#include <WiFi.h>
#include <PubSubClient.h>
#include <DHTesp.h>
 
 
const int DHT_PIN = 15;
DHTesp dht;
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";
 
 
WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
float temp = 0;
float hum = 0;
 
 
void setup_wifi() {
 delay(10);
 Serial.println();
 Serial.print("Connecting to ");
 Serial.println(ssid);
 
 
 WiFi.mode(WIFI_STA);
 WiFi.begin(ssid, password);
 
 
 while (WiFi.status() != WL_CONNECTED) {
   delay(500);
   Serial.print(".");
 }
 
 
 randomSeed(micros());
 
 
 Serial.println("");
 Serial.println("WiFi connected");
 Serial.println("IP address: ");
 Serial.println(WiFi.localIP());
}
void callback(char* topic, byte* payload, unsigned int length) {
 Serial.print("Message arrived [");
 Serial.print(topic);
 Serial.print("] ");
 for (int i = 0; i < length; i++) {
   Serial.print((char)payload[i]);
 }}
void reconnect() {
 while (!client.connected()) {
   Serial.print("Attempting MQTT connection...");
   String clientId = "ESP32Client-";
   clientId += String(random(0xffff), HEX);
   if (client.connect(clientId.c_str())) {
     Serial.println("Connected");
     client.publish("/iot/Publish", "Welcome");
     client.subscribe("/iot/Subscribe");
   } else {
     Serial.print("failed, rc=");
     Serial.print(client.state());
     Serial.println(" try again in 5 seconds");
     delay(5000);
   }}
}
void setup() {
 pinMode(2, OUTPUT);    
 Serial.begin(115200);
 setup_wifi();
 client.setServer(mqtt_server, 1883);
 client.setCallback(callback);
 dht.setup(DHT_PIN, DHTesp::DHT22);
}
void loop() {
 if (!client.connected()) {
   reconnect();
 }
 client.loop();
 
 
 unsigned long now = millis();
 if (now - lastMsg > 2000) {
   lastMsg = now;
   TempAndHumidity  data = dht.getTempAndHumidity();
 
 
   String temp = String(data.temperature, 2);
   client.publish("/iot/temp", temp.c_str());
   String hum = String(data.humidity, 1);
   client.publish("/iot/humidity", hum.c_str());
 
 
   Serial.print("Temperature: ");
   Serial.println(temp);
   Serial.print("Humidity: ");
   Serial.println(hum);
 }
}