// Budget Management CLI - Question 2
// Author: Esraa Mohamed Abduljaleel
// ID: 251001040
// Simple Dart console app to manage incomes and expenses.

import 'dart:io';

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

  print('Welcome to Budget Management CLI.');

  while (true) {
    print('\nMenu:');
    print('1) Add income');
    print('2) Add expense');
    print('3) View summary (total income, total expenses, net)');
    print('4) Exit');
    stdout.write('Enter choice (1-4): ');
    String? input = stdin.readLineSync();
    if (input == null) continue;
    int? choice = int.tryParse(input);
    if (choice == null) {
      print('Invalid input. Enter a number 1-4.');
      continue;
    }
    if (choice == 4) {
      print('Exiting Budget CLI. Goodbye!');
      break;
    } else if (choice == 1) {
      stdout.write('Enter income description: ');
      String? desc = stdin.readLineSync() ?? '';
      double amount = _readPositiveAmount();
      incomeList.add({'description': desc, 'amount': amount});
      print('Income added.');
    } else if (choice == 2) {
      stdout.write('Enter expense description: ');
      String? desc = stdin.readLineSync() ?? '';
      double amount = _readPositiveAmount();
      expenseList.add({'description': desc, 'amount': amount});
      print('Expense added.');
    } else if (choice == 3) {
      double totalIncome = incomeList.fold(0.0, (prev, e) => prev + (e['amount'] as double));
      double totalExpenses = expenseList.fold(0.0, (prev, e) => prev + (e['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)}');
        double tax = net > 0 ? net * 0.15 : 0.0;
        if (tax > 0) {
          print('Tax (15% of profit): \$${tax.toStringAsFixed(2)}');
        }
      } else {
        print('Your net loss is \$${(-net).toStringAsFixed(2)}');
      }
      print('----------------\n');
    } else {
      print('Choice out of range. Please pick 1-4.');
    }
  }
}

double _readPositiveAmount() {
  while (true) {
    stdout.write('Enter amount (positive number): ');
    String? amtStr = stdin.readLineSync();
    double? amt = double.tryParse(amtStr ?? '');
    if (amt == null || amt.isNaN || amt <= 0) {
      print('Invalid amount. Please enter a positive number.');
      continue;
    }
    return amt;
  }
}