/*
 * MojoZoom 0.1.6 - 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 - parent.scrollLeft;
            y += parent.offsetTop - parent.scrollTop;
            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);
            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";

        zoomImg.style.maxWidth = "none";
        zoomImg.style.maxHeight = "none";
        zoomImg.style.zIndex = 10000001;


        document.body.appendChild(zoomImg);

        var parent = img.parentNode;

        var ctr = dc("div");
        ctr.style.position = "absolute";
        ctr.style.left = imgLeft+"px";
        ctr.style.top = imgTop+"px";
        ctr.style.width = w+"px";
        ctr.style.height = h+"px";
        ctr.style.overflow = "hidden";
        ctr.style.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.left = 200 + "px";
            zoomImgCtr.style.top = 200 + "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 ? zoomImg.offsetWidth : zoomImg.naturalWidth;
            var zoomHeight = zoomImg.offsetHeight ? zoomImg.offsetHeight : zoomImg.naturalHeight;

            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";
                    }
                    zoomImgCtr.style.left = 775 + "px";
                    zoomImgCtr.style.top = 500 + "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);