var currVisibleDiv;
var firstLoadedMod;
var interval;
var INTERVAL_LENGTH = 10000;

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

addLoadEvent(initPage);

function initPage() {
    var divArr = ["divHsFS", "divKamFS", "divHraFS", "divBiometricFS", "divHvFS", "divAdvocatesFS"];
    var rand = Math.floor(Math.random() * 6);
    firstLoadedMod = $get(divArr[rand]);
    firstLoadedMod.style.visibility = "visible";
    interval = setInterval(loopArticles, INTERVAL_LENGTH);
}

function moduleBtnClick(modToShow) {
    var module = $get(modToShow);
    module.style.visibility = "visible";

    if (currVisibleDiv == null) {
        currVisibleDiv = $get(modToShow);
        if (currVisibleDiv != firstLoadedMod) {
            firstLoadedMod.style.visibility = "hidden";
        }
    }
    else {
        if (currVisibleDiv != module) {
            currVisibleDiv.style.visibility = "hidden";
            currVisibleDiv = module;
        }
    }
}

var currArticleVisible = 1;
function loopArticles() {
    if (currArticleVisible == MAX_ARTICLE_LENGTH) {
        currArticleVisible = 1;
        $get('divArtSummary' + MAX_ARTICLE_LENGTH).style.visibility = 'hidden';
        $get('divArtSummary' + currArticleVisible).style.visibility = 'visible';
    } else {
        pullNextArticleSummary();
    }
}

var MAX_ARTICLE_LENGTH = 3;
function pullNextArticleSummary() {
    clearInterval(interval);
    interval = setInterval(loopArticles, INTERVAL_LENGTH);
    currArticleVisible++;
    var prevArticle = currArticleVisible - 1;
    if (currArticleVisible <= MAX_ARTICLE_LENGTH) {
        $get('divArtSummary' + prevArticle).style.visibility = 'hidden';
        $get('divArtSummary' + currArticleVisible).style.visibility = 'visible';
    }
}

function pullPrevArticleSummary() {
    clearInterval(interval);
    interval = setInterval(loopArticles, INTERVAL_LENGTH);
    var prevArticle = currArticleVisible - 1;
    if (currArticleVisible > 1) {
        $get('divArtSummary' + prevArticle).style.visibility = 'visible';
        $get('divArtSummary' + currArticleVisible).style.visibility = 'hidden';
        currArticleVisible--;
    }
}