BP_REST_Document_Folder_Endpoint::folder_tree_items( WP_REST_Request $request )

	public function folder_tree_items( $request ) {
		global $wpdb, $bp;

		$group_id = $request->get_param( 'group_id' );
		$user_id  = bp_loggedin_user_id();

		if ( empty( $group_id ) ) {
			$group_id = 0;
		}

		// phpcs:ignore
		$documents_folder_query = $wpdb->prepare( "SELECT * FROM {$bp->document->table_name_folder} WHERE user_id = %d AND group_id = %d ORDER BY id DESC", $user_id, $group_id );

		// phpcs:ignore
		$data = $wpdb->get_results( $documents_folder_query, ARRAY_A ); // db call ok; no-cache ok.

		if ( ! empty( $data ) ) {
			// Build array of item references.
			foreach ( $data as $key => &$item ) {
				$items_by_reference[ $item['id'] ] = &$item;
				// Children array.
				$items_by_reference[ $item['id'] ]['children'] = array();
			}
		}

		if ( ! empty( $data ) ) {
			// Set items as children of the relevant parent item.
			foreach ( $data as $key => &$item ) {
				if ( $item['parent'] && isset( $items_by_reference[ $item['parent'] ] ) ) {
					$items_by_reference [ $item['parent'] ]['children'][] = &$item;
				}
			}
		}

		if ( ! empty( $data ) ) {
			// Remove items that were added to parents elsewhere.
			foreach ( $data as $key => &$item ) {
				if ( $item['parent'] && isset( $items_by_reference[ $item['parent'] ] ) ) {
					unset( $data[ $key ] );
				}
			}
		}

		if ( ! empty( $data ) ) {
			$data = array_values( $data );
		}

		$response = rest_ensure_response( $data );

		/**
		 * Fires after a list of document's folder tree is fetched via the REST API.
		 *
		 * @since 0.1.0
		 *
		 * @param WP_REST_Response $response The response data.
		 * @param WP_REST_Request  $request  The request sent to the API.
		 */
		do_action( 'bp_rest_document_folder_tree_items', $response, $request );

		return $response;
	}