/*SIJA 2024 - Praktikum
  Judul Aplikasi    : ESP32 MQTT Publisher
  Deskripsi         : menerima data angka dari internet menggunakan 
                      protokol MQTT dan menampilkan data tersebu
  Author            : Mutiara Sekar Kinasih*/


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

#define rly 2
const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* hostname = "broker.hivemq.com";
int PORTNUM = 1883;
const char* topicLampu = "sekar/iot/lampu";

WiFiClient espClient;
PubSubClient clientMQTT(espClient);

const char* espClientName = "esp32Client_123456xxN";

void setup_wifi()
{
  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 connectMQTT()
{
  while(!clientMQTT.connected() )
  {
    Serial.println("Sedang konek ke MQTT ...");
    if (clientMQTT.connect(espClientName) ) //, mqttUser, mqttPassword) )
    {
      Serial.println("Terkoneksi MQTT Server");
      MQTTSubscribe();
    }
    else
    {
      Serial.print("Gagal koneksi ke MQTT Server: ");
      Serial.print(clientMQTT.state() );
      delay(2000);
    }
  }
}

//   topic    bertipe string
//   payload  bertipe byte, pesan yang diterima
//   length   bertipe integer, panjang data
void callback(String topic, byte* payload, unsigned int length)
{
  String messageTemp;

  Serial.print("Pesan diterima di topic: ");
  Serial.println(topic);

  Serial.print("Isi pesan yang diterima dari broker: ");
  for (int i = 0; i<length; i++)
  {
    Serial.print( (char)payload[i] );
    messageTemp += (char)payload[i];
  }
  Serial.println("");
  if (topic == topicLampu)
  {
    Serial.print("Status LED :  ");
    if (messageTemp == "1")
    {
      digitalWrite(rly, LOW);
      Serial.println("Lampu Off");
    }
    else if (messageTemp == "2")
    {
      digitalWrite(rly, HIGH);
      Serial.println("Lampu On");
    }
  }
}

void MQTTSubscribe() 
{
  clientMQTT.subscribe(topicLampu);
}

void setup_MQTT() 
{
  clientMQTT.setServer(hostname, PORTNUM);
  clientMQTT.setCallback(callback); 

}

void setup() 
{
  Serial.begin(9600);
  delay(5000);
  pinMode(rly, OUTPUT);
  digitalWrite(rly, HIGH);

  setup_wifi();
  setup_MQTT();
}

void loop() 
{
  if ( !clientMQTT.connected() )
  {
    connectMQTT();
  }
  clientMQTT.loop();
}