main.go

package mqttclient

import (
	"fmt"
	"os"
	"strings"

	mqtt "github.com/eclipse/paho.mqtt.golang"
	"jonasled.dev/jonasled/ems-esp-logger/csv"
	"jonasled.dev/jonasled/ems-esp-logger/helper"
	"jonasled.dev/jonasled/ems-esp-logger/log"
)

var messagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
	log.Log.Debugf("Received message: %s from topic: %s\n", msg.Payload(), msg.Topic())
}

var messagePubHandlerBoiler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
	log.Log.Debugf("Received message for boiler: %s from topic: %s\n", msg.Payload(), msg.Topic())
	log.Log.Info("Received new boiler data")
	csv.JsonToCsv(string(msg.Payload()))
	if os.Getenv("OUTPUT_FILE_NAME_RAW") != "" {
		dumpRawData(string(msg.Payload()), os.Getenv("OUTPUT_FILE_NAME_RAW"))
	}

}

var connectHandler mqtt.OnConnectHandler = func(client mqtt.Client) {
	log.Log.Info("Successfully connected to MQTT broker")
}

var connectLostHandler mqtt.ConnectionLostHandler = func(client mqtt.Client, err error) {
	log.Log.Error("Connection to MQTT broker lost: ", err.Error())
}

func Init() {
	opts := mqtt.NewClientOptions()
	opts.AddBroker(fmt.Sprintf("tcp://%s:%s", os.Getenv("MQTT_HOST"), os.Getenv("MQTT_PORT")))
	opts.SetClientID("ems-esp-logger_" + helper.GenerateRandomString(8))
	if os.Getenv("MQTT_USERNAME") != "" {
		opts.SetUsername(os.Getenv("MQTT_USERNAME"))
		opts.SetPassword(os.Getenv("MQTT_PASSWORD"))
	}
	opts.SetDefaultPublishHandler(messagePubHandler)
	opts.OnConnect = connectHandler
	opts.OnConnectionLost = connectLostHandler
	client := mqtt.NewClient(opts)
	if token := client.Connect(); token.Wait() && token.Error() != nil {
		log.Log.Fatal("Failed connecting to MQTT server: ", token.Error())
	}
	client.Subscribe(os.Getenv("MQTT_TOPIC_BOILER"), 1, messagePubHandlerBoiler)
}

func dumpRawData(data string, filename string) {
	data = strings.ReplaceAll(data, "\n", "")
	data = strings.ReplaceAll(data, "\r", "")

	file, err := os.OpenFile(filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		panic(err)
	}
	defer file.Close()

	file.WriteString(data)
	file.WriteString("\n")
}