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

#define DHTPIN 4
#define DHTTYPE DHT22
#define LED_PIN 2

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

const char* mqtt_server = "broker.emqx.io";

WiFiClient espClient;
PubSubClient client(espClient);
DHT dht(DHTPIN, DHTTYPE);

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

  if (String(topic) == "esp32/led") {
    if (message == "on") {
      digitalWrite(LED_PIN, HIGH);
    } else if (message == "off") {
      digitalWrite(LED_PIN, LOW);
    }
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  dht.begin();

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }

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

  while (!client.connected()) {
    client.connect("esp32-client");
  }

  client.subscribe("esp32/led");
}

void loop() {
  client.loop();

  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

  if (!isnan(temp) && !isnan(hum)) {
    String payload = "{\"temp\": " + String(temp) + ", \"hum\": " + String(hum) + "}";
    client.publish("esp32/data", payload.c_str());
  }

  delay(3000);
}