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

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

// MQTT broker
const char* mqttServer = "broker.hivemq.com";
const int mqttPort = 1883;
const char* mqttTopic = "iot/sensor/data";

// DHT22 setup
#define DHTPIN 15
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// WiFi and MQTT clients
WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);
  dht.begin();

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nConnected to WiFi");

  // Connect to MQTT broker
  client.setServer(mqttServer, mqttPort);
  while (!client.connected()) {
    Serial.print("Connecting to MQTT broker...");
    if (client.connect("ESP32Client")) {
      Serial.println("connected");
    } else {
      Serial.print("failed with state ");
      Serial.println(client.state());
      delay(2000);
    }
  }
}

void loop() {
  // Ensure MQTT connection stays alive
  if (!client.connected()) {
    reconnectMQTT();
  }
  client.loop();

  // Read sensor values
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();

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

  // Print to Serial
  Serial.print("Temp: ");
  Serial.print(temp);
  Serial.print(" °C, Humidity: ");
  Serial.print(hum);
  Serial.println(" %");

  // Prepare JSON string
  String payload = "{\"temperature\": " + String(temp) + ", \"humidity\": " + String(hum) + "}";

  // Publish to MQTT
  client.publish(mqttTopic, payload.c_str());

  delay(5000); // Wait 5 seconds
}

void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT reconnect...");
    if (client.connect("ESP32Client")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 2 seconds");
      delay(2000);
    }
  }
}