import 'dart:io';

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

  while (true) {
    print("\n=== Budget Management ===");
    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 application...");
      break;
    }

    if (choice == "1") {
      stdout.write("Enter income description: ");
      String description = stdin.readLineSync() ?? "";

      stdout.write("Enter income amount: ");
      double? amount = double.tryParse(stdin.readLineSync() ?? "");

      if (amount != null && amount > 0) {
        incomeList.add({description: amount});
        print("Income added successfully.");
      } else {
        print("Invalid amount!");
      }
    } else if (choice == "2") {
      stdout.write("Enter expense description: ");
      String description = stdin.readLineSync() ?? "";

      stdout.write("Enter expense amount: ");
      double? amount = double.tryParse(stdin.readLineSync() ?? "");

      if (amount != null && amount > 0) {
        expenseList.add({description: amount});
        print("Expense added successfully.");
      } else {
        print("Invalid amount!");
      }
    } else if (choice == "3") {
      double totalIncome = 0;
      double totalExpense = 0;

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

      for (var item in expenseList) {
        totalExpense += item.values.first;
      }

      double net = totalIncome - totalExpense;

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

      if (net > 0) {
        print("Your net profit is \$${net}");
        double tax = net > 0 ? net * 0.15 : 0;
        print("Tax to pay (15%): \$${tax}");
      } else {
        print("Your net loss is \$${net.abs()}");
      }
    } else {
      print("Invalid choice!");
    }
  }
}