#define BLYNK_TEMPLATE_ID "TMPL2glgtocFK"
#define BLYNK_TEMPLATE_NAME "reservation"
#define BLYNK_AUTH_TOKEN "eEdWOob9Kh7KrYNJC8OGUwo_0DJn4nwz"
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASSWORD ""
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <ESP32Servo.h>
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>

const int trigPin1 = 27;
const int echoPin1 = 26;

const int trigPin2 = 2;
const int echoPin2 = 15;

const int trigPin3 = 18;
const int echoPin3 = 5;

const int ledPin1 = 13;
const int ledPin2 = 12;
const int ledPin3 = 14;

const int switchPinEntrance = 32;
const int switchPinExit = 33;

Servo servo;

long duration;
int distance;

bool isSwitchOnEntrance = false;
bool isSwitchOnExit = false;

// LCD initialization (replace the address with the actual I2C address of your LCD)
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Blynk authentication token
char auth[] = "Your_Blynk_Auth_Token";

void setup() {
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);

  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);

  pinMode(trigPin3, OUTPUT);
  pinMode(echoPin3, INPUT);

  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);

  pinMode(switchPinEntrance, INPUT_PULLUP);
  pinMode(switchPinExit, INPUT_PULLUP);

  servo.attach(25); // Attach servo to pin D25
  servo.write(0);   // Initialize the servo position

  // LCD setup
  lcd.init(); // Initialize the LCD
  lcd.backlight(); // Turn on the backlight
  lcd.setCursor(0, 0);
  lcd.print("Smart Parking");

  Serial.begin(9600); // Initialize Serial Monitor

  Blynk.begin(BLYNK_AUTH_TOKEN, WIFI_SSID , WIFI_PASSWORD );
}

void loop() {
  Blynk.run();
  
  isSwitchOnEntrance = digitalRead(switchPinEntrance) == LOW;
  isSwitchOnExit = digitalRead(switchPinExit) == LOW;

  if (isSwitchOnEntrance && !isSwitchOnExit) {
    // Entrance gate is open, measure distance for each space
    Serial.println("Entrance Gate Opened. Measuring Distances...");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Entrance Opened");
    delay(2000);

    for (int space = 1; space <= 3; ++space) {
      measureDistance(space);
      delay(1000); // Delay for stability, adjust as needed
    }
  }

  if (isSwitchOnExit) {
    // Exit gate is open, allow cars to leave
    Serial.println("Exit Gate Opened. Allowing Cars to Leave...");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Exit Opened");
    
    servo.write(90);
    delay(5000); // Delay for cars to leave
    servo.write(0);
    isSwitchOnExit = false; // Reset exit switch status
    
    Serial.println("Exit Gate Closed.");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Exit Closed");
  }
}

void measureDistance(int space) {
  int trigPin, echoPin, ledPin;
  String spaceText;

  // Assign pins and text based on space number
  switch (space) {
    case 1:
      trigPin = trigPin1;
      echoPin = echoPin1;
      ledPin = ledPin1;
      spaceText = "Space 1: ";
      break;
    case 2:
      trigPin = trigPin2;
      echoPin = echoPin2;
      ledPin = ledPin2;
      spaceText = "Space 2: ";
      break;
    case 3:
      trigPin = trigPin3;
      echoPin = echoPin3;
      ledPin = ledPin3;
      spaceText = "Space 3: ";
      break;
    default:
      return;
  }

  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;

  lcd.clear();
  lcd.setCursor(0, 0);
  
  if (distance < 200) {
    digitalWrite(ledPin, LOW);
    lcd.print(spaceText + "Occupied");
    Serial.println(spaceText + "Occupied");
  } else {
    digitalWrite(ledPin, HIGH);
    lcd.print(spaceText + "Vacant");
    Serial.println(spaceText + "Vacant");
    
    if (isSwitchOnEntrance) {
      // Reservation logic - Blynk button widget on V0
      Blynk.virtualWrite(V0, space);
    }
  }

  delay(1000);
}