import 'dart:io';

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

  while (true) {
    print('Welcome to the Budget Management Application!');
    print('Please 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();

    if (choice == '1') {
      stdout.write('Enter income description: ');
      String desc = stdin.readLineSync()!;

      stdout.write('Enter income amount: ');
      double? amount = double.parse(stdin.readLineSync()!);

      if (amount <= 0) {
        print('Invalid amount.');
      } else {
        incomeList.add({desc: amount});
        print('Income added!');
      }
    } else if (choice == '2') {
      stdout.write('Enter expense description: ');
      String desc = stdin.readLineSync()!;

      stdout.write('Enter expense amount: ');
      double amount = double.parse(stdin.readLineSync()!);

      if (amount <= 0) {
        print('Invalid amount.');
      } else {
        expenseList.add({desc: amount});
        print('Expense added!');
      }
    } else if (choice == '3') {
      double totalIncome = incomeList.fold(
        0,
        (sum, item) => sum + item.values.first,
      );
      double totalExpenses = expenseList.fold(
        0,
        (sum, item) => sum + item.values.first,
      );
      double netProfit = totalIncome - totalExpenses;

      print('Summary:');
      print('Total income: \$${totalIncome.toStringAsFixed(2)}');
      print('Total expenses: \$${totalExpenses.toStringAsFixed(2)}');

      if (netProfit > 0) {
        print('Net profit: \$${netProfit.toStringAsFixed(2)}');
        double tax = netProfit * 0.15;
        print('Tax to be paid: \$${tax.toStringAsFixed(2)}');
      } else if (netProfit < 0) {
        print('Net loss: \$${netProfit.abs().toStringAsFixed(2)}');
      } else {
        print('You broke even. No profit or loss.');
      }
    } else if (choice == '4') {
      print('Exiting the application. Goodbye!');
      break;
    } else {
      print('Invalid choice. Enter a number between 1 and 4.');
    }
  }
}