#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

// Initialize the LCD
LiquidCrystal_I2C lcd(0x27, 20, 4); // Set the LCD address to 0x27 for a 20 chars and 4 line display

// Keypad setup
const byte ROWS = 4; // Four rows
const byte COLS = 4; // Four columns
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; // Connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

const int lockPin = 10; // Output pin for the lock
const int alertPin = 11; // Output pin for the alert
const int emergencyPin = 12; // Output pin for the emergency signal
const String correctPasscode = "1234"; // Change this to your desired passcode
const String resetCode = "BAD9791"; // Change this to your desired reset code
String enteredPasscode = "";
int attempts = 0; // Track the number of attempts for passcode
int resetAttempts = 0; // Track the number of attempts for reset code
bool isLocked = false; // Track if the keypad is locked
bool emergencyLock = false; // Track if the system is in emergency lock

void setup() {
  pinMode(lockPin, OUTPUT);
  pinMode(alertPin, OUTPUT);
  pinMode(emergencyPin, OUTPUT);
  digitalWrite(lockPin, LOW); // Lock is initially locked
  digitalWrite(alertPin, LOW); // Alert is initially off
  digitalWrite(emergencyPin, LOW); // Emergency signal is initially off

  lcd.init();       // Initialize the LCD
  lcd.backlight();  // Turn on the backlight
  lcd.setCursor(0, 0);
  lcd.print("Enter Passcode:");
  lcd.setCursor(0, 1);
}

void loop() {
  if (isLocked || emergencyLock) {
    handleLock();
    return;
  }

  char key = keypad.getKey();

  if (key) {
    if (key == '#') {
      // Check if entered passcode is correct
      if (enteredPasscode == correctPasscode) {
        lcd.setCursor(0, 1);
        lcd.print("ACCESS GRANTED  ");
        digitalWrite(lockPin, HIGH); // Unlock the lock
        digitalWrite(alertPin, LOW); // Turn off the alert
        attempts = 0; // Reset attempts on successful entry
      } else {
        attempts++;
        if (attempts >= 3) {
          lcd.setCursor(0, 0);
          lcd.print("CALL MARVIN FOR HELP");
          lcd.setCursor(0, 1);
          lcd.print("KEYPAD IS LOCKED  ");
          isLocked = true; // Lock the keypad
        } else {
          lcd.setCursor(0, 1);
          lcd.print("ACCESS DENIED     ");
          digitalWrite(lockPin, LOW); // Keep the lock locked
          digitalWrite(alertPin, HIGH); // Turn on the alert
        }
      }
      delay(2000); // Show the message for 2 seconds
      enteredPasscode = ""; // Clear the entered passcode
      lcd.setCursor(0, 1);
      lcd.print("                "); // Clear the input line
      lcd.setCursor(0, 1);
    } else if (key == '*') {
      // Clear the entered passcode
      enteredPasscode = "";
      lcd.setCursor(0, 1);
      lcd.print("                "); // Clear the input line
      lcd.setCursor(0, 1);
    } else {
      // Append the key to the entered passcode
      if (enteredPasscode.length() < 10) {
        enteredPasscode += key;
        lcd.print('*'); // Display an asterisk for each entered character
      }
    }
  }
}

void handleLock() {
  static unsigned long lastScroll = 0;
  static int scrollPosition = 0;
  const String message = "CALL MARVIN FOR HELP!!!     ";

  // Scroll the message every 500ms
  if (millis() - lastScroll >= 500) {
    lcd.setCursor(0, 0);
    String displayMessage = message.substring(scrollPosition) + " " + message.substring(0, scrollPosition);
    lcd.print(displayMessage.substring(0, 20)); // Display only the first 20 characters
    scrollPosition = (scrollPosition + 1) % message.length();
    lastScroll = millis();
  }

  lcd.setCursor(0, 1);
  if (emergencyLock) {
    lcd.print("EMERGENCY LOCK    ");
  } else {
    lcd.print("KEYPAD IS LOCKED  ");
  }

  char key = keypad.getKey();
  if (key) {
    if (key == '#') {
      // Check if entered passcode matches the reset code
      if (enteredPasscode == resetCode) {
        lcd.setCursor(0, 0);
        lcd.print("Enter Passcode:  ");
        lcd.setCursor(0, 1);
        lcd.print("                ");
        isLocked = false; // Unlock the keypad
        emergencyLock = false; // Clear the emergency lock
        attempts = 0; // Reset the attempts
        resetAttempts = 0; // Reset reset attempts
        digitalWrite(alertPin, LOW); // Turn off the alert
        digitalWrite(emergencyPin, LOW); // Turn off the emergency signal
      } else {
        resetAttempts++;
        if (resetAttempts >= 3) {
          digitalWrite(emergencyPin, HIGH); // Turn on the emergency signal
          emergencyLock = true; // Set the emergency lock
        }
      }
      enteredPasscode = ""; // Clear the entered passcode
      lcd.setCursor(0, 1);
      lcd.print("                "); // Clear the input line
      lcd.setCursor(0, 1);
    } else if (key == '*') {
      // Clear the entered passcode
      enteredPasscode = "";
      lcd.setCursor(0, 1);
      lcd.print("                "); // Clear the input line
      lcd.setCursor(0, 1);
    } else {
      // Append the key to the entered passcode
      if (enteredPasscode.length() < 10) {
        enteredPasscode += key;
        lcd.print('*'); // Display an asterisk for each entered character
      }
    }
  }
}