import 'dart:io';

void main() {
  List incomes = [];
  List expenses = [];
  bool work = true;

  print("Welcome to Budget Managment appliction!");

  while (work) {
    print("\n1. Add income");
    print("2. Add expense");
    print("3. Show summary");
    print("4. Exit");
    stdout.write("Enter your choice: ");
    var x = stdin.readLineSync();

    if (x == "1") {
      stdout.write("Enter income description: ");
      var n = stdin.readLineSync();
      stdout.write("Amount: ");
      var a = stdin.readLineSync();
      var aa = double.tryParse(a ?? "0");
      if (aa == null || aa < 0) {
        print("wrong amount");
      } else {
        incomes.add(aa);
        print("added income $n = $aa");
      }
    } else if (x == "2") {
      stdout.write("Enter expense description: ");
      var n = stdin.readLineSync();
      stdout.write("Amount: ");
      var a = stdin.readLineSync();
      var aa = double.tryParse(a ?? "0");
      if (aa == null || aa < 0) {
        print("wrong amount");
      } else {
        expenses.add(aa);
        print("added expense $n = $aa");
      }
    } else if (x == "3") {
      print("Summary:");
      double inc = 0;
      for (var i in incomes) {
        inc += i;
      }
      double exp = 0;
      for (var e in expenses) {
        exp += e;
      }
      double net = inc - exp;

      print("\nTotal income: $inc");
      print("Total expense: $exp");
      if (net >= 0) {
        print("Profit: $net");
        var tax = net * 0.15;
        print("Tax (15%): $tax");
      } else {
        print("Loss: ${net.abs()}");
      }
    } else if (x == "4") {
      print("exiting the application, goodbye!");
      work = false;
    } else {
      print("wrong option");
    }
  }
}