// Budget Management CLI (Dart)
// Filename suggestion: Shimaa Abdulhameed_251001669_question2.txt

import 'dart:io';

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

  print('Welcome to Budget Manager CLI!');

  while (true) {
    print('\nMenu:');
    print('1. Add Income');
    print('2. Add Expense');
    print('3. View Summary');
    print('4. Exit');

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

    if (choice == '4') {
      print('Goodbye!');
      break;
    }

    if (choice == '1') {
      stdout.write('Enter income description: ');
      String? desc = stdin.readLineSync();
      if (desc == null || desc.trim().isEmpty) {
        print('Description cannot be empty.');
        continue;
      }
      stdout.write('Enter income amount: ');
      String? amtStr = stdin.readLineSync();
      double? amt = amtStr != null ? double.tryParse(amtStr) : null;
      if (amt == null || amt < 0) {
        print('Please enter a valid non-negative number for amount.');
        continue;
      }
      incomeList.add({'description': desc.trim(), 'amount': amt});
      print('Income added.');
    } else if (choice == '2') {
      stdout.write('Enter expense description: ');
      String? desc = stdin.readLineSync();
      if (desc == null || desc.trim().isEmpty) {
        print('Description cannot be empty.');
        continue;
      }
      stdout.write('Enter expense amount: ');
      String? amtStr = stdin.readLineSync();
      double? amt = amtStr != null ? double.tryParse(amtStr) : null;
      if (amt == null || amt < 0) {
        print('Please enter a valid non-negative number for amount.');
        continue;
      }
      expenseList.add({'description': desc.trim(), 'amount': amt});
      print('Expense added.');
    } else if (choice == '3') {
      double totalIncome = 0;
      double totalExpenses = 0;

      for (var entry in incomeList) {
        totalIncome += (entry['amount'] as double);
      }
      for (var entry in expenseList) {
        totalExpenses += (entry['amount'] as double);
      }
      double net = totalIncome - totalExpenses;

      print('\n--- Summary ---');
      print('Total Income: \$${totalIncome.toStringAsFixed(2)}');
      print('Total Expenses: \$${totalExpenses.toStringAsFixed(2)}');
      if (net >= 0) {
        print('Your net profit is \$${net.toStringAsFixed(2)}');
      } else {
        print('Your net loss is \$${(-net).toStringAsFixed(2)}');
      }

      // Optional: Tax calculation (15% of profit)
      double tax = net > 0 ? (net * 0.15) : 0.0;
      if (tax > 0) {
        print('Tax to pay (15% of profit): \$${tax.toStringAsFixed(2)}');
      } else {
        print('No tax, no profit.');
      }

      print('----------------');
    } else {
      print('Invalid menu choice.');
    }
  }
}