var TXT_DIV = "div.header-middle-content-left-product-description-contetnt";
var IMG_DIV = "div.header-middle-content-picture";
var ANIM_SPEED = 500;
var SWITCH_DELAY = 10000;

var numberOfItems = itemPresenterImg.length;
var currentItemID = 0; // It is also the start element ID
var animating = false;

imagesToPreload[imagesToPreloadIndex++] = IMAGES_URL+"../arrow_big_left_over.png";
imagesToPreload[imagesToPreloadIndex++] = IMAGES_URL+"../arrow_big_right_over.png";
imagesToPreload[imagesToPreloadIndex++] = IMAGES_URL+itemPresenterImg[currentItemID];

function preloadAllPresenterImages() {
    for(var i = 0; i < itemPresenterImg.length; i++) {
        preloadImage(IMAGES_URL+itemPresenterImg[i]);
    }
}

function setItem(itemID) {
    jQuery(TXT_DIV).html(itemPresenterTxt[itemID]);
    jQuery(IMG_DIV).css({'background-image' : 'url('+IMAGES_URL+itemPresenterImg[itemID]+')', 'background-repeat' : 'no-repeat', 'background-position' : 'center center'});
}

function switchItem(direction) {
    if(animating == true) {
        return;
    }
    animating = true;
    setTimeout('animating = false', ANIM_SPEED*2);

    if(direction == 'forward') {
        currentItemID = (currentItemID+1) % numberOfItems;
    }
    else if(direction == 'backward') {
        currentItemID = (currentItemID-1+numberOfItems) % numberOfItems;
    }

    jQuery(TXT_DIV).slideToggle(ANIM_SPEED);
    jQuery(IMG_DIV).fadeOut(ANIM_SPEED);
    setTimeout('setItem('+currentItemID+')', ANIM_SPEED);
    jQuery(TXT_DIV).slideToggle(ANIM_SPEED);
    jQuery(IMG_DIV).fadeIn(ANIM_SPEED);
}

function switchItemsConstantly() {
    setTimeout('switchItem(\'forward\'); switchItemsConstantly();', SWITCH_DELAY);
}

function setUpItemPresenter() {
    switchItem('');
    switchItemsConstantly();
    setTimeout('preloadAllPresenterImages()', 2000);

    jQuery("div.header-middle-content-left-outter-arrow").click(function () {
         switchItem('backward');
    });

    jQuery("div.header-middle-content-right-outter-arrow").click(function () {
         switchItem('forward');
    });
}

jQuery(document).ready(function() {
    setUpItemPresenter();
});