import 'dart:io';

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

  while (true) {
    print("\n=== Budget App ===");
    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 amount: ");
      double? amount = double.tryParse(stdin.readLineSync() ?? '');
      if (amount != null && amount > 0) {
        incomeList.add({desc ?? 'Income': amount});
        print("Added income: $desc - $amount SR");
      } else {
        print("Invalid amount!");
      }
    } else if (choice == '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 ?? 'Expense': amount});
        print("Added expense: $desc - $amount SR");
      } else {
        print("Invalid amount!");
      }
    } else if (choice == '3') {
      double totalIncome = incomeList.fold(0, (sum, e) => sum + e.values.first);
      double totalExpense = expenseList.fold(0, (sum, e) => sum + e.values.first);
      double net = totalIncome - totalExpense;

      print("\n--- Summary ---");
      print("Total Income: $totalIncome SR");
      print("Total Expenses: $totalExpense SR");

      if (net > 0) {
        double tax = net * 0.15;
        print("Net Profit: $net SR");
        print("Tax to Pay: $tax SR");
      } else if (net < 0) {
        print("Net Loss: ${net.abs()} SR");
      } else {
        print("No profit or loss.");
      }
    } else if (choice == '4') {
      print("Exiting...");
      break;
    } else {
      print("Invalid choice!");
    }
  }
}