src.dualinventive.com/go/cp3000-interface/internal/device/zkl3000rc.go

package device

import (
	"errors"
	"fmt"
	"time"

	"src.dualinventive.com/go/cp3000-interface/internal/statusupdate"
	"src.dualinventive.com/go/dinet/rpc"
	"src.dualinventive.com/go/lib/cp3000"
	"src.dualinventive.com/go/lib/dilog"
)

// zkl3000RcMaximumWaitForMeasurement is the maximum time to wait until a measurement should arrive
//nolint: gochecknoglobals
var zkl3000RcMaximumWaitForMeasurement = 3 * time.Second

// errZKL3000RcSwitchStatsRetriesExceeded when the switch status is not valid after retries
var errZKL3000RcSwitchStatsRetriesExceeded = errors.New("zkl3000rc: switch status retries exceeded")

// SwitchCommand is a command to request a switch change.
// The algorithm to calculate the right value is defined in: mtinfo/common: include/zkl-common.h:902
type SwitchCommand byte

const (
	// SwitchStatusCommand (0xF0)
	SwitchStatusCommand SwitchCommand = ((iota) | ((^(iota) & 0xF) << 4))
	//ShortCircuitOffSwitchCommand turns the short circuit off (0xE1)
	ShortCircuitOffSwitchCommand
	//ShortCircuitOnSwitchCommand turns the short circuit on (0xD2)
	ShortCircuitOnSwitchCommand
	//MeasurementOffSwitchCommand turns the measurement off (0xC3)
	MeasurementOffSwitchCommand
	//MeasurementOnSwitchCommand turns the measurement on (0xB4)
	MeasurementOnSwitchCommand
	//RemoveTokenSwitchCommand removes the token in the switch (0xA5)
	RemoveTokenSwitchCommand
	//WriteTokenSwichCommand writes the token in the switch (0x96)
	WriteTokenSwichCommand
)

// Zkl3000Rc is a ZKL 3000 RC device
type Zkl3000Rc struct {
	Zkl3000

	switchInfo *SwitchInfo
	active     bool
}

// construct is called when the device is created. This should be non blocking
func (z *Zkl3000Rc) construct() {
	z.decoder = statusupdate.NewStatusDecoder(z.dev.Logger(), statusupdate.StatUpdateAll)

	z.dev.Subscribe(rpc.ClassMethodSensorInfo, rpc.MsgTypeRequest, z.sensorInfo)
	z.dev.AddConfig(rpc.ConfigToken, z.configGetToken, z.configSetToken, z.configResetToken)
	z.dev.AddConfig(rpc.ConfigActive, z.configGetActivate, z.configSetActivate, z.configResetActivate)
	z.dev.AddConfig(rpc.ConfigEndpoint, z.configGetEndpoint, z.configSetEndpoint, nil)
}

// init is called when the device is created. This can be blocking
func (z *Zkl3000Rc) init() {
	if _, _, err := z.requestSwitchInfo(); err != nil {
		z.dev.Logger().WithError(err).Warning("problem reading token")
	}
}

// Below are all the CP3000 callbacks

// Statusupdate is a callback for the $STAT message
// Suppress the linter because statusUpdateCmd needs to satisfy the interface
//nolint: unparam
func (z *Zkl3000Rc) statusUpdateCmd(r cp3000.Router, args []string) error {
	err := z.updateSensorData(args)
	if z.updateErrors() {
		z.dev.Logger().Info("send device:data")
		if pErr := z.dev.SendDeviceData(); pErr != nil {
			return pErr
		}
	}
	return err
}

// heartbeatCmd is the Watchdog callback (used as heartbeat)
// Suppress the linter because heartbeatCmd needs to satisfy the interface
//nolint: unparam
func (z *Zkl3000Rc) heartbeatCmd(r cp3000.Router, args []string) error {
	if err := z.dev.SendDeviceData(); err != nil {
		return err
	}
	if z.dev.GetState() == rpc.DeviceStateActive {
		go z.continueHeartbeats()
	}
	return z.client.Send("WD")
}

// RegisterCallbacks overrides the heartbeat command
func (z *Zkl3000Rc) RegisterCallbacks() error {
	err := z.Zkl3000.RegisterCallbacks()
	z.client.Register(cp3000.CommandWatchdog, z.heartbeatCmd)
	z.client.Register(cp3000.CommandStatus, z.statusUpdateCmd)
	return err
}

