var sliderthumbsTR;
var rowsLength;
var orgPictureName;
var imgItemSelected = -1;

function pictureLoaded() { 
	var debug = "";
	var orgPicture = document.getElementById("pictureLarge");
	var orgPictureSrc = orgPicture.src;
	
	orgPictureName = getPictureName(orgPictureSrc);
	sliderthumbsTR = document.getElementById("sliderthumbsTR");
	rowsLength = sliderthumbsTR.cells.length;
	
	for (var i=0; i < rowsLength; i++)
	{
	    var tdItem = sliderthumbsTR.cells[i];
	    var imgItem = tdItem.getElementsByTagName("img");
	    var imgItemSrc = imgItem[0].src;
	    var imgItemName = getPictureName(imgItemSrc);

	    if (orgPictureName==imgItemName)
	    {
			imgItemSelected = i;
		}
	}
	var cnt = 0;
	if (imgItemSelected <2)
	{
		cnt = 2-imgItemSelected;
		for (i=1;i<=cnt;i++)
		{
			sliderNavigate(-1);
			imgItemSelected++;
		}
	}

	if (imgItemSelected >rowsLength-3)
	{
		if (rowsLength-imgItemSelected == 1) { cnt = 2; }
		if (rowsLength-imgItemSelected == 2) { cnt = 1; }
		for (i=1;i<=cnt;i++)
		{
			sliderNavigate(1);
			imgItemSelected--;
		}
	}
	reduceSlider();

	//debug += imgItemSelected + "\n\n";
	if (debug!="") { alert(debug + "\n"); }
}

function reduceSlider()
{
	var debug = "";
	//alert(rowsLength);
	for (var i=0; i < rowsLength; i++)
	{
		//debug += i + "\n";
	    var tdItem = sliderthumbsTR.cells[i];
	    var imgItem = tdItem.getElementsByTagName("img");
	    var imgItemSrc = imgItem[0].src;
	    var imgItemName = getPictureName(imgItemSrc);
		if ((i < imgItemSelected - 2) || (i > imgItemSelected + 2))
		{
			sliderthumbsTR.cells[i].className = "sliderthumbsoff";
		}
		else
		{
			if (orgPictureName==imgItemName)
			{
				sliderthumbsTR.cells[i].className = "sliderthumbsonacitve";
			}
			else
			{
				sliderthumbsTR.cells[i].className = "sliderthumbson";
			}
		}
	}
	if (debug!="") { alert(debug + "\n"); }
}

function getPictureName(url)
{
	var pictureName = "";
	posLastSlash = url.lastIndexOf("/");
	pictureName = url.substring(posLastSlash+1);
	return pictureName;
}

function getPictureSize(url)
{
	var path = "";

	posLastSlash = url.lastIndexOf("/");
	path = url.substring(0,posLastSlash);

	posLastSlash = path.lastIndexOf("/");
	path = path.substring(posLastSlash+1);

	return path;
}

function getPictureBaseURL(url)
{
	var path = "";

	posLastSlash = url.lastIndexOf("/");
	path = url.substring(0,posLastSlash);

	posLastSlash = path.lastIndexOf("/");
	path = path.substring(0,posLastSlash);

	return path;
}

function getNewPictureURL(sourceURL, targetURL)
{
	var newURL;
	var size = getPictureSize(targetURL);
	var pictureBaseURL = getPictureBaseURL(sourceURL);
	var pictureName = getPictureName(sourceURL)

	newURL = pictureBaseURL + "/"  + size + "/" + pictureName;
	
	return newURL;
}

function sliderNavigate(move)
{
	for (var i=0; i < rowsLength; i++)
	{
		// to be able to access
	    sliderthumbsTR.cells[i].className = "sliderthumbson";
	}
	var insertPos, deletePos, copyPos
	if (move==-1)
	{
		insertPos = 0; 
		copyPos = rowsLength-1;
		deletePos = rowsLength;
	}
	else
	{
		insertPos = rowsLength; 
		copyPos = 0;
		deletePos = 0;
	}
	var tdItem = sliderthumbsTR.cells[copyPos];
	sliderthumbsTR.insertCell(insertPos);
	sliderthumbsTR.cells[insertPos].innerHTML =  tdItem.innerHTML;
	sliderthumbsTR.deleteCell(deletePos);
	reduceSlider();
} 

function sliderChosen(item)
{
	var sourcePictureSrc = item.src;
	var sourcePictureDescription = item.alt;
	var targetPicture = document.getElementById("pictureLarge");
	var targetPictureSrc = targetPicture.src;
	var targetDescription = document.getElementById("pictureDescription");
	
	var newURL = getNewPictureURL(sourcePictureSrc, targetPictureSrc)
	
	targetPicture.src = newURL;
	targetPicture.alt = sourcePictureDescription;
	targetPicture.title = sourcePictureDescription;
	targetDescription.innerHTML = sourcePictureDescription;
}