interface CommentManagerInterface

interface CommentManagerInterface {
    
    /**
     * Comments are displayed in a flat list - expanded.
     */
    const COMMENT_MODE_FLAT = 0;
    
    /**
     * Comments are displayed as a threaded list - expanded.
     */
    const COMMENT_MODE_THREADED = 1;
    
    /**
     * Utility function to return an array of comment fields.
     *
     * @param string $entity_type_id
     *   The content entity type to which the comment fields are attached.
     *
     * @return array
     *   An array of comment field map definitions, keyed by field name. Each
     *   value is an array with two entries:
     *   - type: The field type.
     *   - bundles: The bundles in which the field appears, as an array with entity
     *     types as keys and the array of bundle names as values.
     */
    public function getFields($entity_type_id);
    
    /**
     * Creates a comment_body field.
     *
     * @param string $comment_type
     *   The comment bundle.
     */
    public function addBodyField($comment_type);
    
    /**
     * Provides a message if posting comments is forbidden.
     *
     * If authenticated users can post comments, a message is returned that
     * prompts the anonymous user to log in (or register, if applicable) that
     * redirects to entity comment form. Otherwise, no message is returned.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The entity to which comments are attached to.
     * @param string $field_name
     *   The field name on the entity to which comments are attached to.
     *
     * @return string
     *   HTML for a "you can't post comments" notice.
     */
    public function forbiddenMessage(EntityInterface $entity, $field_name);
    
    /**
     * Returns the number of new comments available on a given entity for a user.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The entity to which the comments are attached to.
     * @param string $field_name
     *   (optional) The field_name to count comments for. Defaults to any field.
     * @param int $timestamp
     *   (optional) Time to count from. Defaults to time of last user access the
     *   entity.
     *
     * @return int|false
     *   The number of new comments or FALSE if the user is not authenticated.
     */
    public function getCountNewComments(EntityInterface $entity, $field_name = NULL, $timestamp = 0);

}