/*
---

script: Browser.js

description: The Browser Core. Contains Browser initialization, Window and Document, and the Browser Hash.

license: MIT-style license.

requires: 
- /Native
- /$util

provides: [Browser, Window, Document, $exec]

...
*/

var Browser = $merge({

	Engine: {name: 'unknown', version: 0},

	Platform: {name: (window.orientation != undefined) ? 'ipod' : (navigator.platform.match(/mac|win|linux/i) || ['other'])[0].toLowerCase()},

	Features: {xpath: !!(document.evaluate), air: !!(window.runtime), query: !!(document.querySelector)},

	Plugins: {},

	Engines: {

		presto: function(){
			return (!window.opera) ? false : ((arguments.callee.caller) ? 960 : ((document.getElementsByClassName) ? 950 : 925));
		},

		trident: function(){
			return (!window.ActiveXObject) ? false : ((window.XMLHttpRequest) ? ((document.querySelectorAll) ? 6 : 5) : 4);
		},

		webkit: function(){
			return (navigator.taintEnabled) ? false : ((Browser.Features.xpath) ? ((Browser.Features.query) ? 525 : 420) : 419);
		},

		gecko: function(){
			return (!document.getBoxObjectFor && window.mozInnerScreenX == null) ? false : ((document.getElementsByClassName) ? 19 : 18);
		}

	}

}, Browser || {});

Browser.Platform[Browser.Platform.name] = true;

Browser.detect = function(){

	for (var engine in this.Engines){
		var version = this.Engines[engine]();
		if (version){
			this.Engine = {name: engine, version: version};
			this.Engine[engine] = this.Engine[engine + version] = true;
			break;
		}
	}

	return {name: engine, version: version};

};

Browser.detect();

Browser.Request = function(){
	return $try(function(){
		return new XMLHttpRequest();
	}, function(){
		return new ActiveXObject('MSXML2.XMLHTTP');
	}, function(){
		return new ActiveXObject('Microsoft.XMLHTTP');
	});
};

Browser.Features.xhr = !!(Browser.Request());

Browser.Plugins.Flash = (function(){
	var version = ($try(function(){
		return navigator.plugins['Shockwave Flash'].description;
	}, function(){
		return new ActiveXObject('ShockwaveFlash.ShockwaveFlash').GetVariable('$version');
	}) || '0 r0').match(/\d+/g);
	return {version: parseInt(version[0] || 0 + '.' + version[1], 10) || 0, build: parseInt(version[2], 10) || 0};
})();

function $exec(text){
	if (!text) return text;
	if (window.execScript){
		window.execScript(text);
	} else {
		var script = document.createElement('script');
		script.setAttribute('type', 'text/javascript');
		script[(Browser.Engine.webkit && Browser.Engine.version < 420) ? 'innerText' : 'text'] = text;
		document.head.appendChild(script);
		document.head.removeChild(script);
	}
	return text;
};

Native.UID = 1;

var $uid = (Browser.Engine.trident) ? function(item){
	return (item.uid || (item.uid = [Native.UID++]))[0];
} : function(item){
	return item.uid || (item.uid = Native.UID++);
};

var Window = new Native({

	name: 'Window',

	legacy: (Browser.Engine.trident) ? null: window.Window,

	initialize: function(win){
		$uid(win);
		if (!win.Element){
			win.Element = $empty;
			if (Browser.Engine.webkit) win.document.createElement("iframe"); //fixes safari 2
			win.Element.prototype = (Browser.Engine.webkit) ? window["[[DOMElement.prototype]]"] : {};
		}
		win.document.window = win;
		return $extend(win, Window.Prototype);
	},

	afterImplement: function(property, value){
		window[property] = Window.Prototype[property] = value;
	}

});

Window.Prototype = {$family: {name: 'window'}};

new Window(window);

var Document = new Native({

	name: 'Document',

	legacy: (Browser.Engine.trident) ? null: window.Document,

	initialize: function(doc){
		$uid(doc);
		doc.head = doc.getElementsByTagName('head')[0];
		doc.html = doc.getElementsByTagName('html')[0];
		if (Browser.Engine.trident && Browser.Engine.version <= 4) $try(function(){
			doc.execCommand("BackgroundImageCache", false, true);
		});
		if (Browser.Engine.trident) doc.window.attachEvent('onunload', function(){
			doc.window.detachEvent('onunload', arguments.callee);
			doc.head = doc.html = doc.window = null;
		});
		return $extend(doc, Document.Prototype);
	},

	afterImplement: function(property, value){
		document[property] = Document.Prototype[property] = value;
	}

});

Document.Prototype = {$family: {name: 'document'}};

new Document(document);