ess.
 * @param int    $page          Comment page number.
 * @return array {
 *     Data removal results.
 *
 *     @type bool     $items_removed  Whether items were actually removed.
 *     @type bool     $items_retained Whether items were retained.
 *     @type string[] $messages       An array of messages to add to the personal data export file.
 *     @type bool     $done           Whether the eraser is finished.
 * }
 */
function wp_comments_personal_data_eraser( $email_address, $page = 1 ) {
	global $wpdb;

	if ( empty( $email_address ) ) {
		return array(
			'items_removed'  => false,
			'items_retained' => false,
			'messages'       => array(),
			'done'           => true,
		);
	}

	// Limit us to 500 comments at a time to avoid timing out.
	$number         = 500;
	$page           = (int) $page;
	$items_removed  = false;
	$items_retained = false;

	$comments = get_comments(
		array(
			'author_email'       => $email_address,
			'number'             => $number,
			'paged'              => $page,
			'orderby'            => 'comment_ID',
			'order'              => 'ASC',
			'include_unapproved' => true,
		)
	);

	/* translators: Name of a comment's author after being anonymized. */
	$anon_author = __( 'Anonymous' );
	$messages    = array();

	foreach ( (array) $comments as $comment ) {
		$anonymized_comment                         = array();
		$anonymized_comment['comment_agent']        = '';
		$anonymized_comment['comment_author']       = $anon_author;
		$anonymized_comment['comment_author_email'] = '';
		$anonymized_comment['comment_author_IP']    = wp_privacy_anonymize_data( 'ip', $comment->comment_author_IP );
		$anonymized_comment['comment_author_url']   = '';
		$anonymized_comment['user_id']              = 0;

		$comment_id = (int) $comment->comment_ID;

		/**
		 * Filters whether to anonymize the comment.
		 *
		 * @since 4.9.6
		 *
		 * @param bool|string $anon_message       Whether to apply the comment anonymization (bool) or a custom
		 *                                        message (string). Default true.
		 * @param WP_Comment  $comment            WP_Comment object.
		 * @param array       $anonymized_comment Anonymized comment data.
		 */
		$anon_message = apply_filters( 'wp_anonymize_comment', true, $comment, $anonymized_comment );

		if ( true !== $anon_message ) {
			if ( $anon_message && is_string( $anon_message ) ) {
				$messages[] = esc_html( $anon_message );
			} else {
				/* translators: %d: Comment ID. */
				$messages[] = sprintf( __( 'Comment %d contains personal data but could not be anonymized.' ), $comment_id );
			}

			$items_retained = true;

			continue;
		}

		$args = array(
			'comment_ID' => $comment_id,
		);

		$updated = $wpdb->update( $wpdb->comments, $anonymized_comment, $args );

		if ( $updated ) {
			$items_removed = true;
			clean_comment_cache( $comment_id );
		} else {
			$items_retained = true;
		}
	}

	$done = count( $comments ) < $number;

	return array(
		'items_removed'  => $items_removed,
		'items_retained' => $items_retained,
		'messages'       => $messages,
		'done'           => $done,
	);
}

/**
 * Sets the last changed time for the 'comment' cache group.
 *
 * @since 5.0.0
 */
function wp_cache_set_comments_last_changed() {
	wp_cache_set_last_changed( 'comment' );
}

/**
 * Updates the comment type for a batch of comments.
 *
 * @since 5.5.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 */
function _wp_batch_update_comment_type() {
	global $wpdb;

	$lock_name = 'update_comment_type.lock';

	// Try to lock.
	$lock_result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` ( `option_name`, `option_value`, `autoload` ) VALUES (%s, %s, 'no') /* LOCK */", $lock_name, time() ) );

	if ( ! $lock_result ) {
		$lock_result = get_option( $lock_name );

		// Bail if we were unable to create a lock, or if the existing lock is still valid.
		if ( ! $lock_result || ( $lock_result > ( time() - HOUR_IN_SECONDS ) ) ) {
			wp_schedule_single_event( time() + ( 5 * MINUTE_IN_SECONDS ), 'wp_update_comment_type_batch' );
			return;
		}
	}

	// Update the lock, as by this point we've definitely got a lock, just need to fire the actions.
	update_option( $lock_name, time() );

	// Check if there's still an empty comment type.
	$empty_comment_type = $wpdb->get_var(
		"SELECT comment_ID FROM $wpdb->comments
		WHERE comment_type = ''
		LIMIT 1"
	);

	// No empty comment type, we're done here.
	if ( ! $empty_comment_type ) {
		update_option( 'finished_updating_comment_type', true );
		delete_option( $lock_name );
		return;
	}

	// Empty comment type found? We'll need to run this script again.
	wp_schedule_single_event( time() + ( 2 * MINUTE_IN_SECONDS ), 'wp_update_comment_type_batch' );

	/**
	 * Filters the comment batch size for updating the comment type.
	 *
	 * @since 5.5.0
	 *
	 * @param int $comment_batch_size The comment batch size. Default 100.
	 */
	$comment_batch_size = (int) apply_filters( 'wp_update_comment_type_batch_size', 100 );

	// Get the IDs of the comments to update.
	$comment_ids = $wpdb->get_col(
		$wpdb->prepare(
			"SELECT comment_ID
			FROM {$wpdb->comments}
			WHERE comment_type = ''
			ORDER BY comment_ID DESC
			LIMIT %d",
			$comment_batch_size
		)
	);

	if ( $comment_ids ) {
		$comment_id_list = implode( ',', $comment_ids );

		// Update the `comment_type` field value to be `comment` for the next batch of comments.
		$wpdb->query(
			"UPDATE {$wpdb->comments}
			SET comment_type = 'comment'
			WHERE comment_type = ''
			AND comment_ID IN ({$comment_id_list})" // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
		);

		// Make sure to clean the comment cache.
		clean_comment_cache( $comment_ids );
	}

	delete_option( $lock_name );
}

/**
 * In order to avoid the _wp_batch_update_comment_type() job being accidentally removed,
 * check that it's still scheduled while we haven't finished updating comment types.
 *
 * @ignore
 * @since 5.5.0
 */
function _wp_check_for_scheduled_update_comment_type() {
	if ( ! get_option( 'finished_updating_comment_type' ) && ! wp_next_scheduled( 'wp_update_comment_type_batch' ) ) {
		wp_schedule_single_event( time() + MINUTE_IN_SECONDS, 'wp_update_comment_type_batch' );
	}
}