// Below are all the DI Net callbacks

// sensorInfo returns all the sensor information
func (z *Zkl3000Rc) sensorInfo(req *rpc.Msg) *rpc.Msg {
	rep := req.CreateReply()
	// dupl with the test, so suppress it
	// nolint: dupl
	rep.Result = rpc.NewResult([]rpc.ResultInfoItem{
		rpc.SensorBattery1Voltage.Info(),
		rpc.SensorBattery1State.Info(),
		rpc.SensorBattery2Voltage.Info(),
		rpc.SensorBattery2State.Info(),
		rpc.SensorCharger1State.Info(),
		rpc.SensorGPS.Info(),
		rpc.SensorRSSI.Info(),
		rpc.SensorBER.Info(),
		rpc.ZKLSensorDetectionQuality.Info(),
		rpc.ZKLSensorDetection.Info(),
		rpc.ZKLSensorMeasurement.Info(),
		rpc.ZKLSensorBa.Info(),
		rpc.ZKLSensorFrequency.Info(),
		rpc.ZKLSensorRMS.Info(),
		rpc.ZKLSensorBAAutocal.Info(),
		rpc.ZKLSensorTempOnboard.Info(),
		rpc.ZKLSensorTempNTC.Info(),
		rpc.ZKLRCSensorSectionsShort.Info(),
		rpc.ZKLRCSensorSectionsBattery.Info(),
		rpc.ZKLRCSensorSwitchShort.Info(),
		rpc.ZKLRCSensorKeySwitch.Info(),
	})
	return rep
}

// configSetToken request is called when the project is released
func (z *Zkl3000Rc) configSetToken(p rpc.ConfigParam) rpc.ErrorCode {
	logger := z.dev.Logger().WithField("action", "config:set token")
	val, err := p.ValueInt64()
	if err != nil {
		logger.WithError(err).WithField("type", fmt.Sprintf("%T", p.Value)).Error("token is not an int64")
		return rpc.EParam
	}
	newToken := uint32(val)

	up, switchInfo, retVal := z.preflightChecks(logger, true, true)
	if retVal != rpc.Ok {
		return retVal
	}

	// When there is already a different token, deny operation
	if switchInfo.Released && switchInfo.Token != newToken {
		logger.WithFields(dilog.Fields{
			"currenttoken": switchInfo.Token,
			"newtoken":     newToken,
		}).Error("token mismatch")
		return rpc.EFirmwareMismatchToken
	}

	if up.KeySwitch() != rpc.KeyswitchStateOperational {
		logger.WithField("keyswitch", up.KeySwitch()).Error("keyswitch is not operational")
		return rpc.EFirmwareKeyswitchNotOperational
	}

	retVal = z.batteryChecks(logger, up, false)
	if retVal.IsError() {
		return retVal
	}

	// Always at the end, because you cannot for example release with an invalid keyswitch even if the device is
	// already released
	if switchInfo.Released {
		if up.Released() {
			logger.Info("device is already released")
			return rpc.Ok
		}
		logger.Warning("device already released, but STAT data say otherwise. DEADLOCK")
	}
	// It is possible that the token was already written, but the status update is still reporting not released
	// We are in a deadlock! Just write it again to the switch and hopefully it is fixed.
	return z.writeSwitchToken(retVal, newToken)
}

// configSetActivate request is called when the project is activated
func (z *Zkl3000Rc) configSetActivate(p rpc.ConfigParam) rpc.ErrorCode {
	logger := z.dev.Logger().WithFields(dilog.Fields{
		"action": "config:set activate",
		"value":  p.Value,
	})
	activationState, ok := p.Value.(bool)
	if !ok {
		logger.WithField("type", fmt.Sprintf("%T", p.Value)).Error("activate is not a bool")
		return rpc.EParam
	}
	return z.activateDeactivateSwitch(logger, activationState)
}

// configResetToken request is called when the project is returned
func (z *Zkl3000Rc) configResetToken() rpc.ErrorCode {
	logger := z.dev.Logger().WithField("action", "config:reset token")

