/*
 * MojoZoom 0.1 - JavaScript Image Zoom
 * Copyright (c) 2008 Jacob Seidelin, cupboy@gmail.com, http://blog.nihilogic.dk/
 * MIT License [http://www.opensource.org/licenses/mit-license.php]
 */


var MojoZoom = (function() {

	var $ = function(id) {return document.getElementById(id);};
	var dc = function(tag) {return document.createElement(tag);};

	var iDefaultWidth = 256;
	var iDefaultHeight = 256;

	function addEvent(oElement, strEvent, fncHandler)
	{
		var fncEvent = function(e) {
			return fncHandler(e||window.event);
		}
		if (oElement.addEventListener) {
			oElement.addEventListener(strEvent, fncEvent, false);
		} else if (oElement.attachEvent) {
			oElement.attachEvent("on" + strEvent, fncEvent);
		}
	}

	function getElementPos(oElement)
	{
		var x = oElement.offsetLeft;
		var y = oElement.offsetTop;
		var oParent = oElement.offsetParent;
		while (oParent) {
			x += oParent.offsetLeft;
			y += oParent.offsetTop;
			oParent = oParent.offsetParent;
		}
		return {
			x : x,
			y : y
		}
	}

	function getEventMousePos(oElement, e) {
		var iScrollX = $("MB_content").scrollLeft;
		var iScrollY = $("MB_content").scrollTop;

		if (e.currentTarget) {
			var oElPos = getElementPos(oElement);
			return {
				x : e.clientX - oElPos.x + iScrollX,
				y : e.clientY - oElPos.y + iScrollY
			}

		}

		return {
			x : e.offsetX,
			y : e.offsetY
		}
	}

	function isIE() { // sorry
		return !!document.all && !!window.attachEvent && !window.opera;
	}


	function makeZoomable(oImg, strZoomSrc, oZoomImgCtr, iZWidth, iZHeight, deactivate) {

		var iWidth = oImg.offsetWidth;
		var iHeight = oImg.offsetHeight;

		var oOldParent = oImg.parentNode;
		if (oOldParent.nodeName != "A") {
			var oLinkParent = dc("a");
			oLinkParent.writeAttribute("href", strZoomSrc);
			oOldParent.replaceChild(oLinkParent, oImg);
			oLinkParent.appendChild(oImg);
		} else {
			var oLinkParent = oOldParent;
		}

		oLinkParent.style.position = "relative";
		oLinkParent.style.display = "block";
		oLinkParent.style.width = iWidth+"px";
		oLinkParent.style.height = iHeight+"px";

		if ($('mojozoom_marker'))
		{
			$('mojozoom_marker').parentNode.removeChild($('mojozoom_marker'));
		}

		if ($('mojozoom_img'))
		{
			$('mojozoom_img').parentNode.removeChild($('mojozoom_img'));
		}
		if ($('mojozoom_imgctr'))
		{
			$('mojozoom_imgctr').parentNode.removeChild($('mojozoom_imgctr'));
		}
		if ($('oCtr'))
		{
			$('oCtr').parentNode.removeChild($('oCtr'));
		}
		if ($('mojozoom_fill'))
		{
			$('mojozoom_fill').parentNode.removeChild($('mojozoom_fill'));
		}
		if ($('mojozoom_border'))
		{
			$('mojozoom_border').parentNode.removeChild($('mojozoom_border'));
		}

		if (deactivate)
		{
			return;
		}

		//Это то, что внутри квадратика, перемещающегося по картинке...
		var oZoom = dc("div");
		oZoom.className = "mojozoom_marker";
		oZoom.id = 'mojozoom_marker';

		var oZoomImg = dc("img");
		oZoomImg.className = "mojozoom_img";
		oZoomImg.id = "mojozoom_img";

		oZoomImg.style.position = "absolute";
		oZoomImg.style.left = "-9999px";
		$("viewlargediv").appendChild(oZoomImg);

		var oParent = oImg.parentNode;

		var oCtr = dc("div");
		oCtr.id = "oCtr";
		oCtr.style.position = "absolute";
		oCtr.style.left = "0px";
		oCtr.style.top = "0px";
		//alert(iHeight);
		oCtr.style.width = iWidth+"px";
		oCtr.style.height = iHeight+"px";
		oCtr.style.overflow = "hidden";
		oCtr.style.display = "none";
		//oCtr.style.background = "green";

		oCtr.appendChild(oZoom);
		oParent.appendChild(oCtr);

		var oZoomInput = oParent;

		var bDefaultCtr = false;
		if (!oZoomImgCtr) {
			//Контейнер увеличенной картинки...
			oZoomImgCtr = dc("div");
			oZoomImgCtr.id = "mojozoom_imgctr";
			oZoomImgCtr.className = "mojozoom_imgctr";

			var oImgPos = getElementPos(oImg);
			oZoomImgCtr.style.left = iWidth + "px";
			oZoomImgCtr.style.top = "-9999px";

			oZoomImgCtr.style.width = (iWidth ? iWidth : iDefaultWidth) +"px";
			oZoomImgCtr.style.height = (iHeight ? iHeight : iDefaultHeight) +"px";

