#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// LCD address and size
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Pin definitions
const int buttonPin = 2;
const int greenLED = 8;
const int redLED = 9;

// Occupancy status
bool occupied = false;

// Button variables
bool lastButtonState = HIGH;
bool currentButtonState;

void setup() {

  // Initialize LCD
  lcd.init();
  lcd.backlight();

  // Pin modes
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT);

  // Initial status
  showStatus();
}

void loop() {

  currentButtonState = digitalRead(buttonPin);

  // Detect button press
  if (lastButtonState == HIGH && currentButtonState == LOW) {

    // Change occupancy status
    occupied = !occupied;

    // Update LCD and LEDs
    showStatus();

    // Small debounce delay
    delay(300);
  }

  lastButtonState = currentButtonState;
}


// Function to display occupancy status
void showStatus() {

  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("ROOM STATUS:");

  if (occupied == true) {

    lcd.setCursor(0, 1);
    lcd.print("OCCUPIED");

    digitalWrite(redLED, HIGH);
    digitalWrite(greenLED, LOW);

  } 
  else {

    lcd.setCursor(0, 1);
    lcd.print("VACANT");

    digitalWrite(redLED, LOW);
    digitalWrite(greenLED, HIGH);
  }
}