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

const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";

int button, nim;

WiFiClient espClient;
PubSubClient client(espClient);

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]);
  }
  Serial.println();
}

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.subscribe("KDR5B2023"); 
    } 
    else 
    {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(500);
    }
  }
}

void setup() 
{
  pinMode(15, INPUT_PULLUP);

  Serial.begin(115200);
  setup_wifi();
  client.setServer(mqtt_server, 1883);
  client.setCallback(callback);

  reconnect();
}

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

  if (Serial.available() > 0) 
  {
    nim = Serial.parseInt();
    Serial.print("NIM : ");
    Serial.println(nim);
    client.publish("KDR5B2023", String(nim).c_str(), true);
  }
  client.loop();
  client.setCallback(callback);
  delay(500);
}