/*
 * MojoZoom 0.1.4 - JavaScript Image Zoom
 * Copyright (c) 2008 Jacob Seidelin, jseidelin@nihilogic.dk, http://blog.nihilogic.dk/
 * Licensed under the MPL License [http://www.nihilogic.dk/licenses/mpl-license.txt]
 */


var MojoZoom = (function() {

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

	var defaultWidth = 256;
	var defaultHeight = 256;

	function addEvent(element, ev, handler) {

		var doHandler = function(e) {
			return handler(e || window.event);
		}
		if (element.addEventListener) {
			element.addEventListener(ev, doHandler, false);
		} else if (element.attachEvent) {
			element.attachEvent("on" + ev, doHandler);
		}
	}

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

	function getEventMousePos(element, e) {
		var scrollX = document.body.scrollLeft || document.documentElement.scrollLeft;
		var scrollY = document.body.scrollTop || document.documentElement.scrollTop;

		if (e.currentTarget) {
			var pos = getElementPos(element);
			return {
				x: e.clientX - pos.x + scrollX,
				y: e.clientY - pos.y + scrollY
			}
		}
		return {
			x: e.offsetX,
			y: e.offsetY
		}
	}

	function makeZoomable(img, zoomSrc, zoomImgCtr, zoomWidth, zoomHeight, alwaysShow) {


		// make sure the image is loaded, if not then add an onload event and return
		if (!img.complete && !img.__mojoZoomQueued) {
			addEvent(img, "load", function() {
				img.__mojoZoomQueued = true;
				setTimeout(function() {
					makeZoomable(img, zoomSrc, zoomImgCtr, zoomWidth, zoomHeight, alwaysShow);
				}, 1);
			});
			return;
		}

		img.__mojoZoomQueued = false;

		// Wrap everything in a timeout.
		// this fixes a problem where, if makeZoomable is called a second time after changing the src,
		// FF would not have figured out the new offsetHeight of the image yet. A small timeout helps though it's rather hackish.
		setTimeout(function() {

			// sorry
			var isIE = !!document.all && !!window.attachEvent && !window.opera;

			var w = img.offsetWidth;
			var h = img.offsetHeight;

			var oldParent = img.parentNode;
			if (oldParent.nodeName != "A") {
				var linkParent = dc("a");
				linkParent.setAttribute("href", zoomSrc);
				linkParent.setAttribute("target", "_blank"); //Added by NATIVE SOFTWARE MAY2010
				oldParent.replaceChild(linkParent, img);
				linkParent.appendChild(img);
			} else {
				var linkParent = oldParent;
			}

			linkParent.style.position = "relative";
			linkParent.style.display = "block";
			linkParent.style.width = w + "px";
			linkParent.style.height = h + "px";

			var imgLeft = img.offsetLeft;
			var imgTop = img.offsetTop;

			var zoom = dc("div");
			zoom.className = "mojozoom_marker";

			var zoomImg = dc("img");
			zoomImg.className = "mojozoom_img";

			zoomImg.style.position = "absolute";
			zoomImg.style.left = "-9999px";
			zoomImg.style.top = "-9999px";

			document.body.appendChild(zoomImg);

			var parent = img.parentNode;

			var ctr = dc("div");
			with (ctr.style) {
				position = "absolute";
				left = imgLeft + "px";
				top = imgTop + "px";
				width = w + "px";
				height = h + "px";
				overflow = "hidden";
				display = "none";
			}

			ctr.appendChild(zoom);
			parent.appendChild(ctr);

			var zoomInput = parent;

			// clear old overlay
			if (img.__mojoZoomOverlay)
				parent.removeChild(img.__mojoZoomOverlay);
			img.__mojoZoomOverlay = ctr;

			// clear old high-res image
			if (img.__mojoZoomImage && img.__mojoZoomImage.parentNode)
				img.__mojoZoomImage.parentNode.removeChild(img.__mojoZoomImage);
			img.__mojoZoomImage = zoomImg;

			var useDefaultCtr = false;
			if (!zoomImgCtr) {
				zoomImgCtr = dc("div");
				zoomImgCtr.className = "mojozoom_imgctr";

				var imgPos = getElementPos(img);
				zoomImgCtr.style.left = w + imgPos.x + "px";
				zoomImgCtr.style.top = imgPos.y + "px";

				zoomImgCtr.style.width = (zoomWidth ? zoomWidth : defaultWidth) + "px";
				zoomImgCtr.style.height = (zoomHeight ? zoomHeight : defaultHeight) + "px";

				document.body.appendChild(zoomImgCtr);
				useDefaultCtr = true;
			}
			zoomImgCtr.style.overflow = "hidden";

