var APPLICATION_ID = 'oQ8aDpqIgZlWv4i42BfByjQp0ABeKcm8LkDlcdbX';
var REST_API_KEY = '6K0s7FdX5ZQz8alsxn0xa53PF1Wuurl53NEbeBor';

function getBooks () {
    $.ajax({
        method: 'GET',
        headers: {
            'X-Parse-Application-Id': APPLICATION_ID,
            'X-Parse-REST-API-Key': REST_API_KEY
        },
        url: 'https://api.parse.com/1/classes/Book',
        success: listBooks,
        error: error
    });
};

function listBooks (data) {
    var booksList = $('<ul></ul>'),
        book = {};

    $('body').empty();
    booksList.appendTo('body');

    for(book in data.results) {
        $('<li></li>')
            .text('Title: ' + data.results[book].title + ', author: ' + data.results[book].author +', isbn: ' +
                data.results[book].isbn)
            .data('book', data.results[book])
            .click(showDataInHTMLForm)
            .appendTo(booksList);
    }
};

function showDataInHTMLForm () {
    var book = $(this).data('book');

    $('<form></form>')
        .append($('<label></label>').text('Title: ' + book.title))
        .append($('<label></label>').text('Author: ' + book.author))
        .append($('<label></label>').text('Isbn: ' + book.isbn))
        .append($('<button></button>').text('Edit book').click(editBook(book.objectId)))
        .appendTo('body');
};

function editBook (bookObjectId) {
    var newBookTitle = prompt('New book title:');
        newBookAuthor = prompt('new book author:');
        newBookIsdn = prompt('new book isdn:');

    $.ajax({
        method: 'PUT',
        headers: {
            'X-Parse-Application-Id': APPLICATION_ID,
            'X-Parse-REST-API-Key': REST_API_KEY
        },
        data: JSON.stringify({
            'title': newBookTitle,
            'author': newBookAuthor,
            'isbn': newBookIsdn
        }),
        url: 'https://api.parse.com/1/classes/Book/' + bookObjectId,
        success: getBooks,
        error: error
    });
};

function error (err) {
    throw new Error('AJAX request failure.');
};

getBooks();