#include <Servo.h>

// === PIN DEFINISI ===
#define TRIG_PIN     3
#define ECHO_PIN     4
#define PIR_PIN      2
#define BUZZER_PIN   6
#define SERVO_PIN    9

Servo gateServo;

// === KONSTANTA DAN VARIABEL ===
const int bukaSudut = 90;
const int tutupSudut = 0;
const int batasJarak = 50;
const int intervalPrint = 1000; // 1 detik

unsigned long lastPrintTime = 0;
unsigned long lastToneTime = 0;
bool toneState = false;

void setup() {
  Serial.begin(9600);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(PIR_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  gateServo.attach(SERVO_PIN);
  gateServo.write(tutupSudut);         // Gerbang awal tertutup
  noTone(BUZZER_PIN);                  // Pastikan buzzer mati
}

void loop() {
  int jarak = bacaJarak();
  bool pirTerdeteksi = digitalRead(PIR_PIN);

  bool kondisiBuka = (jarak < batasJarak && pirTerdeteksi);

  // === LOGIKA AKSI ===
  nyalakanAlarm(kondisiBuka);
  gateServo.write(kondisiBuka ? bukaSudut : tutupSudut);

  // === CETAK SERIAL MONITOR SETIAP 1 DETIK ===
  if (millis() - lastPrintTime >= intervalPrint) {
    Serial.print("Jarak: ");
    Serial.print(jarak);
    Serial.print(" cm ; PIR: ");
    Serial.print(pirTerdeteksi ? "Detected" : "Not Detected");
    Serial.print(" ; Gerbang: ");
    Serial.println(kondisiBuka ? "Terbuka" : "Tertutup");

    lastPrintTime = millis();
  }

  delay(50); // Delay ringan
}

int bacaJarak() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long durasi = pulseIn(ECHO_PIN, HIGH, 30000); // timeout 30 ms
  if (durasi == 0) return 999; // Tidak terbaca
  return durasi * 0.034 / 2;   // cm
}

void nyalakanAlarm(bool status) {
  unsigned long now = millis();

  if (status) {
    if (!toneState && now - lastToneTime >= 600) {
      tone(BUZZER_PIN, 1000);   // Nada 1000 Hz
      toneState = true;
      lastToneTime = now;
    }
    if (toneState && now - lastToneTime >= 200) {
      noTone(BUZZER_PIN);       // Matikan nada setelah 200 ms
      toneState = false;
      lastToneTime = now;
    }
  } else {
    noTone(BUZZER_PIN);         // Matikan buzzer sepenuhnya
    toneState = false;
  }
}