class CommentLazyBuilders

class CommentLazyBuilders implements TrustedCallbackInterface {
    
    /**
     * The entity type manager service.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity form builder service.
     *
     * @var \Drupal\Core\Entity\EntityFormBuilderInterface
     */
    protected $entityFormBuilder;
    
    /**
     * Comment manager service.
     *
     * @var \Drupal\comment\CommentManagerInterface
     */
    protected $commentManager;
    
    /**
     * Current logged in user.
     *
     * @var \Drupal\Core\Session\AccountInterface
     */
    protected $currentUser;
    
    /**
     * The module handler service.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * The renderer service.
     *
     * @var \Drupal\Core\Render\RendererInterface
     */
    protected $renderer;
    
    /**
     * Constructs a new CommentLazyBuilders object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager service.
     * @param \Drupal\Core\Entity\EntityFormBuilderInterface $entity_form_builder
     *   The entity form builder service.
     * @param \Drupal\Core\Session\AccountInterface $current_user
     *   The current logged in user.
     * @param \Drupal\comment\CommentManagerInterface $comment_manager
     *   The comment manager service.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler service.
     * @param \Drupal\Core\Render\RendererInterface $renderer
     *   The renderer service.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFormBuilderInterface $entity_form_builder, AccountInterface $current_user, CommentManagerInterface $comment_manager, ModuleHandlerInterface $module_handler, RendererInterface $renderer) {
        $this->entityTypeManager = $entity_type_manager;
        $this->entityFormBuilder = $entity_form_builder;
        $this->currentUser = $current_user;
        $this->commentManager = $comment_manager;
        $this->moduleHandler = $module_handler;
        $this->renderer = $renderer;
    }
    
    /**
     * #lazy_builder callback; builds the comment form.
     *
     * @param string $commented_entity_type_id
     *   The commented entity type ID.
     * @param string $commented_entity_id
     *   The commented entity ID.
     * @param string $field_name
     *   The comment field name.
     * @param string $comment_type_id
     *   The comment type ID.
     *
     * @return array
     *   A renderable array containing the comment form.
     */
    public function renderForm($commented_entity_type_id, $commented_entity_id, $field_name, $comment_type_id) {
        $values = [
            'entity_type' => $commented_entity_type_id,
            'entity_id' => $commented_entity_id,
            'field_name' => $field_name,
            'comment_type' => $comment_type_id,
            'pid' => NULL,
        ];
        $comment = $this->entityTypeManager
            ->getStorage('comment')
            ->create($values);
        return $this->entityFormBuilder
            ->getForm($comment);
    }
    
    /**
     * #lazy_builder callback; builds a comment's links.
     *
     * @param string $comment_entity_id
     *   The comment entity ID.
     * @param string $view_mode
     *   The view mode in which the comment entity is being viewed.
     * @param string $langcode
     *   The language in which the comment entity is being viewed.
     * @param bool $is_in_preview
     *   Whether the comment is currently being previewed.
     *
     * @return array
     *   A renderable array representing the comment links.
     */
    public function renderLinks($comment_entity_id, $view_mode, $langcode, $is_in_preview) {
        $links = [
            '#theme' => 'links__comment',
            '#pre_render' => [
                [
                    Link::class,
                    'preRenderLinks',
                ],
            ],
            '#attributes' => [
                'class' => [
                    'links',
                    'inline',
                ],
            ],
        ];
        if (!$is_in_preview) {
            
            /** @var \Drupal\comment\CommentInterface $entity */
            $entity = $this->entityTypeManager
                ->getStorage('comment')
                ->load($comment_entity_id);
            if ($commented_entity = $entity->getCommentedEntity()) {
                $links['comment'] = $this->buildLinks($entity, $commented_entity);
            }
            // Allow other modules to alter the comment links.
            $hook_context = [
                'view_mode' => $view_mode,
                'langcode' => $langcode,
                'commented_entity' => $commented_entity,
            ];
            $this->moduleHandler
                ->alter('comment_links', $links, $entity, $hook_context);
        }
        return $links;
    }
    
    /**
     * Build the default links (reply, edit, delete …) for a comment.
     *
     * @param \Drupal\comment\CommentInterface $entity
     *   The comment object.
     * @param \Drupal\Core\Entity\EntityInterface $commented_entity
     *   The entity to which the comment is attached.
     *
     * @return array
     *   An array that can be processed by Link::preRenderLinks().
     *
     * @see \Drupal\Core\Render\Element\Link::preRenderLinks()
     */
    protected function buildLinks(CommentInterface $entity, EntityInterface $commented_entity) {
        $links = [];
        $status = $commented_entity->get($entity->getFieldName())->status;
        if ($status == CommentItemInterface::OPEN) {
            if ($entity->access('delete')) {
                $links['comment-delete'] = [
                    'title' => t('Delete'),
                    'url' => $entity->toUrl('delete-form'),
                ];
            }
            if ($entity->access('update')) {
                $links['comment-edit'] = [
                    'title' => t('Edit'),
                    'url' => $entity->toUrl('edit-form'),
                ];
            }
            $field_definition = $commented_entity->getFieldDefinition($entity->getFieldName());
            if ($entity->isPublished() && $entity->access('create') && $field_definition->getSetting('default_mode') === CommentManagerInterface::COMMENT_MODE_THREADED) {
                $links['comment-reply'] = [
                    'title' => t('Reply'),
                    'url' => Url::fromRoute('comment.reply', [
                        'entity_type' => $entity->getCommentedEntityTypeId(),
                        'entity' => $entity->getCommentedEntityId(),
                        'field_name' => $entity->getFieldName(),
                        'pid' => $entity->id(),
                    ]),
                ];
            }
            if (!$entity->isPublished() && $entity->access('approve')) {
                $links['comment-approve'] = [
                    'title' => t('Approve'),
                    'url' => Url::fromRoute('comment.approve', [
                        'comment' => $entity->id(),
                    ]),
                ];
            }
            if (empty($links) && $this->currentUser
                ->isAnonymous()) {
                $links['comment-forbidden']['title'] = $this->commentManager
                    ->forbiddenMessage($commented_entity, $entity->getFieldName());
            }
        }
        // Add translations link for translation-enabled comment bundles.
        if ($this->moduleHandler
            ->moduleExists('content_translation') && $this->access($entity)
            ->isAllowed()) {
            $links['comment-translations'] = [
                'title' => t('Translate'),
                'url' => $entity->toUrl('drupal:content-translation-overview'),
            ];
        }
        return [
            '#theme' => 'links__comment__comment',
            // The "entity" property is specified to be present, so no need to check.
'#links' => $links,
            '#attributes' => [
                'class' => [
                    'links',
                    'inline',
                ],
            ],
        ];
    }
    
    /**
     * Wraps content_translation_translate_access.
     */
    protected function access(EntityInterface $entity) {
        return content_translation_translate_access($entity);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function trustedCallbacks() {
        return [
            'renderLinks',
            'renderForm',
        ];
    }

}