var loadingImage = 'imagens/internas/produtos/load.gif';		
var closeButton = 'imagens/internas/produtos/bt_fechar_foto.gif';		

function getPageScroll(){
    
    var yScroll;
    
    if (self.pageYOffset) {
        yScroll = self.pageYOffset;
    } else if (document.documentElement && document.documentElement.scrollTop){
        yScroll = document.documentElement.scrollTop;
    } else if (document.body) {
        yScroll = document.body.scrollTop;
    }
    
    arrayPageScroll = new Array('',yScroll) 
    return arrayPageScroll;
}

function getPageSize(){
    
    var xScroll, yScroll;
    
    if (window.innerHeight && window.scrollMaxY) {	
        xScroll = document.body.scrollWidth;
        yScroll = window.innerHeight + window.scrollMaxY;
    } else if (document.body.scrollHeight > document.body.offsetHeight){
        xScroll = document.body.scrollWidth;
        yScroll = document.body.scrollHeight;
    } else {
        xScroll = document.body.offsetWidth;
        yScroll = document.body.offsetHeight;
    }
    
    var windowWidth, windowHeight;
    if (self.innerHeight) {
        windowWidth = self.innerWidth;
        windowHeight = self.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) {
        windowWidth = document.documentElement.clientWidth;
        windowHeight = document.documentElement.clientHeight;
    } else if (document.body) {
        windowWidth = document.body.clientWidth;
        windowHeight = document.body.clientHeight;
    }	
    
    if(yScroll < windowHeight){
        pageHeight = windowHeight;
    } else { 
        pageHeight = yScroll;
    }
    if(xScroll < windowWidth){	
        pageWidth = windowWidth;
    } else {
        pageWidth = xScroll;
    }
    
    
    arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
    return arrayPageSize;
}

function pause(numberMillis) {
    var now = new Date();
    var exitTime = now.getTime() + numberMillis;
    while (true) {
        now = new Date();
        if (now.getTime() > exitTime)
            return;
    }
}

function getKey(e){
    if (e == null) {
        keycode = event.keyCode;
    } else {
        keycode = e.which;
    }
    key = String.fromCharCode(keycode).toLowerCase();
    
    if(key == 'x'){ hideLightbox(); }
}

function listenKey() {	document.onkeypress = getKey; }

function showLightbox(objLink) {
    var objOverlay = document.getElementById('overlay');
    var objLightbox = document.getElementById('lightbox');
    var objCaption = document.getElementById('lightboxCaption');
    var objImage = document.getElementById('lightboxImage');
    var objLoadingImage = document.getElementById('loadingImage');
    var objLightboxDetails = document.getElementById('lightboxDetails');
    
    
    var arrayPageSize = getPageSize();
    var arrayPageScroll = getPageScroll();
    
    if (objLoadingImage) {
        objLoadingImage.style.top = (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2) + 'px');
        objLoadingImage.style.left = (((arrayPageSize[0] - 20 - objLoadingImage.width) / 2) + 'px');
        objLoadingImage.style.display = 'block';
    }
    
    objOverlay.style.height = (arrayPageSize[1] + 'px');
    objOverlay.style.display = 'block';
    
    imgPreload = new Image();
    
    imgPreload.onload=function(){
        objImage.src = objLink.href;
        
        var lightboxTop = arrayPageScroll[1] + ((arrayPageSize[3] - 35 - imgPreload.height) / 2);
        var lightboxLeft = ((arrayPageSize[0] - 20 - imgPreload.width) / 2);
        
        objLightbox.style.top = (lightboxTop < 0) ? "0px" : lightboxTop + "px";
        objLightbox.style.left = (lightboxLeft < 0) ? "0px" : lightboxLeft + "px";
        
        
        objLightboxDetails.style.width = imgPreload.width + 'px';
        
        if(objLink.getAttribute('title')){
            objCaption.style.display = 'block';
            objCaption.innerHTML = objLink.getAttribute('title');
        } else {
            objCaption.style.display = 'none';
        }
        
        if (navigator.appVersion.indexOf("MSIE")!=-1){
            pause(250);
        } 
        
        if (objLoadingImage) {	objLoadingImage.style.display = 'none'; }
        
        selects = document.getElementsByTagName("select");
        for (i = 0; i != selects.length; i++) {
            selects[i].style.visibility = "hidden";
        }
        
        
        objLightbox.style.display = 'block';
        
        arrayPageSize = getPageSize();
        objOverlay.style.height = (arrayPageSize[1] + 'px');
        
        listenKey();
        
        return false;
    }
    
    imgPreload.src = objLink.href;
    
