Add contexts and improve error handling

infinitime.go

@@ -2,6 +2,7 @@ package infinitime
 
 import (
 	"bytes"
+	"context"
 	"encoding/binary"
 	"errors"
 	"reflect"
@@ -39,6 +40,20 @@ const (
 	WeatherDataChar = "00040001-78fc-48fe-8e23-433b3a1942d0"
 )
 
+var charNames = map[string]string{
+	NewAlertChar:    "New Alert",
+	NotifEventChar:  "Notification Event",
+	StepCountChar:   "Step Count",
+	MotionValChar:   "Motion Values",
+	FirmwareVerChar: "Firmware Version",
+	CurrentTimeChar: "Current Time",
+	BatteryLvlChar:  "Battery Level",
+	HeartRateChar:   "Heart Rate",
+	FSTransferChar:  "Filesystem Transfer",
+	FSVersionChar:   "Filesystem Version",
+	WeatherDataChar: "Weather Data",
+}
+
 type Device struct {
 	device          *device.Device1
 	newAlertChar    *gatt.GattCharacteristic1
@@ -62,11 +77,18 @@ var (
 	ErrNoDevices        = errors.New("no InfiniTime devices found")
 	ErrNotFound         = errors.New("could not find any advertising InfiniTime devices")
 	ErrNotConnected     = errors.New("not connected")
-	ErrCharNotAvail     = errors.New("required characteristic is not available")
 	ErrNoTimelineHeader = errors.New("events must contain the timeline header")
 	ErrPairTimeout      = errors.New("reached timeout while pairing")
 )
 
+type ErrCharNotAvail struct {
+	uuid string
+}
+
+func (e ErrCharNotAvail) Error() string {
+	return "characteristic " + e.uuid + " (" + charNames[e.uuid] + ") not available"
+}
+
 type Options struct {
 	AttemptReconnect bool
 	WhitelistEnabled bool
@@ -90,7 +112,7 @@ var DefaultOptions = &Options{
 //
 // It will also attempt to reconnect to the device
 // if it disconnects and that is enabled in the options.
-func Connect(opts *Options) (*Device, error) {
+func Connect(ctx context.Context, opts *Options) (*Device, error) {
 	if opts == nil {
 		opts = DefaultOptions
 	}
@@ -101,7 +123,7 @@ func Connect(opts *Options) (*Device, error) {
 	setOnPasskeyReq(opts.OnReqPasskey)
 
 	// Connect to bluetooth device
-	btDev, err := connect(opts, true)
+	btDev, err := connect(ctx, opts, true)
 	if err != nil {
 		return nil, err
 	}
@@ -119,7 +141,7 @@ func Connect(opts *Options) (*Device, error) {
 }
 
 // connect connects to the InfiniTime bluez device
-func connect(opts *Options, first bool) (dev *device.Device1, err error) {
+func connect(ctx context.Context, opts *Options, first bool) (dev *device.Device1, err error) {
 	// Get devices
 	devs, err := defaultAdapter.GetDevices()
 	if err != nil {
@@ -161,8 +183,10 @@ func connect(opts *Options, first bool) (dev *device.Device1, err error) {
 			return nil, err
 		}
 
-		// For every discovery event
+	discoverLoop:
-		for event := range discoverCh {
+		for {
+			select {
+			case event := <-discoverCh:
 				// If event type is not device added, skip
 				if event.Type != adapter.DeviceAdded {
 					continue
@@ -194,9 +218,14 @@ func connect(opts *Options, first bool) (dev *device.Device1, err error) {
 				log.Debug().
 					Str("mac", dev.Properties.Address).
 					Msg("InfiniTime device discovered")
-			break
+				break discoverLoop
+			case <-ctx.Done():
+				break discoverLoop
+
 			}
-		// Stop discovery
+		}
+
+		// Cancel discovery
 		cancel()
 	}
 
@@ -233,7 +262,7 @@ func connect(opts *Options, first bool) (dev *device.Device1, err error) {
 	// If this is the first connection and reconnect
 	// is enabled, start reconnect goroutine
 	if first && opts.AttemptReconnect {
-		go reconnect(opts, dev)
+		go reconnect(ctx, opts, dev)
 	}
 
 	// If this is not the first connection, a reonnect
@@ -248,7 +277,7 @@ func connect(opts *Options, first bool) (dev *device.Device1, err error) {
 }
 
 // reconnect reconnects to a device if it disconnects
-func reconnect(opts *Options, dev *device.Device1) {
+func reconnect(ctx context.Context, opts *Options, dev *device.Device1) {
 	// Watch device properties
 	propCh := watchProps(dev)
 
@@ -288,7 +317,7 @@ func reconnect(opts *Options, dev *device.Device1) {
 				opts.Logger.Warn().Msg("Multiple connection attempts have failed. If this continues, try removing the InfiniTime device from bluetooth.")
 			}
 			// Connect to device
-			newDev, err := connect(opts, false)
+			newDev, err := connect(ctx, opts, false)
 			if err != nil {
 				time.Sleep(time.Second)
 				continue
@@ -407,6 +436,7 @@ func (i *Device) resolveChars() error {
 		if charResolved {
 			log.Debug().
 				Str("uuid", char.Properties.UUID).
+				Str("name", charNames[char.Properties.UUID]).
 				Msg("Resolved characteristic")
 		}
 	}
@@ -420,7 +450,7 @@ func (i *Device) Address() string {
 
