// ---------------- PIN DEFINITIONS ----------------
#define PIR_PIN     14
#define BUTTON_PIN  27
#define SERVO_PIN   16

// ---------------- SERVO SETTINGS ----------------
#define SERVO_FREQ    50
#define SERVO_RES     16

#define OPEN_ANGLE   90
#define CLOSE_ANGLE  0

// ---------------- TIMING ----------------
const unsigned long OPEN_TIME = 5000;   // 5 seconds
const unsigned long DEBOUNCE_TIME = 50;

// ---------------- STATE ----------------
enum GateState { CLOSED, OPEN };
GateState gateState = CLOSED;

unsigned long gateOpenTimestamp = 0;
unsigned long lastButtonChangeTime = 0;

bool lastButtonState = HIGH;
bool stableButtonState = HIGH;

// ---------------- SERVO FUNCTION ----------------
void setServoAngle(int angle) {
  uint32_t duty = map(angle, 0, 180, 1638, 8192);
  ledcWrite(SERVO_PIN, duty);   // ESP32 core v3.x style
}

// ---------------- SETUP ----------------
void setup() {
  Serial.begin(115200);

  pinMode(PIR_PIN, INPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

  ledcAttach(SERVO_PIN, SERVO_FREQ, SERVO_RES);

  setServoAngle(CLOSE_ANGLE);

  Serial.println("System ready. Gate CLOSED.");
}

// ---------------- LOOP ----------------
void loop() {
  unsigned long now = millis();

  // ---------------- AUTO CLOSE ----------------
  if (gateState == OPEN && (now - gateOpenTimestamp >= OPEN_TIME)) {
    closeGate();
  }

  // ---------------- PIR (ONLY WHEN CLOSED) ----------------
  if (gateState == CLOSED && digitalRead(PIR_PIN) == HIGH) {
    triggerGate("PIR motion detected", now);
  }

  // ---------------- BUTTON DEBOUNCE (ONLY WHEN CLOSED) ----------------
  bool reading = digitalRead(BUTTON_PIN);

  if (reading != lastButtonState) {
    lastButtonChangeTime = now;
  }

  if ((now - lastButtonChangeTime) > DEBOUNCE_TIME) {
    if (reading != stableButtonState) {
      stableButtonState = reading;

      if (gateState == CLOSED && stableButtonState == LOW) {
        triggerGate("Button pressed", now);
      }
    }
  }

  lastButtonState = reading;
}

// ---------------- TRIGGER ----------------
void triggerGate(const char* source, unsigned long now) {
  if (gateState == OPEN) return;

  Serial.print("[TRIGGER] ");
  Serial.println(source);

  openGate();
  gateOpenTimestamp = now;
}

// ---------------- OPEN ----------------
void openGate() {
  setServoAngle(OPEN_ANGLE);
  gateState = OPEN;
  gateOpenTimestamp = millis();

  Serial.println("Gate OPENED");
}

// ---------------- CLOSE ----------------
void closeGate() {
  setServoAngle(CLOSE_ANGLE);
  gateState = CLOSED;

  Serial.println("Gate CLOSED");
}