/// Résultat d’un `POST /oauth/token` (connexion ou refresh).
class OAuthTokenPair {
  const OAuthTokenPair({
    required this.accessToken,
    this.refreshToken,
  });

  final String accessToken;
  final String? refreshToken;
}

OAuthTokenPair? parseOAuthTokenResponse(Map<String, dynamic> json) {
  final access = json['access_token'];
  if (access is! String || access.isEmpty) return null;

  final refresh = json['refresh_token'];
  return OAuthTokenPair(
    accessToken: access,
    refreshToken: refresh is String && refresh.isNotEmpty ? refresh : null,
  );
}