/**
 * Class to show toast messages.
 */
module.exports =
{
	 maxMessages: 6
	,timeout: 10 /* Seconds */
	,_container: null
	,_timeouts: null
	,_topHeap: []

	/**
	 * Shows a normal toast message.
	 *
	 * @param {String} message The message text
	 */
	,showMessage: function (message)
	{
		this._showText (message, 'message');
	}
	
	/**
	 * Shows a warning toast message.
	 *
	 * @param {String} message The message text
	 */
	,showWarning: function (message)
	{
		this._showText (message, 'warning');
	}
	
	/**
	 * Shows an error toast message.
	 *
	 * @param {String} message The message text
	 */
	,showError: function (message)
	{
		this._showText (message, 'error');
	}
	
	,pushTop: function (top)
	{
		this._topHeap.push (top);
		this._refreshPosition ();
	}
	
	,popTop: function ()
	{
		var top = this._topHeap.pop ();
		this._refreshPosition ();
		return top;
	}

	,_refreshPosition: function ()
	{
		if (!this._container)
			return;
		
		var left;
		var heapLen = this._topHeap.length;
		
		if (heapLen > 0)
		{
			var top = this._topHeap[heapLen - 1];
			var rect = top.getBoundingClientRect ();
			left = (rect.left + parseInt (rect.width / 2) - window.pageXOffset) +'px';
		}
		else
			left = '';

		this._container.style.left = left;
	}
	
	/**
	 * Hides all currently displayed toast messages.
	 */
	,hide: function ()
	{
		if (!this._container)
			return;

		if (this._timeouts)
		for (var i = 0; i < this._timeouts.length; i++)
			clearTimeout (this._timeouts[i]);

		this._timeouts = null;			

		document.removeEventListener ('mousedown', this.hideHandler);
		Vn.Node.remove (this._container);
		this._container = null;
		this.nodes = [];
	}

	,_createContainer: function ()
	{
		if (!this._container)
		{
			var container = document.createElement ('div');
			container.className = 'htk-toast';
			document.body.appendChild (container);

			this.hideHandler = this.hide.bind (this);
			document.addEventListener ('mousedown', this.hideHandler);

			this._timeouts = [];
			this._container = container;
		}

		this._refreshPosition ();
	}

	,_showText: function (message, className)
	{
		this._createContainer ();

		if (this._timeouts.length >= this.maxMessages)
			this._onMessageTimeout ();
		
		var toast = document.createElement ('div');
		toast.className = className;
		toast.addEventListener ('mousedown', this._onMessageMouseDown);

		var textNode = document.createTextNode (message);
		toast.appendChild (textNode);

		this._container.appendChild (toast);

		var timeoutId = setTimeout (this._onMessageTimeout.bind (this), this.timeout * 1000);
		this._timeouts.push (timeoutId);
		
		setTimeout (this._onShowToastTimeout.bind (this, toast), 50);
	}
	
	,_onShowToastTimeout: function (toast)
	{
		Vn.Node.addClass (toast, 'show');
	}

	,_onMessageTimeout: function ()
	{
		if (!this._container)
			return;
	
		var nodes = this._container.childNodes;
	
		if (nodes.length > 0)
		{
			clearTimeout (this._timeouts.shift ());
			Vn.Node.remove (nodes[0]);
		}
		if (nodes.length == 0)
			this.hide ();
	}
	
	,_onMessageMouseDown: function (event)
	{
		event.stopPropagation ();
	}
};