package mqttclient

import (
	"encoding/json"
	"errors"
	"fmt"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"

	"git.coadcorp.com/nathan/invertergui/mk2driver"
	mqtt "github.com/eclipse/paho.mqtt.golang"
	"github.com/sirupsen/logrus"
)

var log = logrus.WithField("ctx", "inverter-gui-mqtt")

const keepAlive = 5 * time.Second

const (
	commandKindSetting = "setting"
	commandKindRAMVar  = "ram_var"
	commandKindPanel   = "panel_state"
	commandKindStandby = "standby"
	commandKindESSMode = "ess_mode"
	commandKindESSSet  = "ess_setpoint"
	commandKindESSMaxC = "ess_max_charge_power"
	commandKindESSMaxD = "ess_max_discharge_power"

	writeStatusOK    = "ok"
	writeStatusError = "error"
)

type HomeAssistantConfig struct {
	Enabled         bool
	DiscoveryPrefix string
	NodeID          string
	DeviceName      string
}

type VenusConfig struct {
	Enabled         bool
	PortalID        string
	Service         string
	SubscribeWrites bool
	TopicPrefix     string
	GuideCompat     bool
}

// Config sets MQTT client configuration
type Config struct {
	Broker        string
	ClientID      string
	Topic         string
	CommandTopic  string
	StatusTopic   string
	DeviceID      string
	HistorySize   int
	InstanceID    int
	Phase         string
	PhaseGroup    string
	HomeAssistant HomeAssistantConfig
	Venus         VenusConfig
	Username      string
	Password      string
}

type writeCommand struct {
	Source        mk2driver.CommandSource
	RequestID     string
	Kind          string
	ID            uint16
	Value         int16
	FloatValue    *float64
	HasSwitch     bool
	SwitchState   mk2driver.PanelSwitchState
	SwitchName    string
	CurrentLimitA *float64
	Standby       *bool
}

type writeCommandPayload struct {
	RequestID     string          `json:"request_id"`
	Kind          string          `json:"kind"`
	Type          string          `json:"type"`
	ID            *uint16         `json:"id"`
	Value         json.RawMessage `json:"value"`
	Switch        string          `json:"switch"`
	SwitchState   string          `json:"switch_state"`
	CurrentLimitA *float64        `json:"current_limit"`
	Standby       *bool           `json:"standby"`
}

type writeStatus struct {
	RequestID     string    `json:"request_id,omitempty"`
	Status        string    `json:"status"`
	Kind          string    `json:"kind,omitempty"`
	ID            uint16    `json:"id"`
	Value         int16     `json:"value"`
	FloatValue    *float64  `json:"float_value,omitempty"`
	Switch        string    `json:"switch,omitempty"`
	CurrentLimitA *float64  `json:"current_limit,omitempty"`
	Standby       *bool     `json:"standby,omitempty"`
	Error         string    `json:"error,omitempty"`
	Timestamp     time.Time `json:"timestamp"`
}

type telemetryCache struct {
	mu   sync.Mutex
	last telemetrySnapshot
}

type essControlSnapshot struct {
	HasSetpoint      bool
	SetpointW        float64
	HasMaxCharge     bool
	MaxChargeW       float64
	HasMaxDischarge  bool
	MaxDischargeW    float64
	HasBatteryLife   bool
	BatteryLifeState int
}

type essControlCache struct {
	mu sync.Mutex

	hasSetpoint      bool
	setpointW        float64
	hasMaxCharge     bool
	maxChargeW       float64
	hasMaxDischarge  bool
	maxDischargeW    float64
	hasBatteryLife   bool
	batteryLifeState int
}

type haDiscoveryDefinition struct {
	Component string
	ObjectID  string
	Config    map[string]any
}

type panelStateCache struct {
	mu          sync.Mutex
	hasSwitch   bool
	switchName  string
	switchState mk2driver.PanelSwitchState
	hasCurrent  bool
	currentA    float64
	hasStandby  bool
	standby     bool
}

type panelStateSnapshot struct {
	Switch       string  `json:"switch,omitempty"`
	CurrentLimit float64 `json:"current_limit,omitempty"`
	Standby      bool    `json:"standby"`
	HasSwitch    bool    `json:"has_switch"`
	HasCurrent   bool    `json:"has_current_limit"`
	HasStandby   bool    `json:"has_standby"`
}

type telemetrySnapshot struct {
	Timestamp       time.Time         `json:"timestamp"`
	Valid           bool              `json:"valid"`
	InputVoltage    float64           `json:"input_voltage"`
	InputCurrent    float64           `json:"input_current"`
	InputFrequency  float64           `json:"input_frequency"`
	OutputVoltage   float64           `json:"output_voltage"`
	OutputCurrent   float64           `json:"output_current"`
	OutputFrequency float64           `json:"output_frequency"`
	BatteryVoltage  float64           `json:"battery_voltage"`
	BatteryCurrent  float64           `json:"battery_current"`
	BatteryCharge   float64           `json:"battery_charge"`
	InputPower      float64           `json:"input_power"`
	OutputPower     float64           `json:"output_power"`
	BatteryPower    float64           `json:"battery_power"`
	LEDs            map[string]string `json:"leds"`
}

type historySample struct {
	Timestamp      time.Time
	InputPowerVA   float64
	OutputPowerVA  float64
	BatteryPowerW  float64
	BatteryVoltage float64
	Valid          bool
	State          operatingState
}

type historySummary struct {
	Samples             int     `json:"samples"`
	WindowSeconds       float64 `json:"window_seconds"`
	AverageInputPower   float64 `json:"average_input_power"`
	AverageOutputPower  float64 `json:"average_output_power"`
	AverageBatteryPower float64 `json:"average_battery_power"`
	MaxOutputPower      float64 `json:"max_output_power"`
	MinBatteryVoltage   float64 `json:"min_battery_voltage"`
	EnergyInWh          float64 `json:"energy_in_wh"`
	EnergyOutWh         float64 `json:"energy_out_wh"`
	BatteryChargeWh     float64 `json:"battery_charge_wh"`
	BatteryDischargeWh  float64 `json:"battery_discharge_wh"`
	UptimeSeconds       float64 `json:"uptime_seconds"`
	FaultCount          uint64  `json:"fault_count"`
	LastFaultAt         string  `json:"last_fault_at,omitempty"`
	CurrentState        string  `json:"current_state"`
}

type orchestrationState struct {
	DeviceID       string             `json:"device_id"`
	InstanceID     int                `json:"instance_id"`
	Phase          string             `json:"phase"`
	PhaseGroup     string             `json:"phase_group"`
	Timestamp      time.Time          `json:"timestamp"`
	OperatingState string             `json:"operating_state"`
	Telemetry      telemetrySnapshot  `json:"telemetry"`
	PanelState     panelStateSnapshot `json:"panel_state"`
	History        historySummary     `json:"history"`
	Alarms         []alarmState       `json:"alarms"`
}

type alarmState struct {
	Code        string    `json:"code"`
	Level       string    `json:"level"`
	Message     string    `json:"message"`
	ActiveSince time.Time `json:"active_since"`
}

type alarmTracker struct {
	mu     sync.Mutex
	active map[string]alarmState
	rules  map[string]*alarmRule

	debounceOn  time.Duration
	debounceOff time.Duration

	faultCount uint64
	lastFault  time.Time
}

type historyTracker struct {
	mu      sync.Mutex
	max     int
	samples []historySample

	energyInWh         float64
	energyOutWh        float64
	batteryChargeWh    float64
	batteryDischargeWh float64
	uptimeSeconds      float64
	lastSample         *historySample
	lastState          operatingState
	lastFaultCount     uint64
	lastFaultAt        time.Time
}

type alarmRule struct {
	code        string
	level       string
	message     string
	pendingFrom time.Time
	clearFrom   time.Time
	activeSince time.Time
	active      bool
}

type diagnosticsBundle struct {
	DeviceID    string                       `json:"device_id"`
	InstanceID  int                          `json:"instance_id"`
	Phase       string                       `json:"phase"`
	PhaseGroup  string                       `json:"phase_group"`
	GeneratedAt time.Time                    `json:"generated_at"`
	HealthScore int                          `json:"health_score"`
	Driver      *mk2driver.DriverDiagnostics `json:"driver,omitempty"`
	Commands    []mk2driver.CommandEvent     `json:"commands,omitempty"`
}

type operatingState string

const (
	operatingStateOff      operatingState = "Off"
	operatingStateInverter operatingState = "Inverter"
	operatingStateCharger  operatingState = "Charger"
	operatingStatePassthru operatingState = "Passthru"
	operatingStateFault    operatingState = "Fault"
)

