import 'dart:io';

void main() {

  List<Map<String, double>> incomeList = [];

  List<Map<String, double>> expenseList = [];

  print("Welcome to the Budget Management Application!");

  while (true) {

    print("\nPlease choose an option:");

    print("1. Add income");

    print("2. Add expense");

    print("3. View summary");

    print("4. Exit");

    stdout.write("\nEnter your choice: ");

    String? choice = stdin.readLineSync();

    if (choice == '1') {

      addIncome(incomeList);

    } else if (choice == '2') {

      addExpense(expenseList);

    } else if (choice == '3') {

      viewSummary(incomeList, expenseList);

    } else if (choice == '4') {

      print("Exiting the application. Goodbye!");

      break;

    } else {

      print("Invalid choice! Please try again.");

    }

  }

}

void addIncome(List<Map<String, double>> incomeList) {

  stdout.write("Enter income description: ");

  String? desc = stdin.readLineSync();

  stdout.write("Enter income amount: ");

  double? amount = double.tryParse(stdin.readLineSync() ?? '');

  if (amount == null || amount < 0) {

    print("Invalid amount. Please enter a positive number.");

    return;

  }

  incomeList.add({desc ?? 'Unnamed Income': amount});

  print("Income added!");

}

void addExpense(List<Map<String, double>> expenseList) {

  stdout.write("Enter expense description: ");

  String? desc = stdin.readLineSync();

  stdout.write("Enter expense amount: ");

  double? amount = double.tryParse(stdin.readLineSync() ?? '');

  if (amount == null || amount < 0) {

    print("Invalid amount. Please enter a positive number.");

    return;

  }

  expenseList.add({desc ?? 'Unnamed Expense': amount});

  print("Expense added!");

}

void viewSummary(List<Map<String, double>> incomeList, List<Map<String, double>> expenseList) {

  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("\nSummary:");

  print("Total income: \$${totalIncome.toStringAsFixed(2)}");

  print("Total expenses: \$${totalExpenses.toStringAsFixed(2)}");

  if (net > 0) {

    double tax = net * 0.15;

    print("Net profit: \$${net.toStringAsFixed(2)}");

    print("Tax to be paid: \$${tax.toStringAsFixed(2)}");

  } else if (net < 0) {

    print("Net loss: \$${net.abs().toStringAsFixed(2)}");

  } else {

    print("Break-even: No profit, no loss.");

  }

}