var urlGallery = "/gallery/";
var imgRoot = "/gallery/photos/";
var category = "";
var activeSpace = 200;

var scrollAmount = 3;
var scrollRepeat = 20;
var directionDown = 0;
var directionUp = 1;
var directionLeft = 2;
var directionRight = 3;
var contentTop = null;
var contentLeft = null;
var scrollDirection = null;
var scrollTimer = null;

function PointToElement(el, e) {
	elPos = GetElementPosition(el);
	evPos = GetEventPosition(e);
	return [evPos[0] - elPos[0], evPos[1] - elPos[1]];
}

function GetEventPosition(e) {
	var left = top = 0;
	
	if (!e) {
		e = window.event;
	}
	if (e.pageX || e.pageY) {
		left = e.pageX;
		top = e.pageY;
	} else if (e.clientX || e.clientY) {
		left = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
		top = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
	}

	return [left, top];
}

function GetElementPosition(el) {
	var left = top = 0;

	if (el.offsetParent) {
		left = el.offsetLeft;
		top = el.offsetTop;
		el = el.offsetParent;
		while (el != null) {
			left += el.offsetLeft;
			top += el.offsetTop;
			el = el.offsetParent;
		}
	}
	return [left, top];
}

function InitScroll(type) {
	
	if (type == "web") {

		scrollAmount = 3;
		scrollRepeat = 20;

		el = document.getElementById("page");
	
		btn = document.createElement("div");
		btn.id = "btnScrollUp";
		btn.onmouseover = function() {ScrollUp("content");};
		btn.onmouseout = function() {StopScroll();};
		el.appendChild(btn);
	
		btn = document.createElement("div");
		btn.id = "btnScrollDown";
		btn.onmouseover = function() {ScrollDown("content");};
		btn.onmouseout = function() {StopScroll();};
		el.appendChild(btn);
		
		document.getElementById("contentOuter").style.overflow = "hidden";
	
	} else if (type == "gallery") {

		scrollAmount = 5;
		scrollRepeat = 15;

		el = document.getElementById("thumbnails");
		if (el != null) {
			el.style.overflow = "visible";
			el = document.getElementById("thumbnailsOuter");
			el.style.overflow = "hidden";

			el = document.getElementById("content");
			
			div = document.createElement("div");
			div.id = "btnScrollRight";
			div.onmouseover = function() {ScrollLeft("thumbnails");};
			div.onmouseout = function() {StopScroll();};
			el.appendChild(div);
	
			div = document.createElement("div");
			div.id = "btnScrollLeft";
			div.onmouseover = function() {ScrollRight("thumbnails");};
			div.onmouseout = function() {StopScroll();};
			el.appendChild(div);
		}

	}
}

function StopScroll() {
	scrollDirection = null;
	if (scrollTimer != null) {
		clearTimeout(scrollTimer);
		scrollTimer = null;
	}
}

function Scroll(elementId) {
	if (scrollDirection == null) {
		return;
	}
	
	stopScroll = false;
	
	el = document.getElementById(elementId);
	
	if ((scrollDirection == directionUp) || (scrollDirection == directionDown)) {

		if (contentTop == null) {
			contentTop = el.offsetTop;
		}
		if (scrollDirection == directionDown) {
			contentTop -= scrollAmount;
			if (contentTop < (el.parentNode.offsetHeight - el.offsetHeight)) {
				contentTop = el.parentNode.offsetHeight - el.offsetHeight;
			}
		} else {
			contentTop += scrollAmount;
			if (contentTop > 0) {
				contentTop = 0;
				stopScroll = true;
			}
		}
		el.style.top = contentTop + "px";

	} else {

		if (contentLeft == null) {
			contentLeft = el.offsetLeft;
		}
		if (scrollDirection == directionLeft) {
			contentLeft -= (scrollAmount * 2);
			if (contentLeft < (el.parentNode.offsetWidth - el.offsetWidth)) {
				contentLeft = el.parentNode.offsetWidth - el.offsetWidth;
			}
		} else {
			contentLeft += (scrollAmount * 2);
			if (contentLeft > 0) {
				contentLeft = 0;
				stopScroll = true;
			}
		}
		el.style.left = contentLeft + "px";

