// Pins
const int lightSensorPin = 2;  // digital photoresistor pin
const int ledPin         = 9;
const int buttonPin      = 7;
const int buzzerPin      = 8;

// State
bool ledOn = true;

// Debounce
int lastButtonState = HIGH;
unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 50;

void setup() {
  // Pin modes
  pinMode(buttonPin, INPUT_PULLUP);      // button to GND
  pinMode(lightSensorPin, INPUT);        // digital photoresistor
  pinMode(ledPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  digitalWrite(ledPin, HIGH);            // start LED ON
  ledOn = true;
}

void loop() {
  // ---- Button handling (toggle LED) ----
  int reading = digitalRead(buttonPin);

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

  if ((millis() - lastDebounceTime) > debounceDelay) {
    static int stableButtonState = HIGH;
    if (reading != stableButtonState) {
      stableButtonState = reading;
      if (stableButtonState == LOW) {
        // button pressed -> toggle LED
        ledOn = !ledOn;
        digitalWrite(ledPin, ledOn ? HIGH : LOW);
      }
    }
  }
  lastButtonState = reading;

  // ---- Light sensor + buzzer ----
  if (!ledOn) {
    // LED OFF => sensor disabled, buzzer OFF
    noTone(buzzerPin);
  } else {
    // LED ON => allow sensor to control buzzer
    int lightState = digitalRead(lightSensorPin);

    // Adjust this depending on wiring:
    // If using pull-up: bright -> LOW, dark -> HIGH
    // If using external divider: bright -> HIGH, dark -> LOW
    bool brightDetected = (lightState == LOW);  

    if (brightDetected) {
      tone(buzzerPin, 1000); // buzzer ON
    } else {
      noTone(buzzerPin);     // buzzer OFF
    }
  }

  delay(20);
}