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

#define DHTPIN 9         // DHT22 data pin connected to GPIO 15
#define DHTTYPE DHT22

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";  // Public MQTT broker for demo

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

void setup_wifi() {
  delay(10);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32Client")) break;
    delay(5000);
  }
}

void setup() {
  Serial.begin(115200);
  dht.begin();
  setup_wifi();
  client.setServer(mqtt_server, 1883);
}

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

  float temperature = dht.readTemperature();
  if (!isnan(temperature)) {
    char tempString[8];
    dtostrf(temperature, 1, 2, tempString);
    client.publish("wokwi/esp32/dht22/temperature", tempString);
    Serial.print("Published temp: ");
    Serial.println(tempString);
  }
  delay(5000); // publish every 5 seconds
}