			if (!alwaysShow) {
				zoomImgCtr.style.visibility = "hidden";
			}

			addEvent(zoomImg, "load", function() {

				// bail out if img has been removed from dom
				if (!zoomImg.parentNode) return;

				var zoomWidth = zoomImg.offsetWidth;
				var zoomHeight = zoomImg.offsetHeight;

				var ctrWidth = zoomImgCtr.offsetWidth;
				var ctrHeight = zoomImgCtr.offsetHeight;

				var ratioW = zoomWidth / w;
				var ratioH = zoomHeight / h;

				var markerWidth = Math.round(ctrWidth / ratioW);
				var markerHeight = Math.round(ctrHeight / ratioH);

				document.body.removeChild(zoomImg);
				zoomImgCtr.appendChild(zoomImg);

				var zoomFill = dc("div");
				zoomFill.className = "mojozoom_fill";
				zoom.appendChild(zoomFill);

				var zoomBorder = dc("div");
				zoomBorder.className = "mojozoom_border";
				zoom.appendChild(zoomBorder);

				zoom.style.width = markerWidth + "px";
				zoom.style.height = markerHeight + "px";


				if (alwaysShow) {
					zoom.style.left = "0px";
					zoom.style.top = "0px";

					zoomImg.style.left = "0px";
					zoomImg.style.top = "0px";
				}

				var isInImage = false;

				if (!alwaysShow) {
					addEvent(zoomInput, "mouseout",
					function(e) {
						var target = e.target || e.srcElement;
						if (!target) return;
						if (target.nodeName != "DIV") return;
						var relTarget = e.relatedTarget || e.toElement;
						if (!relTarget) return;
						while (relTarget != target && relTarget.nodeName != "BODY" && relTarget.parentNode) {
							relTarget = relTarget.parentNode;
						}
						if (relTarget != target) {
							isInImage = false;
							ctr.style.display = "none";
							zoomImgCtr.style.visibility = "hidden";
						}
					}
				);
					// a bit of a hack, mouseout is sometimes not caught if moving mouse really fast
					addEvent(document.body, "mouseover",
					function(e) {
						if (isInImage && !(e.toElement == zoomBorder || e.target == zoomBorder)) {
							ctr.style.display = "none";
							zoomImgCtr.style.visibility = "hidden";
							isInImage = false;
						}
					}
				);
				}

				addEvent(zoomInput, "mousemove",
				function(e) {
					isInImage = true;

					var imgPos = getElementPos(img);

					if (useDefaultCtr) {
						zoomImgCtr.style.left = w + imgPos.x + "px";
						zoomImgCtr.style.top = imgPos.y + "px";
					}
					ctr.style.display = "block";
					zoomImgCtr.style.visibility = "visible";

					var pos = getEventMousePos(zoomInput, e);
					if (e.srcElement && isIE) {
						if (e.srcElement == zoom) return;
						if (e.srcElement != zoomInput) {
							var zoomImgPos = getElementPos(e.srcElement);
							pos.x -= (imgPos.x - zoomImgPos.x);
							pos.y -= (imgPos.y - zoomImgPos.y);
						}
					}
					var x = markerWidth / 2;
					var y = markerHeight / 2;

					if (!isIE) {
						pos.x -= imgLeft;
						pos.y -= imgTop;
					}

					if (pos.x < x) pos.x = x;
					if (pos.x > w - x) pos.x = w - x;
					if (pos.y < y) pos.y = y;
					if (pos.y > h - y) pos.y = h - y;

					var left = ((pos.x - x) | 0);
					var top = ((pos.y - y) | 0);

					zoom.style.left = left + "px";
					zoom.style.top = top + "px";

					zoomImg.style.left = -((pos.x * ratioW - ctrWidth / 2) | 0) + "px";
					zoomImg.style.top = -((pos.y * ratioH - ctrHeight / 2) | 0) + "px";
				}
			);
			});

			// I've no idea. Simply setting the src will make IE screw it self into a 100% CPU fest. In a timeout, it's ok.
			setTimeout(function() {
				zoomImg.src = zoomSrc;
			}, 1);

		}, 1);
	}

	function init() {
		var images = document.getElementsByTagName("img");
		for (var i = 0; i < images.length; i++) {
			var img = images[i];
			var zoomSrc = img.getAttribute("data-zoomsrc");
			if (zoomSrc) {
				makeZoomable(img, zoomSrc, document.getElementById(img.getAttribute("id") + "_zoom"), null, null, img.getAttribute("data-zoomalwaysshow") == "true");
			}
		}
	}

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

})();

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