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

// Define DHT Sensor
#define DHT_PIN 15
#define DHT_TYPE DHT22
DHT dht(DHT_PIN, DHT_TYPE);

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

// MQTT Server
const char* mqtt_server = "test.mosquitto.org";
WiFiClient espClient;
PubSubClient client(espClient);

// Function to Connect WiFi
void setup_wifi() {
  Serial.print("Connecting to WiFi...");
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nWiFi connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());
}

// Callback Function (Handles Incoming MQTT Messages)
void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message received [");
  Serial.print(topic);
  Serial.print("]: ");

  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    String clientId = "ESP32Client-" + String(random(0xFFFF), HEX);

    if (client.connect(clientId.c_str())) {
      Serial.println("Connected!");
      client.publish("/esp32/Publish", "ESP32 Connected!");
      client.subscribe("/esp32/Subscribe");
    } else {
      Serial.print("Failed (rc=");
      Serial.print(client.state());
      Serial.println("), retrying in 5 seconds...");
      delay(5000);
    }
  }
}

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

void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
    short temperature = dht.readTemperature() ; 
    short humidity = dht.readHumidity() ; 
    client.publish("/esp32/temp", String(temperature, 1).c_str());
    client.publish("/esp32/hum", String(humidity, 1).c_str());
    delay(3000); // Avoid sending data too frequently
}