#include <LiquidCrystal.h>


const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

const int ledPin = 13;    
const int tamperPin = 8;  
const int maxAttempts = 3; 

String fullName = "Vishnu Nair";
String regNum = "2347131";  
int incorrectAttempts = 0;
bool tampered = false;

String enteredCode = ""; 

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(tamperPin, INPUT_PULLUP); 
  
  lcd.begin(16, 2); 
  lcd.clear();
  
  Serial.begin(9600); 
  Serial.println("Enter Security Code:");

  displayPattern();  
}

void loop() {
  
  if (Serial.available() > 0) {
    enteredCode = Serial.readStringUntil('\n');  
    enteredCode.trim(); 

    
    checkSecurityCode(enteredCode);
  }

  
  if (digitalRead(tamperPin) == LOW) {
    tampered = true;
  }

  
  if (incorrectAttempts >= maxAttempts || tampered) {
    blinkLED();
  }
}


void displayPattern() {
  
  String initials = String(fullName[0]) + "." + String(fullName[fullName.indexOf(' ') + 1]) + ".";
  String lastFourDigits = regNum.substring(4, 8);
  
  lcd.setCursor(0, 0);
  lcd.print(initials + " " + lastFourDigits); 

  
  lcd.setCursor(0, 1);
  for (int i = 0; i < 4; i++) {
    
    lcd.print((int)fullName[i]);
    lcd.print(" ");
  }
}


void checkSecurityCode(String enteredCode) {
  String correctCode = regNum; 

  if (enteredCode != correctCode) {
    incorrectAttempts++;
    Serial.println("Incorrect Code. Attempts left: " + String(maxAttempts - incorrectAttempts));
    if (incorrectAttempts >= maxAttempts) {
      Serial.println("Too many incorrect attempts. Alert triggered!");
    }
  } else {
    Serial.println("Access Granted!");
    incorrectAttempts = 0; 
  }
}


void blinkLED() {
  digitalWrite(ledPin, HIGH);  
  delay(200);                  
  digitalWrite(ledPin, LOW);   
  delay(200);                  
}