//Define libraries
#include "WiFi.h"
#include "PubSubClient.h"



int led_pin = 5;

char clientID[50];

WiFiClient myespClient;
PubSubClient client(myespClient);


void setup() 
{
  Serial.begin(115200);
  pinMode(led_pin,OUTPUT);

  WiFi.mode(WIFI_STA);
  WiFi.begin("Wowki-GUEST","");


  client.setServer("broker.emqx.io",1883);
  client.setCallback(callback);

}


void mqttReconnect() 
{ 
  while(!client.connected()){
    Serial.println("Attempting to Connect MQTT Server");
    if (client.connect(clientID))
    {
      Serial.println("Connected");
      client.subscribe("led_topic");

      
    }
    else{
      Serial.println("Reconnecting in 5 secondes");
      delay(3000);

    }
  }
}

void callback(char* topic, byte* message, unsigned int length) 
{
  String stMessage;
  for (int i = 0; i < length; i++) 
  {
    stMessage += (char)message[i];
  }
  Serial.println(stMessage);

  if (stMessage == "off"){
    digitalWrite(led_pin, LOW);
    Serial.println("Light Off");
  }
  else if (stMessage == "on"){
    digitalWrite(led_pin, HIGH);
    Serial.println("Light On");
  }
  else{
    Serial.println("INVALID COMMAND");
  }
}

void loop() 
{
  delay(10000);
  if (!client.connected()){
    mqttReconnect();
    client.loop();
  }

}