/**
 * Created by Merrie on 12/20/16.
 */
function startApp() {
    const kinveyBaseUrl = "https://baas.kinvey.com/";
    const kinveyAppKey = "kid_BkgrHyPNx";
    const kinveyAppSecret = "0a80d7870a094292ab4f8e89484ccf62";
    const kinveyAppAuthHeaders = {
        'Authorization': "Basic " + btoa(kinveyAppKey + ":" + kinveyAppSecret),
    };

    //Hide status boxes
    $('#infoBox').hide();
    $('#errorBox').hide();
    $('#loadingBox').hide();

    sessionStorage.clear(); // Clear user auth data

    showHideMenuLinks();

    if(sessionStorage.getItem('authToken')) {
        $('#spanMenuLoggedInUser').text('Welcome, ' + sessionStorage.getItem('name') + '!');
        showUserHomeView()
    }else {
        $('#spanMenuLoggedInUser').empty();
        showAppHomeView();
    }

    //Bind menu links with views
    $("#linkMenuAppHome").click(showAppHomeView);
    $("#linkMenuLogin").click(showLoginView);
    $("#linkMenuRegister").click(showRegisterView);

    $("#linkMenuUserHome").click(showUserHomeView);
    $("#linkMenuShop").click(showShopView);
    $("#linkMenuCart").click(showCartView);
    $("#linkMenuLogout").click(logoutUser);

    // Bind the form submit buttons
    $(`#formLogin input[type="submit"]`).click(loginUser);
    $(`#formRegister input[type="submit"]`).click(registerUser);


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

// Attach AJAX "loading" event listener
    $(document).on({
        ajaxStart: function () {
            $("#loadingBox").show()
        },
        ajaxStop: function () {
            $("#loadingBox").hide()
        }
    });

    function showHideMenuLinks() {
        if (sessionStorage.getItem('authToken')) {
            // We have logged in user
            $("#linkMenuAppHome").hide();
            $("#linkMenuLogin").hide();
            $("#linkMenuRegister").hide();
            $("#linkMenuUserHome").show();
            $("#linkMenuShop").show();
            $("#linkMenuCart").show();
            $("#linkMenuLogout").show();
        } else {
            // No logged in user
            $("#linkMenuAppHome").show();
            $("#linkMenuLogin").show();
            $("#linkMenuRegister").show();
            $("#linkMenuUserHome").hide();
            $("#linkMenuShop").hide();
            $("#linkMenuCart").hide();
            $("#linkMenuLogout").hide();
        }
    }

    function showView(viewName) {
        // Hide all views and show the selected view only
        $('main > section').hide();
        $('#' + viewName).show();
    }

    function showAppHomeView() {
        //Bind the user home buttons
        $("#linkUserHomeShop").click(showShopView);
        $("#linkUserHomeCart").click(showCartView);
        showView('viewAppHome');
    }

    function showUserHomeView() {
        $('#viewUserHomeHeading').text('Welcome, ' + sessionStorage.getItem('name') + '!');
        showView('viewUserHome');
    }

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

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

    function showShopView() {
        $('#viewShop').empty();
        const getShopUrl = kinveyBaseUrl + "appdata/" + kinveyAppKey + `/products`;
        let table = $('<table>').append(
                    `<thead>
                        <tr>
                            <th>Product</th>
                            <th>Description</th>
                            <th>Price</th>
                            <th>Actions</th>
                        </tr>
                    </thead>`);
        $.ajax({
            method: "GET",
            url: getShopUrl,
            headers: getKinveyUserAuthHeaders(),
            success: fillTable,
            error: handleAjaxError
        });
        function fillTable(products) {
            if (products.length == 0) {
                $('#viewShop').empty();
                $('#viewShop').text('No products found.')
            }
            else {
                let tbody = $('<tbody>');
                for (let prd of products) {
                    let prcBtn = $('<button>').text("Purchase");
                    prcBtn.click(x => purchaseProduct(prd._id));
                    tbody.append($('<tr>')
                        .append($(`<td>`).text(prd.name))
                        .append($(`<td>`).text(prd.description))
                        .append($(`<td>`).text(prd.price.toFixed(2)))
                        .append($('<td>').append(prcBtn)));
                }

                table.append(tbody);
                $('#viewShop').empty();
                $('#viewShop').append(table);
            }
        }
        showView('viewShop');
    }

