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

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

// MQTT broker details
const char* mqtt_server = "broker.hivemq.com";
const int mqtt_port = 1883;
const char* topic = "/gauri/dht22";

// DHT sensor settings
#define DHTPIN 13      // Data pin connected to GPIO15
#define DHTTYPE DHT22  // Sensor type
DHT dht(DHTPIN, DHTTYPE);

WiFiClient espClient;
PubSubClient client(espClient);

// Function to connect WiFi
void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected!");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

// Function to connect MQTT broker
void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    if (client.connect("ESP32Client_Gauri_DHT")) {
      Serial.println("connected!");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

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

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

  // Read temperature and humidity
  float h = dht.readHumidity();
  float t = dht.readTemperature();

  // Check if readings are valid
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Prepare data string
  String payload = "Temp: " + String(t) + "°C, Humidity: " + String(h) + "%";
  
  // Publish data to MQTT topic
  client.publish(topic, payload.c_str());
  Serial.println("Data published -> " + payload);

  delay(5000); // Publish every 5 seconds
}