// 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 {
	if strings.TrimSpace(config.DeviceID) == "" {
		config.DeviceID = haNodeID(config)
	}
	if config.HistorySize <= 0 {
		config.HistorySize = 120
	}
	if strings.TrimSpace(config.Venus.PortalID) == "" {
		config.Venus.PortalID = config.DeviceID
	}
	if strings.TrimSpace(config.Venus.Service) == "" {
		config.Venus.Service = "vebus/257"
	}
	if strings.TrimSpace(config.Venus.TopicPrefix) != "" {
		config.Venus.TopicPrefix = strings.Trim(strings.TrimSpace(config.Venus.TopicPrefix), "/")
	}
	if strings.TrimSpace(config.Phase) == "" {
		config.Phase = "L1"
	}
	if strings.TrimSpace(config.PhaseGroup) == "" {
		config.PhaseGroup = "default"
	}
	if config.InstanceID < 0 {
		config.InstanceID = 0
	}

	log.WithFields(logrus.Fields{
		"broker":         config.Broker,
		"client_id":      config.ClientID,
		"topic":          config.Topic,
		"command_topic":  config.CommandTopic,
		"status_topic":   config.StatusTopic,
		"device_id":      config.DeviceID,
		"history_size":   config.HistorySize,
		"ha_enabled":     config.HomeAssistant.Enabled,
		"ha_node_id":     config.HomeAssistant.NodeID,
		"ha_device_name": config.HomeAssistant.DeviceName,
		"venus_enabled":  config.Venus.Enabled,
		"venus_portal":   config.Venus.PortalID,
		"venus_service":  config.Venus.Service,
		"venus_prefix":   config.Venus.TopicPrefix,
		"venus_guide":    config.Venus.GuideCompat,
		"instance_id":    config.InstanceID,
		"phase":          config.Phase,
		"phase_group":    config.PhaseGroup,
	}).Info("Initializing MQTT client")

	c := mqtt.NewClient(getOpts(config))
	if token := c.Connect(); token.Wait() && token.Error() != nil {
		return token.Error()
	}
	cache := &panelStateCache{}
	alarms := newAlarmTracker()
	history := newHistoryTracker(config.HistorySize)
	telemetry := &telemetryCache{}
	ess := newESSControlCache()
	diagControl, hasDiag := mk2.(mk2driver.DiagnosticsControl)
	commandHistory, hasCommandHistory := writer.(mk2driver.CommandHistoryProvider)

	if config.HomeAssistant.Enabled {
		if err := publishHAAvailability(c, config, "online"); err != nil {
			return fmt.Errorf("could not publish Home Assistant availability: %w", err)
		}
		if err := publishHADiscovery(c, config); err != nil {
			return fmt.Errorf("could not publish Home Assistant discovery payloads: %w", err)
		}
		if writer != nil {
			if err := subscribeHAPanelModeState(c, config, cache); err != nil {
				log.Warnf("Could not subscribe to Home Assistant panel mode state topic: %v", err)
			}
			if err := subscribeHACurrentLimitState(c, config, cache); err != nil {
				log.Warnf("Could not subscribe to Home Assistant current limit state topic: %v", err)
			}
			if err := subscribeHAStandbyState(c, config, cache); err != nil {
				log.Warnf("Could not subscribe to Home Assistant standby state topic: %v", err)
			}
		}
	}

	if config.CommandTopic != "" {
		if writer == nil {
			log.Warnf("MQTT command topic %q configured, but no settings writer is available", config.CommandTopic)
		} else {
			t := c.Subscribe(config.CommandTopic, 1, commandHandler(c, writer, config, cache, alarms, ess, telemetry))
			t.Wait()
			if t.Error() != nil {
				return fmt.Errorf("could not subscribe to MQTT command topic %q: %w", config.CommandTopic, t.Error())
			}
			log.Infof("Subscribed to MQTT command topic: %s", config.CommandTopic)
		}
	}

	if config.Venus.Enabled {
		if err := publishVenusServiceInfo(c, config); err != nil {
			log.WithError(err).Warn("Could not publish initial Venus service metadata")
		}
		if writer != nil && config.Venus.SubscribeWrites {
			if err := subscribeVenusWriteTopics(c, writer, config, cache, alarms, ess, telemetry); err != nil {
				log.WithError(err).Warn("Could not subscribe to Venus write topics")
			}
		}
	}

	go func() {
		for e := range mk2.C() {
			if e == nil {
				log.Debug("Skipping nil MK2 event for MQTT publish")
				continue
			}

			snapshot := buildTelemetrySnapshot(e)
			telemetry.set(snapshot)
			panel := cache.snapshot()
			essSnapshot := ess.snapshot()
			activeAlarms := alarms.Update(snapshot)
			state := deriveOperatingState(snapshot, panel, activeAlarms)
			faultCount, lastFaultAt := alarms.Stats()
			var summary historySummary
			if snapshot.Valid {
				summary = history.Add(snapshot, state, faultCount, lastFaultAt)
			} else {
				summary = history.Summary(state, faultCount, lastFaultAt)
			}

			if err := publishOrchestrationTopics(c, config, snapshot, panel, summary, activeAlarms, state); err != nil {
				log.WithError(err).Warn("Could not publish orchestration MQTT topics")
			}

			if config.Venus.Enabled {
				if err := publishVenusTelemetry(c, config, snapshot, panel, activeAlarms, state, summary, essSnapshot); err != nil {
					log.WithError(err).Warn("Could not publish Venus MQTT topics")
				}
			}
			if hasDiag {
				var commands []mk2driver.CommandEvent
				if hasCommandHistory {
					commands = commandHistory.History(25)
				}
				if err := publishDiagnostics(c, config, diagControl.DriverDiagnostics(100), commands); err != nil {
					log.WithError(err).Warn("Could not publish diagnostics topic")
				}
			}

			if !e.Valid {
				log.Debug("Skipping invalid MK2 event for legacy MQTT update topic")
				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
}

func subscribeHAPanelModeState(client mqtt.Client, config Config, cache *panelStateCache) error {
	if cache == nil {
		return nil
	}

	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{
			Kind:        commandKindPanel,
			HasSwitch:   true,
			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()
}

func subscribeHACurrentLimitState(client mqtt.Client, config Config, cache *panelStateCache) error {
	if cache == nil {
		return nil
	}

	stateTopic := haCurrentLimitStateTopic(config)
	log.WithField("topic", stateTopic).Info("Subscribing to Home Assistant current limit state topic for panel cache")
	t := client.Subscribe(stateTopic, 1, func(_ mqtt.Client, msg mqtt.Message) {
		trimmed := strings.TrimSpace(string(msg.Payload()))
		if trimmed == "" {
			return
		}
		limit, err := strconv.ParseFloat(trimmed, 64)
		if err != nil {
			log.WithFields(logrus.Fields{
				"topic":   msg.Topic(),
				"payload": string(msg.Payload()),
			}).WithError(err).Warn("Ignoring invalid Home Assistant current limit payload")
			return
		}
		cache.setCurrentLimit(limit)
	})
	t.Wait()
	return t.Error()
}

func subscribeHAStandbyState(client mqtt.Client, config Config, cache *panelStateCache) error {
	if cache == nil {
		return nil
	}

	stateTopic := haStandbyStateTopic(config)
	log.WithField("topic", stateTopic).Info("Subscribing to Home Assistant standby state topic for panel cache")
	t := client.Subscribe(stateTopic, 1, func(_ mqtt.Client, msg mqtt.Message) {
		standby, err := parseStandbyText(string(msg.Payload()))
		if err != nil {
			log.WithFields(logrus.Fields{
				"topic":   msg.Topic(),
				"payload": string(msg.Payload()),
			}).WithError(err).Warn("Ignoring invalid Home Assistant standby payload")
			return
		}
		cache.setStandby(standby)
	})
	t.Wait()
	return t.Error()
}

func commandHandler(client mqtt.Client, writer mk2driver.SettingsWriter, config Config, cache *panelStateCache, alarms *alarmTracker, ess *essControlCache, telemetry *telemetryCache) mqtt.MessageHandler {
	if cache == nil {
		cache = &panelStateCache{}
	}

	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)
			publishWriteStatus(client, config.StatusTopic, writeStatus{
				Status:    writeStatusError,
				Error:     err.Error(),
				Timestamp: time.Now().UTC(),
			})
			return
		}

		status := applyWriteCommand(client, writer, config, cache, alarms, ess, telemetry, cmd)
		publishWriteStatus(client, config.StatusTopic, status)
	}
}

func applyWriteCommand(client mqtt.Client, writer mk2driver.SettingsWriter, config Config, cache *panelStateCache, alarms *alarmTracker, ess *essControlCache, telemetry *telemetryCache, cmd writeCommand) writeStatus {
	if ess == nil {
		ess = newESSControlCache()
	}
	if telemetry == nil {
		telemetry = &telemetryCache{}
	}

	execCmd := cmd
	status := writeStatus{
		RequestID: cmd.RequestID,
		Status:    writeStatusOK,
		Kind:      cmd.Kind,
		Timestamp: time.Now().UTC(),
	}

	switch cmd.Kind {
	case commandKindPanel:
		resolved, err := cache.resolvePanelCommand(cmd)
		if err != nil {
			status.Status = writeStatusError
			status.Error = err.Error()
			log.Errorf("Invalid MQTT write command %s: %v", formatWriteCommandLog(cmd), err)
			return status
		}
		execCmd = resolved
		status.Switch = execCmd.SwitchName
		status.CurrentLimitA = execCmd.CurrentLimitA
	case commandKindStandby:
		status.Standby = copyBoolPtr(execCmd.Standby)
	case commandKindESSSet, commandKindESSMode, commandKindESSMaxC, commandKindESSMaxD:
		if cmd.FloatValue != nil {
			status.FloatValue = float64Ptr(*cmd.FloatValue)
		}
		mapped, err := resolveESSWriteCommand(cmd, ess, telemetry)
		if err != nil {
			status.Status = writeStatusError
			status.Error = err.Error()
			log.Errorf("Invalid ESS compatibility command %s: %v", formatWriteCommandLog(cmd), err)
			return status
		}
		if mapped != nil {
			execCmd = *mapped
			status.Kind = execCmd.Kind
			status.Switch = execCmd.SwitchName
			status.CurrentLimitA = execCmd.CurrentLimitA
		} else {
			if config.Venus.Enabled {
				if err := publishVenusESSState(client, config, ess.snapshot()); err != nil {
					log.WithError(err).Warn("Could not publish ESS compatibility state")
				}
			}
			return status
		}
	default:
		status.ID = cmd.ID
		status.Value = cmd.Value
	}

	if err := executeWriteCommand(writer, execCmd); err != nil {
		status.Status = writeStatusError
		status.Error = err.Error()
		log.Errorf("Failed MQTT write command %s: %v", formatWriteCommandLog(execCmd), err)
		if alarms != nil {
			active := alarms.RecordCommandFailure(err, time.Now().UTC())
			if publishErr := publishActiveAlarms(client, config, active); publishErr != nil {
				log.WithError(publishErr).Warn("Could not publish active alarms after command failure")
			}
		}
		return status
	}
	if alarms != nil {
		alarms.RecordCommandSuccess(time.Now().UTC())
	}

	log.Infof("Applied MQTT write command %s", formatWriteCommandLog(execCmd))
	cache.remember(execCmd)

	if config.HomeAssistant.Enabled {
		if err := publishHAControlState(client, config, execCmd); err != nil {
			log.Errorf("Could not publish Home Assistant control state update: %v", err)
		}
	}
	if config.Venus.Enabled {
		if err := publishVenusControlState(client, config, execCmd, cache.snapshot()); err != nil {
			log.Errorf("Could not publish Venus control state update: %v", err)
		}
		if err := publishVenusESSState(client, config, ess.snapshot()); err != nil {
			log.WithError(err).Warn("Could not publish ESS compatibility state")
		}
	}
	return status
}

func (c *panelStateCache) resolvePanelCommand(cmd writeCommand) (writeCommand, error) {
	if cmd.Kind != commandKindPanel {
		return cmd, nil
	}

	if cmd.HasSwitch {
		return cmd, nil
	}

	c.mu.Lock()
	defer c.mu.Unlock()
	if !c.hasSwitch {
		return writeCommand{}, errors.New("panel_state command missing switch and no prior mode is known; set mode once first")
	}

