import 'dart:io';

const int minTemp = 15;
const int maxTemp = 30;

void main() {
  bool lightsOn = false;
  int thermostat = 20;
  bool securityArmed = false;

  while (true) {
    stdout.writeln('\n=== Smart Home ===');
    stdout.writeln('1) Toggle lights On/Off');
    stdout.writeln('2) Set thermostat ($minTemp–$maxTemp °C)');
    stdout.writeln('3) Security: arm/disarm');
    stdout.writeln('4) Show status');
    stdout.writeln('5) Exit');
    stdout.write('Your choice: ');
    final input = stdin.readLineSync()?.trim() ?? '';

    switch (input) {
      case '1':
        if (lightsOn) {
          lightsOn = false;
          stdout.writeln('Lights turned OFF.');
        } else {
          lightsOn = true;
          stdout.writeln('Lights turned ON.');
        }
        break;

      case '2':
        stdout.write('Enter a temperature between $minTemp and $maxTemp: ');
        final tStr = stdin.readLineSync()?.trim() ?? '';
        final t = int.tryParse(tStr);
        if (t != null && t >= minTemp && t <= maxTemp) {
          thermostat = t;
          stdout.writeln('Thermostat set to $thermostat°C');
        } else {
          stdout.writeln('Invalid value. Please enter a number between $minTemp and $maxTemp.');
        }
        break;

      case '3':
        stdout.write('Type arm or disarm: ');
        final cmd = (stdin.readLineSync() ?? '').trim().toLowerCase();
        if (cmd == 'arm') {
          if (!securityArmed) {
            securityArmed = true;
            stdout.writeln('System armed.');
          } else {
            stdout.writeln('System already armed.');
          }
        } else if (cmd == 'disarm') {
          if (securityArmed) {
            securityArmed = false;
            stdout.writeln('System disarmed.');
          } else {
            stdout.writeln('System already disarmed.');
          }
        } else {
          stdout.writeln('Unknown command.');
        }
        break;

      case '4':
        final lightsStatus = lightsOn ? 'ON' : 'OFF';
        final securityStatus = securityArmed ? 'ARMED' : 'DISARMED';
        final tag = _tempTag(thermostat);
        stdout.writeln(
            'Status: Lights=$lightsStatus | Temp=$thermostat°C${tag.isEmpty ? '' : ' [$tag]'} | Security=$securityStatus');
        break;

      case '5':
        stdout.writeln('Exited.');
        return;

      default:
        stdout.writeln('Invalid choice.');
    }
  }
}

String _tempTag(int t) {
  final mult3 = t % 3 == 0;
  final mult5 = t % 5 == 0;
  if (mult3 && mult5) return 'Perfect Day';
  if (mult3) return 'Cool Day';
  if (mult5) return 'Warm Day';
  return '';
}