#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

const int ledPin = 8;
char fullName[] = "Visesh Agarwal";
const double registerNumber = 2347164;

// Initialize variables for tracking unauthorized attempts
int attempts = 0;
bool unauthorizedAccess = false;

void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(ledPin, OUTPUT);

  Serial.begin(9600);  // Start serial communication
  Serial.println("System Initialized.");
  Serial.println("Please enter your code followed by ENTER.");
  displayPattern();
}

void loop() {
  if (Serial.available() > 0) {
    // Read user input from Serial Monitor
    String input = Serial.readStringUntil('\n');
    double enteredCode = input.toDouble();
    Serial.print("Entered Code: ");
    Serial.println(enteredCode);

    // Check for unauthorized access
    if (enteredCode != registerNumber) {
      attempts++;
      Serial.println("Incorrect Code. Attempt " + String(attempts));
      unauthorizedAccess = (attempts >= 3);
    } else {
      attempts = 0;
      unauthorizedAccess = false;  // Reset unauthorized access if the code is correct
      Serial.println("Code Correct. Access Granted.");
    }

    // Handle unauthorized access
    if (unauthorizedAccess) {
      blinkLED();
    } else {
      glowLED();
    }
  }
}

// Function to display the pattern on the LCD
void displayPattern() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Name: ");
  lcd.print(fullName[0]);
  lcd.print(".");
  
  int lastIndex = strlen(fullName) - 7;
  lcd.print(fullName[lastIndex]);
  lcd.print(" - ");

  // Calculate and display the last 4 digits of the registerNumber
  int last_4 =(int) registerNumber % 10000;
  lcd.print(last_4);

  lcd.setCursor(0, 1);
  for (int i = 0; i < 4; i++) {
    lcd.print((int)fullName[i], HEX);
    lcd.print(" ");
  }
  lcd.print((int)registerNumber % 100, HEX);
}

// Function to blink the LED continuously
void blinkLED() {
  digitalWrite(ledPin, HIGH);
  delay(500);
  digitalWrite(ledPin, LOW);
  delay(500);
}

// Function to glow the LED steadily
void glowLED() {
  digitalWrite(ledPin, HIGH);
}