	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
}

func (c *panelStateCache) remember(cmd writeCommand) {
	c.mu.Lock()
	defer c.mu.Unlock()

	switch cmd.Kind {
	case commandKindPanel:
		if cmd.HasSwitch {
			c.hasSwitch = true
			c.switchName = cmd.SwitchName
			c.switchState = cmd.SwitchState
		}
		if cmd.CurrentLimitA != nil {
			c.hasCurrent = true
			c.currentA = *cmd.CurrentLimitA
		}
	case commandKindStandby:
		if cmd.Standby != nil {
			c.hasStandby = true
			c.standby = *cmd.Standby
		}
	}
}

func (c *panelStateCache) setCurrentLimit(limit float64) {
	c.mu.Lock()
	c.hasCurrent = true
	c.currentA = limit
	c.mu.Unlock()
}

func (c *panelStateCache) setStandby(standby bool) {
	c.mu.Lock()
	c.hasStandby = true
	c.standby = standby
	c.mu.Unlock()
}

func (c *panelStateCache) snapshot() panelStateSnapshot {
	c.mu.Lock()
	defer c.mu.Unlock()
	return panelStateSnapshot{
		Switch:       c.switchName,
		CurrentLimit: c.currentA,
		Standby:      c.standby,
		HasSwitch:    c.hasSwitch,
		HasCurrent:   c.hasCurrent,
		HasStandby:   c.hasStandby,
	}
}

func newESSControlCache() *essControlCache {
	return &essControlCache{
		hasBatteryLife:   true,
		batteryLifeState: 10,
	}
}

func (e *essControlCache) snapshot() essControlSnapshot {
	e.mu.Lock()
	defer e.mu.Unlock()
	return essControlSnapshot{
		HasSetpoint:      e.hasSetpoint,
		SetpointW:        e.setpointW,
		HasMaxCharge:     e.hasMaxCharge,
		MaxChargeW:       e.maxChargeW,
		HasMaxDischarge:  e.hasMaxDischarge,
		MaxDischargeW:    e.maxDischargeW,
		HasBatteryLife:   e.hasBatteryLife,
		BatteryLifeState: e.batteryLifeState,
	}
}

func (e *essControlCache) setSetpoint(value float64) {
	e.mu.Lock()
	e.hasSetpoint = true
	e.setpointW = value
	e.mu.Unlock()
}

func (e *essControlCache) setMaxCharge(value float64) {
	e.mu.Lock()
	e.hasMaxCharge = true
	e.maxChargeW = value
	e.mu.Unlock()
}

func (e *essControlCache) setMaxDischarge(value float64) {
	e.mu.Lock()
	e.hasMaxDischarge = true
	e.maxDischargeW = value
	e.mu.Unlock()
}

func (e *essControlCache) setBatteryLifeState(value int) {
	e.mu.Lock()
	e.hasBatteryLife = true
	e.batteryLifeState = value
	e.mu.Unlock()
}

func (t *telemetryCache) set(snapshot telemetrySnapshot) {
	t.mu.Lock()
	t.last = snapshot
	t.mu.Unlock()
}

func (t *telemetryCache) snapshot() telemetrySnapshot {
	t.mu.Lock()
	defer t.mu.Unlock()
	return t.last
}

func resolveESSWriteCommand(cmd writeCommand, ess *essControlCache, telemetry *telemetryCache) (*writeCommand, error) {
	if ess == nil {
		ess = newESSControlCache()
	}
	switch cmd.Kind {
	case commandKindESSMaxC:
		if cmd.FloatValue == nil {
			return nil, errors.New("missing ess max charge power value")
		}
		if *cmd.FloatValue < 0 {
			return nil, fmt.Errorf("ess max charge power must be >= 0, got %.3f", *cmd.FloatValue)
		}
		ess.setMaxCharge(*cmd.FloatValue)
		return nil, nil
	case commandKindESSMaxD:
		if cmd.FloatValue == nil {
			return nil, errors.New("missing ess max discharge power value")
		}
		if *cmd.FloatValue < 0 {
			return nil, fmt.Errorf("ess max discharge power must be >= 0, got %.3f", *cmd.FloatValue)
		}
		ess.setMaxDischarge(*cmd.FloatValue)
		return nil, nil
	case commandKindESSMode:
		mode := int(cmd.Value)
		if mode == 0 && cmd.FloatValue != nil {
			mode = int(*cmd.FloatValue)
		}
		if mode != 9 && mode != 10 {
			return nil, fmt.Errorf("unsupported ess mode %d; expected 9 or 10", mode)
		}
		ess.setBatteryLifeState(mode)
		switchState := mk2driver.PanelSwitchOn
		switchName := "on"
		if mode == 9 {
			switchState = mk2driver.PanelSwitchChargerOnly
			switchName = "charger_only"
		}
		mapped := writeCommand{
			Source:      cmd.Source,
			RequestID:   cmd.RequestID,
			Kind:        commandKindPanel,
			HasSwitch:   true,
			SwitchState: switchState,
			SwitchName:  switchName,
		}
		return &mapped, nil
	case commandKindESSSet:
		if cmd.FloatValue == nil {
			return nil, errors.New("missing ess setpoint value")
		}
		setpoint := *cmd.FloatValue
		essSnapshot := ess.snapshot()
		if setpoint > 0 && essSnapshot.HasMaxCharge && setpoint > essSnapshot.MaxChargeW {
			setpoint = essSnapshot.MaxChargeW
		}
		if setpoint < 0 && essSnapshot.HasMaxDischarge && -setpoint > essSnapshot.MaxDischargeW {
			setpoint = -essSnapshot.MaxDischargeW
		}
		ess.setSetpoint(setpoint)

		if setpoint > 1 {
			voltage := 230.0
			if telemetry != nil {
				last := telemetry.snapshot()
				if last.InputVoltage > 1 {
					voltage = last.InputVoltage
				}
			}
			currentLimit := setpoint / voltage
			mapped := writeCommand{
				Source:        cmd.Source,
				RequestID:     cmd.RequestID,
				Kind:          commandKindPanel,
				HasSwitch:     true,
				SwitchState:   mk2driver.PanelSwitchChargerOnly,
				SwitchName:    "charger_only",
				CurrentLimitA: &currentLimit,
			}
			return &mapped, nil
		}
		if setpoint < -1 {
			mapped := writeCommand{
				Source:      cmd.Source,
				RequestID:   cmd.RequestID,
				Kind:        commandKindPanel,
				HasSwitch:   true,
				SwitchState: mk2driver.PanelSwitchInverterOnly,
				SwitchName:  "inverter_only",
			}
			return &mapped, nil
		}
		mapped := writeCommand{
			Source:      cmd.Source,
			RequestID:   cmd.RequestID,
			Kind:        commandKindPanel,
			HasSwitch:   true,
			SwitchState: mk2driver.PanelSwitchOn,
			SwitchName:  "on",
		}
		return &mapped, nil
	default:
		return &cmd, nil
	}
}

func decodeWriteCommand(payload []byte) (writeCommand, error) {
	msg := writeCommandPayload{}
	if err := json.Unmarshal(payload, &msg); err != nil {
		return writeCommand{}, fmt.Errorf("invalid JSON payload: %w", err)
	}

	kind := msg.Kind
	if kind == "" {
		kind = msg.Type
	}
	normalizedKind, err := normalizeWriteKind(kind)
	if err != nil {
		return writeCommand{}, err
	}

	if normalizedKind == commandKindPanel {
		switchName := msg.Switch
		if switchName == "" {
			switchName = msg.SwitchState
		}

		hasSwitch := false
		switchState := mk2driver.PanelSwitchState(0)
		normalizedSwitchName := ""
		if switchName != "" {
			var err error
			switchState, normalizedSwitchName, err = normalizePanelSwitch(switchName)
			if err != nil {
				return writeCommand{}, err
			}
			hasSwitch = true
		}
		if msg.CurrentLimitA != nil && *msg.CurrentLimitA < 0 {
			return writeCommand{}, fmt.Errorf("current_limit must be >= 0, got %.3f", *msg.CurrentLimitA)
		}
		if !hasSwitch && msg.CurrentLimitA == nil {
			return writeCommand{}, errors.New(`missing required field "switch" (or "switch_state"), or "current_limit"`)
		}

		return writeCommand{
			Source:        mk2driver.CommandSourceMQTT,
			RequestID:     msg.RequestID,
			Kind:          normalizedKind,
			HasSwitch:     hasSwitch,
			SwitchState:   switchState,
			SwitchName:    normalizedSwitchName,
			CurrentLimitA: msg.CurrentLimitA,
		}, nil
	}

	if normalizedKind == commandKindStandby {
		standby, err := decodeStandbyValue(msg)
		if err != nil {
			return writeCommand{}, err
		}

		return writeCommand{
			Source:    mk2driver.CommandSourceMQTT,
			RequestID: msg.RequestID,
			Kind:      normalizedKind,
			Standby:   &standby,
		}, nil
	}