	_, switchInfo, retVal := z.preflightChecks(logger, false, false)
	if retVal != rpc.Ok {
		return retVal
	}

	// When there is no token it is already returned
	if !switchInfo.Released {
		logger.Info("device is already returned")
		return rpc.Ok
	}
	return z.writeSwitchRemoveToken(retVal, switchInfo.Token)
}

// configResetActivate request is called when the project is deactivated
func (z *Zkl3000Rc) configResetActivate() rpc.ErrorCode {
	logger := z.dev.Logger().WithField("action", "config:reset activate")
	return z.activateDeactivateSwitch(logger, false)
}

// configGetToken request is called when the backend wants to know what the token is
func (z *Zkl3000Rc) configGetToken(rep *rpc.Msg) *rpc.Msg {
	logger := z.dev.Logger().WithField("action", "config:get token")
	switchInfo, rpcerr, err := z.requestSwitchInfo()
	if err != nil {
		logger.WithError(err).Error("cannot read switch information")
		return rep.SetError(rpcerr)
	}
	rep.Result = rpc.NewResult([]*rpc.ResultConfigValueItem{rpc.ConfigToken.Data(switchInfo.Token)})
	return rep
}

// configGetActivate is called when the backend wants to know if the project is active
func (z *Zkl3000Rc) configGetActivate(rep *rpc.Msg) *rpc.Msg {
	rep.Result = rpc.NewResult([]*rpc.ResultConfigValueItem{rpc.ConfigActive.Data(z.active)})
	return rep
}

// Below are all the child device callbacks

// Versions returns the firmware and hardware versions
func (z *Zkl3000Rc) Versions() (rpc.VersionMap, rpc.ErrorCode) {
	var mcu, wcpu, fwSwitchMeas, fwSwitchDrive string
	var rpcerr rpc.ErrorCode
	if mcu, rpcerr = z.requestVersion("FW-MCU"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if wcpu, rpcerr = z.requestVersion("FW-WCPU"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if fwSwitchMeas, rpcerr = z.requestVersion("FW-SW3000-M"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}
	if fwSwitchDrive, rpcerr = z.requestVersion("FW-SW3000-D"); rpcerr != rpc.Ok {
		return nil, rpcerr
	}

	// Legacy Zkl3000RC don't have "VersionKeyFwZKLRCSwitchConrol" and "rpc.VersionKeyHwZKLRCSwitch"
	return rpc.VersionMap{
		rpc.VersionKeyHwZKLRCMain:        z.hwVersion,
		rpc.VersionKeyFwZKLRCMain:        mcu,
		rpc.VersionKeyFwZKLRCWcpu:        wcpu,
		rpc.VersionKeyFwZKLRCSwitchMeas:  fwSwitchMeas,
		rpc.VersionKeyFwZKLRCSwitchDrive: fwSwitchDrive,
	}, rpc.Ok
}

// TimeoutDuration returns when the device should be considered offline
func (z *Zkl3000Rc) TimeoutDuration() time.Duration {
	return time.Minute
}

// Transport returns the transportation type
func (z *Zkl3000Rc) Transport() (interface{}, rpc.ErrorCode) {
	return z.cp3000Transport()
}

// updateDeviceState is called when the device state needs to be updated
func (z *Zkl3000Rc) updateDeviceState() bool {
	curState := z.dev.GetState()
	switch {
	case !z.switchInfo.Released:
		z.dev.SetState(rpc.DeviceStateIdle)
	case z.active:
		z.dev.SetState(rpc.DeviceStateActive)
	default:
		z.dev.SetState(rpc.DeviceStateArmed)
	}
	return curState != z.dev.GetState()
}

// batteryStateError returns the error code when the device needs to be released or activated.
// When activation is true, the code expects that the device should be activated, false means release.
func (z *Zkl3000Rc) batteryStateError(state rpc.BatteryState, activation bool) rpc.ErrorCode {
	switch state {
	case rpc.BatteryStateFull:
		// Valid
		return rpc.Ok
	case rpc.BatteryStateHalf:
		// Should not occur set it on valid
		return rpc.Ok
	case rpc.BatteryStateLow:
		// Should not occur set it on valid
		return rpc.Ok
	case rpc.BatteryStateCritical:
		// Warning
		return rpc.EWrnFirmwareBattery2Critical
	case rpc.BatteryStateEmpty:
		if activation {
			// Warning
			return rpc.EWrnFirmwareBattery2Empty
		}
		// Error
		return rpc.EFirmwareBattery2Empty
	case rpc.BatteryStateRemoved:
		if activation {
			// Warning
			return rpc.EWrnFirmwareBattery2Removed
		}
		return rpc.EFirmwareBattery2Removed
	default:
		// Unknown
		return rpc.EOpdenied
	}
}