}

function hideLightbox() {
    objOverlay = document.getElementById('overlay');
    objLightbox = document.getElementById('lightbox');
    
    objOverlay.style.display = 'none';
    objLightbox.style.display = 'none';
    
    selects = document.getElementsByTagName("select");
    for (i = 0; i != selects.length; i++) {
        selects[i].style.visibility = "visible";
    }
    
    document.onkeypress = '';
}

function initLightbox() {
    
    if (!document.getElementsByTagName){ return; }
    var anchors = document.getElementsByTagName("a");
    
    // loop through all anchor tags
    for (var i=0; i<anchors.length; i++){
        var anchor = anchors[i];
        
        if (anchor.getAttribute("href") && (anchor.getAttribute("rel") == "lightbox")){
            anchor.onclick = function () {showLightbox(this); return false;}
        }
    }
    
    var objBody = document.getElementsByTagName("body").item(0);
    
    var objOverlay = document.createElement("div");
    objOverlay.setAttribute('id','overlay');
    objOverlay.onclick = function () {hideLightbox(); return false;}
    objOverlay.style.display = 'none';
    objOverlay.style.position = 'absolute';
    objOverlay.style.top = '0';
    objOverlay.style.left = '0';
    objOverlay.style.zIndex = '90';
    objOverlay.style.width = '100%';
    objBody.insertBefore(objOverlay, objBody.firstChild);
    
    var arrayPageSize = getPageSize();
    var arrayPageScroll = getPageScroll();
    
    var imgPreloader = new Image();
    
    imgPreloader.onload=function(){
        
        var objLoadingImageLink = document.createElement("a");
        objLoadingImageLink.setAttribute('href','#');
        objLoadingImageLink.onclick = function () {hideLightbox(); return false;}
        objOverlay.appendChild(objLoadingImageLink);
        
        var objLoadingImage = document.createElement("img");
        objLoadingImage.src = loadingImage;
        objLoadingImage.setAttribute('id','loadingImage');
        objLoadingImage.style.position = 'absolute';
        objLoadingImage.style.zIndex = '150';
        objLoadingImageLink.appendChild(objLoadingImage);
        
        imgPreloader.onload=function(){};
        
        return false;
    }
    
    imgPreloader.src = loadingImage;
    
    var objLightbox = document.createElement("div");
    objLightbox.setAttribute('id','lightbox');
    objLightbox.style.display = 'none';
    objLightbox.style.position = 'absolute';
    objLightbox.style.zIndex = '100';	
    objBody.insertBefore(objLightbox, objOverlay.nextSibling);
    
    var objLink = document.createElement("a");
    objLink.setAttribute('href','#');
    objLink.setAttribute('title','Fechar');
    objLink.onclick = function () {hideLightbox(); return false;}
    objLightbox.appendChild(objLink);
    
    var imgPreloadCloseButton = new Image();
    imgPreloadCloseButton.onload=function(){
        var objCloseButton = document.createElement("img");
        objCloseButton.src = closeButton;
        objCloseButton.setAttribute('id','closeButton');
        objCloseButton.style.position = 'absolute';
        objCloseButton.style.zIndex = '200';
        objLink.appendChild(objCloseButton);
        
        return false;
    }
    
    imgPreloadCloseButton.src = closeButton;
    
    var objImage = document.createElement("img");
    objImage.setAttribute('id','lightboxImage');
    objLink.appendChild(objImage);
    
    var objLightboxDetails = document.createElement("div");
    objLightboxDetails.setAttribute('id','lightboxDetails');
    objLightbox.appendChild(objLightboxDetails);
    
    var objCaption = document.createElement("div");
    objCaption.setAttribute('id','lightboxCaption');
    objCaption.style.display = 'none';
    objCaption.style.fontSize = '11px';
    objLightboxDetails.appendChild(objCaption);
}

function addLoadEvent(func) {	
    var oldonload = window.onload;
    if (typeof window.onload != 'function'){
        window.onload = func;
    } else {
        window.onload = function(){
            oldonload();
            func();
        }
    }
    
}

addLoadEvent(initLightbox);