#include <Keypad.h>
#include <ESP32Servo.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#define ROWS 4 
#define COLS 4 
const int sensorpin = 26; 
int initialstate= LOW;  
int finalstate  = LOW;
const int ledpin=33;
const int timeout=20000;
int errorcount=0;
int initialtime=0;
int finaltime=0;
int count=1;
bool inputTimeoutReached = false;
String passcode="5090";
const int buzzer=32;
LiquidCrystal_I2C lcd(0x27,16,2);
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

byte rowpins[ROWS] = {4, 5, 18, 19}; 
byte colpins[COLS] = {15, 14, 27, 23};   
String inpString="";
Keypad keypad = Keypad( makeKeymap(keys), rowpins, colpins, ROWS, COLS);
Servo motor;
void setup() {
  Serial.begin(9600);
  lcd.backlight();
  lcd.init();
  pinMode(sensorpin,OUTPUT);
  pinMode(ledpin,OUTPUT);
  motor.attach(2,500,2400);
}

void loop() {
  motionCheck();
  pinInput();
}

void pinInput(){
  lcd.setCursor(0,0);
  lcd.print("ENTER PASSKEY:");
  while(inpString.length()!=4){
      char key=keypad.getKey();
      if (key) {
        inpString+=key;
        lcd.setCursor(inpString.length()-1,1);
        lcd.print(inpString[inpString.length()-1]);
      }
      if (inpString.length()==1) {
       finaltime = millis();
      }
      if (finaltime-initialtime>timeout) {
        inputTimeoutReached = true;
        initialtime=finaltime+count*20000;
        count++;
      }
      break;
    }
  if (inputTimeoutReached) {
    // Reset variables after input or timeout
    lcd.clear();
    inpString = "";
    inputTimeoutReached = false;
  }

  if (inpString.length() == 4) {
    if(inpString==passcode){
      digitalWrite(2, HIGH);
       motor.writeMicroseconds(1500);
      errorcount=0;
      tone(buzzer, 300, 250);
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("UNLOCKED");
      delay(3000);
    }
    else{
      errorcount+=1;
     digitalWrite(2,LOW);
     motor.writeMicroseconds(1000);
      tone(buzzer, 262, 250);
      lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("INCORRECT");
      delay(3000);
      if(errorcount==3){
        Serial.println("CAUTION");
        digitalWrite(buzzer, HIGH);
        delayMicroseconds(25000);
        digitalWrite(buzzer, LOW);
        errorcount=0; 
      }
    }
    // Reset variables after input or timeout
    inpString = "";
    inputTimeoutReached = false;
  }
}

void motionCheck(){
  initialstate = finalstate;
  finalstate = digitalRead(sensorpin);   
  if (initialstate == LOW && finalstate == HIGH){   
    Serial.println("Motion detected!");
    digitalWrite(ledpin,HIGH);
  }
  else
  if (initialstate == HIGH && finalstate == LOW){
    Serial.println("Motion stopped!");
    digitalWrite(ledpin,LOW);
  }
}