#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h> // Include ArduinoJson library

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

const char* mqttServer = "demo.thingsboard.io";
const int mqttPort = 1883;
const char* mqttUser = "";
const char* mqttPassword = "";
const char* deviceToken = "3PYgZqEMhK5u3Lu4ZKvK";

const char* switchStateTopic = "v1/devices/me/attributes/switchState";
const char* switchControlTopic = "v1/devices/me/rpc/request/+";
const char* ledStateTopic = "v1/devices/me/attributes/ledState";

const int ledPin = 2;

WiFiClient wifiClient;
PubSubClient mqttClient(wifiClient);

bool ledState = false; // Initial LED state

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
  setupWiFi();
  setupMQTT();
}

void setupWiFi() {
  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected to WiFi!");
}

void setupMQTT() {
  mqttClient.setServer(mqttServer, mqttPort);
  mqttClient.setCallback(callback);
  mqttClient.subscribe(switchStateTopic);
  mqttClient.subscribe(ledStateTopic); // Subscribe to LED state updates
  reconnect();
}

void callback(char* topic, byte* payload, unsigned int length) {
  String message = "";
  for (int i = 0; i < length; i++) {
    message += (char)payload[i];
  }
  Serial.println("Message arrived on topic: " + String(topic) + ", payload: " + message);
  
  if (strcmp(topic, switchStateTopic) == 0) {
    // Received switch state update from ThingsBoard
    if (message.equals("on")) {
      digitalWrite(ledPin, HIGH); // Turn on the LED
      ledState = true; // Update LED state
    } else {
      digitalWrite(ledPin, LOW); // Turn off the LED
      ledState = false; // Update LED state
    }
    // Publish LED state to ThingsBoard as an attribute
    mqttClient.publish(ledStateTopic, ledState ? "true" : "false");
  } else if (strcmp(topic, switchControlTopic) == 0) {
    // Received switch control message from ThingsBoard
    // Process the message if needed
  }
}

void reconnect() {
  while (!mqttClient.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (mqttClient.connect("ESP32Client", deviceToken, NULL)) {
      Serial.println("connected");
      mqttClient.subscribe(switchControlTopic);
    } else {
      Serial.print("failed, rc=");
      Serial.print(mqttClient.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

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