#include "DHT.h"

#define PIR_PIN 13
#define DHT_PIN 15
#define DHT_TYPE DHT22

#define FAN_LED 26
#define BUZZER_PIN 14
#define GREEN_LED 26
#define RED_LED 26

DHT dht(DHT_PIN, DHT_TYPE);
int peopleCount = 0;

void setup() {
  Serial.begin(115200);

  pinMode(PIR_PIN, INPUT);
  pinMode(FAN_LED, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);

  dht.begin();

  Serial.println("Smart Classroom System - Wokwi Simulation");
}

void loop() {
  float temp = dht.readTemperature();

  if (digitalRead(PIR_PIN) == HIGH) {
    peopleCount++;
    Serial.print("Person detected. Count: ");
    Serial.println(peopleCount);

    if (peopleCount % 3 == 0) {
      unknownPerson();
    } else {
      knownPerson();
    }

    delay(3000);
  }

  if (temp > 30 || peopleCount >= 5) {
    digitalWrite(FAN_LED, HIGH);
    Serial.println("Ventilation ON");
  } else {
    digitalWrite(FAN_LED, LOW);
    Serial.println("Ventilation OFF");
  }

  delay(1000);
}

void knownPerson() {
  digitalWrite(GREEN_LED, HIGH);
  digitalWrite(RED_LED, LOW);
  digitalWrite(BUZZER_PIN, LOW);
  Serial.println("Known student - attendance recorded");
  delay(1000);
  digitalWrite(GREEN_LED, LOW);
}

void unknownPerson() {
  digitalWrite(RED_LED, HIGH);
  digitalWrite(GREEN_LED, LOW);
  digitalWrite(BUZZER_PIN, HIGH);
  Serial.println("⚠ Unknown person detected");
  delay(1500);
  digitalWrite(RED_LED, LOW);
  digitalWrite(BUZZER_PIN, LOW);
}