import 'school_navigation_policy.dart';

/// Only the authenticated graduate system may advance the service handshake.
class SchoolLoginFlow {
  Uri? _target;
  bool _requested = false;
  int _attempts = 0;
  void begin(Uri target) {
    _target = target;
    _requested = false;
    _attempts = 0;
  }

  void reset() {
    _target = null;
    _requested = false;
    _attempts = 0;
  }

  Uri? onLoaded(Uri uri, {required bool authenticated}) {
    if (_target == null || !SchoolNavigationPolicy.isSchoolPage(uri)) {
      return null;
    }
    if (uri.host == 'idas.uestc.edu.cn') {
      _requested = false;
      return null;
    }
    if (uri.path == _target!.path ||
        _requested ||
        _attempts >= 2 ||
        !authenticated ||
        !SchoolNavigationPolicy.isGraduatePage(uri)) {
      return null;
    }
    _requested = true;
    _attempts++;
    return _target;
  }
}