/*
 * yuga.js 0.7.1 - ?????????Web??????????????????JS
 *
 * Copyright (c) 2009 Kyosuke Nakamura (kyosuke.jp)
 * Licensed under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 *
 * Since:     2006-10-30
 * Modified:  2009-01-27
 *
 * jQuery 1.3.1
 * ThickBox 3.1
 */

/*
 * [????????????] XHTML???head????????????????????????????????????????????????
 
<link rel="stylesheet" href="css/thickbox.css" type="text/css" media="screen" />
<script type="text/javascript" src="js/jquery.js"></script>
<script type="text/javascript" src="js/thickbox.js"></script>
<script type="text/javascript" src="js/yuga.js" charset="utf-8"></script>

 */

(function($) {

	$(function() {
		$.yuga.scroll();
	});

	//---------------------------------------------------------------------

	$.yuga = {
		// URI??????????????????????????????????????????function
		Uri: function(path){
			var self = this;
			this.originalPath = path;
			//?????????????????????
			this.absolutePath = (function(){
				var e = document.createElement('span');
				e.innerHTML = '<a href="' + path + '" />';
				return e.firstChild.href;
			})();
			//?????????????????????
			var fields = {'schema' : 2, 'username' : 5, 'password' : 6, 'host' : 7, 'path' : 9, 'query' : 10, 'fragment' : 11};
			var r = /^((\w+):)?(\/\/)?((\w+):?(\w+)?@)?([^\/\?:]+):?(\d+)?(\/?[^\?#]+)?\??([^#]+)?#?(\w*)/.exec(this.absolutePath);
			for (var field in fields) {
				this[field] = r[fields[field]];
			}
			this.querys = {};
			if(this.query){
				$.each(self.query.split('&'), function(){
					var a = this.split('=');
					if (a.length == 2) self.querys[a[0]] = a[1];
				});
			}
		},

		//???????????????????????????????????????????????????
		scroll: function(options) {
			//?????????????????????????????????????????????????????????????????????
			var scroller = (function() {
				var c = $.extend({
					easing:100,
					step:30,
					fps:60,
					fragment:''
				}, options);
				c.ms = Math.floor(1000/c.fps);
				var timerId;
				var param = {
					stepCount:0,
					startY:0,
					endY:0,
					lastY:0
				};
				//????????????????????????????????????function
				function move() {
					if (param.stepCount == c.step) {
						//????????????????????????
						setFragment(param.hrefdata.absolutePath);
						window.scrollTo(getCurrentX(), param.endY);
					} else if (param.lastY == getCurrentY()) {
						//????????????????????????
						param.stepCount++;
						window.scrollTo(getCurrentX(), getEasingY());
						param.lastY = getEasingY();
						timerId = setTimeout(move, c.ms); 
					} else {
						//?????????????????????
						if (getCurrentY()+getViewportHeight() == getDocumentHeight()) {
							//???????????????????????????????????????
							setFragment(param.hrefdata.absolutePath);
						}
					}
				}
				function setFragment(path){
					location.href = path
				}
				function getCurrentY() {
					return document.body.scrollTop  || document.documentElement.scrollTop;
				}
				function getCurrentX() {
					return document.body.scrollLeft  || document.documentElement.scrollLeft;
				}
				function getDocumentHeight(){
					return document.documentElement.scrollHeight || document.body.scrollHeight;
				}
				function getViewportHeight(){
					return (!$.browser.safari && !$.browser.opera) ? document.documentElement.clientHeight || document.body.clientHeight || document.body.scrollHeight : window.innerHeight;
				}
				function getEasingY() {
					return Math.floor(getEasing(param.startY, param.endY, param.stepCount, c.step, c.easing));
				}
				function getEasing(start, end, stepCount, step, easing) {
					var s = stepCount / step;
					return (end - start) * (s + easing / (100 * Math.PI) * Math.sin(Math.PI * s)) + start;
				}
				return {
					set: function(options) {
						this.stop();
						if (options.startY == undefined) options.startY = getCurrentY();
						param = $.extend(param, options);
						param.lastY = param.startY;
						timerId = setTimeout(move, c.ms); 
					},
					stop: function(){
						clearTimeout(timerId);
						param.stepCount = 0;
					}
				};
			})();
			$('a[href*=#], area[href*=#]').not('a[href=#], area[href=#]').each(function(){
				this.hrefdata = new $.yuga.Uri(this.getAttribute('href'));
			}).click(function(){
				var target = $('#'+this.hrefdata.fragment);
				if (target.length == 0) target = $('a[name='+this.hrefdata.fragment+']');
				if (target.length) {
					scroller.set({
						endY: target.offset().top,
						hrefdata: this.hrefdata
					});
					return false;
				}
			});
		}
	};
})(jQuery);