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

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "16.171.230.182";

WiFiClient espClient;
PubSubClient client(espClient);

const int ledPin = 23; 
const char* ledTopic = "led/control1";

void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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

void callback(char* topic, byte* payload, unsigned int length) {
  payload[length] = '\0';
  if (strcmp(topic, ledTopic) == 0) {
    if (strcmp((char*)payload, "ON") == 0) {
      digitalWrite(ledPin, HIGH);
    } else if (strcmp((char*)payload, "OFF") == 0) {
      digitalWrite(ledPin, LOW);
    }
  }
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32_LED")) {
      client.subscribe(ledTopic);
    } else {
      delay(5000);
    }
  }
}