class OverwriteExistingPackagesValidator

final class OverwriteExistingPackagesValidator implements EventSubscriberInterface {
  use StringTranslationTrait;
  public function __construct(private readonly PathLocator $pathLocator, private readonly ComposerInspector $composerInspector, #[Autowire(param: 'package_manager.allow_overwrite')] private readonly array $allowOverwrite = []) {
  }
  
  /**
   * Validates that new installed packages don't overwrite existing directories.
   *
   * @param \Drupal\package_manager\Event\PreApplyEvent $event
   *   The event being handled.
   */
  public function validate(PreApplyEvent $event) : void {
    $active_dir = $this->pathLocator
      ->getProjectRoot();
    $stage_dir = $event->sandboxManager
      ->getSandboxDirectory();
    $active_packages = $this->composerInspector
      ->getInstalledPackagesList($active_dir);
    $new_packages = $this->composerInspector
      ->getInstalledPackagesList($stage_dir)
      ->getPackagesNotIn($active_packages);
    foreach ($new_packages as $package) {
      if (empty($package->path)) {
        // Packages without a `path` cannot overwrite existing directories.
        continue;
      }
      $relative_path = str_replace($stage_dir, '', $package->path);
      foreach ($this->allowOverwrite as $pattern) {
        if (preg_match($pattern, $relative_path)) {
          continue 2;
        }
      }
      if (is_dir($active_dir . DIRECTORY_SEPARATOR . $relative_path)) {
        $event->addError([
          $this->t('The new package @package will be installed in the directory @path, which already exists but is not managed by Composer.', [
            '@package' => $package->name,
            '@path' => $relative_path,
          ]),
        ]);
      }
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() : array {
    return [
      PreApplyEvent::class => 'validate',
    ];
  }

}