#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <esp32-hal-ledc.h>
#include <ESP32Servo.h>
#include <Wire.h>

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Adjust the I2C address if needed

// Servo setup
Servo myServo;
const int servoPin = 2; // Replace with the appropriate servo pin
// LED pins
const int ledRed = 14;    // Pin connected to the red LED
const int ledGreen = 27;  // Pin connected to the green LED

// Keypad setup
const byte ROW_NUM = 4;    // four rows
const byte COLUMN_NUM = 4; // four columns

char keys[ROW_NUM][COLUMN_NUM] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

byte pinRows[ROW_NUM] = {26, 25, 33, 32}; // Connect to the row pinouts of the keypad
byte pinColumns[COLUMN_NUM] = {23, 22, 21, 19}; // Connect to the column pinouts of the keypad

Keypad keypad = Keypad(makeKeymap(keys), pinRows, pinColumns, ROW_NUM, COLUMN_NUM);

// Variables for OTP
char generatedOTP[5];
char inputPIN[5];
int inputIndex = 0;

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);
  // Initialize the LCD
  lcd.init();            // Initialize the LCD for I2C
  lcd.backlight();       // Turn on the backlight
  lcd.print("Generating OTP");

  // Initialize LEDs
  pinMode(ledRed, OUTPUT);
  pinMode(ledGreen, OUTPUT);

  myServo.attach(servoPin); // Attach the servo to the pin
  myServo.write(0); // Initial position (locked)

  // Initialize Servo

  delay(2000);
  generateOTP();  // Generate OTP when the system starts
  lcd.clear();
  lcd.print("Enter OTP:");
}
void generateOTP() {
  int otp = random(1000, 9999);  // Generate a 4-digit OTP
  snprintf(generatedOTP, 5, "%04d", otp);  // Store OTP as a string
  
  // Print the generated OTP to the Serial monitor
  Serial.print("Generated OTP: ");
  Serial.println(generatedOTP);

  lcd.clear();
  lcd.print("OTP Generated");  // Display OTP generated message
  delay(1000);  // Show message for 1 second
  lcd.clear();
  lcd.print("Enter OTP:");
}
void loop() {
  char key = keypad.getKey();

  if (key) {
    lcd.setCursor(inputIndex, 1);  // Move cursor to the correct position on second line
    lcd.print(key);  // Display the pressed key

    if (key == '#') {  // '#' is the enter key
      if (inputIndex == 4) {  // Only check if 4 digits have been entered
        inputPIN[4] = '\0';  // Null-terminate the string
        if (strcmp(inputPIN, generatedOTP) == 0) {
          unlockDoor();
        } else {
          lcd.clear();
          lcd.print("Wrong PIN!");
          digitalWrite(ledRed, HIGH);
          delay(2000);
          digitalWrite(ledRed, LOW);
        }
        inputIndex = 0;  // Reset input index
        lcd.clear();
        lcd.print("Enter OTP:");
      }
    } else if (key == '*') {  // '*' to clear input
      inputIndex = 0;
      lcd.clear();
      lcd.print("Enter OTP:");
    } else {
      if (inputIndex < 4) {  // Only allow up to 4 characters
        inputPIN[inputIndex] = key;
        inputIndex++;
      }
    }
  }
}
void unlockDoor() {
  digitalWrite(ledGreen, HIGH);
  myServo.write(90);
  Serial.println("Servo position: " + String(myServo.read()));  // Open the lock (adjust angle as needed)
  lcd.clear();
  lcd.print("Unlocked!");
  Serial.println("Door unlocked!");  // Debug message
  delay(15000);       // Keep it unlocked for 5 seconds
  myServo.write(0);  // Lock again
  digitalWrite(ledGreen, LOW);
  lcd.clear();
  lcd.print("Locked");
  Serial.println("Door locked!");  // Debug message
  delay(1000);
  generateOTP();  // Generate a new OTP after locking
}