// Noor Bandar ALabsi_242000818_question2.
// Budget Management Application
// – Question 2

import 'dart:io';

void main() {
  print('==============================');
  print('Welcome to Budget Manager');
  print('==============================');

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

  bool running = true;

  while (running) {
    print('\nPlease choose an option:');
    print('1. Add Income');
    print('2. Add Expense');
    print('3. View Summary (Profit or Loss)');
    print('4. Exit');

    stdout.write('Enter your choice (1-4): ');
    String? input = stdin.readLineSync();
    if (input == null) continue;

    int? choice = int.tryParse(input);
    if (choice == null || choice < 1 || choice > 4) {
      print('Invalid choice! Please enter a number between 1 and 4.');
      continue;
    }

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

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

      if (amount == null || amount < 0) {
        print('Invalid amount! Please enter a positive number.');
      } else {
        incomeList.add({description ?? 'Unnamed Income': amount});
        print('Income added successfully.');
      }

    } else if (choice == 2) {
      stdout.write('Enter expense description: ');
      String? description = stdin.readLineSync();

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

      if (amount == null || amount < 0) {
        print('Invalid amount! Please enter a positive number.');
      } else {
        expenseList.add({description ?? 'Unnamed Expense': amount});
        print('Expense added successfully.');
      }

    } else if (choice == 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 netProfit = totalIncome - totalExpenses;

      print('\n========= BUDGET SUMMARY =========');
      print('Total Income: \$${totalIncome.toStringAsFixed(2)}');
      print('Total Expenses: \$${totalExpenses.toStringAsFixed(2)}');

      if (netProfit > 0) {
        print('Your net profit is \$${netProfit.toStringAsFixed(2)}');
      } else if (netProfit < 0) {
        print('Your net loss is \$${netProfit.abs().toStringAsFixed(2)}');
      } else {
        print('You broke even – no profit or loss.');
      }

      double tax = netProfit > 0 ? netProfit * 0.15 : 0;
      if (tax > 0) {
        print('Tax to pay (15%): \$${tax.toStringAsFixed(2)}');
      }
      print('=================================');

    } else if (choice == 4) {
      running = false;
      print('\nExiting Budget Manager...');
      print('Goodbye!');
    }
  }
}