#define PIR_PIN PA0
#define LED PA5
#define BUZZER PA4
#define BUTTON PA6

bool systemState = false;   // OFF initially
bool buttonState;
bool lastButtonState = HIGH;

unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 50;

void setup() {
  pinMode(PIR_PIN, INPUT);
  pinMode(LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(BUTTON, INPUT_PULLUP);

  Serial.begin(9600);
}

void loop() {

  // -------- BUTTON (DEBOUNCED TOGGLE) --------
  bool reading = digitalRead(BUTTON);

  if (reading != lastButtonState) {
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState) {
      buttonState = reading;

      if (buttonState == LOW) {
        systemState = !systemState;

        Serial.print("System: ");
        Serial.println(systemState ? "ARMED" : "DISARMED");
      }
    }
  }

  lastButtonState = reading;

  // -------- SECURITY LOGIC --------
  if (systemState) {
    int motion = digitalRead(PIR_PIN);

    if (motion == HIGH) {
      digitalWrite(LED, HIGH);
      digitalWrite(BUZZER, HIGH);
      Serial.println("🚨 Motion Detected!");
    } else {
      digitalWrite(LED, LOW);
      digitalWrite(BUZZER, LOW);
    }

  } else {
    // System OFF
    digitalWrite(LED, LOW);
    digitalWrite(BUZZER, LOW);
  }
}