class NodeNewComments

class NodeNewComments extends NumericField {
    
    /**
     * {@inheritdoc}
     */
    public function usesGroupBy() {
        return FALSE;
    }
    
    /**
     * Database Service Object.
     *
     * @var \Drupal\Core\Database\Connection
     */
    protected $database;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity field manager.
     *
     * @var \Drupal\Core\Entity\EntityFieldManagerInterface
     */
    protected $entityFieldManager;
    
    /**
     * Constructs a \Drupal\comment\Plugin\views\field\NodeNewComments object.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin ID for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Database\Connection $database
     *   Database Service Object.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager service.
     * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
     *   The entity field manager service.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, Connection $database, EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $entity_field_manager) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->database = $database;
        $this->entityTypeManager = $entity_type_manager;
        $this->entityFieldManager = $entity_field_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('database'), $container->get('entity_type.manager'), $container->get('entity_field.manager'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function init(ViewExecutable $view, DisplayPluginBase $display, ?array &$options = NULL) {
        parent::init($view, $display, $options);
        $this->additional_fields['entity_id'] = 'nid';
        $this->additional_fields['type'] = 'type';
        $this->additional_fields['comment_count'] = [
            'table' => 'comment_entity_statistics',
            'field' => 'comment_count',
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    protected function defineOptions() {
        $options = parent::defineOptions();
        $options['link_to_comment'] = [
            'default' => TRUE,
        ];
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildOptionsForm(&$form, FormStateInterface $form_state) {
        $form['link_to_comment'] = [
            '#title' => $this->t('Link this field to new comments'),
            '#description' => $this->t("Enable to override this field's links."),
            '#type' => 'checkbox',
            '#default_value' => $this->options['link_to_comment'],
        ];
        parent::buildOptionsForm($form, $form_state);
    }
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        $this->ensureMyTable();
        $this->addAdditionalFields();
        $this->field_alias = $this->table . '_' . $this->field;
    }
    
    /**
     * {@inheritdoc}
     */
    public function preRender(&$values) {
        $user = \Drupal::currentUser();
        if ($user->isAnonymous() || empty($values)) {
            return;
        }
        $nids = [];
        $ids = [];
        foreach ($values as $id => $result) {
            $nids[] = $result->{$this->aliases['nid']};
            $values[$id]->{$this->field_alias} = 0;
            // Create a reference so we can find this record in the values again.
            if (empty($ids[$result->{$this->aliases['nid']}])) {
                $ids[$result->{$this->aliases['nid']}] = [];
            }
            $ids[$result->{$this->aliases['nid']}][] = $id;
        }
        if ($nids) {
            $result = $this->database
                ->query("SELECT [n].[nid], COUNT([c].[cid]) AS [num_comments] FROM {node} [n] INNER JOIN {comment_field_data} [c] ON [n].[nid] = [c].[entity_id] AND [c].[entity_type] = 'node' AND [c].[default_langcode] = 1\n        LEFT JOIN {history} [h] ON [h].[nid] = [n].[nid] AND [h].[uid] = :h_uid WHERE [n].[nid] IN ( :nids[] )\n        AND [c].[changed] > GREATEST(COALESCE([h].[timestamp], :timestamp1), :timestamp2) AND [c].[status] = :status GROUP BY [n].[nid]", [
                ':status' => CommentInterface::PUBLISHED,
                ':h_uid' => $user->id(),
                ':nids[]' => $nids,
                ':timestamp1' => HISTORY_READ_LIMIT,
                ':timestamp2' => HISTORY_READ_LIMIT,
            ]);
            foreach ($result as $node) {
                foreach ($ids[$node->nid] as $id) {
                    $values[$id]->{$this->field_alias} = $node->num_comments;
                }
            }
        }
    }
    
    /**
     * Prepares the link to the first new comment.
     *
     * @param string $data
     *   The XSS safe string for the link text.
     * @param \Drupal\views\ResultRow $values
     *   The values retrieved from a single row of a view's query result.
     *
     * @return string
     *   Returns a string for the link text.
     */
    protected function renderLink($data, ResultRow $values) {
        if (!empty($this->options['link_to_comment']) && $data !== NULL && $data !== '') {
            $node_type = $this->getValue($values, 'type');
            $node = Node::create([
                'nid' => $this->getValue($values, 'nid'),
                'type' => $node_type,
            ]);
            // Because there is no support for selecting a specific comment field to
            // reference, we arbitrarily use the first such field name we find.
            // @todo Provide a means for selecting the comment field.
            //   https://www.drupal.org/node/2594201
            $field_map = $this->entityFieldManager
                ->getFieldMapByFieldType('comment');
            $comment_field_name = 'comment';
            foreach ($field_map['node'] as $field_name => $field_data) {
                foreach ($field_data['bundles'] as $bundle_name) {
                    if ($node_type == $bundle_name) {
                        $comment_field_name = $field_name;
                        break 2;
                    }
                }
            }
            $page_number = $this->entityTypeManager
                ->getStorage('comment')
                ->getNewCommentPageNumber($this->getValue($values, 'comment_count'), $this->getValue($values), $node, $comment_field_name);
            $this->options['alter']['make_link'] = TRUE;
            $this->options['alter']['url'] = $node->toUrl();
            $this->options['alter']['query'] = $page_number ? [
                'page' => $page_number,
            ] : NULL;
            $this->options['alter']['fragment'] = 'new';
        }
        return $data;
    }
    
    /**
     * {@inheritdoc}
     */
    public function render(ResultRow $values) {
        $value = $this->getValue($values);
        if (!empty($value)) {
            return $this->renderLink(parent::render($values), $values);
        }
        else {
            $this->options['alter']['make_link'] = FALSE;
        }
    }

}