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

// Replace with your network credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";

// Replace with your MQTT broker details
const char* mqttServer = "broker.emqx.io";
const int mqttPort = 1883;
const char* mqttTopic = "ledControl"; // Topic for subscribing

// Replace with your LED pin
const int ledPin = 5;

WiFiClient espClient;
PubSubClient client(espClient);

// Callback function to handle incoming MQTT messages
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message received on topic: ");
  Serial.println(topic);
  
  // Convert payload to a string
  String message;
  for (unsigned int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.print("Message: ");
  Serial.println(message);

  // Turn LED on or off based on the message
  if (message == "1") {
    digitalWrite(ledPin, HIGH); // Turn LED on
  } else if (message == "0") {
    digitalWrite(ledPin, LOW); // Turn LED off
  }
}

void setup() {
  // Start Serial Monitor
  Serial.begin(115200);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(250);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  // Set the LED pin as an output
  pinMode(ledPin, OUTPUT);

  // Set up MQTT client
  client.setServer(mqttServer, mqttPort);
  client.setCallback(callback);

  // Connect to MQTT broker
  connectToMQTT();
}

void connectToMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32_Client")) {
      Serial.println("connected");
      client.subscribe(mqttTopic); // Subscribe to the topic
      Serial.print("Subscribed to topic: ");
      Serial.println(mqttTopic);
    } else {
      Serial.print("Failed, rc=");
      Serial.print(client.state());
      Serial.println(" trying again in 5 seconds");
      delay(5000);
    }
  }
}

void loop() {
  // Ensure MQTT connection is maintained
  if (!client.connected()) {
    connectToMQTT();
  }
  client.loop();
}