import 'dart:io';

void main() {
  print('Welcome to the Budget Management Application!\n');

  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? choice = stdin.readLineSync();

    switch (choice) {
      case '1':
        stdout.write('Enter income description: ');
        String? desc = stdin.readLineSync();
        stdout.write('Enter income amount: ');
        String? amtInput = stdin.readLineSync();
        double? amount = double.tryParse(amtInput ?? '');

        if (desc != null && desc.isNotEmpty && amount != null && amount >= 0) {
          incomeList.add({desc: amount});
          print('Income added successfully.');
        } else {
          print('Invalid input! Make sure description is not empty and amount is non-negative.');
        }
        break;

      case '2':
        stdout.write('Enter expense description: ');
        String? expDesc = stdin.readLineSync();
        stdout.write('Enter expense amount: ');
        String? expAmtInput = stdin.readLineSync();
        double? expAmount = double.tryParse(expAmtInput ?? '');

        if (expDesc != null && expDesc.isNotEmpty && expAmount != null && expAmount >= 0) {
          expenseList.add({expDesc: expAmount});
          print('Expense added successfully.');
        } else {
          print('Invalid input! Make sure description is not empty and amount is non-negative.');
        }
        break;

      case '3':
        double totalIncome = 0;
        for (var item in incomeList) {
          totalIncome += item.values.first;
        }

        double totalExpenses = 0;
        for (var item in expenseList) {
          totalExpenses += item.values.first;
        }

        double net = totalIncome - totalExpenses;

        print('\n--- Budget Summary ---');
        print('Total Income: \$${totalIncome.toStringAsFixed(2)}');
        print('Total Expenses: \$${totalExpenses.toStringAsFixed(2)}');

        if (net >= 0) {
          print('Your net profit is \$${net.toStringAsFixed(2)}');
        } else {
          print('Your net loss is \$${(-net).toStringAsFixed(2)}');
        }

        double tax = net > 0 ? net * 0.15 : 0;
        if (tax > 0) {
          print('Tax to be paid (15% of profit): \$${tax.toStringAsFixed(2)}');
        }

        break;

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

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