#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 = "broker.emqx.io";

WiFiClient espClient;
PubSubClient client(espClient);
unsigned long lastMsg = 0;
float temp = 0;
float hum = 0;

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Kết nối đến ");
  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("Kết nối với WiFi");
  Serial.println("Địa chỉ IP: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.println("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();

  if ((char)payload[0] == '1') {
    digitalWrite(2, LOW);
  } else {
    digitalWrite(2, HIGH);
  }
}

void reconnect() { 
  while (!client.connected()) {
    Serial.println("Đang thử kết nối MQTT...");
    String clientId = "clientId-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str())) {
      Serial.println("");
      Serial.println("Đã kết nối" + clientId);
      client.publish("21ct114/dht", "Chuc ban may man lan sau");
      client.subscribe("21ct114/dht");
    } else {
      Serial.print("Thất bại, rc=");
      Serial.print(client.state());
      Serial.println(" Thử lại sau 5 giây");
      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("21ct114/dht/temp", temp.c_str());
    
    String hum = String(data.humidity, 1);
    client.publish("21ct114/dht/hum", hum.c_str());

    Serial.print("Nhiệt độ: ");
    Serial.println(temp);
    Serial.print("Độ ẩm: ");
    Serial.println(hum);
  }
}