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

char ssid[] = "Wokwi-GUEST";  // Change to char[] instead of const char*
char password[] = "";  

const char *mqtt_server = "mqtt-dashboard.com";
const int mqtt_port = 1883;
const char *mqtt_topic = "esp32/led";


const int ledPin = 2; 

WiFiClient espClient;
PubSubClient client(espClient);


void setup_wifi() {
  Serial.begin(115200);
  delay(10);

  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);

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

  Serial.println("Connected to WiFi!");
}

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

  Serial.print("Message received: ");
  Serial.println(message);

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

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP32Client";
    if (client.connect(clientId.c_str())) {
      Serial.println("Connected to MQTT broker!");
      client.subscribe(mqtt_topic);  
    } else {
      Serial.print("Failed to connect, rc=");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

void setup() {
  pinMode(ledPin, OUTPUT);  


  setup_wifi();


  client.setServer(mqtt_server, mqtt_port);
  client.setCallback(callback);
}

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

  client.loop(); 
}