MQTTPublisher.cpp

#include "MQTTPublisher.h"
#include "Settings.h"

WiFiClient espClient;
PubSubClient client(espClient);

MQTTPublisher::MQTTPublisher(bool inDebugMode)
{
  randomSeed(micros());
  debugMode = inDebugMode;
}

MQTTPublisher::~MQTTPublisher()
{
  client.publish("CO2Meter", "offline");
  client.disconnect();
}

bool MQTTPublisher::reconnect()
{
  lastConnectionAttempt = millis();

  if (debugMode)
  {
    Serial.print("MQTT) Attempt connection to server: ");
    Serial.print(MQTT_HOST_NAME);
  }

  // Create a random client ID
  String clientId = "CO2Meter-";
  clientId += String(random(0xffff), HEX);

  // Attempt to connect
  bool clientConnected;
  if (String(MQTT_USER_NAME).length())
  {
    Serial.println("MQTT) Connecting with credientials");
    clientConnected = client.connect(clientId.c_str(), MQTT_USER_NAME, MQTT_PASSWORD);
  }
  else
  {
    Serial.println("MQTT) Connecting without credentials");
    clientConnected = client.connect(clientId.c_str());
  }

  if (clientConnected)
  {
    if (debugMode)
    {
      Serial.println("MQTT) connected");
    }

    hasMQTT = true;

    // Once connected, publish an announcement...
    client.publish("CO2Meter", "online");

    return true;
  }
  else
  {

    if (debugMode)
    {
      Serial.print("MQTT)  failed, rc=");
      Serial.print(client.state());
    }
  }

  return false;
}

void MQTTPublisher::start()
{
  if (String(MQTT_HOST_NAME).length() == 0 || MQTT_PORT == 0)
  {
    Serial.println("MQTT) disabled. No hostname or port set.");
    return; //not configured
  }

  if (debugMode)
  {
    Serial.println("MQTT) enabled. Connecting.");
  }

  client.setServer(MQTT_HOST_NAME, MQTT_PORT);
  reconnect();
  isStarted = true;
}

void MQTTPublisher::stop()
{
  isStarted = false;
}

void MQTTPublisher::handle()
{
  if (!isStarted)
    return;

  if (!client.connected() && millis() - lastConnectionAttempt > RECONNECT_TIMEOUT)
  {
    hasMQTT = false;
    if (!reconnect())
      return;
  }

  if (hasWIFI && millis() - lastUpdateMqtt > MQTT_UPDATE_INTERVAL)
  {
    lastUpdateMqtt = millis();

    // Check if last send value differs from new value
    if (lastEco2 != sendEco2)
    {
      if (debugMode)
      {
        Serial.println("MQTT) SEND ECO2");
      }

      // SEND MQTT
      publishOnMQTT(MQTT_TOPIC, "/eco2", String(lastEco2));
    }

    if (lastTVoc != sendTVoc)
    {
      if (debugMode)
      {
        Serial.println("MQTT) SEND TVOC");
      }

      // SEND MQTT
      publishOnMQTT(MQTT_TOPIC, "/tvoc", String(lastTVoc));
    }
  }
}

bool MQTTPublisher::publishOnMQTT(String prepend, String topic, String value)
{
  auto retVal = client.publish((prepend.c_str() + topic).c_str(), value.c_str());
  yield();
  return retVal;
}