constexpr int buzzerPin = 3;
constexpr int lightPin = 6;
constexpr int seatbeltPin = 2;
constexpr int ignitionPin = 4;
constexpr unsigned long waitBeforAlarm = 2000;

unsigned long lastTimeBlinked = 0;
unsigned long alarmTime       = 0;
unsigned long blinkInterval  = 500;
boolean       alarmActive = false;
boolean       doAlarm     = false;


void setup() {
  pinMode(buzzerPin, OUTPUT);
  pinMode(lightPin, OUTPUT);
  pinMode(seatbeltPin, INPUT_PULLUP);
  pinMode(ignitionPin, INPUT_PULLUP);
  digitalWrite(buzzerPin, LOW);
  digitalWrite(lightPin, LOW);
}

void loop() {
  // Check if the seatbelt is fastened and ignition is off
  boolean giveAlarm = (digitalRead(seatbeltPin) == LOW && digitalRead(ignitionPin) == HIGH);
  if (!alarmActive && giveAlarm) {
    alarmActive = true;
    alarmTime = millis();
  } 
  if (alarmActive && !giveAlarm) {
    digitalWrite(buzzerPin, LOW);
    digitalWrite(lightPin, LOW); 
    alarmActive = false;
    doAlarm = false;
    }
  if (alarmActive && millis()-alarmTime > waitBeforAlarm) {
      doAlarm = true;    
    }
  if (doAlarm) {
    if (millis() - lastTimeBlinked > blinkInterval){
      lastTimeBlinked = millis();
      int buzz   = !digitalRead(buzzerPin);
      int light  = !digitalRead(lightPin);
      digitalWrite(buzzerPin, buzz);
      digitalWrite(lightPin, light); 
    }
  }
}