/*
 * This ESP32 code is created by esp32io.com
 *
 * This ESP32 code is released in the public domain
 *
 * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-keypad-solenoid-lock
 */

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

#define RELAY_PIN   5 // ESP32 pin GPIO19 connected to the relay
#define ROW_NUM     4  // keypad four rows
#define COLUMN_NUM  4  // keypad three columns

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

byte pin_rows[ROW_NUM] = {12, 14, 27, 26};   // ESP32 pin: GPIO12, GPIO14, GPIO27, GPIO26 connected to the row pins
byte pin_column[COLUMN_NUM] = {25, 33, 13, 32};  // ESP32 pin: GPIO25, GPIO33, GPIO32 connected to the column pins

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27 (from DIYables LCD), 16 column and 2 rows

int cursorColumn = 0;

const String password_1 = "1234"; // change your password here
String input_password;

void setup() {
  Serial.begin(9600);
  input_password.reserve(32); // maximum password size is 32, change if needed
  pinMode(RELAY_PIN, OUTPUT); // initialize pin as an output.
  digitalWrite(RELAY_PIN, LOW); // lock the solenoid lock
  lcd.init(); // initialize the lcd
  lcd.backlight();
}

void loop() {
  lcd.setCursor(0, 0); // move cursor to   (cursorColumn, 0)
  lcd.print("Enter the OTP");
  char key = keypad.getKey();
  
  if (key) {
    
    
    lcd.setCursor(cursorColumn, 1);
    lcd.print(key);
    cursorColumn++;
    Serial.println(key);
    if (key == '*') {
      input_password = ""; // reset the input password
      lcd.clear();
      cursorColumn=0;
    } else if (key == '#') {
      if (input_password == password_1) {
        Serial.println("The password is correct => unlock");
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("Correct Password");
        delay(2000);
        lcd.clear();
        digitalWrite(RELAY_PIN, HIGH);
        delay(4000);
        digitalWrite(RELAY_PIN, LOW);
      } else {
        Serial.println("The password is incorrect, try again");
        lcd.clear();
        lcd.setCursor(0, 1);
        lcd.print("InCorrect Password");
        delay(2000);
        lcd.clear();
      }
      cursorColumn=0;

      input_password = ""; // reset the input password
    }
    else {
      input_password += key; // append new character to input password string
    }
  }
}