class DefaultsEntityForm

class DefaultsEntityForm extends EntityForm {
    use PreviewToggleTrait;
    
    /**
     * Layout tempstore repository.
     *
     * @var \Drupal\layout_builder\LayoutTempstoreRepositoryInterface
     */
    protected $layoutTempstoreRepository;
    
    /**
     * The entity type bundle info service.
     *
     * @var \Drupal\Core\Entity\EntityTypeBundleInfoInterface
     */
    protected $entityTypeBundleInfo;
    
    /**
     * The section storage.
     *
     * @var \Drupal\layout_builder\SectionStorageInterface
     */
    protected $sectionStorage;
    
    /**
     * Constructs a new DefaultsEntityForm.
     *
     * @param \Drupal\layout_builder\LayoutTempstoreRepositoryInterface $layout_tempstore_repository
     *   The layout tempstore repository.
     * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
     *   The entity type bundle info service.
     */
    public function __construct(LayoutTempstoreRepositoryInterface $layout_tempstore_repository, EntityTypeBundleInfoInterface $entity_type_bundle_info) {
        $this->layoutTempstoreRepository = $layout_tempstore_repository;
        $this->entityTypeBundleInfo = $entity_type_bundle_info;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('layout_builder.tempstore_repository'), $container->get('entity_type.bundle.info'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getBaseFormId() {
        return $this->getEntity()
            ->getEntityTypeId() . '_layout_builder_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state, SectionStorageInterface $section_storage = NULL) {
        $form['#attributes']['class'][] = 'layout-builder-form';
        $form['layout_builder'] = [
            '#type' => 'layout_builder',
            '#section_storage' => $section_storage,
            '#process' => [
                [
                    static::class,
                    'layoutBuilderElementGetKeys',
                ],
            ],
        ];
        $form['layout_builder_message'] = $this->buildMessage($section_storage->getContextValue('display'));
        $this->sectionStorage = $section_storage;
        return parent::buildForm($form, $form_state);
    }
    
    /**
     * Form element #process callback.
     *
     * Save the layout builder element array parents as a property on the top form
     * element so that they can be used to access the element within the whole
     * render array later.
     *
     * @see \Drupal\layout_builder\Controller\LayoutBuilderHtmlEntityFormController
     */
    public static function layoutBuilderElementGetKeys(array $element, FormStateInterface $form_state, &$form) {
        $form['#layout_builder_element_keys'] = $element['#array_parents'];
        return $element;
    }
    
    /**
     * Renders a message to display at the top of the layout builder.
     *
     * @param \Drupal\layout_builder\Entity\LayoutEntityDisplayInterface $entity
     *   The entity view display being edited.
     *
     * @return array
     *   A renderable array containing the message.
     */
    protected function buildMessage(LayoutEntityDisplayInterface $entity) {
        $entity_type_id = $entity->getTargetEntityTypeId();
        $entity_type = $this->entityTypeManager
            ->getDefinition($entity_type_id);
        $bundle_info = $this->entityTypeBundleInfo
            ->getBundleInfo($entity_type_id);
        $args = [
            '@bundle' => $bundle_info[$entity->getTargetBundle()]['label'],
            '@plural_label' => $entity_type->getPluralLabel(),
        ];
        if ($entity_type->hasKey('bundle')) {
            $message = $this->t('You are editing the layout template for all @bundle @plural_label.', $args);
        }
        else {
            $message = $this->t('You are editing the layout template for all @plural_label.', $args);
        }
        return [
            '#type' => 'container',
            '#attributes' => [
                'class' => [
                    'layout-builder__message',
                    'layout-builder__message--defaults',
                ],
            ],
            'message' => [
                '#theme' => 'status_messages',
                '#message_list' => [
                    'status' => [
                        $message,
                    ],
                ],
                '#status_headings' => [
                    'status' => $this->t('Status message'),
                ],
            ],
            '#weight' => -900,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildEntity(array $form, FormStateInterface $form_state) {
        // \Drupal\Core\Entity\EntityForm::buildEntity() clones the entity object.
        // Keep it in sync with the one used by the section storage.
        $this->setEntity($this->sectionStorage
            ->getContextValue('display'));
        $entity = parent::buildEntity($form, $form_state);
        $this->sectionStorage
            ->setContextValue('display', $entity);
        return $entity;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getEntityFromRouteMatch(RouteMatchInterface $route_match, $entity_type_id) {
        $route_parameters = $route_match->getParameters()
            ->all();
        return $this->entityTypeManager
            ->getStorage('entity_view_display')
            ->load($route_parameters['entity_type_id'] . '.' . $route_parameters['bundle'] . '.' . $route_parameters['view_mode_name']);
    }
    
    /**
     * {@inheritdoc}
     */
    protected function actions(array $form, FormStateInterface $form_state) {
        $actions = parent::actions($form, $form_state);
        $actions['#attributes']['role'] = 'region';
        $actions['#attributes']['aria-label'] = $this->t('Layout Builder tools');
        $actions['submit']['#value'] = $this->t('Save layout');
        $actions['#weight'] = -1000;
        $actions['discard_changes'] = [
            '#type' => 'submit',
            '#value' => $this->t('Discard changes'),
            '#submit' => [
                '::redirectOnSubmit',
            ],
            '#redirect' => 'discard_changes',
        ];
        $actions['preview_toggle'] = $this->buildContentPreviewToggle();
        return $actions;
    }
    
    /**
     * Form submission handler.
     */
    public function redirectOnSubmit(array $form, FormStateInterface $form_state) {
        $form_state->setRedirectUrl($this->sectionStorage
            ->getLayoutBuilderUrl($form_state->getTriggeringElement()['#redirect']));
    }
    
    /**
     * {@inheritdoc}
     */
    public function save(array $form, FormStateInterface $form_state) {
        $return = $this->sectionStorage
            ->save();
        $this->layoutTempstoreRepository
            ->delete($this->sectionStorage);
        $this->messenger()
            ->addMessage($this->t('The layout has been saved.'));
        $form_state->setRedirectUrl($this->sectionStorage
            ->getRedirectUrl());
        return $return;
    }
    
    /**
     * Retrieves the section storage object.
     *
     * @return \Drupal\layout_builder\SectionStorageInterface
     *   The section storage for the current form.
     */
    public function getSectionStorage() {
        return $this->sectionStorage;
    }

}