var loadingImage = 'lightbox/loading.gif';
var closeButton = 'lightbox/close.gif';

function getPageScroll() {
	var yScroll;

	if(self.pageYOffset) yScroll = self.pageYOffset;
	else if(document.documentElement && document.documentElement.scrollTop) yScroll = document.documentElement.scrollTop;
	else if(document.body) yScroll = document.body.scrollTop;

	arrayPageScroll = new Array('',yScroll)
	return arrayPageScroll;
}

function getPageSize() {
	var xScroll,yScroll;

	if(window.innerHeight && window.scrollMaxY) {
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if(document.body.scrollHeight > document.body.offsetHeight) {
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else {
		xScroll=document.body.offsetWidth;
		yScroll=document.body.offsetHeight;
	}

	var windowWidth,windowHeight;
	if(self.innerHeight) {
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if(document.documentElement && document.documentElement.clientHeight) {
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if(document.body){
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}

	if(yScroll < windowHeight) pageHeight = windowHeight;
	else pageHeight = yScroll;

	if(xScroll < windowWidth) pageWidth = windowWidth;
	else pageWidth = xScroll;

	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight)
	return arrayPageSize;
}

function pause(numberMillis){
	var now = new Date();
	var exitTime = now.getTime() + numberMillis;
	while(true) {
		now = new Date();
		if(now.getTime()>exitTime)
		return;
	}
}

function getKey(e){
	if(e == null) keycode=event.keyCode;
	else keycode = e.which;

	key = String.fromCharCode(keycode).toLowerCase();
	if(key == 'x') hideLightbox();
}

function listenKey() { document.onkeypress = getKey; }

function showLightbox(objLink)
{
	var objOverlay = document.getElementById('overlay');
	var objLightbox = document.getElementById('lightbox');
	var objCaption = document.getElementById('lightboxCaption');
	var objImage = document.getElementById('lightboxImage');
	var objLoadingImage = document.getElementById('loadingImage');
	var objLightboxDetails = document.getElementById('lightboxDetails');
	var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();

	if(objLoadingImage) {
		objLoadingImage.style.top = (arrayPageScroll[1]+((arrayPageSize[3]-35-objLoadingImage.height)/2)+'px');
		objLoadingImage.style.left = (((arrayPageSize[0]-20-objLoadingImage.width)/2)+'px');
		objLoadingImage.style.display = 'block';
	}

	objOverlay.style.height = (arrayPageSize[1]+'px');
	objOverlay.style.display = 'block';

	imgPreload = new Image();
	imgPreload.onload = function()
	{
		objImage.src = objLink.href;

		var lightboxTop = arrayPageScroll[1]+((arrayPageSize[3]-35-imgPreload.height)/2);
		var lightboxLeft = ((arrayPageSize[0]-20-imgPreload.width)/2);

		objLightbox.style.top = (lightboxTop<0)?"0px":lightboxTop+"px";
		objLightbox.style.left = (lightboxLeft<0)?"0px":lightboxLeft+"px";
		objLightboxDetails.style.width = imgPreload.width+'px';

		if(objLink.getAttribute('title')) {
			objCaption.style.display = 'block';
			objCaption.innerHTML = objLink.getAttribute('title');
		} else objCaption.style.display = 'none';

		if(navigator.appVersion.indexOf("MSIE")!=-1) pause(250);

		if(objLoadingImage) objLoadingImage.style.display = 'none';
		objLightbox.style.display = 'block';
		arrayPageSize = getPageSize();
		objOverlay.style.height = (arrayPageSize[1]+'px');
		listenKey();

		return false;
	}

	imgPreload.src=objLink.href;
}

function hideLightbox()
{
	objOverlay = document.getElementById('overlay');
	objLightbox = document.getElementById('lightbox');
	objOverlay.style.display = 'none';
	objLightbox.style.display = 'none';
	document.onkeypress = '';
}

function initLightbox()
{
	if(!document.getElementsByTagName) return;

	var anchors=document.getElementsByTagName("a");
	for(var i=0;i<anchors.length;i++) {
		var anchor=anchors[i];

		if(anchor.getAttribute("href") && (anchor.getAttribute("rel") == "lightbox"))
			anchor.onclick = function() { showLightbox(this); return false; }
	}

	var objBody = document.getElementsByTagName("body").item(0);
	var objOverlay = document.createElement("div");

	objOverlay.setAttribute('id','overlay');
	objOverlay.onclick = function() { hideLightbox(); return false; }
	objOverlay.style.display = 'none';
	objOverlay.style.position = 'absolute';
	objOverlay.style.top = '0';
	objOverlay.style.left = '0';
	objOverlay.style.zIndex = '90';
	objOverlay.style.width = '100%';
	objBody.insertBefore(objOverlay,objBody.firstChild);

	var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();
	var imgPreloader = new Image();

	imgPreloader.onload = function() {
		var objLoadingImageLink = document.createElement("a");
		objLoadingImageLink.setAttribute('href','#');
		objLoadingImageLink.onclick = function() { hideLightbox(); return false; }
		objOverlay.appendChild(objLoadingImageLink);

		var objLoadingImage = document.createElement("img");
		objLoadingImage.src = loadingImage;
		objLoadingImage.setAttribute('id','loadingImage');
		objLoadingImage.style.position = 'absolute';
		objLoadingImage.style.zIndex = '150';
		objLoadingImageLink.appendChild(objLoadingImage);
		imgPreloader.onload = function() {};

		return false;
	}

	imgPreloader.src = loadingImage;
	var objLightbox = document.createElement("div");
	objLightbox.setAttribute('id','lightbox');
	objLightbox.style.display = 'none';
	objLightbox.style.position = 'absolute';
	objLightbox.style.zIndex = '100';
	objBody.insertBefore(objLightbox,objOverlay.nextSibling);

	var objLink = document.createElement("a");
	objLink.setAttribute('href','#');
//	objLink.setAttribute('title','Нажмите для закрытия');
	objLink.onclick = function() { hideLightbox(); return false; }
	objLightbox.appendChild(objLink);

	var imgPreloadCloseButton = new Image();
	imgPreloadCloseButton.onload = function() {
		var objCloseButton = document.createElement("img");
		objCloseButton.src = closeButton;
		objCloseButton.setAttribute('id','closeButton');
		objCloseButton.style.position = 'absolute';
		objCloseButton.style.zIndex = '200';
		objLink.appendChild(objCloseButton);
		return false;
	}

	imgPreloadCloseButton.src = closeButton;
	var objImage = document.createElement("img");
	objImage.setAttribute('id','lightboxImage');
	objLink.appendChild(objImage);

	var objLightboxDetails = document.createElement("div");
	objLightboxDetails.setAttribute('id','lightboxDetails');
	objLightbox.appendChild(objLightboxDetails);

	var objCaption = document.createElement("div");
	objCaption.setAttribute('id','lightboxCaption');
	objCaption.style.display = 'none';
	objLightboxDetails.appendChild(objCaption);

//	var objKeyboardMsg = document.createElement("div");
//	objKeyboardMsg.setAttribute('id','keyboardMsg');
//	objKeyboardMsg.innerHTML = 'Нажмите X для закрытия.';
//	objLightboxDetails.appendChild(objKeyboardMsg);
}

function addLoadEvent(func)
{
	var oldonload = window.onload;
	if(typeof window.onload != 'function') window.onload = func;
	else window.onload = function() { oldonload(); func(); }
}

addLoadEvent(initLightbox);