import 'dart:io';

void main(){
  String lights ="OFF";
  int thermostat =20 ;
  String security ="DISADRMED";


  const  minTemp = 15;
  const  maxTemp = 30;
   bool running = true ;
   while (running){
  print("--welcom to the smart home system--");
  print("please choose an action :");
  print("1.Toggle lights");
  print("2.set thermostat tempreature");
  print("3.Arm/Disarmed security system");
  print("4.view system status");
  print("5. Exit");

 
  print ("enter your choice:");
  String? choice  = stdin.readLineSync();
  switch (choice){
    case "1":
    lights =(lights=="off")?" on" : "off";
    print ("lights are now $lights");

    case "2":
    print ("enter tempreature($minTemp-$maxTemp:)");
    int? tempr = int .tryParse(stdin.readLineSync()!);
    if (tempr!=null && tempr >= 15 && tempr <=30 ){
    thermostat = tempr ;
    print ("thermostatset to $thermostat");
    }else {
    print("Invalid tempreature!");
    }
    case "3": 
    security =(security=="DISARMED")? "ARMED" : "DISARMED";
    print("securi System isnow $security");
break;

    case "4" :
void main(){
String  daytype  = "";
if (thermostat % 3 == 0 && thermostat % 5 == 0){
    

  daytype = "perfect day";
  } 
  else if (thermostat % 3 ==0){
  daytype ="Cool day";
  }else if (thermostat %5 ==0){
  daytype ="warm day";
  }
}
  break;

case "5":
print ("goodbye");
running = false ;
break;
 default: 
 print("Invalid choice! please try again.");
  }
  }
 

  
  
 

  }