// DYNAMIC FUNCTIONALITY FOR HOME PAGE
var DISPLAY_NONE = "none";
var DISPLAY_BLOCK = "block";

var currentFeature = 1; // starting feature image
var featureCount = 6;   // number of features on home page
var showDetail = false; // is the detail information being shown?
var nextInterval = null;

function selectFeature(i) {
    clearInterval(nextInterval);
    nextInterval = setInterval(nextFeature, 5000);    

    var curHeadID = "feat-head-" + currentFeature;
    var curImgID = "feat-img-" + currentFeature;
    var curCopyID = "feat-copy-" + currentFeature;
    
    var newHeadID = "feat-head-" + i;
    var newImgID = "feat-img-" + i;
    var newCopyID = "feat-copy-" + i;

    // hide current header and image.
    document.getElementById(curHeadID).style.display = DISPLAY_NONE;
    document.getElementById(curImgID).style.display = DISPLAY_NONE;
    document.getElementById(curCopyID).style.display = DISPLAY_NONE;

    // display new header and image.
    document.getElementById(newHeadID).style.display = DISPLAY_BLOCK;
    document.getElementById(newImgID).style.display = DISPLAY_BLOCK;
    if (showDetail) {
        document.getElementById(newCopyID).style.display = DISPLAY_BLOCK;
        document.getElementById("more-" + i).innerHTML = " (hide info)";
    } else {
        document.getElementById(newCopyID).style.display = DISPLAY_NONE;
        document.getElementById("more-" + i).innerHTML = " (more info)";
    }
    
    // set the current feature to new item
    currentFeature = i;
}

function toggleDetail() {
    var copyID = "feat-copy-" + currentFeature;
    var moreID = "more-" + currentFeature;

    if (!showDetail) {
        document.getElementById(copyID).style.display = DISPLAY_BLOCK;
        document.getElementById(moreID).innerHTML = " (hide info)";
        showDetail = true;
    } else {
        document.getElementById(copyID).style.display = DISPLAY_NONE;
        document.getElementById(moreID).innerHTML = " (more info)";
        showDetail = false;
    }
}

function startFeatureTmr() {
    nextInterval = setInterval(nextFeature, 7500);
}

function nextFeature() {
    if (!showDetail) {
        if (currentFeature == featureCount) {
            selectFeature(1);
        } else {
            selectFeature(currentFeature + 1);
        }
    }
    else {
        clearInterval(nextInterval);
        nextInterval = setInterval(nextFeature, 5000); 
    }
}

function changeFontSize(newSize) {
    document.body.style.fontSize = newSize + "em";
}