if (!window.Modalbox)
	var Modalbox = new Object();

Modalbox.Methods = {
	focusableElements: new Array,
	
	setOptions: function(options) {
		this.options = {
			overlayClose: true, // Close modal box by clicking on overlay
			width: 400, // Default width in px
			height: 400, // Default height in px
			overlayDuration: .50, // Default overlay fade in/out duration in seconds
			slideDownDuration: .75, // Default Modalbox appear slide down effect in seconds
			slideUpDuration: .35, // Default Modalbox hiding slide up effect in seconds
			resizeDuration: .50, // Default resize duration seconds
			loadingString: "Attendere. Caricamento...", // Default loading string message
			closeString: "Chiudi la Finestra", // Default title attribute for close window link
			params: {},
			method: 'get' // Default Ajax request method
		};
		Object.extend(this.options, options || {});
	},
	
	_init: function() {
		//Create the overlay
		this.MBoverlay = Builder.node("div", { id: "MB_overlay" });
		//Create the window
		this.MBwindow = Builder.node("div", {id: "MB_window", style: "display: none"}, [
			this.MBframe = Builder.node("div", {id: "MB_frame"}, [
				this.MBheader = Builder.node("div", {id: "MB_header"}, [
					this.MBcaption = Builder.node("div", {id: "MB_caption"}),
					this.MBclose = Builder.node("a", {id: "MB_close", title: this.options.closeString, href: "#"}, [
						Builder.build("<span>&times;</span>"),
					]),
				]),
				this.MBcontent = Builder.node("div", {id: "MB_content"}, [
					this.MBloading = Builder.node("div", {id: "MB_loading"}, this.options.loadingString),
				]),
			]),
		]);
		// Inserting into DOM
		document.body.insertBefore(this.MBwindow, document.body.childNodes[0]);
		document.body.insertBefore(this.MBoverlay, document.body.childNodes[0]);
		//Adding event observers
		this.hide = this.hide.bindAsEventListener(this);
		this.close = this._hide.bindAsEventListener(this);
		
		// Initial scrolling position of the window. To be used for remove scrolling effect during ModalBox appearing
		this.initScrollX = window.pageXOffset || document.body.scrollLeft || document.documentElement.scrollLeft;
		this.initScrollY = window.pageYOffset || document.body.scrollTop || document.documentElement.scrollTop;
		
		Event.observe(this.MBclose, "click", this.close); // Close link overver
		if(this.options.overlayClose) Event.observe(this.MBoverlay, "click", this.hide); // Overlay close obersver

		this.isInitialized = true; // Mark as initialized
	},
	
	show: function(title, url, options) {
		this.title = title;
		this.url = url;
		this.setOptions(options);
		if(!this.isInitialized) this._init(); // Check for is already initialized
		Element.update(this.MBcaption, title); // Updating title of the MB
		
		if(this.MBwindow.style.display == "none") { // First modal box appearing
			this._appear();
			this.event("onShow"); // Passing onShow callback
		}
		else { // If MB already on the screen, update it
			this._update();
			this.event("onUpdate"); // Passing onShow callback
		} 
	},
	
	hide: function(options) { // External hide method to use from external HTML and JS
		if(options) Object.extend(this.options, options); // Passing callbacks
		Effect.SlideUp(this.MBwindow, { duration: this.options.slideUpDuration, afterFinish: this._deinit.bind(this) } );
	},
	
	_hide: function(event) { // Internal hide method to use inside MB class
		if(event) Event.stop(event);
		this.hide();
	},
	
	_appear: function() { // First appearing of MB
		this._toggleSelects();
		this._setOverlay();
		this._setWidth();
		this._setPosition();
		new Effect.Fade(this.MBoverlay, {
				from: 0, 
				to: 0.75, 
				duration: this.options.overlayDuration, 
				afterFinish: function() {
					new Effect.SlideDown(this.MBwindow, {
						duration: this.options.slideDownDuration, 
						afterFinish: function(){ 
							this._setPosition(); 
							this.loadContent();
						}.bind(this)
					});
				}.bind(this)
		});
		
		this._setWidthAndPosition = this._setWidthAndPosition.bindAsEventListener(this);
		Event.observe(window, "resize", this._setWidthAndPosition);
		
		this.kbdHandler = this.kbdHandler.bindAsEventListener(this);
		Event.observe(document, "keypress", this.kbdHandler);
	},
	
	resize: function(byWidth, byHeight, options) { // Change size of MB without loading content
		if(options) Object.extend(this.options, options); // Passing callbacks
		this.currentDims = [this.MBwindow.offsetWidth, this.MBwindow.offsetHeight];
		new Effect.ScaleBy(this.MBwindow, 
			(byWidth), //New width calculation
			(byHeight), //New height calculation
			{ duration: this.options.resizeDuration, 
			  afterFinish: function() { this.event("afterResize") }.bind(this) // Passing callback
			});
	},
	
