function startApp() {
    sessionStorage.clear();

    showHideMenuLinks();

    showView('viewHome');

    $("#linkHome").click(showHomeView);

    $("#formLogin").submit(loginUser);

    $("form").submit(function(e) { e.preventDefault() });

    $("#linkHome").click(showHomeView);
    $("#linkLogin").click(showLoginView);
    $("#linkRegister").click(showRegisterView);
    $("#linkListBooks").click(listBooks);
    $("#linkCreateBook").click(showCreateBookView);
    $("#linkLogout").click(logoutUser);

    $("#buttonLoginUser").click(loginUser);
    $("#buttonRegisterUser").click(registerUser);
    $("#buttonCreateBook").click(createBook);
    $("#buttonEditBook").click(editBook);

    $("#infoBox, #errorBox").click(function() {
        $(this).fadeOut();
    });

    $(document).on({
        ajaxStart: function() { $("#loadingBox").show() },
        ajaxStop: function() { $("#loadingBox").hide() }
    });

    const kinveyBaseUrl = "https://baas.kinvey.com/";
    const kinveyAppKey = "kid_rJgqxWyml";
    const kinveyAppSecret = "a69a6d3222ce4cca9f4d2c075d6090fb";
    const kinveyAppAuthHeaders = {
        'Authorization': "Basic " +
        btoa(kinveyAppKey + ":" + kinveyAppSecret)
    };

    function showHideMenuLinks() {
        $("#linkHome").show();
        if (sessionStorage.getItem('authToken')) {
            // We have logged in user
            $("#linkLogin").hide();
            $("#linkRegister").hide();
            $("#linkListBooks").show();
            $("#linkCreateBook").show();
            $("#linkLogout").show();
        } else {
            // No logged in user
            $("#linkLogin").show();
            $("#linkRegister").show();
            $("#linkListBooks").hide();
            $("#linkCreateBook").hide();
            $("#linkLogout").hide();
        }


    }

    function showView(viewName) {
        $('main > section').hide();
        $('#' + viewName).show();

    }

    function showHomeView() {
            showView('viewHome');
    }

    function showLoginView() {
        showView('viewLogin');
        $('#formLogin').trigger('reset');

    }

    function showRegisterView() {
        $('#formRegister').trigger('reset');
        showView('viewRegister');

    }

    function listBooks() {

    }

    function showCreateBookView() {
        $('#formCreateBook').trigger('reset');
        showView('viewCreateBook');
    }

    function logoutUser() {

    }

    function loginUser() {

    }

    function registerUser() {
        let userData = {
            username: $('#formRegister input[name=username]').val(),
            password: $('#formRegister input[name=passwd]').val()
        };
        console.dir(userData)

        $.ajax({
            method: "POST",
            url: kinveyBaseUrl + "user/" + kinveyAppKey + "/",
            headers: kinveyAppAuthHeaders,
            data: Json.stringify(userData),
            contentType: 'application/json',
            success: registerSuccess,
            error: handleAjaxError
        });

        function registerSuccess() {
            alert('ok');
            //saveAuthInSession(userInfo);
            //showHideMenuLinks();
            //listBooks();
            //showInfo('User registration successful.');
        }
    }

    function createBook() {

    }

    function editBook() {

    }

    function handleAjaxError() {
        alert('error')
    }
}