	if normalizedKind == commandKindESSSet || normalizedKind == commandKindESSMaxC || normalizedKind == commandKindESSMaxD {
		value, err := decodeFloatValue(msg.Value)
		if err != nil {
			return writeCommand{}, err
		}
		return writeCommand{
			Source:     mk2driver.CommandSourceMQTT,
			RequestID:  msg.RequestID,
			Kind:       normalizedKind,
			FloatValue: &value,
		}, nil
	}

	if normalizedKind == commandKindESSMode {
		modeValue, err := decodeIntValue(msg.Value)
		if err != nil {
			return writeCommand{}, err
		}
		modeFloat := float64(modeValue)
		return writeCommand{
			Source:     mk2driver.CommandSourceMQTT,
			RequestID:  msg.RequestID,
			Kind:       normalizedKind,
			Value:      int16(modeValue),
			FloatValue: &modeFloat,
		}, nil
	}

	if msg.ID == nil {
		return writeCommand{}, errors.New(`missing required field "id"`)
	}
	value, err := decodeInt16Value(msg.Value)
	if err != nil {
		return writeCommand{}, err
	}

	return writeCommand{
		Source:    mk2driver.CommandSourceMQTT,
		RequestID: msg.RequestID,
		Kind:      normalizedKind,
		ID:        *msg.ID,
		Value:     value,
	}, nil
}

func normalizeWriteKind(raw string) (string, error) {
	switch strings.ToLower(strings.TrimSpace(raw)) {
	case "setting", "settings":
		return commandKindSetting, nil
	case "ram", "ramvar", "ram_var", "ram-variable", "ramvariable":
		return commandKindRAMVar, nil
	case "panel", "panel_state", "switch", "remote_panel":
		return commandKindPanel, nil
	case "standby", "panel_standby", "remote_panel_standby":
		return commandKindStandby, nil
	case "ess_mode", "ess_battery_life_state", "battery_life_state":
		return commandKindESSMode, nil
	case "ess_setpoint", "ac_power_setpoint", "grid_setpoint":
		return commandKindESSSet, nil
	case "ess_max_charge_power", "max_charge_power":
		return commandKindESSMaxC, nil
	case "ess_max_discharge_power", "max_discharge_power":
		return commandKindESSMaxD, nil
	default:
		return "", fmt.Errorf("unsupported write command kind %q", raw)
	}
}

func normalizePanelSwitch(raw string) (mk2driver.PanelSwitchState, string, error) {
	switch strings.ToLower(strings.TrimSpace(raw)) {
	case "1", "charger_only", "charger-only", "charger":
		return mk2driver.PanelSwitchChargerOnly, "charger_only", nil
	case "2", "inverter_only", "inverter-only", "inverter":
		return mk2driver.PanelSwitchInverterOnly, "inverter_only", nil
	case "3", "on":
		return mk2driver.PanelSwitchOn, "on", nil
	case "4", "off":
		return mk2driver.PanelSwitchOff, "off", nil
	default:
		return 0, "", fmt.Errorf("unsupported panel switch %q", raw)
	}
}

func executeWriteCommand(writer mk2driver.SettingsWriter, cmd writeCommand) error {
	if writer == nil {
		return errors.New("settings writer is not available")
	}
	source := cmd.Source
	if source == "" {
		source = mk2driver.CommandSourceMQTT
	}
	if sourceAware, ok := writer.(mk2driver.SourceAwareSettingsWriter); ok {
		switch cmd.Kind {
		case commandKindPanel:
			if !cmd.HasSwitch {
				return errors.New("panel_state command requires a switch state")
			}
			return sourceAware.SetPanelStateWithSource(source, cmd.SwitchState, cmd.CurrentLimitA)
		case commandKindStandby:
			if cmd.Standby == nil {
				return errors.New("standby command missing standby value")
			}
			return sourceAware.SetStandbyWithSource(source, *cmd.Standby)
		case commandKindRAMVar:
			return sourceAware.WriteRAMVarWithSource(source, cmd.ID, cmd.Value)
		case commandKindSetting:
			return sourceAware.WriteSettingWithSource(source, cmd.ID, cmd.Value)
		default:
			return fmt.Errorf("unsupported write command kind %q", cmd.Kind)
		}
	}
	switch cmd.Kind {
	case commandKindPanel:
		if !cmd.HasSwitch {
			return errors.New("panel_state command requires a switch state")
		}
		return writer.SetPanelState(cmd.SwitchState, cmd.CurrentLimitA)
	case commandKindStandby:
		if cmd.Standby == nil {
			return errors.New("standby command missing standby value")
		}
		return writer.SetStandby(*cmd.Standby)
	case commandKindRAMVar:
		return writer.WriteRAMVar(cmd.ID, cmd.Value)
	case commandKindSetting:
		return writer.WriteSetting(cmd.ID, cmd.Value)
	default:
		return fmt.Errorf("unsupported write command kind %q", cmd.Kind)
	}
}

func formatWriteCommandLog(cmd writeCommand) string {
	switch cmd.Kind {
	case commandKindPanel:
		switchName := cmd.SwitchName
		if switchName == "" {
			switchName = "<cached>"
		}
		if cmd.CurrentLimitA == nil {
			return fmt.Sprintf("kind=%s switch=%s", cmd.Kind, switchName)
		}
		return fmt.Sprintf("kind=%s switch=%s current_limit=%.3f", cmd.Kind, switchName, *cmd.CurrentLimitA)
	case commandKindStandby:
		if cmd.Standby == nil {
			return fmt.Sprintf("kind=%s standby=<unset>", cmd.Kind)
		}
		return fmt.Sprintf("kind=%s standby=%t", cmd.Kind, *cmd.Standby)
	case commandKindESSSet, commandKindESSMaxC, commandKindESSMaxD:
		if cmd.FloatValue == nil {
			return fmt.Sprintf("kind=%s value=<unset>", cmd.Kind)
		}
		return fmt.Sprintf("kind=%s value=%.3f", cmd.Kind, *cmd.FloatValue)
	case commandKindESSMode:
		return fmt.Sprintf("kind=%s value=%d", cmd.Kind, cmd.Value)
	default:
		return fmt.Sprintf("kind=%s id=%d value=%d", cmd.Kind, cmd.ID, cmd.Value)
	}
}

func decodeInt16Value(raw json.RawMessage) (int16, error) {
	if len(raw) == 0 {
		return 0, errors.New(`missing required field "value"`)
	}

	var value int16
	if err := json.Unmarshal(raw, &value); err != nil {
		return 0, fmt.Errorf(`field "value" must be a signed integer: %w`, err)
	}
	return value, nil
}

func decodeIntValue(raw json.RawMessage) (int, error) {
	if len(raw) == 0 {
		return 0, errors.New(`missing required field "value"`)
	}
	var intValue int
	if err := json.Unmarshal(raw, &intValue); err == nil {
		return intValue, nil
	}

	var floatValue float64
	if err := json.Unmarshal(raw, &floatValue); err == nil {
		return int(floatValue), nil
	}

	var stringValue string
	if err := json.Unmarshal(raw, &stringValue); err == nil {
		parsed, parseErr := strconv.Atoi(strings.TrimSpace(stringValue))
		if parseErr != nil {
			return 0, fmt.Errorf(`field "value" must be integer-like: %w`, parseErr)
		}
		return parsed, nil
	}

	return 0, errors.New(`field "value" must be integer-like`)
}

func decodeFloatValue(raw json.RawMessage) (float64, error) {
	if len(raw) == 0 {
		return 0, errors.New(`missing required field "value"`)
	}

	var floatValue float64
	if err := json.Unmarshal(raw, &floatValue); err == nil {
		return floatValue, nil
	}

	var intValue int
	if err := json.Unmarshal(raw, &intValue); err == nil {
		return float64(intValue), nil
	}

	var stringValue string
	if err := json.Unmarshal(raw, &stringValue); err == nil {
		parsed, parseErr := strconv.ParseFloat(strings.TrimSpace(stringValue), 64)
		if parseErr != nil {
			return 0, fmt.Errorf(`field "value" must be numeric: %w`, parseErr)
		}
		return parsed, nil
	}

	return 0, errors.New(`field "value" must be numeric`)
}

func parseStandbyText(raw string) (bool, error) {
	switch strings.ToLower(strings.TrimSpace(raw)) {
	case "1", "true", "on", "enable", "enabled":
		return true, nil
	case "0", "false", "off", "disable", "disabled":
		return false, nil
	default:
		return false, fmt.Errorf("field \"standby\" must be true/false, got %q", raw)
	}
}

func decodeStandbyValue(msg writeCommandPayload) (bool, error) {
	if msg.Standby != nil {
		return *msg.Standby, nil
	}
	if len(msg.Value) == 0 {
		return false, errors.New(`missing required field "standby" (or boolean "value")`)
	}

	var boolValue bool
	if err := json.Unmarshal(msg.Value, &boolValue); err == nil {
		return boolValue, nil
	}

	var stringValue string
	if err := json.Unmarshal(msg.Value, &stringValue); err == nil {
		return parseStandbyText(stringValue)
	}

	var intValue int
	if err := json.Unmarshal(msg.Value, &intValue); err == nil {
		switch intValue {
		case 1:
			return true, nil
		case 0:
			return false, nil
		}
	}

	return false, errors.New(`field "standby" must be true/false`)
}

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 {
		log.Errorf("Could not publish command status to MQTT topic %q: %v", topic, err)
	}
}

type venusValueEnvelope struct {
	Value any `json:"value"`
}

func subscribeVenusWriteTopics(client mqtt.Client, writer mk2driver.SettingsWriter, config Config, cache *panelStateCache, alarms *alarmTracker, ess *essControlCache, telemetry *telemetryCache) error {
	if writer == nil {
		return nil
	}
	subscribeTopics := []string{venusWriteTopicWildcard(config)}
	if config.Venus.GuideCompat {
		guideTopic := venusWriteTopicWildcardWithService(config, "settings/0")
		if guideTopic != subscribeTopics[0] {
			subscribeTopics = append(subscribeTopics, guideTopic)
		}
	}
	handler := func(_ mqtt.Client, msg mqtt.Message) {
		cmd, err := decodeVenusWriteCommand(config, msg.Topic(), msg.Payload())
		if err != nil {
			log.WithFields(logrus.Fields{
				"topic":   msg.Topic(),
				"payload": string(msg.Payload()),
			}).WithError(err).Warn("Ignoring unsupported Venus write request")
			return
		}
		status := applyWriteCommand(client, writer, config, cache, alarms, ess, telemetry, cmd)
		publishWriteStatus(client, config.StatusTopic, status)
	}
	for _, topic := range subscribeTopics {
		log.WithField("topic", topic).Info("Subscribing to Venus write topic wildcard")
		t := client.Subscribe(topic, 1, handler)
		t.Wait()
		if t.Error() != nil {
			return t.Error()
		}
	}
	return nil
}

