#include <WiFi.h>
#include <PubSubClient.h>

const char* ssid = "Wokwi-GUEST";     // Wokwi's default WiFi
const char* password = "";            // No password for Wokwi
const char* mqtt_server = "broker.hivemq.com"; // Free public MQTT broker

WiFiClient espClient;
PubSubClient client(espClient);

const int ledPin = 2;

void setup_wifi() {
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
}

void callback(char* topic, byte* message, unsigned int length) {
  String msg = "";
  for (int i = 0; i < length; i++) {
    msg += (char)message[i];
  }

  if (msg == "ON") {
    digitalWrite(ledPin, HIGH);
  } else if (msg == "OFF") {
    digitalWrite(ledPin, LOW);
  }
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32Client")) {
      client.subscribe("home/light");
    } else {
      delay(5000);
    }
  }
}

void setup() {
  pinMode(ledPin, OUTPUT);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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