timetable-mgr/vstp/subscribe.go

package vstp

import (
	"time"

	"git.fjla.uk/owlboard/timetable-mgr/log"
	"git.fjla.uk/owlboard/timetable-mgr/messaging"
	"github.com/go-stomp/stomp/v3"
	"go.uber.org/zap"
)

func Subscribe() {
	var sub *stomp.Subscription
	var err error
	retryCount := 0
	maxRetries := 5

	for retryCount < maxRetries {
		sub, err = messaging.Client.Subscribe("/topic/VSTP_ALL", stomp.AckAuto)
		if err != nil {
			log.Warn("Unable to start subscription", zap.Error(err))
			time.Sleep(10 * time.Second)
			retryCount++
			continue
		}
		break
	}

	if sub == nil {
		log.Fatal("Failed to subscribe to VSTP topic", zap.Int("attempts", maxRetries))
	}

	log.Info("Subscription to VSTP topic successful, listening")

	go func() {
		for {
			func() {
				defer func() {
					if r := recover(); r != nil {
						log.Warn("VSTP Message Handler Stopped, waiting for recovery")
						time.Sleep(time.Second * 10)
					}
				}()
				log.Info("VSTP Message handler started")
				for {
					msg := <-sub.C
					if msg.Err != nil {
						log.Error("VSTP Message Error", zap.Error(msg.Err))
					} else {
						if msg != nil {
							log.Info("VSTP Message Received")
							handle(msg)
						} else {
							log.Info("VSTP Message Empty")
						}
					}
				}
			}()
		}
	}()

	select {}
}