fix: better event loop error handling

internal/store/event_loop.go

@@ -394,7 +394,7 @@ func (loop *eventLoop) processLabels(eventLog *logrus.Entry, labels []*pmapi.Eve
 	return nil
 }
 
-func (loop *eventLoop) processMessages(eventLog *logrus.Entry, messages []*pmapi.EventMessage) (err error) {
+func (loop *eventLoop) processMessages(eventLog *logrus.Entry, messages []*pmapi.EventMessage) (err error) { // nolint[funlen]
 	eventLog.Debug("Processing message change event")
 
 	for _, message := range messages {
@@ -422,18 +422,23 @@ func (loop *eventLoop) processMessages(eventLog *logrus.Entry, messages []*pmapi
 			}
 
 			var msg *pmapi.Message
-			msg, err = loop.store.getMessageFromDB(message.ID)
-			if err == ErrNoSuchAPIID {
-				msgLog.WithError(err).Warning("Cannot get message from DB for updating. Trying fetch...")
-				msg, err = loop.store.fetchMessage(message.ID)
-				// If message does not exist anywhere, update event is probably old and off topic - skip it.
-				if err == ErrNoSuchAPIID {
-					msgLog.Warn("Skipping message update, because message does not exist nor in local DB or on API")
-					continue
+
+			if msg, err = loop.store.getMessageFromDB(message.ID); err != nil {
+				if err != ErrNoSuchAPIID {
+					return errors.Wrap(err, "failed to get message from DB for updating")
+				}
+
+				msgLog.WithError(err).Warning("Message was not present in DB. Trying fetch...")
+
+				if msg, err = loop.store.fetchMessage(message.ID); err != nil {
+					if err != pmapi.ErrAPINotReachable {
+						msgLog.WithError(err).Warn("Skipping message update because message exists neither in local DB nor on API")
+						err = nil
+						continue
+					}
+
+					return errors.Wrap(err, "failed to get message from API for updating")
 				}
-			}
-			if err != nil {
-				return errors.Wrap(err, "failed to get message from DB for updating")
 			}
 
 			updateMessage(msgLog, msg, message.Updated)

internal/store/user_message.go

@@ -147,12 +147,7 @@ func (store *Store) getMessageFromDB(apiID string) (msg *pmapi.Message, err erro
 // NOTE: Do not update the database here to prevent issues (extreme edge case).
 // The database will be updated by the event loop anyway.
 func (store *Store) fetchMessage(apiID string) (msg *pmapi.Message, err error) {
-	if msg, err = store.api.GetMessage(apiID); err != nil {
-		if err.Error() == "Message does not exist" {
-			return nil, ErrNoSuchAPIID
-		}
-	}
-	return
+	return store.api.GetMessage(apiID)
 }
 
 func (store *Store) txGetMessage(tx *bolt.Tx, apiID string) (*pmapi.Message, error) {