// batteryChecks checks if the battery levels are correct
func (z *Zkl3000Rc) batteryChecks(logger dilog.Logger, up *statusupdate.StatusUpdate, activation bool) rpc.ErrorCode {
	batteryError := z.batteryStateError(up.Battery2State(), activation)
	if batteryError.IsError() {
		logger.WithFields(dilog.Fields{
			"state":   up.Battery2State(),
			"battery": 2,
		}).Error("device battery")
	}
	// the warning is the new default return error
	if batteryError.IsWarning() {
		logger.WithFields(dilog.Fields{
			"state":   up.Battery2State(),
			"battery": 2,
		}).Warning("device battery")
	}
	return batteryError
}

func (z *Zkl3000Rc) preflightChecks(logger dilog.Logger,
	checkKeyswitch bool, checkDeviceErrors bool) (*statusupdate.StatusUpdate, *SwitchInfo, rpc.ErrorCode) {
	// Always ask for the newest STAT value
	up, retVal := z.requestNewSensorData()
	if retVal != rpc.Ok {
		logger.Error("cannot request new sensor data")
		return nil, nil, retVal
	}

	// Always ask for the newest switch information
	switchInfo, retVal, err := z.requestSwitchInfo()
	if err != nil {
		logger.WithError(err).Error("cannot read switch information")
		return nil, nil, retVal
	}

	// Start the preflight checks

	if up.ErrMCU() {
		// Should never occur. Just log
		logger.Warning("internal device error")
	}

	if up.ErrSecureHandshake() {
		logger.Warning("secure handshake failed")
	}

	if checkDeviceErrors && z.dev.HasError() {
		logger.Error("device contains errors")
		return nil, nil, rpc.EFirmwareDeviceContainsErrors
	}

	if z.dev.GetState() == rpc.DeviceStateService {
		logger.Error("device is in service")
		return nil, nil, rpc.EFirmwareDeviceService
	}

	if checkKeyswitch && up.KeySwitch() != rpc.KeyswitchStateOperational {
		logger.WithField("keyswitch", up.KeySwitch()).Error("keyswitch is not operational")
		return nil, nil, rpc.EFirmwareKeyswitchNotOperational
	}
	return up, switchInfo, rpc.Ok
}

// StatusUpdatePredicate is called in the function waitForValidSensorData to check if the status update is valid
type StatusUpdatePredicate func(up *statusupdate.StatusUpdate) bool

// waitForValidSensorData requests the latest STAT data and waits until the given predicate is valid or when there is a
// timeout. When there is a timeout, rpc.EFirmwareNoMeasurement is returned
func (z *Zkl3000Rc) waitForValidStatusUpdate(f StatusUpdatePredicate) (*statusupdate.StatusUpdate, rpc.ErrorCode) {
	var lastSensorData *statusupdate.StatusUpdate

	timer := time.NewTimer(zkl3000RcMaximumWaitForMeasurement)
	defer timer.Stop()

	for {
		select {
		case <-timer.C:
			z.dev.Logger().Error("didn't received a measurement in time")
			return lastSensorData, rpc.Ok
		default:
			sensorData, rpcErr := z.requestNewSensorData()
			if rpcErr != rpc.Ok {
				return nil, rpcErr
			}
			if f(sensorData) {
				return sensorData, rpc.Ok
			}
			lastSensorData = sensorData
		}
	}
}

// requestNewSensorData requests the latest sensor data
func (z *Zkl3000Rc) requestNewSensorData() (*statusupdate.StatusUpdate, rpc.ErrorCode) {
	value, dierr := z.requestValue("STAT")
	if dierr != rpc.Ok {
		return nil, dierr
	}
	// Fire the callback, because the router doesn't fire reply messages
	// We drop the errors, because this is an error when we cannot write to the SMP which is not imported for
	// requesting the sensor data
	err := z.statusUpdateCmd(nil, []string{"", value})
	_ = err
	// Grab the current status update of the zkl3000RC
	return z.decoder.StatusUpdate(), rpc.Ok
}