func decodeVenusWriteCommand(config Config, topic string, payload []byte) (writeCommand, error) {
	service, path, err := parseVenusWriteTopic(config, topic)
	if err != nil {
		return writeCommand{}, err
	}
	if path == "" {
		return writeCommand{}, errors.New("missing Venus write path")
	}

	value, err := decodeVenusValue(payload)
	if err != nil {
		return writeCommand{}, err
	}

	switch path {
	case "Mode":
		switchState, switchName, err := decodePanelSwitchFromAny(value)
		if err != nil {
			return writeCommand{}, err
		}
		return writeCommand{
			Source:      mk2driver.CommandSourceMQTT,
			Kind:        commandKindPanel,
			HasSwitch:   true,
			SwitchState: switchState,
			SwitchName:  switchName,
		}, nil
	case "Ac/ActiveIn/CurrentLimit":
		limit, err := toFloat64(value)
		if err != nil {
			return writeCommand{}, fmt.Errorf("invalid current limit payload: %w", err)
		}
		if limit < 0 {
			return writeCommand{}, fmt.Errorf("current_limit must be >= 0, got %.3f", limit)
		}
		return writeCommand{
			Source:        mk2driver.CommandSourceMQTT,
			Kind:          commandKindPanel,
			CurrentLimitA: &limit,
		}, nil
	case "Settings/Standby", "RemotePanel/Standby":
		standby, err := toBool(value)
		if err != nil {
			return writeCommand{}, fmt.Errorf("invalid standby payload: %w", err)
		}
		return writeCommand{
			Source:  mk2driver.CommandSourceMQTT,
			Kind:    commandKindStandby,
			Standby: &standby,
		}, nil
	case "Settings/CGwacs/AcPowerSetPoint":
		setpoint, err := toFloat64(value)
		if err != nil {
			return writeCommand{}, fmt.Errorf("invalid ESS setpoint payload: %w", err)
		}
		return writeCommand{
			Source:     mk2driver.CommandSourceMQTT,
			Kind:       commandKindESSSet,
			FloatValue: &setpoint,
		}, nil
	case "Settings/CGwacs/MaxChargePower":
		maxCharge, err := toFloat64(value)
		if err != nil {
			return writeCommand{}, fmt.Errorf("invalid ESS max charge power payload: %w", err)
		}
		return writeCommand{
			Source:     mk2driver.CommandSourceMQTT,
			Kind:       commandKindESSMaxC,
			FloatValue: &maxCharge,
		}, nil
	case "Settings/CGwacs/MaxDischargePower":
		maxDischarge, err := toFloat64(value)
		if err != nil {
			return writeCommand{}, fmt.Errorf("invalid ESS max discharge power payload: %w", err)
		}
		return writeCommand{
			Source:     mk2driver.CommandSourceMQTT,
			Kind:       commandKindESSMaxD,
			FloatValue: &maxDischarge,
		}, nil
	case "Settings/CGwacs/BatteryLife/State":
		modeValue, err := toInt(value)
		if err != nil {
			return writeCommand{}, fmt.Errorf("invalid ESS battery life state payload: %w", err)
		}
		modeFloat := float64(modeValue)
		return writeCommand{
			Source:     mk2driver.CommandSourceMQTT,
			Kind:       commandKindESSMode,
			Value:      int16(modeValue),
			FloatValue: &modeFloat,
		}, nil
	default:
		return writeCommand{}, fmt.Errorf("unsupported Venus write path %q for service %q", path, service)
	}
}

func parseVenusWriteTopic(config Config, topic string) (service string, path string, err error) {
	withoutPrefix := stripVenusTopicPrefix(config, topic)
	withoutPrefix = strings.Trim(withoutPrefix, "/")
	parts := strings.Split(withoutPrefix, "/")
	if len(parts) < 4 || parts[0] != "W" {
		return "", "", fmt.Errorf("topic %q does not appear to be a Venus write topic", topic)
	}
	if parts[1] != venusPortalID(config) {
		return "", "", fmt.Errorf("topic %q is for portal %q, expected %q", topic, parts[1], venusPortalID(config))
	}
	remainder := parts[2:]

	primary := strings.Split(venusService(config), "/")
	if len(remainder) >= len(primary) && strings.EqualFold(strings.Join(remainder[:len(primary)], "/"), strings.Join(primary, "/")) {
		return strings.Join(primary, "/"), strings.Join(remainder[len(primary):], "/"), nil
	}

	guide := []string{"settings", "0"}
	if config.Venus.GuideCompat && len(remainder) >= len(guide) && strings.EqualFold(strings.Join(remainder[:len(guide)], "/"), strings.Join(guide, "/")) {
		return "settings/0", strings.Join(remainder[len(guide):], "/"), nil
	}

	return "", "", fmt.Errorf("topic %q does not match expected Venus services", topic)
}

func decodeVenusValue(payload []byte) (any, error) {
	var envelope venusValueEnvelope
	if err := json.Unmarshal(payload, &envelope); err == nil {
		if envelope.Value != nil {
			return envelope.Value, nil
		}
	}

	var out any
	if err := json.Unmarshal(payload, &out); err != nil {
		return nil, fmt.Errorf("invalid Venus payload: %w", err)
	}
	return out, nil
}

func decodePanelSwitchFromAny(value any) (mk2driver.PanelSwitchState, string, error) {
	switch typed := value.(type) {
	case string:
		return normalizePanelSwitch(typed)
	case float64:
		asInt := int(typed)
		if typed != float64(asInt) {
			return 0, "", fmt.Errorf("mode must be integer-like, got %.3f", typed)
		}
		return normalizePanelSwitch(strconv.Itoa(asInt))
	default:
		return 0, "", fmt.Errorf("unsupported mode payload type %T", value)
	}
}

func toFloat64(value any) (float64, error) {
	switch typed := value.(type) {
	case float64:
		return typed, nil
	case string:
		return strconv.ParseFloat(strings.TrimSpace(typed), 64)
	case int:
		return float64(typed), nil
	case int64:
		return float64(typed), nil
	default:
		return 0, fmt.Errorf("unsupported numeric payload type %T", value)
	}
}

func toInt(value any) (int, error) {
	switch typed := value.(type) {
	case int:
		return typed, nil
	case int64:
		return int(typed), nil
	case float64:
		return int(typed), nil
	case string:
		return strconv.Atoi(strings.TrimSpace(typed))
	default:
		return 0, fmt.Errorf("unsupported integer payload type %T", value)
	}
}

func toBool(value any) (bool, error) {
	switch typed := value.(type) {
	case bool:
		return typed, nil
	case float64:
		if typed == 0 {
			return false, nil
		}
		if typed == 1 {
			return true, nil
		}
		return false, fmt.Errorf("unsupported numeric boolean value %.3f", typed)
	case string:
		return parseStandbyText(typed)
	default:
		return false, fmt.Errorf("unsupported boolean payload type %T", value)
	}
}

func publishHADiscovery(client mqtt.Client, config Config) error {
	definitions := buildHADiscoveryDefinitions(config)
	prefix := haDiscoveryPrefix(config)
	nodeID := haNodeID(config)

	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)
		}
	}

	return nil
}

func buildHADiscoveryDefinitions(config Config) []haDiscoveryDefinition {
	if !config.HomeAssistant.Enabled {
		return nil
	}

	nodeID := haNodeID(config)
	device := map[string]any{
		"identifiers":  []string{fmt.Sprintf("invertergui_%s", nodeID)},
		"name":         haDeviceName(config),
		"manufacturer": "Victron Energy",
		"model":        "MultiPlus",
		"sw_version":   "invertergui",
	}
	availabilityTopic := haAvailabilityTopic(config)
	stateTopic := config.Topic

	sensors := []haDiscoveryDefinition{
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "battery_voltage", "Battery Voltage", "{{ value_json.BatVoltage }}", "V", "voltage", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "battery_current", "Battery Current", "{{ value_json.BatCurrent }}", "A", "current", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "battery_charge", "Battery Charge", "{{ ((value_json.ChargeState | float(0)) * 100) | round(1) }}", "%", "battery", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "input_voltage", "Input Voltage", "{{ value_json.InVoltage }}", "V", "voltage", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "input_current", "Input Current", "{{ value_json.InCurrent }}", "A", "current", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "input_frequency", "Input Frequency", "{{ value_json.InFrequency }}", "Hz", "frequency", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "output_voltage", "Output Voltage", "{{ value_json.OutVoltage }}", "V", "voltage", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "output_current", "Output Current", "{{ value_json.OutCurrent }}", "A", "current", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "output_frequency", "Output Frequency", "{{ value_json.OutFrequency }}", "Hz", "frequency", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "input_power", "Input Power", "{{ ((value_json.InVoltage | float(0)) * (value_json.InCurrent | float(0))) | round(1) }}", "VA", "", "measurement"),
		buildHASensor(device, availabilityTopic, stateTopic, nodeID, "output_power", "Output Power", "{{ ((value_json.OutVoltage | float(0)) * (value_json.OutCurrent | float(0))) | round(1) }}", "VA", "", "measurement"),
		{
			Component: "binary_sensor",
			ObjectID:  "data_valid",
			Config: map[string]any{
				"name":               "Data Valid",
				"unique_id":          fmt.Sprintf("%s_data_valid", nodeID),
				"state_topic":        stateTopic,
				"value_template":     "{{ value_json.Valid }}",
				"payload_on":         "true",
				"payload_off":        "false",
				"availability_topic": availabilityTopic,
				"device":             device,
				"entity_category":    "diagnostic",
			},
		},
	}

