/**
 * The main namespace.
 **/
var Vn =
{
	Config: {}
	,includes: {}
	,cssIncludes: {}
	,xmlIncludes: {}
	,tmpIncludes: []
	,tmpDefine: null
	,customTags: {}
	,head: document.getElementsByTagName ('head')[0]
	,isMobileCached: null

	/**
	 * Includes a new CSS stylesheet in the current document, if the stylesheet
	 * is already included, does nothing.
	 *
	 * @param {string} fileName The stylesheet file name
	 **/
	,includeCss: function (fileName)
	{	
		var cssData = this.cssIncludes[fileName];

		if (!cssData)
		{
			var link = document.createElement ('link');
			link.rel = 'stylesheet';
			link.type = 'text/css';
			link.href = fileName +'?'+ Vn.Cookie.get ('hedera_version');
			this.head.appendChild (link);
			
			this.cssIncludes[fileName] = 
			{
				 included: true
				,link: link
			};
		}
		else if (!cssData.included)
		{
			cssData.link.disabled = false;
			cssData.included = true;
		}
	}
	
	/**
	 * Excludes a CSS stylesheet from the current document.
	 *
	 * @param {string} fileName The stylesheet file name
	 **/
	,excludeCss: function (fileName)
	{
		var cssData = this.cssIncludes[fileName];
	
		if (cssData && cssData.included)
		{
			cssData.link.disabled = true;
			cssData.included = false;
		}		
	}

	/**
	 * Initializes the library and calls the passed function when all
	 * includes and its dependencies are resolved.
	 * Should be called on the last statically incuded script.
	 *
	 * @param {Function} callback The main function
	 **/
	,main: function (callback)
	{
		if (this.mainCalled)
		{
			Vn.warning ("Vn: main method should be called only once");
			return;
		}
	
		this.mainCalled = true;
		this.mainCallback = callback;

		var basePath = location.protocol +'//'+ location.host;
		basePath += location.port ? ':'+ location.port : '';
		basePath += location.pathname;

		var scripts = this.head.getElementsByTagName ('script');
		var includes = this.tmpIncludes;

		for (var i = 0; i < scripts.length; i++)
		{
			var relPath = scripts[i].src.substr (basePath.length);
			relPath = relPath.substr (0, relPath.indexOf ('.js'));

			var includeData = this.includes[relPath];
			
			if (includeData === undefined)
			{
				includeData = {
					 depCount: 0
					,callbacks: []
					,loaded: true
					,dependants: []
					,success: true
				};

				this.includes[relPath] = includeData;
			}
			
			if (i == scripts.length - 1)
				includeData.callbacks.push (this._onMainDepsLoad.bind (this));
			
			this.tmpIncludes = includes;
			this._onScriptLoad (includeData, true);
		}

		window.addEventListener ('load', this._onWindowLoad.bind (this));
	}
	
	,_onMainDepsLoad: function ()
	{
		this.mainDepsLoaded = true;
		this._callMain ();
	}
	
	,_onWindowLoad: function ()
	{
		this.windowReady = true;
		this._callMain ();
	}
	
	,_callMain: function ()
	{
		if (this.mainCallback && this.windowReady && this.mainDepsLoaded)
			this.mainCallback ();
	}
	
	,_handleCallback: function (includeData, callback)
	{
		if (!callback)
			return;
	
		if (includeData.loaded)
			callback (includeData.success);
		else
			includeData.callbacks.push (callback);
	}
	
	/**
	 * Includes a set of javascript files and sets it as dependecies of the
	 * current script.
	 *
	 * @param {...} The list of files as function arguments
	 **/
	,include: function ()
	{
		for (var i = 0; i < arguments.length; i++)
		{
			var includeData = this._realIncludeJs (arguments[i] +'.js');
			
			if (!includeData.loaded)
				this.tmpIncludes.push (includeData);
		}
	}

	/**
	 * Downloads a set of resources and sets it as dependecies of the
	 * current script.
	 *
	 * @param {...} The list of files as function arguments
	 **/
	,resource: function ()
	{
		for (var i = 0; i < arguments.length; i++)
		{
			var includeData = this._realLoadXml (arguments[i]);
			
			if (!includeData.loaded)
				this.tmpIncludes.push (includeData);
		}
	}
	
	/**
	 * Sets the function that will be called when current script dependencies
	 * are resolved.
	 *
	 * @param {Function} callback The callback function
	 **/
	,define: function (callback)
	{
		this.tmpDefine = callback;
	}
	