// writeSwitchToken writes the token in the switch. It also checks if the write is successful
func (z *Zkl3000Rc) writeSwitchToken(currErr rpc.ErrorCode, token uint32) rpc.ErrorCode {
	if currErr.IsError() {
		// There was already an error. Don't proceed
		return currErr
	}
	switchInfo, rpcErr := z.writeSwitch(token, WriteTokenSwichCommand)
	if rpcErr != rpc.Ok {
		z.dev.Logger().Error("communication to switch failed")
		return rpcErr
	}
	if !switchInfo.Released {
		z.dev.Logger().Error("token is written, but device replied with no token")
		return rpc.EBackendCp3000CommError
	}
	if switchInfo.Token != token {
		z.dev.Logger().WithField("token", switchInfo.Token).
			Error("token is written, but the device replied with a wrong token")
		return rpc.EBackendCp3000CommError
	}
	lastSensorData, retVal := z.waitForValidStatusUpdate(func(up *statusupdate.StatusUpdate) bool {
		// stop when the device is reporting released
		return up.Released()
	})
	if retVal != rpc.Ok {
		return retVal
	}
	switch {
	case lastSensorData.ErrSwitch3000():
		z.dev.Logger().Error("switch error")
		return rpc.EFirmwareReleaseSwitchComm
	case !lastSensorData.Released():
		z.dev.Logger().Warning("STAT data says device is not released. DEADLOCK")
	}
	return currErr
}

// writeSwitchRemoveToken removes the token from the switch. It also checks if the removal is successful
func (z *Zkl3000Rc) writeSwitchRemoveToken(currErr rpc.ErrorCode, token uint32) rpc.ErrorCode {
	if currErr.IsError() {
		// There was already an error. Don't proceed
		return currErr
	}
	switchInfo, rpcErr := z.writeSwitch(token, RemoveTokenSwitchCommand)
	if rpcErr != rpc.Ok {
		z.dev.Logger().Error("communication to switch failed")
		return rpcErr
	}
	if switchInfo.Released {
		z.dev.Logger().Error("token in switch info is not removed")
		return rpc.EBackendCp3000CommError
	}
	lastSensorData, retVal := z.waitForValidStatusUpdate(func(up *statusupdate.StatusUpdate) bool {
		// stop when the device is reporting not released
		return !up.Released()
	})
	if retVal != rpc.Ok {
		return retVal
	}
	if lastSensorData.Released() {
		z.dev.Logger().Warning("STAT data is still released. DEADLOCK")
	}
	return currErr
}

// activateDeactivateSwitch activates of deactivates the short circuit. It also checks if the change is successful.
func (z *Zkl3000Rc) activateDeactivateSwitch(logger dilog.Logger, enable bool) rpc.ErrorCode {
	up, switchInfo, retVal := z.preflightChecks(logger, true, enable)
	if retVal != rpc.Ok {
		return retVal
	}

	// When there is no token, deny the transaction
	if !switchInfo.Released {
		logger.Error("switch info has no token")
		return rpc.EFirmwareDeviceIdle
	}

	// Only do battery checks during activate
	if enable {
		retVal = z.batteryChecks(logger, up, true)
		if retVal.IsError() {
			return retVal
		}
	}

	if !up.Released() {
		// If this occur we have a serious problem. We are in a deadlock, so just ignore it...
		logger.Warning("STAT data is not released. DEADLOCK")
	}

	if up.SwitchShort() && enable {
		logger.WithField("status", up.SwitchShort).Info("switch already changed")
	}

	if enable {
		// Turn short circuit on
		retVal = z.turnMeasurementOn(retVal, switchInfo.Token)
		retVal = z.turnSwitchOn(retVal, switchInfo.Token)
	} else {
		// Turn short circuit off
		retVal = z.turnSwitchOff(retVal, switchInfo.Token)
		retVal = z.turnMeasurementOff(retVal, switchInfo.Token)
	}
	if !retVal.IsError() {
		z.active = enable
		// possible transition from armed <--> active
		z.updateDeviceState()
	}
	return retVal
}