	if config.CommandTopic != "" {
		sensors = append(sensors,
			haDiscoveryDefinition{
				Component: "select",
				ObjectID:  "remote_panel_mode",
				Config: map[string]any{
					"name":               "Remote Panel Mode",
					"unique_id":          fmt.Sprintf("%s_remote_panel_mode", nodeID),
					"state_topic":        haPanelSwitchStateTopic(config),
					"command_topic":      config.CommandTopic,
					"command_template":   "{\"kind\":\"panel_state\",\"switch\":\"{{ value }}\"}",
					"options":            []string{"charger_only", "inverter_only", "on", "off"},
					"availability_topic": availabilityTopic,
					"device":             device,
					"icon":               "mdi:transmission-tower-export",
				},
			},
			haDiscoveryDefinition{
				Component: "number",
				ObjectID:  "remote_panel_current_limit",
				Config: map[string]any{
					"name":                "Remote Panel Current Limit",
					"unique_id":           fmt.Sprintf("%s_remote_panel_current_limit", nodeID),
					"state_topic":         haCurrentLimitStateTopic(config),
					"command_topic":       config.CommandTopic,
					"command_template":    "{\"kind\":\"panel_state\",\"current_limit\":{{ value | float(0) }}}",
					"unit_of_measurement": "A",
					"device_class":        "current",
					"mode":                "box",
					"min":                 0,
					"max":                 100,
					"step":                0.1,
					"availability_topic":  availabilityTopic,
					"device":              device,
					"icon":                "mdi:current-ac",
				},
			},
			haDiscoveryDefinition{
				Component: "switch",
				ObjectID:  "remote_panel_standby",
				Config: map[string]any{
					"name":               "Remote Panel Standby",
					"unique_id":          fmt.Sprintf("%s_remote_panel_standby", nodeID),
					"state_topic":        haStandbyStateTopic(config),
					"command_topic":      config.CommandTopic,
					"payload_on":         "{\"kind\":\"standby\",\"standby\":true}",
					"payload_off":        "{\"kind\":\"standby\",\"standby\":false}",
					"state_on":           "ON",
					"state_off":          "OFF",
					"availability_topic": availabilityTopic,
					"device":             device,
					"icon":               "mdi:power-sleep",
				},
			},
		)
	}

	return sensors
}

func buildHASensor(device map[string]any, availabilityTopic, stateTopic, nodeID, objectID, name, valueTemplate, unit, deviceClass, stateClass string) haDiscoveryDefinition {
	config := map[string]any{
		"name":               name,
		"unique_id":          fmt.Sprintf("%s_%s", nodeID, objectID),
		"state_topic":        stateTopic,
		"value_template":     valueTemplate,
		"availability_topic": availabilityTopic,
		"device":             device,
	}
	if unit != "" {
		config["unit_of_measurement"] = unit
	}
	if deviceClass != "" {
		config["device_class"] = deviceClass
	}
	if stateClass != "" {
		config["state_class"] = stateClass
	}

	return haDiscoveryDefinition{
		Component: "sensor",
		ObjectID:  objectID,
		Config:    config,
	}
}

func publishHAAvailability(client mqtt.Client, config Config, status string) error {
	return publishString(client, haAvailabilityTopic(config), status, 1, true)
}

func publishHAControlState(client mqtt.Client, config Config, cmd writeCommand) error {
	switch cmd.Kind {
	case commandKindPanel:
		if err := publishString(client, haPanelSwitchStateTopic(config), cmd.SwitchName, 1, true); err != nil {
			return err
		}
		if cmd.CurrentLimitA != nil {
			limit := strconv.FormatFloat(*cmd.CurrentLimitA, 'f', 1, 64)
			if err := publishString(client, haCurrentLimitStateTopic(config), limit, 1, true); err != nil {
				return err
			}
		}
	case commandKindStandby:
		if cmd.Standby == nil {
			return nil
		}
		state := "OFF"
		if *cmd.Standby {
			state = "ON"
		}
		if err := publishString(client, haStandbyStateTopic(config), state, 1, true); err != nil {
			return err
		}
	}

	return nil
}

func buildTelemetrySnapshot(info *mk2driver.Mk2Info) telemetrySnapshot {
	snapshot := telemetrySnapshot{
		Timestamp:       info.Timestamp.UTC(),
		Valid:           info.Valid,
		InputVoltage:    info.InVoltage,
		InputCurrent:    info.InCurrent,
		InputFrequency:  info.InFrequency,
		OutputVoltage:   info.OutVoltage,
		OutputCurrent:   info.OutCurrent,
		OutputFrequency: info.OutFrequency,
		BatteryVoltage:  info.BatVoltage,
		BatteryCurrent:  info.BatCurrent,
		BatteryCharge:   info.ChargeState * 100,
		InputPower:      info.InVoltage * info.InCurrent,
		OutputPower:     info.OutVoltage * info.OutCurrent,
		BatteryPower:    info.BatVoltage * info.BatCurrent,
		LEDs:            map[string]string{},
	}

	if snapshot.Timestamp.IsZero() {
		snapshot.Timestamp = time.Now().UTC()
	}

	for led, state := range info.LEDs {
		name, ok := mk2driver.LedNames[led]
		if !ok {
			continue
		}
		if stateName, exists := mk2driver.StateNames[state]; exists {
			snapshot.LEDs[name] = stateName
		}
	}

	return snapshot
}

func newHistoryTracker(max int) *historyTracker {
	if max <= 0 {
		max = 120
	}
	return &historyTracker{
		max: max,
	}
}

func (h *historyTracker) Add(snapshot telemetrySnapshot, state operatingState, faultCount uint64, lastFaultAt *time.Time) historySummary {
	h.mu.Lock()
	defer h.mu.Unlock()

	sample := historySample{
		Timestamp:      snapshot.Timestamp,
		InputPowerVA:   snapshot.InputPower,
		OutputPowerVA:  snapshot.OutputPower,
		BatteryPowerW:  snapshot.BatteryPower,
		BatteryVoltage: snapshot.BatteryVoltage,
		Valid:          snapshot.Valid,
		State:          state,
	}
	if h.lastSample != nil && sample.Timestamp.After(h.lastSample.Timestamp) {
		delta := sample.Timestamp.Sub(h.lastSample.Timestamp)
		deltaHours := delta.Hours()
		if sample.InputPowerVA > 0 {
			h.energyInWh += sample.InputPowerVA * deltaHours
		}
		if sample.OutputPowerVA > 0 {
			h.energyOutWh += sample.OutputPowerVA * deltaHours
		}
		if sample.BatteryPowerW > 0 {
			h.batteryChargeWh += sample.BatteryPowerW * deltaHours
		}
		if sample.BatteryPowerW < 0 {
			h.batteryDischargeWh += -sample.BatteryPowerW * deltaHours
		}
		if sample.Valid && sample.State != operatingStateOff {
			h.uptimeSeconds += delta.Seconds()
		}
	}
	h.samples = append(h.samples, sample)
	if len(h.samples) > h.max {
		h.samples = h.samples[len(h.samples)-h.max:]
	}
	sampleCopy := sample
	h.lastSample = &sampleCopy
	h.lastState = state
	h.lastFaultCount = faultCount
	if lastFaultAt != nil {
		h.lastFaultAt = lastFaultAt.UTC()
	}

	return h.summaryLocked(state, faultCount, lastFaultAt)
}

func (h *historyTracker) Summary(state operatingState, faultCount uint64, lastFaultAt *time.Time) historySummary {
	h.mu.Lock()
	defer h.mu.Unlock()
	return h.summaryLocked(state, faultCount, lastFaultAt)
}

func (h *historyTracker) summaryLocked(state operatingState, faultCount uint64, lastFaultAt *time.Time) historySummary {
	summary := summarizeHistory(h.samples)
	summary.EnergyInWh = h.energyInWh
	summary.EnergyOutWh = h.energyOutWh
	summary.BatteryChargeWh = h.batteryChargeWh
	summary.BatteryDischargeWh = h.batteryDischargeWh
	summary.UptimeSeconds = h.uptimeSeconds
	if faultCount == 0 {
		faultCount = h.lastFaultCount
	}
	summary.FaultCount = faultCount
	if lastFaultAt == nil && !h.lastFaultAt.IsZero() {
		lastFaultAt = &h.lastFaultAt
	}
	if lastFaultAt != nil && !lastFaultAt.IsZero() {
		summary.LastFaultAt = lastFaultAt.UTC().Format(time.RFC3339)
	}
	if state == "" {
		state = h.lastState
	}
	summary.CurrentState = string(state)
	return summary
}

func summarizeHistory(samples []historySample) historySummary {
	summary := historySummary{
		Samples: len(samples),
	}
	if len(samples) == 0 {
		return summary
	}

	first := samples[0]
	last := samples[len(samples)-1]
	if last.Timestamp.After(first.Timestamp) {
		summary.WindowSeconds = last.Timestamp.Sub(first.Timestamp).Seconds()
	}

	minBatteryVoltage := samples[0].BatteryVoltage
	maxOutputPower := samples[0].OutputPowerVA
	var inTotal, outTotal, batTotal float64
	for _, sample := range samples {
		inTotal += sample.InputPowerVA
		outTotal += sample.OutputPowerVA
		batTotal += sample.BatteryPowerW
		if sample.BatteryVoltage < minBatteryVoltage {
			minBatteryVoltage = sample.BatteryVoltage
		}
		if sample.OutputPowerVA > maxOutputPower {
			maxOutputPower = sample.OutputPowerVA
		}
	}

	count := float64(len(samples))
	summary.AverageInputPower = inTotal / count
	summary.AverageOutputPower = outTotal / count
	summary.AverageBatteryPower = batTotal / count
	summary.MaxOutputPower = maxOutputPower
	summary.MinBatteryVoltage = minBatteryVoltage
	return summary
}

