import 'dart:io';

void main() {
  List<Map<String, double>> incomeList = [];
  List<Map<String, double>> expenseList = [];

  while (true) {
    // Display menu options to the user
    print('\nChoose an action:');
    print('1. Add income');
    print('2. Add expense');
    print('3. View summary');
    print('4. Exit');

    String? choice = stdin.readLineSync();

    switch (choice) {
      case '1':
        print('Enter income description:');
        String description = stdin.readLineSync() ?? '';
        print('Enter income amount:');
        double? amount = double.tryParse(stdin.readLineSync() ?? '');
        if (amount != null && amount > 0) {
          incomeList.add({description: amount});
          print('Income added.');
        } else {
          print('Invalid amount.');
        }
        break;
      case '2':
        print('Enter expense description:');
        String description = stdin.readLineSync() ?? '';
        print('Enter expense amount:');
        double? amount = double.tryParse(stdin.readLineSync() ?? '');
        if (amount != null && amount > 0) {
          expenseList.add({description: amount});
          print('Expense added.');
        } else {
          print('Invalid amount.');
        }
        break;
      case '3':
        double totalIncome = incomeList.fold(0, (sum, item) => sum + item.values.first);
        double totalExpense = expenseList.fold(0, (sum, item) => sum + item.values.first);
        double net = totalIncome - totalExpense;
        print('Total Income: \$${totalIncome.toStringAsFixed(2)}');
        print('Total Expenses: \$${totalExpense.toStringAsFixed(2)}');
        print(net >= 0 ? 'Net Profit: \$${net.toStringAsFixed(2)}' : 'Net Loss: \$${net.abs().toStringAsFixed(2)}');
        
        if (net > 0) {
          double tax = net * 0.15;
          print('Tax Due: \$${tax.toStringAsFixed(2)}');
        }
        break;
      case '4':
        print('Goodbye!');
        return;
      default:
        print('Invalid choice.');
    }
  }
}