<?php
/**
 * Serialized read/modify/write for small plugin options.
 *
 * @package TurtleReport
 */

namespace TurtleReport\Support;

defined( 'ABSPATH' ) || exit;

/** Keeps independent concurrent edits from overwriting each other. */
final class OptionUpdate {

	/**
	 * Changes an array option after reloading it under an owned lock.
	 *
	 * @param string   $name   Option name.
	 * @param callable $change Receives current array and returns the new array.
	 * @return array Saved value.
	 * @throws \RuntimeException When the lock or write cannot be completed.
	 */
	public static function change( $name, callable $change ) {
		$lock     = null;
		$deadline = microtime( true ) + 2;
		do {
			$lock = OptionLock::acquire( 'turtlereport_write_' . md5( $name ), 30 );
			if ( null !== $lock ) {
				break;
			}
			usleep( 20000 );
		} while ( microtime( true ) < $deadline );
		if ( null === $lock ) {
			throw new \RuntimeException( __( 'Another request is saving these settings. Try again.', 'turtlereport' ) ); // phpcs:ignore WordPress.Security.EscapeOutput.ExceptionNotEscaped -- Plain domain exception, not HTML output; preserve message bytes and escape at the response boundary.
		}
		try {
			wp_cache_delete( $name, 'options' );
			wp_cache_delete( 'notoptions', 'options' );
			$current = get_option( $name, array() );
			$current = is_array( $current ) ? $current : array();
			$next    = $change( $current );
			if ( ! is_array( $next ) ) {
				throw new \RuntimeException( __( 'The settings could not be saved.', 'turtlereport' ) );
			}
			if ( $next !== $current && ! update_option( $name, $next, false ) ) {
				throw new \RuntimeException( __( 'The settings could not be saved. Try again.', 'turtlereport' ) );
			}
			return $next;
		} finally {
			$lock->release();
		}
	}
}