// Smart Home Automation CLI - Dart
// Save this file as question1.txt

import 'dart:io';

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

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

  print('Welcome to Smart Home CLI');
  while (true) {
    print('\nChoose an option:');
    print('1. Control Lights');
    print('2. Set Thermostat');
    print('3. Control Security System');
    print('4. View System Status');
    print('5. Exit');

    stdout.write('Enter choice (1-5): ');
    String? input = stdin.readLineSync();
    if (input == null) continue;

    if (input == '5') {
      print('Exiting Smart Home CLI. Goodbye!');
      break;
    }

    if (input != '1' && input != '2' && input != '3' && input != '4') {
      print('Invalid choice. Please enter a number between 1 and 5.');
      continue;
    }

    switch (input) {
      case '1':
        stdout.write('Turn lights ON or OFF? (on/off): ');
        String? li = stdin.readLineSync();
        if (li == null) break;
        li = li.trim().toLowerCase();
        if (li == 'on') {
          lightsOn = true;
          print('Lights turned ON.');
        } else if (li == 'off') {
          lightsOn = false;
          print('Lights turned OFF.');
        } else {
          print('Invalid input for lights. Use "on" or "off".');
        }
        break;

      case '2':
        while (true) {
          stdout.write('Enter thermostat temperature ($minTemp-$maxTemp °C): ');
          String? t = stdin.readLineSync();
          if (t == null) break;
          int? value = int.tryParse(t.trim());
          if (value == null) {
            print('Please enter a valid integer temperature.');
            continue;
          }
          if (value < minTemp || value > maxTemp) {
            print('Temperature out of range. Please enter between $minTemp and $maxTemp.');
            continue;
          }
          thermostat = value;
          print('Thermostat set to ${thermostat}°C.');
          break;
        }
        break;

      case '3':
        stdout.write('Arm or Disarm security system? (arm/disarm): ');
        String? s = stdin.readLineSync();
        if (s == null) break;
        s = s.trim().toLowerCase();
        if (s == 'arm') {
          securityArmed = true;
          print('Security system ARMED.');
        } else if (s == 'disarm') {
          securityArmed = false;
          print('Security system DISARMED.');
        } else {
          print('Invalid input for security system. Use "arm" or "disarm".');
        }
        break;

      case '4':
        String lightsStatus = lightsOn ? 'ON' : 'OFF';
        String securityStatus = securityArmed ? 'armed' : 'disarmed';
        String securityDisplay = securityStatus.toUpperCase();

        String tempNote = '';
        bool multipleOf3 = (thermostat % 3 == 0);
        bool multipleOf5 = (thermostat % 5 == 0);
        if (multipleOf3 && multipleOf5) {
          tempNote = ' - Perfect Day';
        } else if (multipleOf3) {
          tempNote = ' - Cool Day';
        } else if (multipleOf5) {
          tempNote = ' - Warm Day';
        }

        print('\n--- System Status ---');
        print('Lights: ${lightsStatus}');
        print('Thermostat: ${thermostat}°C${tempNote}');
        print('Security System: ${securityDisplay}');
        print('---------------------');
        break;
    }
  }
}