	_update: function() { // Updating MB in case of wizards
		this.currentDims = [this.MBwindow.offsetWidth, this.MBwindow.offsetHeight];
		if((this.options.width + 10 != this.currentDims[0]) || (this.options.height + 5 != this.currentDims[1]))
			new Effect.ScaleBy(this.MBwindow, 
				(this.options.width + 10 - this.currentDims[0]), //New width calculation
				(this.options.height + 5 - this.currentDims[1]), //New height calculation
			{
				duration: this.options.resizeDuration, 
				afterFinish: this._loadAfterResize.bind(this), 
				beforeStart: function(effect) { 
					Element.update(this.MBcontent, "");
					this.MBcontent.appendChild(this.MBloading);
					Element.update(this.MBloading, this.options.loadingString);
				}.bind(this) 
			});
		else {
			Element.update(this.MBcontent, "");
			this.MBcontent.appendChild(this.MBloading);
			Element.update(this.MBloading, this.options.loadingString);
			this._loadAfterResize();
		}
	},
	
	loadContent: function () { // Load content into MB through AJAX
		if(this.event("beforeLoad") != false) // If callback passed false, skip loading of the content
			new Ajax.Request( this.url, { method: this.options.method.toLowerCase(), parameters: this.options.params, 
				onComplete: function(transport) {
					var response = new String(transport.responseText);
					this.MBcontent.innerHTML = response;
					this.focusableElements = this._findFocusableElements();
					this._moveFocus(); // Setting focus on first 'focusable' element in content (input, select, textarea, link or button)
					this.event("afterLoad"); // Passing callback
					response.extractScripts().map(function(script) { 
						return eval(script.replace("<!--", "").replace("// -->", ""));
					}).bind(window);
				}.bind(this)
			});
	},
	
	_loadAfterResize: function() {
		this._setWidth();
		this._setPosition();
		this.loadContent();
	},
	
	_moveFocus: function() { // Setting focus to be looped inside current MB
		if(this.focusableElements.length > 0)
			this.focusableElements.first().focus(); // Focus on first focusable element except close button
		else
			$("MB_close").focus(); // If no focusable elements exist focus on close button
	},
	
	_findFocusableElements: function(){ // Collect form elements or links from MB content
		return $A($("MB_content").descendants()).findAll(function(node){
			return (["INPUT", "TEXTAREA", "SELECT", "A", "BUTTON"].include(node.tagName));
		});
	},
	
	kbdHandler: function(e) {
		var node = Event.element(e);
		switch(e.keyCode) {
			case Event.KEY_TAB:
				if(Event.element(e) == this.focusableElements.last()) {
					Event.stop(e);
					this._moveFocus();  // Find last element in MB to handle event on it. If no elements found, uses close ModalBox button
				}
			break;			
			case Event.KEY_ESC:
				this._hide(e);
			break;
			case 32:
				this._preventScroll(e);
			break;
			case 0: // For Gecko browsers compatibility
				if(e.which == 32) this._preventScroll(e);
			break;
			case Event.KEY_UP:
			case Event.KEY_DOWN:
			case Event.KEY_PAGEDOWN:
			case Event.KEY_PAGEUP:
			case Event.KEY_HOME:
			case Event.KEY_END:
				if(!["TEXTAREA", "SELECT"].include(node.tagName) || 
				(node.tagName == "INPUT" && (node.type == "submit" || node.type == "button")) ) Event.stop(e);
			break;
		}
	},
	
	_preventScroll: function(event) { // Disabling scrolling by "space" key
		if(!["INPUT", "TEXTAREA", "SELECT", "BUTTON"].include(Event.element(event).tagName)) Event.stop(event);
	},
	
	_deinit: function()
	{	
		this._toggleSelects(); // Toggle back 'select' element in IE
		Event.stopObserving(this.MBclose, "click", this.close );
		if(this.options.overlayClose)
			Event.stopObserving(this.MBoverlay, "click", this.hide );
		Event.stopObserving(window, "resize", this._setWidthAndPosition );
		Event.stopObserving(document, "keypress", this.kbdHandler );
		Effect.toggle(this.MBoverlay, 'appear', {duration: this.options.overlayDuration, afterFinish: this._removeElements.bind(this) });
	},
	
