#include <LiquidCrystal.h>
#include <Servo.h>

// Initialize LCD with the correct pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// Initialize Servo
Servo gateServo;

// Ultrasonic sensor pins
const int trigPin1 = 7;
const int echoPin1 = 6;
const int trigPin2 = 9;
const int echoPin2 = 8;
const int trigPin3 = A0;
const int echoPin3 = A1;

// LED pins
const int redLED = 13;
const int greenLED = 10;

// Variables
int parkedCars = 0;
const int maxCars = 3;
const int rollNo = 12345; // Replace with your roll number

void setup() {
  // Initialize Serial Monitor for debugging
  Serial.begin(9600);

  // Initialize LCD
  lcd.begin(16, 2);
  lcd.clear();
  
  // Initialize Servo
  gateServo.attach(A2);
  gateServo.write(0);
  
  // Initialize Ultrasonic sensors
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  pinMode(trigPin3, OUTPUT);
  pinMode(echoPin3, INPUT);
  
  // Initialize LEDs
  pinMode(redLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  
  // Display roll number
  lcd.setCursor(0, 0);
  lcd.print("Roll No: ");
  lcd.print(rollNo);
  delay(2000);
  lcd.clear();
}

void loop() {
  int distance1 = getDistance(trigPin1, echoPin1);
  int distance2 = getDistance(trigPin2, echoPin2);
  int distance3 = getDistance(trigPin3, echoPin3);
  
  // Print distances for debugging
  Serial.print("Distance1: ");
  Serial.print(distance1);
  Serial.print(" cm, Distance2: ");
  Serial.print(distance2);
  Serial.print(" cm, Distance3: ");
  Serial.println(distance3);

  // Check for entering vehicle
  if (distance1 < 10 && parkedCars < maxCars) {
    parkedCars++;
    openGate();
    updateDisplay("Vehicle Entered", "Spaces: " + String(maxCars - parkedCars));
    delay(2000);
  }
  
  // Check for leaving vehicle
  if (distance2 < 10 && parkedCars > 0) {
    parkedCars--;
    openGate();
    updateDisplay("Vehicle Left", "Spaces: " + String(maxCars - parkedCars));
    delay(2000);
  }
  
  // Update parking status
  if (parkedCars >= maxCars) {
    digitalWrite(redLED, HIGH);
    digitalWrite(greenLED, LOW);
    updateDisplay("Parking Full", "Spaces: 0");
  } else {
    digitalWrite(redLED, LOW);
    digitalWrite(greenLED, HIGH);
    updateDisplay("Spaces Available", "Spaces: " + String(maxCars - parkedCars));
  }
  
  delay(100);
}

int getDistance(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  long duration = pulseIn(echoPin, HIGH);
  int distance = duration * 0.034 / 2;
  
  return distance;
}

void openGate() {
  gateServo.write(90);
  delay(1000);
  gateServo.write(0);
}

void updateDisplay(String line1, String line2) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(line1);
  lcd.setCursor(0, 1);
  lcd.print(line2);
}