			$("viewlargediv").appendChild(oZoomImgCtr);

			bDefaultCtr = true;
		}

		oZoomImgCtr.style.overflow = "hidden";

		oZoomImg.src = strZoomSrc;

		var iZoomWidth = oZoomImg.offsetWidth;
		var iZoomHeight = oZoomImg.offsetHeight;

		var iCtrWidth = oZoomImgCtr.offsetWidth;
		var iCtrHeight = oZoomImgCtr.offsetHeight;

		var fRatioW = iZoomWidth / iWidth;
		var fRatioH = iZoomHeight / iHeight;

//		var iMarkerWidth = Math.round(iCtrWidth / fRatioW);
//		var iMarkerHeight = Math.round(iCtrHeight / fRatioH);

		var iMarkerWidth = Math.round(iCtrWidth / fRatioW);
		var iMarkerHeight = Math.round(iCtrHeight / fRatioH);

		$("viewlargediv").removeChild(oZoomImg);
		oZoomImgCtr.appendChild(oZoomImg);

		var oZoomFill = dc("div");
		oZoomFill.className = "mojozoom_fill";
		oZoomFill.id = "mojozoom_fill";
		oZoom.appendChild(oZoomFill);

		var oZoomBorder = dc("div");
		oZoomBorder.className = "mojozoom_border";
		oZoomBorder.id = "mojozoom_border";
		oZoom.appendChild(oZoomBorder);

		oZoom.style.width = iMarkerWidth+"px";
		oZoom.style.height = iMarkerHeight+"px";

		oZoomBorder.style.width = iMarkerWidth+"px";
		oZoomBorder.style.height = iMarkerHeight+"px";

		addEvent(oZoomInput, "mouseout",
			function(e) {
				var oTarget = e.target || e.srcElement;
				if (!oTarget) return;
				if (oTarget.nodeName != "DIV") return;
				var oRelated = e.relatedTarget || e.toElement;
				if (!oRelated) return;
				while (oRelated != oTarget && oRelated.nodeName != "BODY" && oRelated.parentNode) {
					oRelated = oRelated.parentNode;
				}
				if (oRelated != oTarget) {
					oCtr.style.display = "none";
					oZoomImgCtr.style.visibility = "hidden";
				}
			}
		);
		addEvent(oZoomInput, "mousemove",
			function(e) {
				var oImgPos = getElementPos(oImg);

				if (bDefaultCtr) {
					oZoomImgCtr.style.left = (iWidth - 15) + "px";
					oZoomImgCtr.style.top = "80px";
				}
				oCtr.style.display = "block";
				oZoomImgCtr.style.visibility = "visible";

				var oPos = getEventMousePos(oZoomInput, e);

				if (e.srcElement && isIE()) {
					if (e.srcElement == oZoom) return;
					if (e.srcElement != oZoomInput) {
						var oZoomImgPos = getElementPos(e.srcElement);
						oPos.x -= (oImgPos.x - oZoomImgPos.x);
						oPos.y -= (oImgPos.y - oZoomImgPos.y);
					}
				}

				oPos.x = Math.min(Math.max(oPos.x, iMarkerWidth/2), iWidth-iMarkerWidth/2);
				oPos.y = Math.min(Math.max(oPos.y, iMarkerHeight/2), iHeight-iMarkerHeight/2);

				var iLeft = oPos.x - iMarkerWidth/2;
				var iTop = oPos.y - iMarkerHeight/2;

				oZoom.style.left = iLeft + "px";
				oZoom.style.top = iTop + "px";

				oZoomImg.style.left = -(oPos.x*fRatioW - iCtrWidth/2)+"px";
				oZoomImg.style.top = -(oPos.y*fRatioH - iCtrHeight/2)+"px";

			}
		);

	}

	function init() {
		var aImages = document.getElementsByTagName("img");
		for (var i=0;i<aImages.length;i++) {

			var oImg = aImages[i];
			var strZoomSrc = oImg.getAttribute("data-zoomsrc");

			if (strZoomSrc) {
				makeZoomable(oImg, strZoomSrc, document.getElementById(oImg.getAttribute("id") + "_zoom"));
			}
		}
	}


	return {
		addEvent : addEvent,
		init : init,
		makeZoomable : makeZoomable
	};

})();

MojoZoom.addEvent(window, "load", MojoZoom.init);