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

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Encoder pins
int encoderPinA = 2;
int encoderPinB = 3;
int encoderButtonPin = 4;

// Alarm pin
int alarmPin = 5;

// Variables
long counter = 0;
long presetValue = 0;
bool setMode = false;
unsigned long buttonPressTime = 0;

// Rotary encoder state
int encoderLastStateA = 0;

void setup() {
  lcd.begin();
  lcd.backlight();
  pinMode(encoderPinA, INPUT_PULLUP);
  pinMode(encoderPinB, INPUT_PULLUP);
  pinMode(encoderButtonPin, INPUT_PULLUP);
  pinMode(alarmPin, OUTPUT);
  digitalWrite(alarmPin, LOW);
  lcd.setCursor(0, 0);
  lcd.print("Counter: ");
  lcd.setCursor(0, 1);
  lcd.print(counter);

  encoderLastStateA = digitalRead(encoderPinA);
}

void loop() {
  int encoderStateA = digitalRead(encoderPinA);
  int encoderStateB = digitalRead(encoderPinB);

  if (encoderStateA != encoderLastStateA) {
    if (encoderStateB != encoderStateA) {
      counter++;
    } else {
      counter--;
    }
    if (setMode) {
      presetValue = counter;
      lcd.setCursor(0, 1);
      lcd.print("Set: ");
      lcd.print(presetValue);
      lcd.print("    ");
    } else {
      lcd.setCursor(0, 1);
      lcd.print("Counter: ");
      lcd.print(counter);
      lcd.print("    ");
    }
  }
  encoderLastStateA = encoderStateA;

  if (digitalRead(encoderButtonPin) == LOW) {
    if (millis() - buttonPressTime > 3000) {
      setMode = !setMode;
      buttonPressTime = millis();
      if (setMode) {
        lcd.setCursor(0, 1);
        lcd.print("Set: ");
        lcd.print(presetValue);
        lcd.print("    ");
      } else {
        lcd.setCursor(0, 1);
        lcd.print("Counter: ");
        lcd.print(counter);
        lcd.print("    ");
      }
    }
  } else {
    buttonPressTime = millis();
  }

  if (counter == presetValue) {
    digitalWrite(alarmPin, HIGH);
  } else {
    digitalWrite(alarmPin, LOW);
  }

  if (setMode) {
    lcd.cursor();
    lcd.blink();
  } else {
    lcd.noCursor();
    lcd.noBlink();
  }
}