class ExecutableFinder

final class ExecutableFinder implements ExecutableFinderInterface, LoggerAwareInterface {
  use LoggerAwareTrait;
  
  /**
   * The path where Composer is installed in the project, or FALSE if it's not.
   */
  private string|false|null $composerPackagePath = NULL;
  
  /**
   * The path of the Composer binary, or NULL if it can't be found.
   */
  private ?string $composerBinaryPath = NULL;
  public function __construct(private readonly ExecutableFinderInterface $decorated, private readonly FileSystemInterface $fileSystem, private readonly ConfigFactoryInterface $configFactory) {
    $this->composerPackagePath = InstalledVersions::isInstalled('composer/composer') ? InstalledVersions::getInstallPath('composer/composer') : FALSE;
  }
  
  /**
   * {@inheritdoc}
   */
  public function find(string $name) : string {
    if ($name === 'rsync') {
      return Settings::get('package_manager_rsync_path', $this->decorated
        ->find($name));
    }
    elseif ($name === 'composer') {
      $path = $this->getLocalComposerPath();
      if ($path && file_exists($path)) {
        return $path;
      }
      // Find the regular Composer executable overridden by a setting.
      return Settings::get('package_manager_composer_path', $this->decorated
        ->find($name));
    }
    return $this->decorated
      ->find($name);
  }
  
  /**
   * Tries to find the Composer binary installed in the project.
   *
   * @return string|null
   *   The path of the `composer` binary installed in the project's vendor
   *   dependencies, or NULL if it is not installed or cannot be found.
   */
  private function getLocalComposerPath() : ?string {
    // Composer is not installed in the project, so there's nothing to do.
    if ($this->composerPackagePath === FALSE) {
      return NULL;
    }
    // This is a bit expensive to compute, so statically cache it.
    if ($this->composerBinaryPath) {
      return $this->composerBinaryPath;
    }
    $composer_json = file_get_contents($this->composerPackagePath . '/composer.json');
    $composer_json = Json::decode($composer_json);
    foreach ($composer_json['bin'] ?? [] as $bin) {
      if (str_ends_with($bin, '/composer')) {
        $bin = $this->composerPackagePath . '/' . $bin;
        // For extra security, try to disable the binary's execute permission.
        // If that fails, it's worth warning about but is not an actual problem.
        if (is_executable($bin) && !$this->fileSystem
          ->chmod($bin, 0644)) {
          $this->logger?->warning('Composer was found at %path, but could not be made read-only.', [
            '%path' => $bin,
          ]);
        }
        return $this->composerBinaryPath = $bin;
      }
    }
    return NULL;
  }

}