// Define pins for entry and exit IR sensors
const int irEntryPin = 2;  // Pin connected to IR receiver for entry
const int irExitPin = 3;   // Pin connected to IR receiver for exit

// Define pins for LEDs and relay
const int greenLEDPin = 4; // Pin connected to green LED (entry)
const int redLEDPin = 5;   // Pin connected to red LED (exit indicator)
const int relayPin = 6;    // Pin connected to relay

// Variables
int peopleInRoom = 0;
bool entryBeamBroken = false;
bool exitBeamBroken = false;
unsigned long lastDebounceTimeEntry = 0;
unsigned long lastDebounceTimeExit = 0;
const unsigned long debounceDelay = 50; // Debounce time in milliseconds

void setup() {
  pinMode(irEntryPin, INPUT);  // Set entry IR receiver pin as input
  pinMode(irExitPin, INPUT);   // Set exit IR receiver pin as input
  pinMode(greenLEDPin, OUTPUT); // Set green LED pin as output
  pinMode(redLEDPin, OUTPUT);   // Set red LED pin as output
  pinMode(relayPin, OUTPUT);    // Set relay pin as output

  // Start serial communication for debugging
  Serial.begin(9600);
}

void loop() {
  // Read the state of the entry IR sensor
  bool entryState = digitalRead(irEntryPin);
  unsigned long currentTime = millis();

  if (entryState == LOW) {
    if ((currentTime - lastDebounceTimeEntry) > debounceDelay) {
      if (!entryBeamBroken) {
        entryBeamBroken = true;
        peopleInRoom++;
        Serial.print("People in room: ");
        Serial.println(peopleInRoom);

        // Blink the green LED to indicate entry
        blinkLED(greenLEDPin);

        // Keep relay on if there are people in the room
        digitalWrite(relayPin, HIGH);  // Activate relay
      }
      lastDebounceTimeEntry = currentTime;
    }
  } else {
    entryBeamBroken = false;
  }

  // Read the state of the exit IR sensor
  bool exitState = digitalRead(irExitPin);

  if (exitState == LOW) {
    if ((currentTime - lastDebounceTimeExit) > debounceDelay) {
      if (!exitBeamBroken) {
        exitBeamBroken = true;
        if (peopleInRoom > 0) {  // Prevent negative count
          peopleInRoom--;
        }
        Serial.print("People in room: ");
        Serial.println(peopleInRoom);

        // Blink the red LED to indicate exit
        blinkLED(redLEDPin);

        // Turn off relay if the room is empty
        if (peopleInRoom == 0) {
          digitalWrite(relayPin, LOW);  // Deactivate relay
        }
      }
      lastDebounceTimeExit = currentTime;
    }
  } else {
    exitBeamBroken = false;
  }
}

// Function to blink an LED
void blinkLED(int ledPin) {
  for (int i = 0; i < 3; i++) { // Blink the LED 3 times
    digitalWrite(ledPin, HIGH);
    delay(250);  // LED on for 250 ms
    digitalWrite(ledPin, LOW);
    delay(250);  // LED off for 250 ms
  }
}