func newAlarmTracker() *alarmTracker {
	return &alarmTracker{
		active:      map[string]alarmState{},
		rules:       map[string]*alarmRule{},
		debounceOn:  1500 * time.Millisecond,
		debounceOff: 3 * time.Second,
	}
}

func (a *alarmTracker) Update(snapshot telemetrySnapshot) []alarmState {
	now := snapshot.Timestamp
	if now.IsZero() {
		now = time.Now().UTC()
	}

	a.mu.Lock()
	defer a.mu.Unlock()

	a.setLocked("invalid_data", "critical", "MK2 data frame marked invalid", !snapshot.Valid, now)
	a.setFromLEDLocked(snapshot, "led_overload", "overload", "critical", "Inverter overload alarm", now)
	a.setFromLEDLocked(snapshot, "led_over_temp", "over_temperature", "critical", "Inverter over temperature alarm", now)
	a.setFromLEDLocked(snapshot, "led_bat_low", "battery_low", "warning", "Battery low warning", now)
	a.setLocked("command_failure", "warning", "Recent command failed", false, now)

	return a.activeLocked()
}

func (a *alarmTracker) RecordCommandFailure(err error, now time.Time) []alarmState {
	if now.IsZero() {
		now = time.Now().UTC()
	}
	a.mu.Lock()
	defer a.mu.Unlock()
	message := "Recent command failed"
	if err != nil {
		message = fmt.Sprintf("Command failed: %v", err)
	}
	a.setLocked("command_failure", "warning", message, true, now)
	return a.activeLocked()
}

func (a *alarmTracker) RecordCommandSuccess(now time.Time) []alarmState {
	if now.IsZero() {
		now = time.Now().UTC()
	}
	a.mu.Lock()
	defer a.mu.Unlock()
	a.setLocked("command_failure", "warning", "Recent command failed", false, now)
	return a.activeLocked()
}

func (a *alarmTracker) Stats() (uint64, *time.Time) {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.lastFault.IsZero() {
		return a.faultCount, nil
	}
	last := a.lastFault
	return a.faultCount, &last
}

func (a *alarmTracker) activeLocked() []alarmState {
	alarms := make([]alarmState, 0, len(a.active))
	for _, alarm := range a.active {
		alarms = append(alarms, alarm)
	}
	sort.Slice(alarms, func(i, j int) bool {
		return alarms[i].Code < alarms[j].Code
	})
	return alarms
}

func (a *alarmTracker) getRuleLocked(code, level, message string) *alarmRule {
	rule, ok := a.rules[code]
	if !ok {
		rule = &alarmRule{
			code:    code,
			level:   level,
			message: message,
		}
		a.rules[code] = rule
		return rule
	}
	rule.level = level
	rule.message = message
	return rule
}

func (a *alarmTracker) setFromLEDLocked(snapshot telemetrySnapshot, ledKey, code, level, message string, now time.Time) {
	state := strings.ToLower(strings.TrimSpace(snapshot.LEDs[ledKey]))
	active := state == "on" || state == "blink"
	a.setLocked(code, level, message, active, now)
}

func (a *alarmTracker) setLocked(code, level, message string, active bool, now time.Time) {
	rule := a.getRuleLocked(code, level, message)
	if active {
		rule.clearFrom = time.Time{}
		if rule.active {
			a.active[code] = alarmState{
				Code:        code,
				Level:       level,
				Message:     message,
				ActiveSince: rule.activeSince,
			}
			return
		}
		if rule.pendingFrom.IsZero() {
			rule.pendingFrom = now
		}
		if now.Sub(rule.pendingFrom) >= a.debounceOn {
			rule.active = true
			rule.activeSince = rule.pendingFrom
			a.active[code] = alarmState{
				Code:        code,
				Level:       level,
				Message:     message,
				ActiveSince: rule.activeSince,
			}
			a.faultCount++
			a.lastFault = now
		}
		return
	}

	rule.pendingFrom = time.Time{}
	if !rule.active {
		delete(a.active, code)
		return
	}
	if rule.clearFrom.IsZero() {
		rule.clearFrom = now
		return
	}
	if now.Sub(rule.clearFrom) >= a.debounceOff {
		rule.active = false
		rule.activeSince = time.Time{}
		rule.clearFrom = time.Time{}
		delete(a.active, code)
	}
}

func deriveOperatingState(snapshot telemetrySnapshot, panel panelStateSnapshot, alarms []alarmState) operatingState {
	for _, alarm := range alarms {
		if strings.EqualFold(alarm.Level, "critical") {
			return operatingStateFault
		}
	}
	if !snapshot.Valid {
		return operatingStateFault
	}
	if panel.HasSwitch && panel.Switch == "off" {
		return operatingStateOff
	}

	mainsState := strings.ToLower(strings.TrimSpace(snapshot.LEDs["led_mains"]))
	inverterState := strings.ToLower(strings.TrimSpace(snapshot.LEDs["led_inverter"]))
	mainsOn := mainsState == "on" || mainsState == "blink"
	inverterOn := inverterState == "on" || inverterState == "blink"
	charging := snapshot.BatteryCurrent > 0.2

	if inverterOn && !mainsOn {
		return operatingStateInverter
	}
	if mainsOn && snapshot.OutputPower > 20 {
		if charging {
			return operatingStateCharger
		}
		return operatingStatePassthru
	}
	if charging {
		return operatingStateCharger
	}
	if snapshot.OutputPower > 20 {
		return operatingStateInverter
	}
	return operatingStateOff
}

func publishOrchestrationTopics(client mqtt.Client, config Config, snapshot telemetrySnapshot, panel panelStateSnapshot, summary historySummary, alarms []alarmState, state operatingState) error {
	deviceRoot := deviceTopicRoot(config)
	payload := orchestrationState{
		DeviceID:       normalizedDeviceID(config),
		InstanceID:     config.InstanceID,
		Phase:          strings.ToUpper(strings.TrimSpace(config.Phase)),
		PhaseGroup:     strings.TrimSpace(config.PhaseGroup),
		Timestamp:      snapshot.Timestamp,
		OperatingState: string(state),
		Telemetry:      snapshot,
		PanelState:     panel,
		History:        summary,
		Alarms:         alarms,
	}

	if err := publishJSON(client, fmt.Sprintf("%s/state", deviceRoot), payload, 0, false); err != nil {
		return err
	}
	if err := publishJSON(client, fmt.Sprintf("%s/history/summary", deviceRoot), summary, 0, false); err != nil {
		return err
	}
	if err := publishActiveAlarms(client, config, alarms); err != nil {
		return err
	}
	groupPhase := strings.ToUpper(strings.TrimSpace(config.Phase))
	if groupPhase == "" {
		groupPhase = "L1"
	}
	groupTopic := fmt.Sprintf("%s/groups/%s/%s/state", mqttTopicRoot(config.Topic), normalizeID(config.PhaseGroup), groupPhase)
	if err := publishJSON(client, groupTopic, payload, 0, false); err != nil {
		return err
	}
	return nil
}

func publishActiveAlarms(client mqtt.Client, config Config, alarms []alarmState) error {
	return publishJSON(client, fmt.Sprintf("%s/alarms/active", deviceTopicRoot(config)), alarms, 1, true)
}

func publishDiagnostics(client mqtt.Client, config Config, driverDiag mk2driver.DriverDiagnostics, commands []mk2driver.CommandEvent) error {
	diag := diagnosticsBundle{
		DeviceID:    normalizedDeviceID(config),
		InstanceID:  config.InstanceID,
		Phase:       strings.ToUpper(strings.TrimSpace(config.Phase)),
		PhaseGroup:  strings.TrimSpace(config.PhaseGroup),
		GeneratedAt: time.Now().UTC(),
		HealthScore: driverDiag.HealthScore,
		Driver:      &driverDiag,
		Commands:    commands,
	}
	return publishJSON(client, fmt.Sprintf("%s/diagnostics", deviceTopicRoot(config)), diag, 1, false)
}

func publishVenusServiceInfo(client mqtt.Client, config Config) error {
	if !config.Venus.Enabled {
		return nil
	}

	if err := publishVenusValue(client, config, "Connected", 1, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "ProductName", "invertergui", true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "DeviceInstance", config.InstanceID, true); err != nil {
		return err
	}
	return nil
}

func publishVenusTelemetry(client mqtt.Client, config Config, snapshot telemetrySnapshot, panel panelStateSnapshot, alarms []alarmState, state operatingState, history historySummary, ess essControlSnapshot) error {
	phase := strings.ToUpper(strings.TrimSpace(config.Phase))
	if phase == "" {
		phase = "L1"
	}
	if err := publishVenusValue(client, config, "Connected", 1, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "State", string(state), true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Dc/0/Voltage", snapshot.BatteryVoltage, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Dc/0/Current", snapshot.BatteryCurrent, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Dc/0/Power", snapshot.BatteryPower, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Soc", snapshot.BatteryCharge, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/ActiveIn/%s/V", phase), snapshot.InputVoltage, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/ActiveIn/%s/I", phase), snapshot.InputCurrent, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/ActiveIn/%s/F", phase), snapshot.InputFrequency, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/ActiveIn/%s/P", phase), snapshot.InputPower, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/Out/%s/V", phase), snapshot.OutputVoltage, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/Out/%s/I", phase), snapshot.OutputCurrent, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/Out/%s/F", phase), snapshot.OutputFrequency, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, fmt.Sprintf("Ac/Out/%s/P", phase), snapshot.OutputPower, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "History/EnergyIn", history.EnergyInWh, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "History/EnergyOut", history.EnergyOutWh, true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "History/FaultCount", history.FaultCount, true); err != nil {
		return err
	}
	if err := publishVenusESSState(client, config, ess); err != nil {
		return err
	}
	if panel.HasSwitch {
		if err := publishVenusValue(client, config, "Mode", panel.Switch, true); err != nil {
			return err
		}
	}
	if panel.HasCurrent {
		if err := publishVenusValue(client, config, "Ac/ActiveIn/CurrentLimit", panel.CurrentLimit, true); err != nil {
			return err
		}
	}
	if panel.HasStandby {
		if err := publishVenusValue(client, config, "Settings/Standby", panel.Standby, true); err != nil {
			return err
		}
	}

