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

LiquidCrystal_I2C lcd(0x27, 20, 4);//for LCD

int LedpinG = 12;
int LedpinR = 13;
//int trigPin = 11;
//int echoPin = 1;

const byte ROW_NUM = 4;
const byte COLUMN_NUM = 4;
const int MAX_PASSWORD_LENGTH = 4;

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] = {9, 8, 7, 6};
byte pin_columns[COLUMN_NUM] = {5, 4, 3, 2};

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_columns, ROW_NUM, COLUMN_NUM);

const String password = "1234";
String input_password = "";

void setup() {
  Serial.begin(9600);
  input_password.reserve(MAX_PASSWORD_LENGTH);
  

  pinMode(LedpinG, OUTPUT);
  pinMode(LedpinR, OUTPUT);
  //pinMode(trigPin, OUTPUT);
  //pinMode(echoPin, INPUT);

  lcd.init();
  lcd.backlight();
  delay(1000);

  lcd.setCursor(3,0.5);
  lcd.print("Hello there !!!");
  delay(1000);

  lcd.setCursor(1,2);
  lcd.print("Enter the password");
  delay(2000);

  lcd.clear();
  lcd.noBacklight();
  delay(1000);

  lcd.backlight();
  lcd.setCursor(1,1.5);
  lcd.print("Password: ");
  delay(1000);

  lcd.noBacklight();

 
}

void loop() {
  char key = keypad.getKey();
  //int distance;
  //int duration;

  //digitalWrite(trigPin, LOW);
  //delayMicroseconds(2);
  //digitalWrite(trigPin, HIGH);
  //delayMicroseconds(10);
  //digitalWrite(trigPin, LOW);

  //duration =pulseIn(echoPin,HIGH);
  //distance = duration*0.0344/2;

  if (key) {
    Serial.println(key);
    lcd.backlight();
    lcd.print("X");

    if (key == '*') {
      input_password = "";
    } else if (key == '#'){
      if (password.equals(input_password)) { 
        Serial.println("Password is correct");
        digitalWrite(LedpinG, HIGH);
        delay(1000);

        digitalWrite(LedpinG, LOW);
        lcd.clear();
        lcd.setCursor(1,1.5);
        lcd.print("Password is correct");
        lcd.setCursor(4,3);
        lcd.print("CONGRAST!!!");
        delay(2000);

        lcd.clear();
        lcd.setCursor(1,1.5);
        lcd.print("Password: ");
        delay(1000);

        lcd.noBacklight();
        
      } else {
        Serial.println("Password is incorrect, try again");
        digitalWrite(LedpinR, HIGH);
        delay(1000);

        digitalWrite(LedpinR, LOW);
        lcd.clear();
        lcd.setCursor(2,1);
        lcd.print("Password INCORRECT");
        lcd.setCursor(4,3);
        lcd.print("Try again!!!");
        delay(2000);

        lcd.clear();
        lcd.setCursor(1,1.5);
        lcd.print("Password: ");
        delay(1000);

        lcd.noBacklight();
      }
      input_password = "";
    } else {
      input_password += key;
    }
  }
}