import '../dto/results.dart';
import '../mappers/results.dart';
import '../models/verification.dart';

abstract interface class SimulationInfo {
  bool get isSimulated;
}

abstract interface class VerificationService {
  Future<VerificationResult> send({
    required String email,
    required String locale,
  });
  Future<VerificationResult> confirm({required String token});
}

/// Explicit preview tokens only. Never use this implementation in production.
class DummyVerificationService implements VerificationService, SimulationInfo {
  const DummyVerificationService({
    this.delay = const Duration(milliseconds: 600),
    this.sendFailure,
    this.verifiedEmail = 'alex@example.com',
  });
  @override
  bool get isSimulated => true;
  final Duration delay;
  final VerificationError? sendFailure;
  final String verifiedEmail;

  @override
  Future<VerificationResult> send({
    required String email,
    required String locale,
  }) async {
    await Future<void>.delayed(delay);
    if (sendFailure case final error?) throw VerificationException(error);
    return VerificationMapper.fromDTO(const VerificationDTO(simulated: true));
  }

  @override
  Future<VerificationResult> confirm({required String token}) async {
    await Future<void>.delayed(delay);
    switch (token) {
      case 'demo-valid':
        return VerificationMapper.fromDTO(
          VerificationDTO(simulated: true, email: verifiedEmail),
        );
      case 'demo-expired':
        throw const VerificationException(VerificationError.expired);
      case 'demo-internal':
        throw const VerificationException(VerificationError.internal);
      default:
        throw const VerificationException(VerificationError.invalid);
    }
  }
}