esp8266_milight_hub/lib/MQTT/MqttClient.cpp

#include <MqttClient.h>
#include <TokenIterator.h>
#include <UrlTokenBindings.h>
#include <IntParsing.h>
#include <ArduinoJson.h>
#include <WiFiClient.h>

MqttClient::MqttClient(Settings& settings, MiLightClient*& milightClient)
  : milightClient(milightClient),
    settings(settings),
    lastConnectAttempt(0)
{
  String strDomain = settings.mqttServer();
  this->domain = new char[strDomain.length() + 1];
  strcpy(this->domain, strDomain.c_str());

  this->mqttClient = new PubSubClient(tcpClient);
}

MqttClient::~MqttClient() {
  mqttClient->disconnect();
  delete this->domain;
}

void MqttClient::begin() {
#ifdef MQTT_DEBUG
  printf_P(
    PSTR("MqttClient - Connecting to: %s\nparsed:%s:%u\n"),
    settings._mqttServer.c_str(),
    settings.mqttServer().c_str(),
    settings.mqttPort()
  );
#endif

  mqttClient->setServer(this->domain, settings.mqttPort());
  mqttClient->setCallback(
    [this](char* topic, byte* payload, int length) {
      this->publishCallback(topic, payload, length);
    }
  );
  reconnect();
}

bool MqttClient::connect() {
  char nameBuffer[30];
  sprintf_P(nameBuffer, PSTR("milight-hub-%u"), ESP.getChipId());

#ifdef MQTT_DEBUG
    Serial.println(F("MqttClient - connecting"));
#endif

  if (settings.mqttUsername.length() > 0) {
    return mqttClient->connect(
      nameBuffer,
      settings.mqttUsername.c_str(),
      settings.mqttPassword.c_str()
    );
  } else {
    return mqttClient->connect(nameBuffer);
  }
}

void MqttClient::reconnect() {
  if (lastConnectAttempt > 0 && (millis() - lastConnectAttempt) < MQTT_CONNECTION_ATTEMPT_FREQUENCY) {
    return;
  }
  
  if (! mqttClient->connected()) {
    if (connect()) {
      subscribe();
    } else {
      Serial.println(F("ERROR: Failed to connect to MQTT server"));
    }
  }

  lastConnectAttempt = millis();
}

void MqttClient::handleClient() {
  reconnect();
  mqttClient->loop();
}

void MqttClient::subscribe() {
  String topic = settings.mqttTopicPattern;

  topic.replace(":device_id", "+");
  topic.replace(":group_id", "+");
  topic.replace(":device_type", "+");

  mqttClient->subscribe(topic.c_str());
}

void MqttClient::publishCallback(char* topic, byte* payload, int length) {
  uint16_t deviceId = 0;
  uint8_t groupId = 0;
  MiLightRadioConfig* config = &MilightRgbCctConfig;
  char cstrPayload[length + 1];
  cstrPayload[length] = 0;
  memcpy(cstrPayload, payload, sizeof(byte)*length);

#ifdef MQTT_DEBUG
  printf_P(PSTR("MqttClient - Got message on topic: %s\n%s\n"), topic, cstrPayload);
#endif

  char topicPattern[settings.mqttTopicPattern.length()];
  strcpy(topicPattern, settings.mqttTopicPattern.c_str());

  TokenIterator patternIterator(topicPattern, settings.mqttTopicPattern.length(), '/');
  TokenIterator topicIterator(topic, strlen(topic), '/');
  UrlTokenBindings tokenBindings(patternIterator, topicIterator);

  if (tokenBindings.hasBinding("device_id")) {
    deviceId = parseInt<uint16_t>(tokenBindings.get("device_id"));
  }

  if (tokenBindings.hasBinding("group_id")) {
    groupId = parseInt<uint16_t>(tokenBindings.get("group_id"));
  }

  if (tokenBindings.hasBinding("device_type")) {
    config = MiLightRadioConfig::fromString(tokenBindings.get("device_type"));
  }

  StaticJsonBuffer<400> buffer;
  JsonObject& obj = buffer.parseObject(cstrPayload);

#ifdef MQTT_DEBUG
  printf_P(PSTR("MqttClient - device %04X, group %u\n"), deviceId, groupId);
#endif

  milightClient->prepare(*config, deviceId, groupId);
  milightClient->update(obj);
}