#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <DHT.h>
#include <PubSubClient.h>
#define DHTPIN 19
#define DHTTYPE DHT22

const char id[] = "MCU-240503";
const char topic[] = "CCN047";
LiquidCrystal_I2C lcd(0x27, 16, 2);
DHT dht(DHTPIN, DHTTYPE);
WiFiClient network;
PubSubClient client(network);
bool doneRead = false;
float temp;

void wifi_connect() {
  WiFi.begin("Wokwi-GUEST", "", 6);
  while(WiFi.status() != WL_CONNECTED) delay(1000);
  lcd.println(WiFi.localIP());
}

void setup() {
  Serial.begin(115200);
  dht.begin();
  lcd.init(); lcd.backlight();
  wifi_connect(); // Kết nối WiFi
  client.setServer("test.mosquitto.org", 1883);	// mqtt.fluux.io, broker.emqx.io
  client.setCallback(xuly);
}

void xuly(char* topic, byte* payload, unsigned int length) {
  if (strncmp((char*) payload, "show", length) == 0) {
    doneRead = true;
    Serial.println("Received");
  }
}

void loop() {
  while (!client.connected()) {
   if (client.connect(id)) {
     client.subscribe(topic);
     client.publish(topic, id);
   } else delay(5000);
  }
  if (doneRead) {
    temp = dht.readTemperature();
    if (isnan(temp)) {
      lcd.print("Cannot read sensors!");
      return;
    } else {
      lcd.clear();
      lcd.print("Temperature="); lcd.print(temp, 1);
      client.publish(topic, String(temp, 1).c_str());
    }
    doneRead = false;
  }
  client.loop();
  delay(3000);
}