	alarmLevels := venusAlarmLevels(alarms)
	if err := publishVenusValue(client, config, "Alarms/LowBattery", alarmLevels["battery_low"], true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Alarms/HighTemperature", alarmLevels["over_temperature"], true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Alarms/Overload", alarmLevels["overload"], true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Alarms/Communication", alarmLevels["invalid_data"], true); err != nil {
		return err
	}
	if err := publishVenusValue(client, config, "Alarms/Command", alarmLevels["command_failure"], true); err != nil {
		return err
	}

	return nil
}

func publishVenusControlState(client mqtt.Client, config Config, cmd writeCommand, panel panelStateSnapshot) error {
	switch cmd.Kind {
	case commandKindPanel:
		if panel.HasSwitch {
			if err := publishVenusValue(client, config, "Mode", panel.Switch, true); err != nil {
				return err
			}
		}
		if panel.HasCurrent {
			if err := publishVenusValue(client, config, "Ac/ActiveIn/CurrentLimit", panel.CurrentLimit, true); err != nil {
				return err
			}
		}
	case commandKindStandby:
		if panel.HasStandby {
			if err := publishVenusValue(client, config, "Settings/Standby", panel.Standby, true); err != nil {
				return err
			}
		}
	}
	return nil
}

func publishVenusESSState(client mqtt.Client, config Config, ess essControlSnapshot) error {
	if !config.Venus.GuideCompat {
		return nil
	}
	if ess.HasSetpoint {
		if err := publishVenusValueWithService(client, config, "settings/0", "Settings/CGwacs/AcPowerSetPoint", ess.SetpointW, true); err != nil {
			return err
		}
	}
	if ess.HasMaxCharge {
		if err := publishVenusValueWithService(client, config, "settings/0", "Settings/CGwacs/MaxChargePower", ess.MaxChargeW, true); err != nil {
			return err
		}
	}
	if ess.HasMaxDischarge {
		if err := publishVenusValueWithService(client, config, "settings/0", "Settings/CGwacs/MaxDischargePower", ess.MaxDischargeW, true); err != nil {
			return err
		}
	}
	if ess.HasBatteryLife {
		if err := publishVenusValueWithService(client, config, "settings/0", "Settings/CGwacs/BatteryLife/State", ess.BatteryLifeState, true); err != nil {
			return err
		}
	}
	return nil
}

func venusAlarmLevels(alarms []alarmState) map[string]int {
	levels := map[string]int{
		"battery_low":      0,
		"over_temperature": 0,
		"overload":         0,
		"invalid_data":     0,
		"command_failure":  0,
	}
	for _, alarm := range alarms {
		level := 1
		if strings.EqualFold(alarm.Level, "critical") {
			level = 2
		}
		if existing, ok := levels[alarm.Code]; ok && level > existing {
			levels[alarm.Code] = level
		}
	}
	return levels
}

func publishVenusValue(client mqtt.Client, config Config, path string, value any, retained bool) error {
	topic := venusNotifyTopic(config, path)
	payload := venusValueEnvelope{Value: value}
	return publishJSON(client, topic, payload, 1, retained)
}

func publishVenusValueWithService(client mqtt.Client, config Config, service, path string, value any, retained bool) error {
	topic := venusNotifyTopicWithService(config, service, path)
	payload := venusValueEnvelope{Value: value}
	return publishJSON(client, topic, payload, 1, retained)
}

func publishJSON(client mqtt.Client, topic string, payload any, qos byte, retained bool) error {
	if topic == "" {
		return errors.New("topic is empty")
	}

	data, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("could not marshal payload: %w", err)
	}

	t := client.Publish(topic, qos, retained, data)
	t.Wait()
	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
}

func publishString(client mqtt.Client, topic, payload string, qos byte, retained bool) error {
	if topic == "" {
		return errors.New("topic is empty")
	}

	t := client.Publish(topic, qos, retained, payload)
	t.Wait()
	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
}

func mqttTopicRoot(topic string) string {
	t := strings.Trim(strings.TrimSpace(topic), "/")
	if t == "" {
		return "invertergui"
	}
	if strings.HasSuffix(t, "/updates") {
		root := strings.TrimSuffix(t, "/updates")
		if root != "" {
			return root
		}
	}
	return t
}

func normalizedDeviceID(config Config) string {
	deviceID := normalizeID(config.DeviceID)
	if deviceID == "" {
		deviceID = normalizeID(config.ClientID)
	}
	if deviceID == "" {
		return "invertergui"
	}
	return deviceID
}

func deviceTopicRoot(config Config) string {
	return fmt.Sprintf("%s/devices/%s", mqttTopicRoot(config.Topic), normalizedDeviceID(config))
}

func venusPortalID(config Config) string {
	portal := normalizeID(config.Venus.PortalID)
	if portal == "" {
		return normalizedDeviceID(config)
	}
	return portal
}

func venusService(config Config) string {
	service := strings.Trim(strings.TrimSpace(config.Venus.Service), "/")
	if service == "" {
		return "vebus/257"
	}
	return service
}

func venusNotifyTopic(config Config, path string) string {
	return venusNotifyTopicWithService(config, venusService(config), path)
}

func venusNotifyTopicWithService(config Config, service, path string) string {
	cleanPath := strings.Trim(strings.TrimSpace(path), "/")
	cleanService := strings.Trim(strings.TrimSpace(service), "/")
	base := fmt.Sprintf("N/%s/%s/%s", venusPortalID(config), cleanService, cleanPath)
	return venusPrefixedTopic(config, base)
}

func venusWriteTopicRoot(config Config) string {
	return venusWriteTopicRootWithService(config, venusService(config))
}

func venusWriteTopicRootWithService(config Config, service string) string {
	cleanService := strings.Trim(strings.TrimSpace(service), "/")
	base := fmt.Sprintf("W/%s/%s", venusPortalID(config), cleanService)
	return venusPrefixedTopic(config, base)
}

func venusWriteTopicWildcard(config Config) string {
	return fmt.Sprintf("%s/#", venusWriteTopicRoot(config))
}

func venusWriteTopicWildcardWithService(config Config, service string) string {
	return fmt.Sprintf("%s/#", venusWriteTopicRootWithService(config, service))
}

func venusPrefixedTopic(config Config, topic string) string {
	prefix := strings.Trim(strings.TrimSpace(config.Venus.TopicPrefix), "/")
	cleanTopic := strings.Trim(strings.TrimSpace(topic), "/")
	if prefix == "" {
		return cleanTopic
	}
	return fmt.Sprintf("%s/%s", prefix, cleanTopic)
}

func stripVenusTopicPrefix(config Config, topic string) string {
	clean := strings.Trim(strings.TrimSpace(topic), "/")
	prefix := strings.Trim(strings.TrimSpace(config.Venus.TopicPrefix), "/")
	if prefix == "" {
		return clean
	}
	if strings.HasPrefix(clean, prefix+"/") {
		return strings.TrimPrefix(clean, prefix+"/")
	}
	return clean
}

func haAvailabilityTopic(config Config) string {
	return fmt.Sprintf("%s/homeassistant/availability", mqttTopicRoot(config.Topic))
}

func haPanelSwitchStateTopic(config Config) string {
	return fmt.Sprintf("%s/homeassistant/remote_panel_mode/state", mqttTopicRoot(config.Topic))
}

func haCurrentLimitStateTopic(config Config) string {
	return fmt.Sprintf("%s/homeassistant/remote_panel_current_limit/state", mqttTopicRoot(config.Topic))
}

func haStandbyStateTopic(config Config) string {
	return fmt.Sprintf("%s/homeassistant/remote_panel_standby/state", mqttTopicRoot(config.Topic))
}

func haDiscoveryPrefix(config Config) string {
	prefix := strings.Trim(strings.TrimSpace(config.HomeAssistant.DiscoveryPrefix), "/")
	if prefix == "" {
		return "homeassistant"
	}
	return prefix
}

func haNodeID(config Config) string {
	nodeID := normalizeID(config.HomeAssistant.NodeID)
	if nodeID == "" {
		nodeID = normalizeID(config.ClientID)
	}
	if nodeID == "" {
		return "invertergui"
	}
	return nodeID
}

func haDeviceName(config Config) string {
	name := strings.TrimSpace(config.HomeAssistant.DeviceName)
	if name == "" {
		return "Victron Inverter"
	}
	return name
}

func normalizeID(in string) string {
	trimmed := strings.TrimSpace(strings.ToLower(in))
	if trimmed == "" {
		return ""
	}
	var b strings.Builder
	lastUnderscore := false
	for _, r := range trimmed {
		valid := (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') || r == '-' || r == '_'
		if valid {
			b.WriteRune(r)
			lastUnderscore = false
			continue
		}
		if !lastUnderscore {
			b.WriteRune('_')
			lastUnderscore = true
		}
	}

	return strings.Trim(b.String(), "_")
}

func copyBoolPtr(in *bool) *bool {
	if in == nil {
		return nil
	}
	value := *in
	return &value
}

func float64Ptr(in float64) *float64 {
	return &in
}

func getOpts(config Config) *mqtt.ClientOptions {
	opts := mqtt.NewClientOptions()
	opts.AddBroker(config.Broker)
	opts.SetClientID(config.ClientID)

	if config.Username != "" {
		opts.SetUsername(config.Username)
	}
	if config.Password != "" {
		opts.SetPassword(config.Password)
	}
	if config.HomeAssistant.Enabled {
		opts.SetWill(haAvailabilityTopic(config), "offline", 1, true)
	} else if config.Venus.Enabled {
		opts.SetWill(venusNotifyTopic(config, "Connected"), `{"value":0}`, 1, true)
	}
	opts.SetKeepAlive(keepAlive)

	opts.SetOnConnectHandler(func(mqtt.Client) {
		log.Info("Client connected to broker")
	})
	opts.SetConnectionLostHandler(func(_ mqtt.Client, err error) {
		log.Errorf("Client connection to broker lost: %v", err)
	})
	return opts
}