// turnMeasurementOn turns the measurement on. It also checks if the measurement is indeed on.
func (z *Zkl3000Rc) turnMeasurementOn(currErr rpc.ErrorCode, token uint32) rpc.ErrorCode {
	if currErr.IsError() {
		// There was already an error. Don't proceed
		return currErr
	}
	if _, rpcErr := z.writeSwitch(token, MeasurementOnSwitchCommand); rpcErr != rpc.Ok {
		z.dev.Logger().Error("communication to switch failed")
		return rpcErr
	}
	lastSensorData, retVal := z.waitForValidStatusUpdate(func(up *statusupdate.StatusUpdate) bool {
		// stop when the measurement is indeed on or when the BA-value is not 0
		return up.Measurement() || up.Ba() != 0
	})
	if retVal != rpc.Ok {
		return retVal
	}
	if !lastSensorData.SwitchShort() && lastSensorData.DetectionStatus() {
		z.dev.Logger().Warning("short already presented while activating")
		return rpc.EWrnFirmwareActivateShortPresent
	}
	return currErr
}

// turnSwitchOn turns the short circuit on. It also checks if the short circuit is indeed on.
func (z *Zkl3000Rc) turnSwitchOn(currErr rpc.ErrorCode, token uint32) rpc.ErrorCode {
	if currErr.IsError() {
		// There was already an error. Don't proceed
		return currErr
	}
	if _, rpcErr := z.writeSwitch(token, ShortCircuitOnSwitchCommand); rpcErr != rpc.Ok {
		z.dev.Logger().Error("communication to switch failed")
		return rpcErr
	}
	lastSensorData, retVal := z.waitForValidStatusUpdate(func(up *statusupdate.StatusUpdate) bool {
		// stop when the short is on and we have a valid detection
		return up.SwitchShort() && up.DetectionStatus()
	})
	if retVal != rpc.Ok {
		return retVal
	}
	switch {
	case lastSensorData.ErrSwitch3000():
		z.dev.Logger().Error("switch error")
		return rpc.EFirmwareActivateSwitchComm
	case !lastSensorData.SwitchShort():
		z.dev.Logger().Error("switch short circuit is not on")
		return rpc.EFirmwareActivateShortNotEnabled
	case !lastSensorData.DetectionStatus():
		z.dev.Logger().Warning("detection is not ok")
		return rpc.EWrnFirmwareActivateDetectionNok
	}
	return currErr
}

// turnSwitchOn turns the short circuit off. It also checks if the short circuit is indeed off.
func (z *Zkl3000Rc) turnSwitchOff(currErr rpc.ErrorCode, token uint32) rpc.ErrorCode {
	if currErr.IsError() {
		// There was already an error. Don't proceed
		return currErr
	}
	if _, rpcErr := z.writeSwitch(token, ShortCircuitOffSwitchCommand); rpcErr != rpc.Ok {
		z.dev.Logger().Error("communication to switch failed")
		return rpcErr
	}
	lastSensorData, retVal := z.waitForValidStatusUpdate(func(up *statusupdate.StatusUpdate) bool {
		// stop when the short is off and we have an invalid detection
		return !up.SwitchShort() && !up.DetectionStatus()
	})
	if retVal != rpc.Ok {
		return retVal
	}
	switch {
	case lastSensorData.ErrSwitch3000():
		z.dev.Logger().Error("switch error")
		return rpc.EFirmwareDeactivateSwitchComm
	case lastSensorData.SwitchShort():
		z.dev.Logger().Error("switch short circuit is on")
		return rpc.EFirmwareDeactivateShortEnabled
	case lastSensorData.DetectionStatus():
		z.dev.Logger().Warning("short still presented while deactivating")
		return rpc.EWrnFirmwareDeactivateShortPresent
	}
	return currErr
}

// turnMeasurementOff turns the measurement off. It also checks if the measurement is indeed off.
func (z *Zkl3000Rc) turnMeasurementOff(currErr rpc.ErrorCode, token uint32) rpc.ErrorCode {
	if currErr.IsError() {
		// There was already an error. Don't proceed
		return currErr
	}
	if _, rpcErr := z.writeSwitch(token, MeasurementOffSwitchCommand); rpcErr != rpc.Ok {
		z.dev.Logger().Error("communication to switch failed")
		return rpcErr
	}
	return currErr
}

