#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ESP32Servo.h>  // Servo Library for ESP32

#define IR_SENSOR 15   // IR Receiver Pin (Vehicle Detection)
#define PARKING_LED 18 // LED Indicator for Parking Slot
#define BUZZER 23      // Buzzer for Alerts
#define SERVO_PIN 19   // Servo Motor Pin

const char* ssid = "Wokwi-GUEST";  // ✅ Updated WiFi Network
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);
Servo gateServo;  // Servo object

LiquidCrystal_I2C lcd(0x27, 16, 2);  // ✅ Change to 0x3F if LCD doesn't work

void setup() {
    Serial.begin(115200);
    
    pinMode(IR_SENSOR, INPUT);
    pinMode(PARKING_LED, OUTPUT);
    pinMode(BUZZER, OUTPUT);

    gateServo.attach(SERVO_PIN);  // Attach the servo motor

    Serial.println("Initializing LCD...");
    lcd.init();         // ✅ Initialize LCD
    lcd.backlight();    // ✅ Turn on LCD backlight
    lcd.clear();        // ✅ Clear LCD

    lcd.setCursor(0, 0);
    lcd.print("Smart Parking...");
    Serial.println("LCD Initialized!");
    delay(2000);
    lcd.clear();

    setup_wifi();
    client.setServer(mqtt_server, 1883);
}

void setup_wifi() {
    Serial.print("Connecting to WiFi...");
    lcd.setCursor(0, 0);
    lcd.print("Connecting WiFi...");

    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000);
        Serial.print(".");
    }

    Serial.println("Connected to WiFi!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("WiFi Connected!");
    delay(2000);
    lcd.clear();
}

void loop() {
    if (!client.connected()) {
        reconnect_mqtt();
    }
    client.loop();

    int vehicle_detected = digitalRead(IR_SENSOR);

    if (vehicle_detected == LOW) {  // Vehicle detected
        digitalWrite(PARKING_LED, HIGH);
        digitalWrite(BUZZER, HIGH);
        delay(500);
        digitalWrite(BUZZER, LOW);

        // Open Gate
        gateServo.write(90);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Vehicle Detected");
        lcd.setCursor(0, 1);
        lcd.print("Gate Opening...");
        delay(3000);  // Keep gate open for 3 seconds
        gateServo.write(0); // Close gate
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Slot Occupied");

        Serial.println("Vehicle Entered");
        client.publish("smartparking/slot1", "Occupied");
    } else {
        digitalWrite(PARKING_LED, LOW);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Slot Available");
        
        Serial.println("Slot is Free");
        client.publish("smartparking/slot1", "Free");
    }

    delay(1000);
}

void reconnect_mqtt() {
    while (!client.connected()) {
        Serial.print("Connecting to MQTT...");
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Connecting MQTT...");

        if (client.connect("ESP32Client")) {
            Serial.println("Connected to MQTT!");
            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("MQTT Connected!");
            delay(2000);
            lcd.clear();
        } else {
            Serial.print("Failed, rc=");
            Serial.print(client.state());
            Serial.println(" retrying in 5 seconds...");
            delay(5000);
        }
    }
}