/*
 * MQTT communication protocol for home automation
 */

#define WLED_MQTT_PORT 1883

void parseMQTTBriPayload(char* payload)
{
  if      (strcmp(payload, "ON") == 0 || strcmp(payload, "on") == 0) {bri = briLast; colorUpdated(1);}
  else if (strcmp(payload, "T" ) == 0 || strcmp(payload, "t" ) == 0) {toggleOnOff(); colorUpdated(1);}
  else {
    uint8_t in = strtoul(payload, NULL, 10);
    if (in == 0 && bri > 0) briLast = bri;
    bri = in;
    colorUpdated(1);
  }
}


void onMqttConnect(bool sessionPresent)
{
  //(re)subscribe to required topics
  char subuf[38];
  strcpy(subuf, mqttDeviceTopic);
  
  if (mqttDeviceTopic[0] != 0)
  {
    strcpy(subuf, mqttDeviceTopic);
    mqtt->subscribe(subuf, 0);
    strcat(subuf, "/col");
    mqtt->subscribe(subuf, 0);
    strcpy(subuf, mqttDeviceTopic);
    strcat(subuf, "/api");
    mqtt->subscribe(subuf, 0);
  }

  if (mqttGroupTopic[0] != 0)
  {
    strcpy(subuf, mqttGroupTopic);
    mqtt->subscribe(subuf, 0);
    strcat(subuf, "/col");
    mqtt->subscribe(subuf, 0);
    strcpy(subuf, mqttGroupTopic);
    strcat(subuf, "/api");
    mqtt->subscribe(subuf, 0);
  }
  publishMqtt();
}


void onMqttMessage(char* topic, char* payload, AsyncMqttClientMessageProperties properties, size_t len, size_t index, size_t total) {

  DEBUG_PRINT("MQTT callb rec: ");
  DEBUG_PRINTLN(topic);
  DEBUG_PRINTLN(payload);

  //no need to check the topic because we only get topics we are subscribed to

  if (strstr(topic, "/col"))
  {
    colorFromDecOrHexString(col, (char*)payload);
    colorUpdated(1);
  } else if (strstr(topic, "/api"))
  {
    String apireq = "win&";
    apireq += (char*)payload;
    handleSet(nullptr, apireq);
  } else parseMQTTBriPayload(payload);
}


void publishMqtt()
{
  if (mqtt == NULL) return;
  if (!mqtt->connected()) return;
  DEBUG_PRINTLN("Publish MQTT");

  char s[10];
  char subuf[38];
  
  sprintf(s, "%ld", bri);
  strcpy(subuf, mqttDeviceTopic);
  strcat(subuf, "/g");
  mqtt->publish(subuf, 0, true, s);

  sprintf(s, "#%X", col[3]*16777216 + col[0]*65536 + col[1]*256 + col[2]);
  strcpy(subuf, mqttDeviceTopic);
  strcat(subuf, "/c");
  mqtt->publish(subuf, 0, true, s);

  strcpy(subuf, mqttDeviceTopic);
  strcat(subuf, "/v");
  mqtt->publish(subuf, 0, true, XML_response(nullptr, false));
}


bool initMqtt()
{
  if (WiFi.status() != WL_CONNECTED) return false;
  if (mqttServer[0] == 0) return false;
  
  IPAddress mqttIP;
  if (mqttIP.fromString(mqttServer)) //see if server is IP or domain
  {
    mqtt->setServer(mqttIP, WLED_MQTT_PORT);
  } else {
    mqtt->setServer(mqttServer, WLED_MQTT_PORT);
  }
  mqtt->setClientId(escapedMac.c_str());
  mqtt->onMessage(onMqttMessage);
  mqtt->onConnect(onMqttConnect);
  mqtt->connect();
  DEBUG_PRINTLN("MQTT ready.");
  return true;
}