Add read-only mode support and enhance logging throughout the application

plugins/mqttclient/mqtt.go

@@ -99,6 +99,17 @@ type panelStateCache struct {
 
 // New creates an MQTT client that publishes MK2 updates and optionally handles setting write commands.
 func New(mk2 mk2driver.Mk2, writer mk2driver.SettingsWriter, config Config) error {
+	log.WithFields(logrus.Fields{
+		"broker":         config.Broker,
+		"client_id":      config.ClientID,
+		"topic":          config.Topic,
+		"command_topic":  config.CommandTopic,
+		"status_topic":   config.StatusTopic,
+		"ha_enabled":     config.HomeAssistant.Enabled,
+		"ha_node_id":     config.HomeAssistant.NodeID,
+		"ha_device_name": config.HomeAssistant.DeviceName,
+	}).Info("Initializing MQTT client")
+
 	c := mqtt.NewClient(getOpts(config))
 	if token := c.Connect(); token.Wait() && token.Error() != nil {
 		return token.Error()
@@ -135,14 +146,18 @@ func New(mk2 mk2driver.Mk2, writer mk2driver.SettingsWriter, config Config) erro
 	go func() {
 		for e := range mk2.C() {
 			if e == nil || !e.Valid {
+				log.Debug("Skipping invalid/nil MK2 event for MQTT publish")
 				continue
 			}
 			if err := publishJSON(c, config.Topic, e, 0, false); err != nil {
 				log.Errorf("Could not publish update to MQTT topic %q: %v", config.Topic, err)
+			} else {
+				log.WithField("topic", config.Topic).Debug("Published MK2 update to MQTT")
 			}
 		}
 	}()
 
+	log.Info("MQTT client setup complete")
 	return nil
 }
 
@@ -152,9 +167,14 @@ func subscribeHAPanelModeState(client mqtt.Client, config Config, cache *panelSt
 	}
 
 	stateTopic := haPanelSwitchStateTopic(config)
+	log.WithField("topic", stateTopic).Info("Subscribing to Home Assistant mode state topic for panel cache")
 	t := client.Subscribe(stateTopic, 1, func(_ mqtt.Client, msg mqtt.Message) {
 		switchState, switchName, err := normalizePanelSwitch(string(msg.Payload()))
 		if err != nil {
+			log.WithFields(logrus.Fields{
+				"topic":   msg.Topic(),
+				"payload": string(msg.Payload()),
+			}).WithError(err).Warn("Ignoring invalid Home Assistant mode state payload")
 			return
 		}
 		cache.remember(writeCommand{
@@ -163,6 +183,10 @@ func subscribeHAPanelModeState(client mqtt.Client, config Config, cache *panelSt
 			SwitchState: switchState,
 			SwitchName:  switchName,
 		})
+		log.WithFields(logrus.Fields{
+			"topic":       msg.Topic(),
+			"switch_name": switchName,
+		}).Debug("Updated panel mode cache from Home Assistant state topic")
 	})
 	t.Wait()
 	return t.Error()
@@ -174,6 +198,11 @@ func commandHandler(client mqtt.Client, writer mk2driver.SettingsWriter, config
 	}
 
 	return func(_ mqtt.Client, msg mqtt.Message) {
+		log.WithFields(logrus.Fields{
+			"topic":   msg.Topic(),
+			"payload": string(msg.Payload()),
+		}).Debug("Received MQTT command message")
+
 		cmd, err := decodeWriteCommand(msg.Payload())
 		if err != nil {
 			log.Errorf("Invalid MQTT write command payload from topic %q: %v", msg.Topic(), err)
@@ -247,6 +276,7 @@ func (c *panelStateCache) resolvePanelCommand(cmd writeCommand) (writeCommand, e
 	cmd.HasSwitch = true
 	cmd.SwitchName = c.switchName
 	cmd.SwitchState = c.switchState
+	log.WithField("switch", cmd.SwitchName).Debug("Resolved panel command switch from cache")
 	return cmd, nil
 }
 
@@ -260,6 +290,7 @@ func (c *panelStateCache) remember(cmd writeCommand) {
 	c.switchName = cmd.SwitchName
 	c.switchState = cmd.SwitchState
 	c.mu.Unlock()
+	log.WithField("switch", cmd.SwitchName).Debug("Remembered panel switch state in cache")
 }
 
 func decodeWriteCommand(payload []byte) (writeCommand, error) {
@@ -465,6 +496,7 @@ func decodeStandbyValue(msg writeCommandPayload) (bool, error) {
 
 func publishWriteStatus(client mqtt.Client, topic string, status writeStatus) {
 	if topic == "" {
+		log.Debug("Skipping write status publish; status topic is empty")
 		return
 	}
 	if err := publishJSON(client, topic, status, 1, false); err != nil {
@@ -479,6 +511,11 @@ func publishHADiscovery(client mqtt.Client, config Config) error {
 
 	for _, def := range definitions {
 		topic := fmt.Sprintf("%s/%s/%s/%s/config", prefix, def.Component, nodeID, def.ObjectID)
+		log.WithFields(logrus.Fields{
+			"topic":     topic,
+			"component": def.Component,
+			"object_id": def.ObjectID,
+		}).Debug("Publishing Home Assistant discovery definition")
 		if err := publishJSON(client, topic, def.Config, 1, true); err != nil {
 			return fmt.Errorf("could not publish discovery for %s/%s: %w", def.Component, def.ObjectID, err)
 		}
@@ -665,6 +702,12 @@ func publishJSON(client mqtt.Client, topic string, payload any, qos byte, retain
 	if t.Error() != nil {
 		return t.Error()
 	}
+	log.WithFields(logrus.Fields{
+		"topic":    topic,
+		"qos":      qos,
+		"retained": retained,
+		"bytes":    len(data),
+	}).Debug("Published JSON message")
 
 	return nil
 }
@@ -679,6 +722,12 @@ func publishString(client mqtt.Client, topic, payload string, qos byte, retained
 	if t.Error() != nil {
 		return t.Error()
 	}
+	log.WithFields(logrus.Fields{
+		"topic":    topic,
+		"qos":      qos,
+		"retained": retained,
+		"payload":  payload,
+	}).Debug("Published string message")
 	return nil
 }