class ConfigSchemaChecker

class ConfigSchemaChecker implements EventSubscriberInterface {
  use SchemaCheckTrait;
  
  /**
   * The typed config manger.
   *
   * @var \Drupal\Core\Config\TypedConfigManagerInterface
   */
  protected $typedManager;
  
  /**
   * An array of config checked already. Keyed by config name and a checksum.
   *
   * @var array
   */
  protected $checked = [];
  
  /**
   * An array of config object names that are excluded from schema checking.
   *
   * @var string[]
   */
  protected $exclude = [];
  
  /**
   * Constructs the ConfigSchemaChecker object.
   *
   * @param \Drupal\Core\Config\TypedConfigManagerInterface $typed_manager
   *   The typed config manager.
   * @param string[] $exclude
   *   An array of config object names that are excluded from schema checking.
   * @param bool $validateConstraints
   *   Determines if constraints will be validated. If TRUE, constraint
   *   validation errors will be added to the errors found by
   *   SchemaCheckTrait::checkConfigSchema().
   */
  public function __construct(TypedConfigManagerInterface $typed_manager, array $exclude = [], private readonly bool $validateConstraints = FALSE) {
    $this->typedManager = $typed_manager;
    $this->exclude = $exclude;
  }
  
  /**
   * Checks that configuration complies with its schema on config save.
   *
   * @param \Drupal\Core\Config\ConfigCrudEvent $event
   *   The configuration event.
   *
   * @throws \Drupal\Core\Config\Schema\SchemaIncompleteException
   *   Exception thrown when configuration does not match its schema.
   */
  public function onConfigSave(ConfigCrudEvent $event) {
    // Only validate configuration if in the default collection. Other
    // collections may have incomplete configuration (for example language
    // overrides only). These are not valid in themselves.
    $saved_config = $event->getConfig();
    if ($saved_config->getStorage()
      ->getCollectionName() != StorageInterface::DEFAULT_COLLECTION) {
      return;
    }
    $name = $saved_config->getName();
    $data = $saved_config->get();
    $checksum = Crypt::hashBase64(serialize($data));
    if (!in_array($name, $this->exclude) && !isset($this->checked[$name . ':' . $checksum])) {
      $this->checked[$name . ':' . $checksum] = TRUE;
      $errors = $this->checkConfigSchema($this->typedManager, $name, $data, $this->validateConstraints);
      if ($errors === FALSE) {
        throw new SchemaIncompleteException("No schema for {$name}");
      }
      elseif (is_array($errors)) {
        $text_errors = [];
        foreach ($errors as $key => $error) {
          $text_errors[] = new FormattableMarkup('@key @error', [
            '@key' => $key,
            '@error' => $error,
          ]);
        }
        throw new SchemaIncompleteException("Schema errors for {$name} with the following errors: " . implode(', ', $text_errors));
      }
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() : array {
    $events[ConfigEvents::SAVE][] = [
      'onConfigSave',
      255,
    ];
    return $events;
  }

}