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

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 relayPin = 13; // Connect the relay to pin 13

// Define your passcodes and corresponding messages
const char passcodes[][6] = {"70", "0704", "5678"}; // Change this to your desired passcodes
const char messages[][20] = {"\n1879", "\nCyber", "\nother"}; // Messages corresponding to passcodes

char enteredCode[6]; // Buffer to store entered code

// Initialize the LCD
LiquidCrystal_I2C lcd(0x27, 16, 2); // Set the LCD I2C address to 0x27, 16 characters and 2 lines

void setup()
{
  pinMode(relayPin, OUTPUT); // Set the relay pin as output
  Serial.begin(9600); // Initialize serial communication for debugging

  // Initialize LCD...some more
  lcd.init();
  lcd.backlight();
  lcd.print("Enter Passcode:");
  Serial.println("Enter Passcode:");
  lcd.setCursor(0, 1); // Set cursor to the first column of the second row
}

void loop()
{
  char key = keypad.getKey();
  
  if (key)
  {
    if (key == '#') // If # key is pressed, check the passcode
    {
      if (strlen(enteredCode) >= 2) // Check if passcode length is at least 2
      { 
        enteredCode[strlen(enteredCode)] = '\0'; // Null terminate the string
        bool passcodeMatched = false;
        for (int i = 0; i < sizeof(passcodes) / sizeof(passcodes[0]); i++)
        {
          if (strcmp(enteredCode, passcodes[i]) == 0) // If the entered passcode matches one of the stored passcodes, activate the relay
          {
            digitalWrite(relayPin, HIGH);
            lcd.clear();
            centerText(messages[i]); //lcd.print(messages[i]); // Print corresponding message
            Serial.println(messages[i]); // Print corresponding message to Serial monitor
            delay(10000); // Delay to keep the relay activated for a short duration
            digitalWrite(relayPin, LOW); // Deactivate the relay after delay
            lcd.clear();
            lcd.print("Enter Passcode:");
            lcd.setCursor(0, 1); // Set cursor to the first column of the second row
            Serial.println("\nEnter Passcode:");
            passcodeMatched = true;
            break;
          }
        }
        if (!passcodeMatched)
        {
          lcd.clear();
          lcd.print("Access Denied");
          Serial.println("\nAccess Denied");
          delay(1000);
          lcd.clear();
          lcd.print("Enter Passcode:"); // Display prompt for next passcode entry
          lcd.setCursor(0, 1); // Set cursor to the first column of the second row
          Serial.println("\nEnter Passcode:");
        }
        memset(enteredCode, 0, sizeof(enteredCode)); // Clear the entered code buffer
      } 
      
      else
      {
        lcd.clear();
        lcd.print("Invalid Passcode");
        Serial.println("\nInvalid Passcode");
        delay(1000);
        lcd.clear();
        lcd.print("Enter Passcode:"); // Display prompt for next passcode entry
        lcd.setCursor(0, 1); // Set cursor to the first column of the second row
        Serial.println("\nEnter Passcode:");
      }
    } 
    
    else if (strlen(enteredCode) < sizeof(enteredCode) - 1) // If less than the buffer size
    { 
      lcd.print(key); // Print the pressed key on LCD
      Serial.print(key); // Print the pressed key to Serial monitor
      enteredCode[strlen(enteredCode)] = key; // Store the pressed key
      lcd.setCursor(strlen(enteredCode), 1); // Move cursor to the end of entered characters on the second line
    }
  }
}

void centerText(const char* text)
{
  int len = strlen(text);
  int startPos = (16 - len) / 2;
  lcd.setCursor(startPos, 0);
  lcd.print(text);
  
  for (int i = 0; i < 5; i++)
  {
    lcd.setCursor(startPos, 0);
    lcd.print("                ");
    delay(200);
    lcd.setCursor(startPos, 0);
    lcd.print(text);
    delay(200);
  }
}