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

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

// ================= MQTT =================
const char* mqttServer = "test.mosquitto.org";
const int mqttPort = 1883;
const char* mqttTopic = "esp32/wokwi/dht22-2300031039";

// ================= DHT22 =================
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// ================= Clients =================
WiFiClient espClient;
PubSubClient client(espClient);

// ================= WiFi Connect =================
void connectWiFi() {
  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());
}

// ================= MQTT Reconnect =================
void reconnectMQTT() {
  while (!client.connected()) {
    Serial.print("Connecting to MQTT...");
    if (client.connect("ESP32-DHT22-PUB")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" retrying in 5 seconds");
      delay(5000);
    }
  }
}

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

  connectWiFi();
  client.setServer(mqttServer, mqttPort);
}

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

  float temperature = dht.readTemperature();   // °C
  float humidity = dht.readHumidity();         // %

  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("Failed to read from DHT sensor!");
    delay(2000);
    return;
  }

  // Create payload
  String payload = "Temp=" + String(temperature, 1) +
                   "C, Hum=" + String(humidity, 1) + "%";

  Serial.print("Publishing: ");
  Serial.println(payload);

  client.publish(mqttTopic, payload.c_str());

  delay(3000);   // publish every 3 seconds
}