/**
 * Funkce pro posouvani videa na uvodni strance
 */
$(document).ready(function() {
    homepagepage_init();
});

function homepagepage_init() {
    homepage_slider_init();
}

function homepage_slider_init() {
    var visible = 3;
    $("#homepage_slider > div").jCarouselLite({
        btnNext: "#homepage_slider_next",
        btnPrev: "#homepage_slider_prev",
        circular: false,
        visible: visible,
        speed: 700
    });
    $("#homepage_slider_left_bg, #homepage_slider_right_bg")
        .css("opticaly", "50%")
        .css("opacity", "0.5")
        .css("filter", "alpha(opacity=50)")
        .css("-moz-opacity", "0.5")
        .css("-khtml-opacity", "0.5");
        
    // Navigation init
    var position = 0;
    var totalItems = $("#homepage_slider ul > li").length;
    var prev = $("#homepage_slider_prev");
    var prevImg = prev.children("img");
    var next = $("#homepage_slider_next");
    var nextImg = next.children("img");

    if (totalItems > 3) {
        prev.click(function() {
            if (position > 0) {
                position--;
                if (position == 0) {
                    homepage_slider_arrow_control("prev", false);
                }
                homepage_slider_arrow_control("next", true);
            }
//            alert(position);
        });
        next.click(function() {
            if (position + visible < totalItems) {
                position++;
                if (position + visible == totalItems) {
                    homepage_slider_arrow_control("next", false);
                } 
                homepage_slider_arrow_control("prev", true);
            }
//            alert(position);
        });
    }
    
    // Defautl state
    homepage_slider_arrow_control("prev", false);
    if (totalItems < 4) {
        homepage_slider_arrow_control("next", false);
    }
}

function homepage_slider_arrow_control(side, active) {
    var arrow = $("#homepage_slider_" + side);
    var attrClass = "deactive_" + side;
    if (active == false) {
        arrow.addClass(attrClass);
    } else {
        arrow.removeClass(attrClass);
    }
}