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

const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* mqttServer = "broker.hivemq.com";
int mqttPort = 1883;
const char* topicMQTT = "robert/esp32/led";

WiFiClient espClient;

PubSubClient clientMQTT(espClient);

void connectToInternet();  
void setupMQTT();          
void reconnectMQTT();     

#define ledHijau 18

void setup() {
  
  Serial.begin(115200);

  connectToInternet();

  setupMQTT();

  clientMQTT.setCallback(callback); 

  pinMode(ledHijau, OUTPUT);
}

void loop() {
  if ( !clientMQTT.connected() )   {

    reconnectMQTT();
  }
  clientMQTT.loop();
}


void connectToInternet(){
  WiFi.begin(ssid, password);  

  while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
    } 
    Serial.println("");
    Serial.println("Connected to Wi-Fi");
    Serial.print("IP Address : ");
    Serial.println(WiFi.localIP());
}

void reconnectMQTT() {
  Serial.println("Connecting to MQTT Broker...");
  while (!clientMQTT.connected()) {
      Serial.println("Reconnecting to MQTT Broker..");

      String clientId = "ESP32Client-";
      clientId += String(random(0xffff), HEX);

      if (clientMQTT.connect(clientId.c_str())) {
        Serial.println("Connected.");

        clientMQTT.publish(topicMQTT, "LED Ready to control");

        clientMQTT.subscribe(topicMQTT);
      }
      else {
        Serial.print("failed, rc=");
        Serial.print(clientMQTT.state());
        Serial.println(" try again in 5 seconds");

        delay(5000);
      }
  }
}

void setupMQTT() {
  clientMQTT.setServer(mqttServer, mqttPort);
}

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("");
  Serial.print("Status LED :  ");

  if(topic == topicMQTT){
    if(messageTemp=="ON"){
      Serial.println("ON");
      digitalWrite(ledHijau, HIGH);
      clientMQTT.publish("robert/statusled", "ON");
    }

    if(messageTemp=="OFF"){
      Serial.println("OFF");
      digitalWrite(ledHijau, LOW);
      clientMQTT.publish("robert/statusled", "OFF");
    }
  }
}