wp_plupload_default_settings

	foreach ( $attachments as $k => $attachment ) {
		if ( intval( $attachment->ID ) === intval( $post->ID ) ) {
			break;
		}
	}

	$output        = '';
	$attachment_id = 0;

	if ( $attachments ) {
		$k = $prev ? $k - 1 : $k + 1;

		if ( isset( $attachments[ $k ] ) ) {
			$attachment_id = $attachments[ $k ]->ID;
			$output        = wp_get_attachment_link( $attachment_id, $size, true, false, $text );
		}
	}

	$adjacent = $prev ? 'previous' : 'next';

	/**
	 * Filters the adjacent image link.
	 *
	 * The dynamic portion of the hook name, `$adjacent`, refers to the type of adjacency,
	 * either 'next', or 'previous'.
	 *
	 * @since 3.5.0
	 *
	 * @param string $output        Adjacent image HTML markup.
	 * @param int    $attachment_id Attachment ID
	 * @param string $size          Image size.
	 * @param string $text          Link text.
	 */
	echo apply_filters( "{$adjacent}_image_link", $output, $attachment_id, $size, $text );
}

/**
 * Retrieves taxonomies attached to given the attachment.
 *
 * @since 2.5.0
 * @since 4.7.0 Introduced the `$output` parameter.
 *
 * @param int|array|object $attachment Attachment ID, data array, or data object.
 * @param string           $output     Output type. 'names' to return an array of taxonomy names,
 *                                     or 'objects' to return an array of taxonomy objects.
 *                                     Default is 'names'.
 * @return string[]|WP_Taxonomy[] List of taxonomies or taxonomy names. Empty array on failure.
 */
function get_attachment_taxonomies( $attachment, $output = 'names' ) {
	if ( is_int( $attachment ) ) {
		$attachment = get_post( $attachment );
	} elseif ( is_array( $attachment ) ) {
		$attachment = (object) $attachment;
	}

	if ( ! is_object( $attachment ) ) {
		return array();
	}

	$file     = get_attached_file( $attachment->ID );
	$filename = wp_basename( $file );

	$objects = array( 'attachment' );

	if ( false !== strpos( $filename, '.' ) ) {
		$objects[] = 'attachment:' . substr( $filename, strrpos( $filename, '.' ) + 1 );
	}

	if ( ! empty( $attachment->post_mime_type ) ) {
		$objects[] = 'attachment:' . $attachment->post_mime_type;

		if ( false !== strpos( $attachment->post_mime_type, '/' ) ) {
			foreach ( explode( '/', $attachment->post_mime_type ) as $token ) {
				if ( ! empty( $token ) ) {
					$objects[] = "attachment:$token";
				}
			}
		}
	}