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

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";

WiFiClient espClient;
PubSubClient client(espClient);

void setupWifi(){
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);

  while(WiFi.status() != WL_CONNECTED )
  {
    delay(1000);
    Serial.print(".");
  }
  Serial.println();
  Serial.print("Terkoneksi ke : ");
  Serial.println(ssid);
  Serial.print("IP Address : ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length){
  //menampilkan pesan di Serial
  Serial.print("Pesan diterima di topic : ");
  Serial.println(topic);
 
  for (int i = 0; i<length; i++)
  {
    Serial.print( (char)payload[i] );
  }
  Serial.println();
}

void reconnect(){
  while (!client.connected()){
    Serial.print("Attemping MQTT connection...");
    String clientId = "ESP32Client-";
    clientId += String(random(0xffff), HEX);
    if(client.connect(clientId.c_str())){
      Serial.println("Connected");
      client.subscribe("aulia/iot/mqtt/demo");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void setup() {
  Serial.begin(115200);
  setupWifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);
}

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