String userInput = ""; //it use for save input
const String user = "Thunder"; //default user name
const String pass = "Parsa";   //default pass
boolean stringReady = false;   //to check string is ready for prosses
boolean userValidation = false;//for logout and whiles
boolean passValidation = false;//for logout and whiles

void setup() {
  Serial.begin(115200);
  
}

void loop() {
  if(!userValidation && !passValidation){userCheck();}
  

}

void serialEvent(){
  while(Serial.available()){
    char inChar = (char)Serial.read();
    if(inChar == '\n'){stringReady = true;}else{userInput += inChar;}
  }
}

void userCheck(){
  Serial.println("Please enter username : ");

  while(!userValidation){
    serialEvent();
    if(stringReady){
      if(userInput == user ){
        Serial.print("Welcome ");Serial.print(userInput);Serial.println("!");
        stringReady = false;userInput = "";
        userValidation = true;passCheck();
      }else{Serial.println("Doesn't exist ! please try again");}
      stringReady = false;userInput = "";
    }
  }
  
}

void passCheck(){
  Serial.println("Please enter password : ");

  while(!passValidation){
    serialEvent();
    if(stringReady){
      if(userInput == pass ){
        Serial.println("Correct !");
        stringReady = false;userInput = "";
        userValidation = true;
        passValidation = true;mainMenu();
      }else{Serial.println("Wrong password ! please try again");
          stringReady = false;userInput = "";
          passCheck();}
      
    }
  }

}

void mainMenu(){
  Serial.println("welcome to main ");

  while(userValidation && passValidation){
    serialEvent();
    if(stringReady){
      if(userInput == "logout" ){
        Serial.println("Ok - good night ;)");
        stringReady = false;userInput = "";
        userValidation = false;passValidation = false;loop();
      }else{Serial.println("I try to do it");
          stringReady = false;userInput = "";
      }
    }
  }
}