	}
	
	if (stopScroll) {
		StopScroll();
	} else {
		scrollTimer = setTimeout("Scroll('" + elementId + "');", scrollRepeat)
	}
}

function ScrollDown(elementId) {
	scrollDirection = directionDown;
	Scroll(elementId);
}

function ScrollUp(elementId) {
	scrollDirection = directionUp;
	Scroll(elementId);
}

function ScrollLeft(elementId) {
	scrollDirection = directionLeft;
	Scroll(elementId);
}

function ScrollRight(elementId) {
	scrollDirection = directionRight;
	Scroll(elementId);
}


function GetImagesInfo(image) {
	var xmlRequest = (window.XMLHttpRequest) ? new XMLHttpRequest() : new ActiveXObject("Msxml2.XMLHTTP");
	if (xmlRequest == null) {
		return;
	}
	xmlRequest.open("GET", urlGallery + "get-images.php?cat=" + category + "&img=" + image, true);
	xmlRequest.onreadystatechange = function(){GetImagesInfoHandler(xmlRequest);};
	xmlRequest.send(null);
}

function GetImagesInfoHandler(xmlRequest) {
	if (xmlRequest.readyState === 4) {
		prevImg = "";
		tmp = xmlRequest.responseXML.documentElement.getElementsByTagName("prevImage")[0].childNodes[0];
		if (tmp != null) {
			prevImg = tmp.nodeValue;
		}
		nextImg = "";
		tmp = xmlRequest.responseXML.documentElement.getElementsByTagName("nextImage")[0].childNodes[0];
		if (tmp != null) {
			nextImg = tmp.nodeValue;
		}
		img = document.getElementById("imgTag");
		imgDiv = document.getElementById("image");
		pLinks = document.getElementById("navLinks");
		lnkImg = document.getElementById("linkImg");
		lnkPrev = document.getElementById("linkPrev");
		lnkNext = document.getElementById("linkNext");

		if (prevImg == "") {

			if (lnkPrev != null) {
				lnkPrev.parentNode.removeChild(lnkPrev);
			}

		} else {

			if (lnkPrev == null) {
				lnkPrev = document.createElement("a");
				lnkPrev.id = "linkPrev";
				lnkPrev.title = "Predošlá fotografia.";
				lnkPrev.nodeValue = "predošlá";
				lnkPrev.appendChild(document.createElement("span"));
				if (lnkNext == null) {
					pLinks.appendChild(lnkPrev);
				} else {
					pLinks.insertBefore(lnkPrev, lnkNext);
				}
			}
			lnkPrev.href = urlGallery + "?cat=" + category + "&img=" + prevImg;
			lnkPrev.onclick = function() {return ShowImage(prevImg);};
	
		}



		if (nextImg == "") {

			if (lnkNext != null) {
				lnkNext.parentNode.removeChild(lnkNext);
			}
			if (lnkImg != null) {
				lnkImg.removeChild(img);
				imgDiv.removeChild(lnkImg);
				imgDiv.appendChild(img);
			}

		} else {

			if (lnkNext == null) {

				lnkNext = document.createElement("a");
				lnkNext.id = "linkNext";
				lnkNext.title = "Ďalšia fotografia.";
				lnkNext.nodeValue = "ďalšia";
				lnkNext.appendChild(document.createElement("span"));
				pLinks.appendChild(lnkNext);
			}
			if (lnkImg == null) {

				lnkImg = document.createElement("a");
				lnkImg.id = "linkImg";
				lnkImg.title = "Ďalšia fotografia.";
				imgDiv.removeChild(img);
				lnkImg.appendChild(img);
				imgDiv.appendChild(lnkImg);
			}

			href = urlGallery + "?cat=" + category + "&img=" + nextImg;
			lnkNext.href = href;
			lnkNext.onclick = function() {return ShowImage(nextImg);};
			lnkImg.href = href;
			lnkImg.onclick = function() {return ShowImage(nextImg);};

		}

	}
}



function ShowImage(image) {
	GetImagesInfo(image);
	img = document.getElementById("imgTag");
	img.src = imgRoot + category + "/" + image;

	return false;
}