	_removeElements: function () {
		if (navigator.appVersion.match(/\bMSIE\b/)) {
			this._prepareIE("", ""); // If set to auto MSIE will show horizontal scrolling
			window.scrollTo(this.initScrollX, this.initScrollY);
		}
		Element.remove(this.MBoverlay);
		Element.remove(this.MBwindow);
		this.isInitialized = false;
		this.event("afterHide"); // Passing afterHide callback
	},
	
	_setOverlay: function () {
		if (navigator.appVersion.match(/\bMSIE\b/)) {
			this._prepareIE("100%", "hidden");
			if (!navigator.appVersion.match(/\b7.0\b/)) window.scrollTo(0,0); // Disable scrolling on top for IE7
		}
	},
	
	_setWidth: function () { //Set size
		this.MBwindow.style.width = this.options.width + "px";
		this.MBwindow.style.height = this.options.height + "px";
	},
	
	_setPosition: function () {
		this.MBwindow.style.left = Math.round((Element.getWidth(document.body) - Element.getWidth(this.MBwindow)) / 2 ) + "px";
	},
	
	_setWidthAndPosition: function () {
		this._setWidth();
		this._setPosition();
	},
	
	_getScrollTop: function () { //From: http://www.quirksmode.org/js/doctypes.html
		var theTop;
		if (document.documentElement && document.documentElement.scrollTop)
			theTop = document.documentElement.scrollTop;
		else if (document.body)
			theTop = document.body.scrollTop;
		return theTop;
	},
	// For IE browsers -- IE requires height to 100% and overflow hidden (taken from lightbox)
	_prepareIE: function(height, overflow){
		bod = document.getElementsByTagName('body')[0];
		bod.style.height = height;
		bod.style.overflow = overflow;
  
		htm = document.getElementsByTagName('html')[0];
		htm.style.height = height;
		htm.style.overflow = overflow; 
	},
	// For IE browsers -- hiding all SELECT elements
	_toggleSelects: function() {
		if (navigator.appVersion.match(/\bMSIE\b/))
			$$("select").each( function(select) { 
				select.style.visibility = (select.style.visibility == "") ? "hidden" : "";
			});
	},
	event: function(eventName) {
		if(this.options[eventName]) {
			var returnValue = this.options[eventName](); // Executing callback
			this.options[eventName] = null; // Removing callback after execution
			if(returnValue != undefined) 
				return returnValue;
			else 
				return true;
		}
		return true;
	}
}

Object.extend(Modalbox, Modalbox.Methods);

Effect.ScaleBy = Class.create();
Object.extend(Object.extend(Effect.ScaleBy.prototype, Effect.Base.prototype), {
  initialize: function(element, byWidth, byHeight, options) {
    this.element = $(element)
    var options = Object.extend({
	  scaleFromTop: true,
      scaleMode: 'box',        // 'box' or 'contents' or {} with provided values
      scaleByWidth: byWidth,
	  scaleByHeight: byHeight
    }, arguments[3] || {});
    this.start(options);
  },
  setup: function() {
    this.elementPositioning = this.element.getStyle('position');
      
    this.originalTop  = this.element.offsetTop;
    this.originalLeft = this.element.offsetLeft;
	
    this.dims = null;
    if(this.options.scaleMode=='box')
      this.dims = [this.element.offsetHeight, this.element.offsetWidth];
	 if(/^content/.test(this.options.scaleMode))
      this.dims = [this.element.scrollHeight, this.element.scrollWidth];
    if(!this.dims)
      this.dims = [this.options.scaleMode.originalHeight,
                   this.options.scaleMode.originalWidth];
	  
	this.deltaY = this.options.scaleByHeight;
	this.deltaX = this.options.scaleByWidth;
  },
  update: function(position) {
    var currentHeight = this.dims[0] + (this.deltaY * position);
	var currentWidth = this.dims[1] + (this.deltaX * position);
	
    this.setDimensions(currentHeight, currentWidth);
  },

  setDimensions: function(height, width) {
    var d = {};
    d.width = width + 'px';
    d.height = height + 'px';
    
	var topd  = Math.round((height - this.dims[0])/2);
	var leftd = Math.round((width  - this.dims[1])/2);
	if(this.elementPositioning == 'absolute' || this.elementPositioning == 'fixed') {
		if(!this.options.scaleFromTop) d.top = this.originalTop-topd + 'px';
		d.left = this.originalLeft-leftd + 'px';
	} else {
		if(!this.options.scaleFromTop) d.top = -topd + 'px';
		d.left = -leftd + 'px';
	}
    this.element.setStyle(d);
  }
});