class LinkUri

class LinkUri extends ProcessPluginBase implements ContainerFactoryPluginInterface {
  public function __construct(array $configuration, $plugin_id, $plugin_definition, protected EntityTypeManagerInterface $entityTypeManager) {
    $configuration += [
      'validate_route' => TRUE,
    ];
    parent::__construct($configuration, $plugin_id, $plugin_definition);
  }
  
  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    $path = ltrim($value, '/');
    if (parse_url($path, PHP_URL_SCHEME) === NULL) {
      if ($path === '<front>') {
        $path = '';
      }
      elseif (empty($path) || in_array($path, [
        '<nolink>',
        '<none>',
      ], TRUE)) {
        return 'route:<nolink>';
      }
      elseif ($path === '<button>') {
        return 'route:<button>';
      }
      $path = 'internal:/' . $path;
      // Convert entity URIs to the entity scheme, if the path matches a route
      // of the form "entity.$entity_type_id.canonical".
      // @see \Drupal\Core\Url::fromEntityUri()
      $url = Url::fromUri($path);
      if ($url->isRouted()) {
        if (preg_match('/^entity\\.(.*)\\.canonical$/', $url->getRouteName(), $matches)) {
          $entity_type_id = $matches[1];
          if (isset($url->getRouteParameters()[$entity_type_id], $this->entityTypeManager
            ->getDefinitions()[$entity_type_id])) {
            return "entity:{$entity_type_id}/" . $url->getRouteParameters()[$entity_type_id];
          }
        }
      }
      else {
        // If the URL is not routed, we might want to get something back to do
        // other processing. If this is the case, the "validate_route"
        // configuration option can be set to FALSE to return the URI.
        if ($this->configuration['validate_route']) {
          throw new MigrateException(sprintf('The path "%s" failed validation.', $path));
        }
        return $url->getUri();
      }
    }
    return $path;
  }

}