							config.callback.apply(this,[event]);
						}
					}
					else {
						// Recurse
						ScrollTo.scroll(collections,config);
					}
					// Return true
					return true;
				};
			
				// Perform the Scroll
				$container.animate({
					'scrollTop': offsetDifference+'px'
				}, config.duration, config.easing, callback);
			
				// Return true
				return true;
			},
		
			/**
			 * ScrollTo the Element using the Options
			 */
			fn: function(options){
				var ScrollTo = $.ScrollTo;
				
				// Prepare
				var	$target = $(this);
				if ( $target.length === 0 ) {
					// Chain
					return this;
				}
				
				// Fetch
				var	$container = $target.parent(),
					collections = [];
	
				// Handle Options
				config = $.extend({},ScrollTo.config,options);

				// Cycle through the containers
				while ( $container.length === 1 && !$container.is('body') ) {
					// Check Container
					var container = $container.get(0);
					if ( $container.css('overflow-y') !== 'visible' && container.scrollHeight !== container.clientHeight ) {
						// Push the Collection
						collections.push({
							'$container': $container,
							'$target': $target
						});
						// Update the Target
						$target = $container;
					}
					// Update the Container
					$container = $container.parent();
				}
			
				// Add the final collection
				collections.push({
					'$container': $($.browser.msie ? 'html' : 'body'),
					'$target': $target
				});
	
				// Adjust the Config
				if ( config.durationMode === 'all' ) {
					config.duration /= collections.length;
				}
				
				// Handle
				ScrollTo.scroll(collections,config);
			
				// Chain
				return this;
			},
		
			/**
			 * Construct
			 */
			construct: function(options){
				var ScrollTo = $.ScrollTo;
			
				// Apply our jQuery Function
				$.fn.ScrollTo = ScrollTo.fn;
			
				// Apply our Options to the Default Config
				ScrollTo.config = $.extend(ScrollTo.config,options);
			
				// Chain
				return this;
			}
		};
	
		// Construct It
		$.ScrollTo.construct();
	}
	else {
		window.console.warn("$.ScrollTo has already been defined...");
	}
	
})(jQuery);