// ====== Kontrol Otomatis Pencahayaan Ruangan (ESP32) ======
#include <Wire.h>
#include <RTClib.h>
#include <LiquidCrystal_I2C.h>

// ---------------- Pin Mapping (ESP32) ----------------
const int PIN_LDR   = 34;   // Analog input from LDR module (AO/OUT)
const int PIN_RELAY = 26;   // Relay IN (active HIGH or LOW lihat modulmu)
const int PIN_LED   = 33;   // LED indikator via resistor 220Ω

// ---------------- I2C Device Addresses ----------------
const uint8_t LCD_ADDR = 0x27;  // ganti ke 0x3F jika layar tidak muncul

// ---------------- Objects ----------------
RTC_DS3231 rtc;
LiquidCrystal_I2C lcd(LCD_ADDR, 16, 2);

// ---------------- Konfigurasi ----------------
// Jam penjadwalan lampu (24 jam)
const int ON_HOUR  = 18;   // mulai malam (18:00)
const int OFF_HOUR = 6;    // akhir malam (06:00)

// Histeresis LDR (ADC ESP32: 0..4095). Sesuaikan dengan rangkaianmu.
// Misal bernilai makin besar = makin gelap (umum pada modul pembagi tegangan).
const int LDR_ON_THRESHOLD  = 2600; // di atas ini dianggap gelap → ON (saat malam)
const int LDR_OFF_THRESHOLD = 2200; // di bawah ini dianggap cukup terang → OFF

// Relay aktif level (banyak modul relay aktif LOW). Ubah jika perlu.
const bool RELAY_ACTIVE_LEVEL = LOW;   // LOW = ON, HIGH = OFF (relay aktif LOW)
                                        // Jika modulmu aktif HIGH, set ke HIGH.

bool lampOn = false;

// Smoothing bacaan LDR
int readLDRSmooth(uint8_t samples = 10) {
  long sum = 0;
  for (uint8_t i = 0; i < samples; i++) {
    sum += analogRead(PIN_LDR);
    delay(2);
  }
  return sum / samples;
}

void setRelay(bool on) {
  lampOn = on;
  if (RELAY_ACTIVE_LEVEL == LOW) {
    digitalWrite(PIN_RELAY, on ? LOW : HIGH);
  } else {
    digitalWrite(PIN_RELAY, on ? HIGH : LOW);
  }
  digitalWrite(PIN_LED, on ? HIGH : LOW);
}

void printLCD(const DateTime& now, int ldr) {
  lcd.setCursor(0, 0);
  // Format waktu: HH:MM:SS
  char buf[17];
  snprintf(buf, sizeof(buf), "%02d:%02d:%02d ", now.hour(), now.minute(), now.second());
  lcd.print(buf);
  // Sisa 6-7 karakter: tampilkan LDR (0..4095)
  snprintf(buf, sizeof(buf), "L:%4d", ldr);
  lcd.print(buf);

  lcd.setCursor(0, 1);
  // Status & mode
  lcd.print(lampOn ? "LAMP:ON " : "LAMP:OFF");
  bool isNight = (now.hour() >= ON_HOUR) || (now.hour() < OFF_HOUR);
  lcd.print(isNight ? " Night" : " Day  ");
}

void setup() {
  // I2C pada ESP32 (SDA=21, SCL=22)
  Wire.begin(21, 20);

  pinMode(PIN_RELAY, OUTPUT);
  pinMode(PIN_LED, OUTPUT);
  pinMode(PIN_LDR, INPUT);

  // Matikan dulu
  setRelay(false);

  // Serial opsional
  Serial.begin(115200);
  delay(200);

  // LCD
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Auto Lighting");
  lcd.setCursor(0, 1);
  lcd.print("Init...");

  // RTC
  if (!rtc.begin()) {
    lcd.clear();
    lcd.print("RTC not found!");
    while (true) {
      // Tahan di sini agar jelas ada masalah pada RTC
      delay(1000);
    }
  }

  // Set waktu sekali saat pertama kali upload (lalu COMMENT baris ini)
  // rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));

  lcd.clear();
}

void loop() {
  DateTime now = rtc.now();

  // Baca LDR
  int ldr = readLDRSmooth(12);

  // Tentukan siang/malam berdasarkan jam
  bool isNight = (now.hour() >= ON_HOUR) || (now.hour() < OFF_HOUR);

  // Logika kontrol dengan histeresis:
  if (isNight) {
    if (!lampOn && ldr >= LDR_ON_THRESHOLD) {
      setRelay(true);  // cukup gelap → nyalakan
    } else if (lampOn && ldr <= LDR_OFF_THRESHOLD) {
      setRelay(false); // cukup terang → matikan
    }
  } else {
    // Siang → lampu harus OFF
    if (lampOn) setRelay(false);
  }

  // Tampilkan di LCD
  printLCD(now, ldr);

  // Debug opsional
  // Serial.printf("%02d:%02d LDR=%d Lamp=%d\n", now.hour(), now.minute(), ldr, lampOn);

  delay(200); // refresh ~5x per detik
}