const request = new XMLHttpRequest();

const training_handler = () => {

    const url = (condition) => {
        return condition ? '/api/training/complete' : '/api/training/go_back';
    };

    request.open('POST', url(training_data().answer === null || training_data().answer === get_user_answer()))
    request.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
    request.onreadystatechange = function () {//Call a function when the state changes.
        if (request.readyState === 4) {
            if(request.status === 200) {
                parent.frames['main'].location.reload();
            }

            if(request.responseText !== '') {
                let response = JSON.parse(request.responseText);

                if (response.message !== undefined) {
                    alert(response.message);
                }
            }
        }
    }

    request.send(JSON.stringify({
        time: training_data().time,
        token: training_data().token,
        short_name: training_data().short_name,
        answer: get_user_answer(),
    }))
}

function get_user_answer() {
    if(training_data().answer === '') {
        return '';
    }

    return document.getElementsByName('user_answer')[0].value;
}

(function () {
    if (typeof window.CustomEvent === "function") return false;
    function CustomEvent(event, params) {
        params = params || { bubbles: false, cancelable: false, detail: null };
        var evt = document.createEvent('CustomEvent');
        evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
        return evt;
    }
    window.CustomEvent = CustomEvent;
})();

$modal = function (options) {
    var
        _elemModal,
        _eventShowModal,
        _eventHideModal,
        _hiding = false,
        _destroyed = false,
        _animationSpeed = 200;

    function _createModal(options) {
        var
            elemModal = document.createElement('div'),
            modalTemplate = '<div class="modal__backdrop" data-dismiss="modal"><div class="modal__content"><div class="modal__header"><div class="modal__title" data-modal="title">{{title}}</div><span class="modal__btn-close" data-dismiss="modal" title="Закрыть">×</span></div><div id="modal_content" class="modal__body" data-modal="content">{{content}}</div>{{footer}}</div></div>',
            modalFooterTemplate = '<div class="modal__footer">{{buttons}}</div>',
            modalInputAnswer = '',
            modalButtonTemplate = '<button type="button" class="{{button_class}}" data-handler={{button_handler}}>{{button_text}}</button>',
            modalHTML,
            modal_content,
            modalFooterHTML = '';

        if(training_data().answer !== '') {
            modalInputAnswer = '<br><br><input name="user_answer" placeholder="Укажите ответ"/>';
        }

        elemModal.classList.add('modal');
        modalHTML = modalTemplate.replace('{{title}}', options.title || 'Новое окно');

        if (options.footerButtons) {
            for (var i = 0, length = options.footerButtons.length; i < length; i++) {
                var modalFooterButton = modalButtonTemplate.replace('{{button_class}}', options.footerButtons[i].class);
                modalFooterButton = modalFooterButton.replace('{{button_handler}}', options.footerButtons[i].handler);
                modalFooterButton = modalFooterButton.replace('{{button_text}}', options.footerButtons[i].text) + modalInputAnswer;
                modalFooterHTML += modalFooterButton;
            }
            modalFooterHTML = modalFooterTemplate.replace('{{buttons}}', modalFooterHTML);
        }
        modalHTML = modalHTML.replace('{{footer}}', modalFooterHTML);
        elemModal.innerHTML = modalHTML;
        document.body.appendChild(elemModal);

        modal_content = document.getElementById('modal_content')
        modal_content.innerHTML = options.content

        return elemModal;
    }

    function _showModal() {
        if (!_destroyed && !_hiding) {
            _elemModal.classList.add('modal__show');
            document.dispatchEvent(_eventShowModal);
        }
    }

    function _hideModal() {
        _hiding = true;
        _elemModal.classList.remove('modal__show');
        _elemModal.classList.add('modal__hiding');
        setTimeout(function () {
            _elemModal.classList.remove('modal__hiding');
            _hiding = false;
        }, _animationSpeed);
        document.dispatchEvent(_eventHideModal);
    }

    function _handlerCloseModal(e) {
        if (e.target.dataset.dismiss === 'modal') {
            _hideModal();
        }
    }

    _elemModal = _createModal(options || {});


    _elemModal.addEventListener('click', _handlerCloseModal);
    _eventShowModal = new CustomEvent('show.modal', { detail: _elemModal });
    _eventHideModal = new CustomEvent('hide.modal', { detail: _elemModal });

    return {
        show: _showModal,
        hide: _hideModal,
        destroy: function () {
            _elemModal.parentElement.removeChild(_elemModal),
                _elemModal.removeEventListener('click', _handlerCloseModal),
                _destroyed = true;
        },
        setContent: function (html) {
            _elemModal.querySelector('[data-modal="content"]').innerHTML = html;
        },
        setTitle: function (text) {
            _elemModal.querySelector('[data-modal="title"]').innerHTML = text;
        }
    }
};

let modal = $modal({
    title: training_data().title,
    content: training_data().content,
    footerButtons: [
        {
            class: 'btn btn__ok',
            text: 'Продолжить',
            handler: 'next_step'
        }
    ]
});

document.addEventListener('click', function (e) {
    if (e.target.dataset.handler === 'next_step') {
        training_handler()
    }
})