import 'dart:io';

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

  while (true) {
    print("\n💰 Budget Management System 💰");
    print("1. Add Income");
    print("2. Add Expense");
    print("3. View Summary");
    print("4. Exit");
    stdout.write("Choose an option: ");
    String? choice = stdin.readLineSync();

    if (choice == "4") {
      print("Exiting... Have a great day!");
      break;
    }

    switch (choice) {
      case "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 successfully.");
        } else {
          print("❌ Invalid amount.");
        }
        break;

      case "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 successfully.");
        } else {
          print("❌ Invalid amount.");
        }
        break;

      case "3":
        double totalIncome = 0;
        double totalExpenses = 0;

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

        double net = totalIncome - totalExpenses;
        print("\n📊 Summary:");
        print("Total Income: \$${totalIncome}");
        print("Total Expenses: \$${totalExpenses}");
        print(net >= 0
            ? "Your net profit is \$${net}"
            : "Your net loss is \$${net.abs()}");

        // Optional tax calculation (15%)
        if (net > 0) {
          double tax = net * 0.15;
          print("Tax to be paid: \$${tax.toStringAsFixed(2)}");
        }
        break;

      default:
        print("❌ Invalid choice, try again.");
    }
  }
}