    function showCartView() {
        $('#viewCart').empty();
        const getCartUrl = kinveyBaseUrl + "appdata/" + kinveyAppKey + `/shoppingCart`;
        let table = $('<table>').append(
                    `<thead>
                        <tr>
                            <th>Product</th>
                            <th>Description</th>
                            <th>Quantity</th>
                            <th>Total Price</th>
                            <th>Actions</th>
                        </tr>
                    </thead>`);
        $.ajax({
            method: "GET",
            url: getCartUrl,
            headers: getKinveyUserAuthHeaders(),
            success: fillTable,
            error: handleAjaxError
        });
        function fillTable(products) {
            if (products.length == 0) {
                $('#viewCart').empty();
                $('#viewCart').text('No products found.')
            }
            else {
                let tbody = $('<tbody>');
                for (let prd of products) {
                    let prcBtn = $('<button>').text("Discard");
                    prcBtn.click(x => discardProduct(prd._id));
                    tbody.append($('<tr>')
                        .append($(`<td>`).text(prd.name))
                        .append($(`<td>`).text(prd.description))
                        .append($('<td>').text(prd.quantity))
                        .append($(`<td>`).text(prd.totalPrice.toFixed(2)))
                        .append($('<td>').append(prcBtn)));
                }

                table.append(tbody);
                $('#viewCart').empty();
                $('#viewCart').append(table);
            }
        }
        showView('viewCart');
    }

    function purchaseProduct(id) {


        let cartUrl = kinveyBaseUrl + "appdata/" + kinveyAppKey + "/shoppingCart";

        $.ajax({
            method: "GET",
            url: cartUrl,
            headers: getKinveyUserAuthHeaders(),
            success: successGet,
            error: handleAjaxError

        });

        function successGet(data){
            data = data.filter(x => x.UserId == userId && x.ProductId == id);

            if(data){

                data[0].Quantity = Number(data[0].Quantity) + 1;

                $.ajax({
                    method: "PUT",
                    url: cartUrl,
                    headers: getKinveyUserAuthHeaders(),
                    body: JSON.stringify(data[0])
                });

            } else {
                let productData = {
                    UserId: sessionStorage.getItem('userId'),
                    ProductId: id,
                    Quantity: 1
                };

                $.ajax({
                    method: "POST",
                    url: cartUrl,
                    data: productData,
                    headers: getKinveyUserAuthHeaders(),
                    success: purchaseSuccess,
                    error: handleAjaxError
                });
            }
        }

        function purchaseSuccess(){
            showInfo('Product purchased.');
        }

    }

    function loginUser(newUser) {
        newUser.preventDefault();
        let userData = {
            username: $('#loginUsername').val(),
            password: $('#loginPasswd').val()
        };

        $.ajax({
            method: "POST",
            url: kinveyBaseUrl + "user/" + kinveyAppKey + "/login",
            headers: kinveyAppAuthHeaders,
            data: userData,
            success: loginSuccess,
            error: handleAjaxError
        });

        function loginSuccess(userInfo) {
            saveAuthInSession(userInfo);
            showHideMenuLinks();
            $('#spanMenuLoggedInUser').text("Welcome, " + sessionStorage.getItem('name') + '!');
            showUserHomeView();
            showInfo('Login successful.');
        }
    }

    function registerUser(newUser) {
        newUser.preventDefault();
        let userData = {
            username: $('#registerUsername').val(),
            password: $('#registerPasswd').val(),
            name: $('#registerName').val()
        };
        $.ajax({
            method: "POST",
            url: kinveyBaseUrl + "user/" + kinveyAppKey + "/",
            headers: kinveyAppAuthHeaders,
            data: userData,
            success: registerSuccess,
            error: handleAjaxError
        });

        function registerSuccess(userInfo) {
            saveAuthInSession(userInfo);
            showHideMenuLinks();
            showUserHomeView();
            showInfo('User registration successful.');
        }
    }

    function logoutUser() {
        sessionStorage.clear();
        $('#spanMenuLoggedInUser').empty();
        showHideMenuLinks();
        showView('viewAppHome');
        showInfo('Logout successful.');
    }


    function getKinveyUserAuthHeaders() {
        return {
            'Authorization': "Kinvey " +
            sessionStorage.getItem('authToken'),
        };
    }

    function saveAuthInSession(userInfo) {
        let userAuth = userInfo._kmd.authtoken;
        sessionStorage.setItem('authToken', userAuth);
        let userId = userInfo._id;
        sessionStorage.setItem('userId', userId);
        let username = userInfo.username;
        sessionStorage.setItem('username', username);
        let name = userInfo.name;
        sessionStorage.setItem('name', name);
        $('#loggedInUser').text(
            "Welcome, " + username + "!");
    }

    function handleAjaxError(response) {
        let errorMsg = JSON.stringify(response);
        if (response.readyState === 0)
            errorMsg = "Cannot connect due to network error.";
        if (response.responseJSON &&
            response.responseJSON.description)
            errorMsg = response.responseJSON.description;
        showError(errorMsg);
    }
    function showInfo(message) {
        $('#infoBox').text(message);
        $('#infoBox').show();
        setTimeout(function () {
            $('#infoBox').fadeOut();
        }, 2000);
    }
    function showError(errorMsg) {
        $('#errorBox').text("Error: " + errorMsg);
        $('#errorBox').show();
        setTimeout(function () {
            $('#errorBox').fadeOut();
        }, 2000);
    }

}