	/**
	 * Includes an entire Javascript library including it's localized file.
	 *
	 * @param {string} libName The folder of the library
	 * @param {Array<string>} files Array with every library file name
	 **/
	,includeLib: function (libName, files)
	{
		Vn.Locale.loadScript ('js/'+ libName +'.js');

		for (var i = 0; i < files.length; i++)
			this.include ('js/'+ libName +'/'+ files[i]);
	}

	/**
	 * Includes a new Javascript in the current document, if the script
	 * is already included, does nothing and calls the callback.
	 *
	 * @param {string} fileName The script file name
	 * @param {Function} callback The function to call when script is
	 * downloaded and included
	 **/
	,includeJs: function (fileName, callback, skipVersion)
	{
		var includeData = this._realIncludeJs (fileName, skipVersion);
		this._handleCallback (includeData, callback);
	}
	 
	,_realIncludeJs: function (fileName, skipVersion)
	{
		var includeData = this.includes[fileName];
	
		if (includeData === undefined)
		{
			var src = fileName;

			if (!skipVersion)
				src = src +'?'+ Vn.Cookie.get ('hedera_version');

			var script = document.createElement ('script');
			script.type = 'text/javascript';
			script.async = false;
			script.src = src;

			includeData = {
				 depCount: 0
				,callbacks: []
				,loaded: false
				,dependants: []
				,success: false
			};

			script.onload =
				this._onScriptLoad.bind (this, includeData, true);
			script.onerror =
				this._onScriptLoad.bind (this, includeData, false);
			script.onreadystatechange =
				this._onScriptStateChange.bind (this, includeData, script);

			this.includes[fileName] = includeData;
			this.head.appendChild (script);
		}

		return includeData;
	}

	,_onScriptStateChange: function (includeData, script)
	{
		if (script.readyState == 'complete')
			this._onScriptLoad (includeData, true);
	}

	,_onScriptLoad: function (includeData, success)
	{
		includeData.success = success;

		if (success)
		{			
			if (this.tmpDefine)
				includeData.callbacks.push (this.tmpDefine);

			var includes = this.tmpIncludes;
			
			if (includes && includes.length > 0)
			{
				includeData.depCount = includes.length;

				for (var i = 0; i < includes.length; i++)
					includes[i].dependants.push (includeData);
			}
			else
				this.resolveDeps (includeData);
		}
		else
			this.resolveDeps (includeData);
		
		this.tmpIncludes = [];
		this.tmpDefine = null;
	}
	
	,resolveDeps: function (includeData)
	{
		includeData.loaded = true;

		var callbacks = includeData.callbacks;
	
		for (var i = 0; i < callbacks.length; i++)
			callbacks[i] (includeData.success);

		var dependants = includeData.dependants;

		for (var i = 0; i < dependants.length; i++)
		{
			var dependant = dependants[i];
			dependant.depCount--;
			
			if (dependant.depCount == 0)
				this.resolveDeps (dependant);
		}

		delete includeData.callbacks;
	}

	/**
	 * Request an XML file.
	 *
	 * @param {string} path The file path
	 * @param {Function} callback The function to call when file is downloaded
	 **/
	,loadXml: function (path, callback)
	{
		var includeData = this._realLoadXml (path);
		this._handleCallback (includeData, callback);
	}

	,_realLoadXml: function (path)
	{
		var includeData = this.includes[path];
	
		if (includeData === undefined)
		{
			includeData = {
				 callbacks: []
				,loaded: false
				,dependants: []
				,depCount: 0
				,success: false
				,xml: null
			};

			var request = new XMLHttpRequest ();
			request.onreadystatechange =
				this._onXmlReady.bind (this, includeData, request);
			request.open ('get',
				path +'?'+ Vn.Cookie.get ('hedera_version'), true);
			request.send ();

			this.includes[path] = includeData;
		}

		return includeData;
	}
	
	,_onXmlReady: function (includeData, request)
	{
		if (request.readyState != 4)
			return;
			
		includeData.success = request.status == 200;

		if (includeData.success)
			includeData.xml = request.responseXML;
			
		this.resolveDeps (includeData);
	}
	
	/**
	 * Gets the DOM object from an included XML file.
	 *
	 * @param {string} path The file path
	 * @return {Object} The DOM object
	 **/
	,getXml: function (path)
	{
		var includeData = this.includes[path];
		
		if (!(includeData && includeData.success))
			return null;
			
		return includeData.xml;
	}

	/**
	 * Checks if user is using a mobile browser.
	 *
	 * return {boolean} %true if is mobile, %false otherwise.
	 **/
	,isMobile: function ()
	{
		if (this.isMobileCached === null)
		{
			var regExp = /(Android|webOS|iPhone|iPad|iPod|BlackBerry|Windows Phone)/i;
			this.isMobileCached =  navigator.userAgent.match (regExp);
		}

		return this.isMobileCached;
	}
};