enum TransferKind { topUp, exchange, payout }

enum OperationStatus { pending, completed, failed }

enum WalletError {
  unavailable,
  invalidAmount,
  insufficientFunds,
  limitExceeded,
  expiredQuote,
  invalidRecipient,
  unsupported,
  notFound,
  uncertain,
}

class WalletException implements Exception {
  const WalletException(this.code);
  final WalletError code;
}

class CurrencyAccount {
  const CurrencyAccount({
    required this.id,
    required this.currency,
    required this.precision,
    required this.available,
    this.payoutMethod = '',
    this.payoutLabel = '',
    this.canFund = true,
  });
  final String id, currency;
  final int precision, available;
  final String payoutMethod, payoutLabel;
  final bool canFund;

  /// Locale-aware decimal input, integer money. Grouping/exponents are rejected.
  int? parse(String input) {
    final value = input.trim().replaceAll(',', '.');
    if (!RegExp(r'^\d+(\.\d+)?$').hasMatch(value)) return null;
    final parts = value.split('.');
    if (parts.length > 1 && parts[1].length > precision) return null;
    final major = int.tryParse(parts[0]);
    if (major == null || major > 100000000) return null;
    final fraction = parts.length > 1
        ? int.parse(parts[1].padRight(precision, '0'))
        : 0;
    return major * scale + fraction;
  }

  int get scale {
    var v = 1;
    for (var i = 0; i < precision; i++) {
      v *= 10;
    }
    return v;
  }
}

class TransferRequest {
  const TransferRequest({
    required this.kind,
    required this.source,
    required this.amount,
    this.destination,
    this.recipient = '',
  });
  final TransferKind kind;
  final String source;
  final int amount;
  final String? destination;
  final String recipient;
}

class Quote {
  const Quote({
    required this.id,
    required this.request,
    required this.fee,
    required this.debit,
    required this.credit,
    required this.expiresAt,
    required this.rateNumerator,
    required this.rateDenominator,
  });
  final String id;
  final TransferRequest request;
  final int fee, debit, credit, rateNumerator, rateDenominator;
  final DateTime expiresAt;
}

class WalletOperation {
  const WalletOperation({
    required this.id,
    required this.quote,
    required this.status,
    required this.createdAt,
  });
  final String id;
  final Quote quote;
  final OperationStatus status;
  final DateTime createdAt;
}

class WalletSnapshot {
  WalletSnapshot({
    required List<CurrencyAccount> accounts,
    required List<WalletOperation> operations,
  }) : accounts = List.unmodifiable(accounts),
       operations = List.unmodifiable(operations);
  final List<CurrencyAccount> accounts;
  final List<WalletOperation> operations;
}

class AccountProfile {
  const AccountProfile(this.locale);
  final String locale;
}