#include <Servo.h>

// Define names for the ultrasonic sensors
const String sensorNames[] = {"A", "B", "C", "D", "E", "F"};

// Define the pin numbers for the ultrasonic sensors
const int trigPins[] = {2, 4, 6, 8, 10, 12};
const int echoPins[] = {3, 5, 7, 9, 11, 13};

// Define the pin numbers for the LEDs
const int ledPins[] = {14, 15, 16, 17, 18, 19};

// Define the pin number for the IR sensor and servo motor
const int irSensorPin = 26;
const int servoPin = 27;

// Create a servo object
Servo gateServo;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  
  // Initialize the ultrasonic sensors and LED pins
  for (int i = 0; i < 6; i++) {
    pinMode(trigPins[i], OUTPUT);
    pinMode(echoPins[i], INPUT);
    pinMode(ledPins[i], OUTPUT); // Initialize LED pins
  }
  
  // Initialize the IR sensor
  pinMode(irSensorPin, INPUT);
  
  // Attach the servo motor to the pin
  gateServo.attach(servoPin);
  
  // Set the initial position of the servo motor (closed gate)
  gateServo.write(0);
}

void loop() {
  bool parkingAvailable = false;

  // Check the parking spots
  for (int i = 0; i < 6; i++) {
    long duration, distance;
    
    // Send a pulse to trigger the ultrasonic sensor
    digitalWrite(trigPins[i], LOW);
    delayMicroseconds(2);
    digitalWrite(trigPins[i], HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPins[i], LOW);
    
    // Read the pulse duration from the echo pin
    duration = pulseIn(echoPins[i], HIGH);
    
    // Calculate the distance in cm
    distance = (duration / 2) / 29.1;

    // Check if the parking spot is occupied
    if (distance < 10) {
      // Spot is occupied
      digitalWrite(ledPins[i], HIGH); // Turn on corresponding LED
      Serial.print("Parking spot ");
      Serial.print(sensorNames[i]);
      Serial.println(": Occupied");
    } else {
      // Spot is empty
      digitalWrite(ledPins[i], LOW); // Turn off corresponding LED
      parkingAvailable = true; // Set to true if any parking spot is empty
      Serial.print("Parking spot ");
      Serial.print(sensorNames[i]);
      Serial.println(": Empty");
    }
  }
  
  // Check the IR sensor for the gate
  int irValue = digitalRead(irSensorPin);
  
  // Control the servo based on the gate status
  if (irValue == HIGH && parkingAvailable) {
    gateServo.write(90); // Open the gate
    Serial.println("Car detected at the gate: Opening gate");
  } else {
    gateServo.write(0); // Close the gate
    Serial.println("No car at the gate or no parking available: Closing gate");
  }
  
  // Small delay to stabilize the sensor readings
  delay(1000);
}