const int pirPin = 2;      // PIR sensor pin
const int buzzerPin = 9;   // Buzzer pin (using tone for passive buzzer)
const int ledPin = 13;     // Status LED pin
const int buttonPin = 10;  // Button pin for arming/disarming

bool theftDetected = false;
bool systemArmed = false; // System state: armed/disarmed
bool buttonState = false; // Tracks button toggle

// Simulated GPS Coordinates
float simulatedLat = 37.7749; // Example latitude
float simulatedLon = -122.4194; // Example longitude

void setup() {
  pinMode(pirPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP); // Use internal pull-up

  digitalWrite(buzzerPin, LOW);
  digitalWrite(ledPin, LOW);

  Serial.begin(9600); // Initialize Serial Monitor
  Serial.println("Anti-Theft Device Initialized");
}

void loop() {
  // Handle button input to toggle system state
  if (digitalRead(buttonPin) == LOW) { // Button pressed
    delay(10); // Debounce delay
    buttonState = !buttonState;
    systemArmed = buttonState;

    // Update status LED
    if (systemArmed) {
      digitalWrite(ledPin, HIGH);
      Serial.println("System Armed");
    } else {
      digitalWrite(ledPin, LOW);
      Serial.println("System Disarmed");
    }
    delay(20); // Avoid multiple toggles due to button bounce
  }

  if (systemArmed) {
    // Check PIR sensor if system is armed
    if (digitalRead(pirPin) == HIGH) {
      theftDetected = true;
      triggerAlarm();
    }

    if (theftDetected) {
      sendAlert();
      delay(10000); // Wait before sending another alert
      theftDetected = false;
    }
  }

  delay(500);
}

void triggerAlarm() {
  // Start buzzer sound continuously and blink LED
  tone(buzzerPin, 1000);  // Play sound at 1kHz
  for (int i = 0; i < 10; i++) { // Blink LED and sound buzzer 10 times
    digitalWrite(ledPin, HIGH);
    delay(200); // 200ms ON
    digitalWrite(ledPin, LOW);
    delay(200); // 200ms OFF
  }
  // Keep buzzer ON for some time after blinking
  delay(3000); // Continue sound for 3 more seconds after LED blinking
  noTone(buzzerPin);  // Stop buzzer sound after the alarm duration
}

void sendAlert() {
  // Simulate GPS and SMS
  String message = "Theft detected! Location: ";
  message += "Lat: ";
  message += simulatedLat;
  message += ", Lon: ";
  message += simulatedLon;
  Serial.println(message);

  // Simulate sending SMS
  Serial.println("Simulated SMS Sent: " + message);
}