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

#define LED_PIN 23

// Wokwi WiFi
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Public HiveMQ broker
const char* mqtt_server = "broker.hivemq.com";

// 🔥 Use a UNIQUE topic (change if you want)
const char* topic = "mohith123/home/relay1";

WiFiClient espClient;
PubSubClient client(espClient);

// ---------------- WIFI ----------------
void setup_wifi() {
  Serial.println("Connecting to WiFi...");
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi Connected!");
}

// ---------------- CALLBACK ----------------
void callback(char* topicName, 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(LED_PIN, HIGH);
    Serial.println("LED ON");
  } 
  else if (message == "OFF") {
    digitalWrite(LED_PIN, LOW);
    Serial.println("LED OFF");
  }
}

// ---------------- MQTT RECONNECT ----------------
void reconnect() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");

    if (client.connect("MohithESP32_001")) {
      Serial.println("Connected!");
      client.subscribe(topic);
      Serial.println("Subscribed to topic.");
    } else {
      Serial.print("Failed, rc=");
      Serial.println(client.state());
      delay(2000);
    }
  }
}

// ---------------- SETUP ----------------
void setup() {
  Serial.begin(115200);

  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);

  setup_wifi();

  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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