#include <NewPing.h>
#define RED_PIN 15    // Red pin of the RGB LED
#define GREEN_PIN 2   // Green pin of the RGB LED
#define BLUE_PIN 4    // Blue pin of the RGB LED

NewPing sonar(12, 14, 400);

const int pirPin = 34;
const int reserveButton = 35;

enum ParkingState {
  OCCUPIED,
  AVAILABLE,
  RESERVED
};

ParkingState parkingState = AVAILABLE;

void setup() {
  Serial.begin(115200);
  pinMode(pirPin, INPUT);
  pinMode(reserveButton, INPUT_PULLUP);
  pinMode(RED_PIN, OUTPUT);
  pinMode(GREEN_PIN, OUTPUT);
  pinMode(BLUE_PIN, OUTPUT);

  digitalWrite(RED_PIN, 0);
  digitalWrite(GREEN_PIN, 0);
  digitalWrite(BLUE_PIN, 0);
}

void loop() {
  int PIR = digitalRead(pirPin);
  int reserveButtonState = digitalRead(reserveButton);
  int DIS = sonar.ping_cm();

  switch (parkingState) {
    case OCCUPIED:
      if (PIR == HIGH && DIS > 100) {
        Serial.println("Parking Slot is AVAILABLE");
        setColor(0, 255, 0);  // Green
        parkingState = AVAILABLE;
      }
      break;

    case AVAILABLE:
      if (reserveButtonState == HIGH) {
        Serial.println("Parking Slot is RESERVED");
        setColor(255, 255, 0);  // Yellow
        parkingState = RESERVED;
      }
      break;

    case RESERVED:
      if (PIR == HIGH && DIS <= 100) {
        Serial.println("Parking Slot is OCCUPIED");
        setColor(255, 0, 0);  // Red
        parkingState = OCCUPIED;
      }
      break;
  }

  delay(250);
}

// Function to set RGB LED color
void setColor(int red, int green, int blue) {
  digitalWrite(RED_PIN, red);
  digitalWrite(GREEN_PIN, green);
  digitalWrite(BLUE_PIN, blue);
}