import 'dart:io';

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

  while (true) {
    print('\n--- Budget Menu ---');
    print('1. Add Income');
    print('2. Add Expense');
    print('3. View Summary');
    print('4. Exit');
    stdout.write('Enter your choice: ');
    String? bmChoice = stdin.readLineSync();

    if (bmChoice == '1') {
      stdout.write('Enter income description: ');
      String desc = stdin.readLineSync() ?? '';
      stdout.write('Enter amount: ');
      double? amount = double.tryParse(stdin.readLineSync() ?? '');
      if (amount != null && amount >= 0) {
        incomeList.add({desc: amount});
        print('Income added.');
      } else {
        print('Invalid amount.');
      }
    } else if (bmChoice == '2') {
      stdout.write('Enter expense description: ');
      String desc = stdin.readLineSync() ?? '';
      stdout.write('Enter amount: ');
      double? amount = double.tryParse(stdin.readLineSync() ?? '');
      if (amount != null && amount >= 0) {
        expenseList.add({desc: amount});
        print('Expense added.');
      } else {
        print('Invalid amount.');
      }
    } else if (bmChoice == '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('\n--- Budget Summary ---');
      print('Total Income: \$${totalIncome.toStringAsFixed(2)}');
      print('Total Expenses: \$${totalExpense.toStringAsFixed(2)}');
      if (net >= 0) {
        print('Net Profit: \$${net.toStringAsFixed(2)}');
        double tax = net * 0.15;
        print('Tax to pay (15%): \$${tax.toStringAsFixed(2)}');
      } else {
        print('Net Loss: \$${(-net).toStringAsFixed(2)}');
      }
    } else if (bmChoice == '4') {
      print('Exiting Budget Management...');
      return;
    } else {
      print('Invalid choice. Try again.');
    }
  }
}