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

#define LTRUCK 2
#define L20KL 3
#define L50KL 4

LiquidCrystal_I2C lcd(0x27, 20, 4);

const int delayPARKING20KL = 10; // 10 detik
const int distanceA_PARKING20KL = 50; // Contoh batas bawah jarak (dalam cm)
const int distanceB_PARKING20KL = 100; // Contoh batas atas jarak (dalam cm)

bool state = false;
unsigned long startMillis = 0;
int elapsedSeconds20KL = 0;
int lastDisplayedTime = -1;
int distance = 0;

void setup() {
  pinMode(LTRUCK, OUTPUT);
  pinMode(L20KL, OUTPUT);
  pinMode(L50KL, OUTPUT);
  lcd.init();
  lcd.backlight();
  Serial.begin(9600);
}

void loop() {
  distance = 75; // Simulasi jarak, ubah dengan sensor sebenarnya
  
  if (state) {
    lcd.setCursor(0, 1); lcd.print("Selesai Timer    ");
    Serial.println("Selesai Timer");
    return;
  }

  if (distance > distanceA_PARKING20KL && distance < distanceB_PARKING20KL) {
    if (startMillis == 0) startMillis = millis(); // Mulai hitung waktu
    
    elapsedSeconds20KL = (millis() - startMillis) / 1000;

    digitalWrite(LTRUCK, HIGH);
    digitalWrite(L20KL, HIGH);
    digitalWrite(L50KL, LOW);

    if (elapsedSeconds20KL >= delayPARKING20KL) {
      state = true;
    }

    if (elapsedSeconds20KL != lastDisplayedTime) {
      lastDisplayedTime = elapsedSeconds20KL;
      lcd.setCursor(0, 0); lcd.print("Water Filling Machine");
      lcd.setCursor(0, 1); lcd.print("Distance: " + String(distance) + " cm  ");
      lcd.setCursor(0, 2); lcd.print("S. Truck: Truk 20KL ");
      lcd.setCursor(0, 3); lcd.print("Timer   : " + String(elapsedSeconds20KL) + " s  ");
      Serial.println("Timer: " + String(elapsedSeconds20KL) + " s");
    }
  } else {
    startMillis = 0; // Reset waktu jika truk keluar
  }
}