let sidenav = $("#menuSidenav");
let hamburger = $("#hamburger");
let backButton = $("#back-button");

let openedSidenavClass = 'sidenav-open';
let activeBackgroundClass = 'active-background';

/*
 * Open navigation menu, change Hamburger icon to selected state
 * and display the back button overlay over the page
 */

function openNav() {
    sidenav.addClass(openedSidenavClass);
    backButton.addClass(activeBackgroundClass);
    enableHamburger();
}


/*
 * Close navigation menu, change Hamburger icon back to default state
 * and hide the back button overlay
 */
function closeNav() {
    sidenav.removeClass(openedSidenavClass);
    backButton.removeClass(activeBackgroundClass);
    disableHamburger();
}


/*
 * Toggle the navigation bar
 */
function toggleNav() {
    if (sidenav.hasClass(openedSidenavClass)) {
        closeNav();
    } else {
        openNav();
    }
}

function disableHamburger() {
    hamburger.removeClass("change-clic");
}

function enableHamburger() {
    hamburger.addClass("change-clic");
}

/*
 * Open navigation menu when swiping right (if not swiping on an image)
 */
var img = document.querySelector('.sidenav');
// Create a manager to manager the element
var manager = new Hammer.Manager(img, {touchAction: "auto"}); // enable the touch action to allow scrolling on the sidenav
// Create a recognizer
var Swipe = new Hammer.Swipe();
// Add the recognizer to the manager
manager.add(Swipe);

// Subscribe to the swipe event
manager.on('swipe', function(e) {
    var direction = e.offsetDirection;
    if (direction === 4) { // right
        openNav();
    } else if (direction === 2) { // left
        closeNav();
    }
});

// Animate hamburger on hover
hamburger.hover(function(){
    hamburger.addClass("change-hover");
}, function(){
    hamburger.removeClass("change-hover");
});