import 'dart:io';

void main() {
  double totalIncome = 0;
  double totalExpenses = 0;
  const double taxRate = 0.15;

  print('Welcome to the Budget Management Application!');

  while (true) {
    print('\nPlease choose an option:');
    print('1. Add income');
    print('2. Add expense');
    print('3. View summary');
    print('4. Exit');
    stdout.write('Enter your choice: ');

    String? choice = stdin.readLineSync();

    switch (choice) {
      case '1':
        stdout.write('Enter income description: ');
        stdin.readLineSync();
        stdout.write('Enter income amount: ');
        double income = double.parse(stdin.readLineSync()!);
        totalIncome += income;
        print('Income added!');
        break;

      case '2':
        stdout.write('Enter expense description: ');
        stdin.readLineSync();
        stdout.write('Enter expense amount: ');
        double expense = double.parse(stdin.readLineSync()!);
        totalExpenses += expense;
        print('Expense added!');
        break;

      case '3':
        double netProfit = totalIncome - totalExpenses;
        double tax = netProfit > 0 ? netProfit * taxRate : 0;

        print('\nSummary:');
        print('Total income: \$${totalIncome.toStringAsFixed(0)}');
        print('Total expenses: \$${totalExpenses.toStringAsFixed(0)}');
        print('Net profit: \$${netProfit.toStringAsFixed(0)}');
        print('Tax to be paid: \$${tax.toStringAsFixed(0)}');
        break;

      case '4':
        print('Exiting the application. Goodbye!');
        return;

      default:
        print('Invalid choice. Please try again.');
    }
  }
}