import 'dart:io';

void main() {
  // 1. ????? ??????? ?????? ???????? (Data Storage)
  List<Map<String, dynamic>> incomeList = [];
  List<Map<String, dynamic>> expenseList = [];

  print('--- ?????? ?? ?? ???? ????? ????????? ---');

  // 2. ??????? Loop ?????? ???????? ???? (Control Flow)
  bool running = true;
  while (running) {
    print('\n???? ?????:');
    print('1. ????? ??? (Add Income)');
    print('2. ????? ????? (Add Expense)');
    print('3. ??? ?????? (View Summary)');
    print('4. ???? (Exit)');
    stdout.write('???????: ');
    
    String? choice = stdin.readLineSync();

    // 3. ??????? if-else ?????? ?? ????????
    if (choice == '1') {
      // ????? ???
      stdout.write('???? ??? ?????: ');
      String desc = stdin.readLineSync() ?? '???? ???';
      stdout.write('???? ??????: ');
      double amount = double.tryParse(stdin.readLineSync() ?? '0') ?? 0;

      if (amount > 0) {
        incomeList.add({'description': desc, 'amount': amount});
        print('??? ????? ????? ?????.');
      } else {
        print('???: ???? ????? ???? ???? ???? ?? ???.');
      }

    } else if (choice == '2') {
      // ????? ?????
      stdout.write('???? ??? ???????: ');
      String desc = stdin.readLineSync() ?? '???? ???';
      stdout.write('???? ??????: ');
      double amount = double.tryParse(stdin.readLineSync() ?? '0') ?? 0;

      if (amount > 0) {
        expenseList.add({'description': desc, 'amount': amount});
        print('??? ????? ??????? ?????.');
      } else {
        print('???: ???? ????? ???? ???? ???? ?? ???.');
      }

    } else if (choice == '3') {
      // 4. ???????? ???????? ???? ?????? (Arithmetic & Interpolation)
      double totalIncome = 0;
      for (var item in incomeList) {
        totalIncome += item['amount'];
      }

      double totalExpense = 0;
      for (var item in expenseList) {
        totalExpense += item['amount'];
      }

      double netProfit = totalIncome - totalExpense;

      print('\n--- ???? ????????? ---');
      print('?????? ?????: $totalIncome');
      print('?????? ?????????: $totalExpense');
      
      if (netProfit >= 0) {
        print('???? ?????: $netProfit');
      } else {
        print('???? ???????: ${netProfit.abs()}');
      }

    } else if (choice == '4') {
      print('????? ????????? ???????. ??????!');
      running = false;
    } else {
      print('?????? ??? ????? ???? ??? ????.');
    }
  }
}