import 'dart:io';

void main() {
  print("=== Simple Budget Tracker ===");

  List<Map<String, double>> income = [];
  List<Map<String, double>> expenses = [];

  bool active = true;

  while (active) {
    print("\nChoose an action:");
    print("1) Record Income");
    print("2) Record Expense");
    print("3) Show Financial Report");
    print("4) Exit");

    stdout.write("Your choice: ");
    String? option = stdin.readLineSync();

    if (option == null) continue;

    if (option == "1") {
      _record(income, true);
    } else if (option == "2") {
      _record(expenses, false);
    } else if (option == "3") {
      _report(income, expenses);
    } else if (option == "4") {
      print("Exiting... Have a great day!");
      active = false;
    } else {
      print("Invalid selection.");
    }
  }
}

void _record(List<Map<String, double>> list, bool isIncome) {
  stdout.write("Enter description: ");
  String? desc = stdin.readLineSync();

  if (desc == null || desc.isEmpty) {
    print("Description cannot be empty.");
    return;
  }

  stdout.write("Enter amount: ");
  String? amountInput = stdin.readLineSync();

  double? amount = double.tryParse(amountInput ?? "");

  if (amount == null || amount < 0) {
    print("Amount must be a positive number.");
    return;
  }

  list.add({desc: amount});
  print("${isIncome ? "Income" : "Expense"} recorded.");
}

void _report(List<Map<String, double>> income, List<Map<String, double>> expenses) {
  double totalIncome = 0;
  double totalExpenses = 0;

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

  for (var item in expenses) {
    totalExpenses += item.values.first;
  }

  double net = totalIncome - totalExpenses;

  print("\n=== Financial Report ===");
  print("Total Income: \$${totalIncome.toStringAsFixed(2)}");
  print("Total Expenses: \$${totalExpenses.toStringAsFixed(2)}");

  if (net > 0) {
    print("Net Profit: \$${net.toStringAsFixed(2)}");

    // Optional tax calculation
    double tax = net > 0 ? net * 0.15 : 0;
    print("Tax (15%): \$${tax.toStringAsFixed(2)}");
    print("Profit After Tax: \$${(net - tax).toStringAsFixed(2)}");

  } else if (net < 0) {
    print("Net Loss: \$${net.abs().toStringAsFixed(2)}");
    print("No tax applied.");
  } else {
    print("Break-even: No profit, no loss.");
  }
}