#include <Arduino.h>
#include "ESP8266WiFi.h"
#include "PubSubClient.h"

WiFiClient wifi_cli;
PubSubClient client(wifi_cli);
byte tmp;
int tmp_l;
String strPayload;
char* tt;

void callback(char* topic, byte* payload, unsigned int length){
  Serial.println("Arrived");
  Serial.println(topic);
  payload[length] = '\0'; //ovo je jako bitan deo u mom kodu to je specijalan karakter koji oznacava kraj stringa
  strPayload = String((char*)payload);//cuvam u globalnu prom
  Serial.println();
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    // Attempt to connect
    if (client.connect(clientId.c_str(),"guest","guest99")) {
      Serial.println("connected");
      // Once connected, publish an announcement...
      client.publish("outTopic", "hello world");
      // ... and resubscribe
      client.subscribe("inTopic");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);

  // Set WiFi to station mode and disconnect from an AP if it was previously connected
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();

  delay(100);

  WiFi.mode(WIFI_STA);
  WiFi.begin("SSladic", "7zvezdica");
  Serial.println("");

  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to SSladic");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());


  client.setServer("mqtt.inviewscada.com",1883);
  client.setCallback(callback);

  Serial.println("Setup done");
}

void loop() {

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

  Serial.println(strPayload);

  delay(1000);

}