*/
function wp_post_revision_title( $revision, $link = true ) {
	$revision = get_post( $revision );

	if ( ! $revision ) {
		return $revision;
	}

	if ( ! in_array( $revision->post_type, array( 'post', 'page', 'revision' ), true ) ) {
		return false;
	}

	/* translators: Revision date format, see https://www.php.net/manual/datetime.format.php */
	$datef = _x( 'F j, Y @ H:i:s', 'revision date format' );
	/* translators: %s: Revision date. */
	$autosavef = __( '%s [Autosave]' );
	/* translators: %s: Revision date. */
	$currentf = __( '%s [Current Revision]' );

	$date      = date_i18n( $datef, strtotime( $revision->post_modified ) );
	$edit_link = get_edit_post_link( $revision->ID );
	if ( $link && current_user_can( 'edit_post', $revision->ID ) && $edit_link ) {
		$date = "<a href='$edit_link'>$date</a>";
	}

	if ( ! wp_is_post_revision( $revision ) ) {
		$date = sprintf( $currentf, $date );
	} elseif ( wp_is_post_autosave( $revision ) ) {
		$date = sprintf( $autosavef, $date );
	}

	return $date;
}

/**
 * Retrieves formatted date timestamp of a revision (linked to that revisions's page).
 *
 * @since 3.6.0
 *
 * @param int|object $revision Revision ID or revision object.
 * @param bool       $link     Optional. Whether to link to revision's page. Default true.
 * @return string|false gravatar, user, i18n formatted datetimestamp or localized 'Current Revision'.
 */
function wp_post_revision_title_expanded( $revision, $link = true ) {
	$revision = get_post( $revision );

	if ( ! $revision ) {
		return $revision;
	}

	if ( ! in_array( $revision->post_type, array( 'post', 'page', 'revision' ), true ) ) {
		return false;
	}

	$author = get_the_author_meta( 'display_name', $revision->post_author );
	/* translators: Revision date format, see https://www.php.net/manual/datetime.format.php */
	$datef = _x( 'F j, Y @ H:i:s', 'revision date format' );

	$gravatar = get_avatar( $revision->post_author, 24 );

	$date      = date_i18n( $datef, strtotime( $revision->post_modified ) );
	$edit_link = get_edit_post_link( $revision->ID );
	if ( $link && current_user_can( 'edit_post', $revision->ID ) && $edit_link ) {
		$date = "<a href='$edit_link'>$date</a>";
	}

	$revision_date_author = sprintf(
		/* translators: Post revision title. 1: Author avatar, 2: Author name, 3: Time ago, 4: Date. */
		__( '%1$s %2$s, %3$s ago (%4$s)' ),
		$gravatar,
		$author,
		human_time_diff( strtotime( $revision->post_modified_gmt ) ),
		$date
	);

	/* translators: %s: Revision date with author avatar. */
	$autosavef = __( '%s [Autosave]' );
	/* translators: %s: Revision date with author avatar. */
	$currentf = __( '%s [Current Revision]' );

	if ( ! wp_is_post_revision( $revision ) ) {
		$revision_date_author = sprintf( $currentf, $revision_date_author );
	} elseif ( wp_is_post_autosave( $revision ) ) {
		$revision_date_author = sprintf( $autosavef, $revision_date_author );
	}

	/**
	 * Filters the formatted author and date for a revision.
	 *
	 * @since 4.4.0
	 *
	 * @param string  $revision_date_author The formatted string.
	 * @param WP_Post $revision             The revision object.
	 * @param bool    $link                 Whether to link to the revisions page, as passed into
	 *                                      wp_post_revision_title_expanded().
	 */
	return apply_filters( 'wp_post_revision_title_expanded', $revision_date_author, $revision, $link );
}

/**
 * Displays a list of a post's revisions.
 *
 * Can output either a UL with edit links or a TABLE with diff interface, and
 * restore action links.
 *
 * @since 2.6.0
 *
 * @param int|WP_Post $post Optional. Post ID or WP_Post object. Default is global $post.
 * @param string      $type 'all' (default), 'revision' or 'autosave'
 */
function wp_list_post_revisions( $post = 0, $type = 'all' ) {
	$post = get_post( $post );

	if ( ! $post ) {
		return;
	}

	// $args array with (parent, format, right, left, type) deprecated since 3.6.
	if ( is_array( $type ) ) {
		$type = ! empty( $type['type'] ) ? $type['type'] : $type;
		_deprecated_argument( __FUNCTION__, '3.6.0' );
	}

	$revisions = wp_get_post_revisions( $post->ID );

	if ( ! $revisions ) {
		return;
	}

	$rows = '';
	foreach ( $revisions as $revision ) {
		if ( ! current_user_can( 'read_post', $revision->ID ) ) {
			continue;
		}

		$is_autosave = wp_is_post_autosave( $revision );
		if ( ( 'revision' === $type && $is_autosave ) || ( 'autosave' === $type && ! $is_autosave ) ) {
			continue;
		}

		$rows .= "\t<li>" . wp_post_revision_title_expanded( $revision ) . "</li>\n";
	}

	echo "<div class='hide-if-js'><p>" . __( 'JavaScript must be enabled to use this feature.' ) . "</p></div>\n";

	echo "<ul class='post-revisions hide-if-no-js'>\n";
	echo $rows;
	echo '</ul>';
}

/**
 * Retrieves the parent post object for the given post.
 *
 * @since 5.7.0
 *
 * @param int|WP_Post|null $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return WP_Post|null Parent post object, or null if there isn't one.
 */
function get_post_parent( $post = null ) {
	$wp_post = get_post( $post );
	return ! empty( $wp_post->post_parent ) ? get_post( $wp_post->post_parent ) : null;
}

/**
 * Returns whether the given post has a parent post.
 *
 * @since 5.7.0
 *
 * @param int|WP_Post|null $post Optional. Post ID or WP_Post object. Default is global $post.
 * @return bool Whether the post has a parent post.
 */
function has_post_parent( $post = null ) {
	return (bool) get_post_parent( $post );
}