BP_REST_Document_Endpoint::bp_documents_update_rest_field_callback( object $object, object $value, string $attribute )

	protected function bp_documents_update_rest_field_callback( $object, $value, $attribute ) {

		global $bp_activity_edit, $bp_activity_post_update_id, $bp_activity_post_update;

		if ( 'bp_documents' !== $attribute ) {
			$value->bp_documents = null;

			return $value;
		}

		$bp_activity_edit = ( isset( $value->edit ) ? true : false );
		// phpcs:ignore
		$_POST['edit'] = $bp_activity_edit;

		if ( false === $bp_activity_edit && empty( $object ) ) {
			return $value;
		}

		$activity_id = $value->id;
		$privacy     = $value->privacy;
		$group_id    = 0;

		$documents = wp_parse_id_list( $object );

		$old_document_ids      = bp_activity_get_meta( $activity_id, 'bp_document_ids', true );
		$old_document_ids      = ( ! empty( $old_document_ids ) ? explode( ',', $old_document_ids ) : array() );
		$new_documents         = array();
		$old_documents         = array();
		$old_documents_objects = array();

		if ( ! empty( $old_document_ids ) ) {
			foreach ( $old_document_ids as $id ) {
				$document_object = new BP_Document( $id );
				$old_documents_objects[ $document_object->attachment_id ] = $document_object;
				$old_documents[ $id ]                                     = $document_object->attachment_id;
			}
		}

		$bp_activity_post_update    = true;
		$bp_activity_post_update_id = $activity_id;

		if ( ! empty( $value->component ) && 'groups' === $value->component ) {
			$group_id = $value->item_id;
			$privacy  = 'grouponly';
		}

		if ( ! isset( $documents ) || empty( $documents ) ) {

			// delete document ids and meta for activity if empty document in request.
			// delete media ids and meta for activity if empty media in request.
			if ( ! empty( $activity_id ) && ! empty( $old_document_ids ) ) {
				foreach ( $old_document_ids as $document_id ) {
					bp_document_delete( array( 'id' => $document_id ), 'activity' );
				}
				bp_activity_delete_meta( $activity_id, 'bp_document_ids' );
			}

			return $value;
		} else {

			$order_count = 0;
			foreach ( $documents as $id ) {

				$wp_attachment_url = wp_get_attachment_url( $id );

				// when the file found to be empty it's means it's not a valid attachment.
				if ( empty( $wp_attachment_url ) ) {
					continue;
				}

				$order_count ++;

				if ( in_array( $id, $old_documents, true ) ) {
					$new_documents[] = array(
						'document_id' => $old_documents_objects[ $id ]->id,
					);
				} else {
					$new_documents[] = array(
						'id'         => $id,
						'name'       => get_the_title( $id ),
						'folder_id'  => 0,
						'group_id'   => $group_id,
						'menu_order' => $order_count,
						'privacy'    => $privacy,
						'error_type' => 'wp_error',
					);
				}
			}
		}

		remove_action( 'bp_activity_posted_update', 'bp_document_update_activity_document_meta', 10, 3 );
		remove_action( 'bp_groups_posted_update', 'bp_document_groups_activity_update_document_meta', 10, 4 );
		remove_action( 'bp_activity_comment_posted', 'bp_document_activity_comments_update_document_meta', 10, 3 );
		remove_action( 'bp_activity_comment_posted_notification_skipped', 'bp_document_activity_comments_update_document_meta', 10, 3 );

		$document_ids = bp_document_add_handler( $new_documents, $privacy, '', $group_id );

		add_action( 'bp_activity_posted_update', 'bp_document_update_activity_document_meta', 10, 3 );
		add_action( 'bp_groups_posted_update', 'bp_document_groups_activity_update_document_meta', 10, 4 );
		add_action( 'bp_activity_comment_posted', 'bp_document_activity_comments_update_document_meta', 10, 3 );
		add_action( 'bp_activity_comment_posted_notification_skipped', 'bp_document_activity_comments_update_document_meta', 10, 3 );

		// save document meta for activity.
		if ( ! empty( $activity_id ) ) {
			// Delete document if not exists in current document ids.

			if ( true === $bp_activity_edit ) {
				if ( ! empty( $old_document_ids ) ) {
					foreach ( $old_document_ids as $document_id ) {
						if ( ! in_array( (int) $document_id, $document_ids, true ) ) {
							bp_document_delete( array( 'id' => $document_id ) );
						}
					}
				}
			}
			bp_activity_update_meta( $activity_id, 'bp_document_ids', implode( ',', $document_ids ) );
		}
	}