// writeSwitch writes the command to the switch. The returned switch information is just for verification and can be
// ignored
func (z *Zkl3000Rc) writeSwitch(token uint32, code SwitchCommand) (*SwitchInfo, rpc.ErrorCode) {
	logger := z.dev.Logger().WithField("cmd", fmt.Sprintf("%X,%d", code, token))
	logger.Debug("sending switch command to device")
	// Write to the switch
	if err := z.client.Send(cp3000.CommandStore, "SWITCH", fmt.Sprintf("%X,%d", code, token)); err != nil {
		logger.Error("cannot write to switch")
		return nil, rpc.EBackendCp3000CommError
	}
	// Check if we receive something to check the connection
	switchInfo, rpcerr, err := z.requestSwitchInfo()
	if err != nil {
		logger.WithError(err).Error("cannot receive switch info")
		return nil, rpcerr
	}
	return switchInfo, rpc.Ok
}

// requestSwitchInfo requests the latest switch information. This contains the device token and the status
func (z *Zkl3000Rc) requestSwitchInfo() (*SwitchInfo, rpc.ErrorCode, error) {
	if err := z.client.Send(cp3000.CommandStore, "SWITCH", fmt.Sprintf("%X", SwitchStatusCommand)); err != nil {
		z.dev.Logger().WithError(err).Error("cannot write SwitchStatusCommand to device during requestSwitchInfo")
		return nil, rpc.EBackendCp3000CommError, err
	}

	var switchInfo *SwitchInfo
	switchRequestRetries := 1
	switchRetryAttempt := 0

	for {
		msg, rpcerr := z.cp3000ReqRep(DefaultCommandTimeout, cp3000.CommandRetrieve, "SWITCH")
		if rpcerr != rpc.Ok {
			return nil, rpcerr, errors.New("cannot request reply")
		}
		si, err := NewSwitchInfo(msg.Params)
		if err != nil {
			return nil, rpc.EIofailed, err
		}

		if si.Valid() {
			switchInfo = si
			break
		}

		// Always suppress the first retry because the ZKL 3000 RC SWCMD_STATUS takes a second try
		//  as the valid status is async refreshed, next call it is normally valid
		if switchRetryAttempt > 0 {
			z.dev.Logger().WithField("cp3000-reply", msg.String()).Warning(
				"switch status retrying request, due to previous incorrect status")
		}

		// Switch malfunction is only retried once
		if switchRequestRetries == 0 {
			return nil, rpc.EBackendCp3000CommError, errZKL3000RcSwitchStatsRetriesExceeded
		}

		if si.Malfunction() {
			z.dev.Logger().Warning("switch status is malfunction")
			switchRequestRetries--
		}

		// Wait in an exponential backoff fashion
		time.Sleep(DefaultBackoffPolicy.Duration(switchRetryAttempt))
		switchRetryAttempt++
	}

	// Device is released/returned
	if switchInfo.Changed(z.switchInfo) {
		z.switchInfo = switchInfo
		if switchInfo.Released {
			z.dev.Logger().WithField("token", switchInfo.Token).Info("new token value")
		} else {
			z.dev.Logger().WithField("token", nil).Info("new token value")
		}
		// possible transition from idle <--> armed
		if z.updateDeviceState() {
			z.dev.Logger().Info("send device:data")
			if err := z.dev.SendDeviceData(); err != nil {
				return switchInfo, rpc.EBackendCp3000CommError, err
			}
		}
	}
	return switchInfo, rpc.Ok, nil
}

// continueHeartbeats continues to send heartbeats every 1s for 7s
func (z *Zkl3000Rc) continueHeartbeats() {
	ticker := time.NewTicker(time.Second)
	after := time.After(7 * time.Second)

	for {
		select {
		case <-ticker.C:
			if err := z.dev.SendDeviceData(); err != nil {
				z.dev.Logger().WithError(err).Error("failed sending device:data")
			}
		case <-after:
			// escape from the for-loop
			return
		}
	}
}