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

LiquidCrystal_I2C lcd(0x27, 16, 2);

#define ROWS 4
#define 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}; 

int ledPin1 = 12;
int ledPin2 = 11;
int ledPin3 = 10;
int buzzerPin = 13;
int relayPin = A0; // Use A0 as the relay pin

char password[] = "1234"; // Change this to your desired password
char enteredPassword[5]; // The entered password will be stored here
int passwordIndex = 0;
int wrongAttempts = 0; // Counter for wrong attempts

void setup() {
  Serial.begin(9600);
  
  lcd.init();                      
  lcd.backlight();
  
  lcd.print("    Welcome!");
  delay(1000);
  lcd.clear();
  lcd.print(" Enter Password");

  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(relayPin, OUTPUT); // Set the relay pin as output

  for (int i = 0; i < ROWS; i++) {
    pinMode(rowPins[i], INPUT_PULLUP);
  }

  for (int i = 0; i < COLS; i++) {
    pinMode(colPins[i], OUTPUT);
    digitalWrite(colPins[i], HIGH);
  }
}

void loop() {
  char key = getKey();
  if (key != '\0') {
    if (key == 'C') { // Clear all typed passwords
      lcd.clear();
      lcd.print(" Enter Password");
      passwordIndex = 0;
      memset(enteredPassword, 0, sizeof(enteredPassword)); // Clear entered password
    } else if (key == 'D') { // Delete the previous typed letter
      if (passwordIndex > 0) {
        passwordIndex--;
        lcd.setCursor(passwordIndex, 0);
        lcd.print(" ");
      }
    } else if (key == 'A') { // Reset
      lcd.clear();
      lcd.print(" Enter Password");
      passwordIndex = 0;
      memset(enteredPassword, 0, sizeof(enteredPassword)); // Clear entered password
      digitalWrite(ledPin1, LOW); // Turn off all LEDs
      digitalWrite(ledPin2, LOW);
      digitalWrite(ledPin3, LOW);
    } else {
      if (passwordIndex == 0) {
        lcd.clear(); // Clear "Enter Password" message when typing the password
        int startPos = (16 - strlen(password)) / 2; // Calculate starting position
        lcd.setCursor(startPos, 0);
      }
      enteredPassword[passwordIndex] = key;
      lcd.print("*");
      passwordIndex++;
    }

    if (passwordIndex == 4) {
      if (strcmp(enteredPassword, password) == 0) {
        lcd.clear();
        lcd.print(" Access Granted!");
        delay(1000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("   Good Day");
        lcd.setCursor(0, 1);
        animateText("  MASTER RAM"); // Call the function to animate text
        digitalWrite(buzzerPin, HIGH); // Activate buzzer
        digitalWrite(relayPin, HIGH); // Activate relay to turn on the light
        delay(5000); // Buzz and light up for 5 seconds
        digitalWrite(buzzerPin, LOW); // Turn off buzzer
        digitalWrite(relayPin, LOW); // Turn off relay
      } else {
        lcd.clear();
      
        lcd.setCursor (0,0);
        lcd.print ("       3");
        delay (1000);
        lcd.clear();
        lcd.print ("       2");
        delay (1000);
        lcd.clear();
        lcd.print ("       1");
        delay (1000);
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print("      RUN"); // Display "Error" message for wrong password
        delay(1000);
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print(" Enter Password");
        passwordIndex = 0;
        memset(enteredPassword, 0, sizeof(enteredPassword)); // Clear entered password
        
        // Light up LEDs based on wrong attempts
        if (wrongAttempts == 0) {
          digitalWrite(ledPin1, HIGH);
        } else if (wrongAttempts == 1) {
          digitalWrite(ledPin2, HIGH);
        } else if (wrongAttempts == 2) {
          digitalWrite(ledPin3, HIGH);
          // Activate siren-like buzzer
          while (true) {
            digitalWrite(buzzerPin, HIGH); // Activate buzzer
            delay(100); // Beep duration
            digitalWrite(buzzerPin, LOW); // Turn off buzzer
            delay(100); // Silence duration
            if (getKey() == 'A') { // Check for reset condition
              break;
            }
          }
          wrongAttempts = -1; // Reset wrong attempts counter after siren mode
        }
        
        wrongAttempts++;
      }
    }
  }
}

char getKey() {
  for (int col = 0; col < COLS; col++) {
    digitalWrite(colPins[col], LOW);
    for (int row = 0; row < ROWS; row++) {
      if (digitalRead(rowPins[row]) == LOW) {
        delay(50); // Debounce delay
        if (digitalRead(rowPins[row]) == LOW) {
          digitalWrite(colPins[col], HIGH);
          return keys[row][col];
        }
      }
    }
    digitalWrite(colPins[col], HIGH);
  }
  return '\0';
}

// Function to animate text from left to right
void animateText(const char* text) {
  int textLength = strlen(text);
  for (int i = 0; i < textLength; i++) {
    lcd.setCursor(i, 1);
    lcd.print(text[i]);
    delay(200); // Adjust delay for animation speed
  }
}