class OverridesEntityForm

class OverridesEntityForm extends ContentEntityForm implements WorkspaceDynamicSafeFormInterface {
    use PreviewToggleTrait;
    use LayoutBuilderEntityFormTrait;
    use WorkspaceSafeFormTrait;
    
    /**
     * Layout tempstore repository.
     *
     * @var \Drupal\layout_builder\LayoutTempstoreRepositoryInterface
     */
    protected $layoutTempstoreRepository;
    
    /**
     * The section storage.
     *
     * @var \Drupal\layout_builder\SectionStorageInterface
     */
    protected $sectionStorage;
    
    /**
     * Constructs a new OverridesEntityForm.
     *
     * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
     *   The entity repository service.
     * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
     *   The entity type bundle service.
     * @param \Drupal\Component\Datetime\TimeInterface $time
     *   The time service.
     * @param \Drupal\layout_builder\LayoutTempstoreRepositoryInterface $layout_tempstore_repository
     *   The layout tempstore repository.
     */
    public function __construct(EntityRepositoryInterface $entity_repository, EntityTypeBundleInfoInterface $entity_type_bundle_info, TimeInterface $time, LayoutTempstoreRepositoryInterface $layout_tempstore_repository) {
        parent::__construct($entity_repository, $entity_type_bundle_info, $time);
        $this->layoutTempstoreRepository = $layout_tempstore_repository;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('entity.repository'), $container->get('entity_type.bundle.info'), $container->get('datetime.time'), $container->get('layout_builder.tempstore_repository'));
    }
    
    /**
     * {@inheritdoc}
     */
    protected function init(FormStateInterface $form_state) {
        parent::init($form_state);
        $form_display = EntityFormDisplay::collectRenderDisplay($this->entity, $this->getOperation(), FALSE);
        $form_display->setComponent(OverridesSectionStorage::FIELD_NAME, [
            'type' => 'layout_builder_widget',
            'weight' => -10,
            'settings' => [],
        ]);
        $this->setFormDisplay($form_display, $form_state);
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state, ?SectionStorageInterface $section_storage = NULL) {
        $this->sectionStorage = $section_storage;
        $form = parent::buildForm($form, $form_state);
        $form['#attributes']['class'][] = 'layout-builder-form';
        // @todo \Drupal\layout_builder\Field\LayoutSectionItemList::defaultAccess()
        //   restricts all access to the field, explicitly allow access here until
        //   https://www.drupal.org/node/2942975 is resolved.
        $form[OverridesSectionStorage::FIELD_NAME]['#access'] = TRUE;
        $form['layout_builder_message'] = $this->buildMessage($section_storage->getContextValue('entity'), $section_storage);
        return $form;
    }
    
    /**
     * Renders a message to display at the top of the layout builder.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The entity whose layout is being edited.
     * @param \Drupal\layout_builder\OverridesSectionStorageInterface $section_storage
     *   The current section storage.
     *
     * @return array
     *   A renderable array containing the message.
     */
    protected function buildMessage(EntityInterface $entity, OverridesSectionStorageInterface $section_storage) {
        $entity_type = $entity->getEntityType();
        $bundle_info = $this->entityTypeBundleInfo
            ->getBundleInfo($entity->getEntityTypeId());
        $variables = [
            '@bundle' => $bundle_info[$entity->bundle()]['label'],
            '@singular_label' => $entity_type->getSingularLabel(),
            '@plural_label' => $entity_type->getPluralLabel(),
        ];
        $defaults_link = $section_storage->getDefaultSectionStorage()
            ->getLayoutBuilderUrl();
        if ($defaults_link->access($this->currentUser())) {
            $variables[':link'] = $defaults_link->toString();
            if ($entity_type->hasKey('bundle')) {
                $message = $this->t('You are editing the layout for this @bundle @singular_label. <a href=":link">Edit the template for all @bundle @plural_label instead.</a>', $variables);
            }
            else {
                $message = $this->t('You are editing the layout for this @singular_label. <a href=":link">Edit the template for all @plural_label instead.</a>', $variables);
            }
        }
        else {
            if ($entity_type->hasKey('bundle')) {
                $message = $this->t('You are editing the layout for this @bundle @singular_label.', $variables);
            }
            else {
                $message = $this->t('You are editing the layout for this @singular_label.', $variables);
            }
        }
        return $this->buildMessageContainer($message, 'overrides');
    }
    
    /**
     * {@inheritdoc}
     */
    public function save(array $form, FormStateInterface $form_state) {
        $return = parent::save($form, $form_state);
        $this->saveTasks($form_state, $this->t('The layout override has been saved.'));
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function actions(array $form, FormStateInterface $form_state) {
        $actions = parent::actions($form, $form_state);
        $actions = $this->buildActions($actions);
        $actions['delete']['#access'] = FALSE;
        $actions['discard_changes']['#limit_validation_errors'] = [];
        // @todo This button should be conditionally displayed, see
        //   https://www.drupal.org/node/2917777.
        $actions['revert'] = [
            '#type' => 'submit',
            '#value' => $this->t('Revert to defaults'),
            '#submit' => [
                '::redirectOnSubmit',
            ],
            '#redirect' => 'revert',
        ];
        return $actions;
    }

}