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

// Constants and variables
const String pass1 = "1234";
const String pass2 = "5678";
const String pass3 = "9012";
const String pass4 = "3456"; // New password for the fourth relay
const int ledPin1 = 12;
const int ledPin2 = 11;
const int ledPin3 = 10;
const int ledPin4 = 13; // New pin for the fourth relay
String readString;
bool led1_on = false;
bool led2_on = false;
bool led3_on = false;
bool led4_on = false; // New state variable for the fourth relay

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Keypad setup
const byte ROWS = 4;
const byte COLS = 4;
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};
byte colPins[COLS] = {5, 4, 3, 2};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  pinMode(ledPin4, OUTPUT); // Initialize the fourth relay pin
  digitalWrite(ledPin1, HIGH);
  digitalWrite(ledPin2, HIGH);
  digitalWrite(ledPin3, HIGH);
  digitalWrite(ledPin4, HIGH); // Set the fourth relay pin to HIGH

  lcd.setCursor(0, 0);
  lcd.print("PASSWORD BASED");
  lcd.setCursor(0, 1);
  lcd.print("CIRCUIT BREAKER");
  delay(2500);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("#BVRIT...");
  delay(2500);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WELCOME ");
  delay(1500);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Starting.....");
  delay(2000);
  lcd.clear();
}

void loop() {
  lcd.setCursor(0, 0);
  lcd.print("Enter password:");
  char key = keypad.getKey();

  if (key != NO_KEY) {
    Serial.print("Key pressed: ");
    Serial.println(key); // Debug: Print the key to Serial Monitor
    if (key == 'B') {
      readString = "";
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter password:");
    } else if (key == 'C') { // Use 'C' to submit the password
      handlePassword();
    } else {
      readString += key;
      lcd.setCursor(readString.length() - 1, 1);
      lcd.print('*');
    }
  }
}

void handlePassword() {
  if (readString == pass1) {
    toggleLED(ledPin1, led1_on);
  } else if (readString == pass2) {
    toggleLED(ledPin2, led2_on);
  } else if (readString == pass3) {
    toggleLED(ledPin3, led3_on);
  } else if (readString == pass4) { // Check the new password
    toggleLED(ledPin4, led4_on); // Toggle the fourth relay
  } else {
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("WRONG PASSWORD");
    delay(1000);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter password:");
  }
  readString = "";
}

void toggleLED(int pin, bool &led_on) {
  lcd.clear();
  if (led_on) {
    lcd.setCursor(0, 1);
    lcd.print("TURNING OFF");
    digitalWrite(pin, HIGH);
  } else {
    lcd.setCursor(0, 1);
    lcd.print("TURNING ON");
    digitalWrite(pin, LOW);
  }
  delay(1000);
  lcd.clear();
  led_on = !led_on;
  lcd.setCursor(0, 0);
  lcd.print("Enter password:");
}