 // Version returns InfiniTime's reported firmware version string
 func (i *Device) Version() (string, error) {
-	if err := i.checkStatus(i.fwVersionChar); err != nil {
+	if err := i.checkStatus(i.fwVersionChar, FirmwareVerChar); err != nil {
 		return "", err
 	}
 	ver, err := i.fwVersionChar.ReadValue(nil)
@@ -429,7 +459,7 @@ func (i *Device) Version() (string, error) {
 
 // BatteryLevel gets the watch's battery level via the Battery Service
 func (i *Device) BatteryLevel() (uint8, error) {
-	if err := i.checkStatus(i.battLevelChar); err != nil {
+	if err := i.checkStatus(i.battLevelChar, BatteryLvlChar); err != nil {
 		return 0, err
 	}
 	battLevel, err := i.battLevelChar.ReadValue(nil)
@@ -440,7 +470,7 @@ func (i *Device) BatteryLevel() (uint8, error) {
 }
 
 func (i *Device) StepCount() (uint32, error) {
-	if err := i.checkStatus(i.stepCountChar); err != nil {
+	if err := i.checkStatus(i.stepCountChar, StepCountChar); err != nil {
 		return 0, err
 	}
 	stepCountData, err := i.stepCountChar.ReadValue(nil)
@@ -458,7 +488,7 @@ type MotionValues struct {
 
 func (i *Device) Motion() (MotionValues, error) {
 	out := MotionValues{}
-	if err := i.checkStatus(i.motionValChar); err != nil {
+	if err := i.checkStatus(i.motionValChar, MotionValChar); err != nil {
 		return out, err
 	}
 	motionVals, err := i.motionValChar.ReadValue(nil)
@@ -474,7 +504,7 @@ func (i *Device) Motion() (MotionValues, error) {
 }
 
 func (i *Device) HeartRate() (uint8, error) {
-	if err := i.checkStatus(i.heartRateChar); err != nil {
+	if err := i.checkStatus(i.heartRateChar, HeartRateChar); err != nil {
 		return 0, err
 	}
 	heartRate, err := i.heartRateChar.ReadValue(nil)
@@ -484,35 +514,33 @@ func (i *Device) HeartRate() (uint8, error) {
 	return uint8(heartRate[1]), nil
 }
 
-func (i *Device) WatchHeartRate() (<-chan uint8, func(), error) {
+func (i *Device) WatchHeartRate(ctx context.Context) (<-chan uint8, error) {
-	if err := i.checkStatus(i.heartRateChar); err != nil {
+	if err := i.checkStatus(i.heartRateChar, HeartRateChar); err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Start notifications on heart rate characteristic
 	err := i.heartRateChar.StartNotify()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Watch characteristics of heart rate characteristic
 	ch, err := i.heartRateChar.WatchProperties()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out := make(chan uint8, 2)
 	currentHeartRate, err := i.HeartRate()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out <- currentHeartRate
-	cancel, done := cancelFunc()
 	go func() {
 		// For every event
 		for {
 			select {
-			case <-done:
+			case <-ctx.Done():
 				log.Debug().Str("func", "WatchMotion").Msg("Received done signal")
 				close(out)
-				close(done)
 				i.heartRateChar.StopNotify()
 				return
 			case event := <-ch:
@@ -527,38 +555,36 @@ func (i *Device) WatchHeartRate() (<-chan uint8, func(), error) {
 			}
 		}
 	}()
-	return out, cancel, nil
+	return out, nil
 }
 
-func (i *Device) WatchBatteryLevel() (<-chan uint8, func(), error) {
+func (i *Device) WatchBatteryLevel(ctx context.Context) (<-chan uint8, error) {
-	if err := i.checkStatus(i.battLevelChar); err != nil {
+	if err := i.checkStatus(i.battLevelChar, BatteryLvlChar); err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Start notifications on heart rate characteristic
 	err := i.battLevelChar.StartNotify()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Watch characteristics of heart rate characteristic
 	ch, err := i.battLevelChar.WatchProperties()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out := make(chan uint8, 2)
 	currentBattLevel, err := i.BatteryLevel()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out <- currentBattLevel
-	cancel, done := cancelFunc()
 	go func() {
 		// For every event
 		for {
 			select {
-			case <-done:
+			case <-ctx.Done():
 				log.Debug().Str("func", "WatchMotion").Msg("Received done signal")
 				close(out)
-				close(done)
 				i.battLevelChar.StopNotify()
 				return
 			case event := <-ch:
@@ -573,38 +599,36 @@ func (i *Device) WatchBatteryLevel() (<-chan uint8, func(), error) {
 			}
 		}
 	}()
-	return out, cancel, nil
+	return out, nil
 }
 
-func (i *Device) WatchStepCount() (<-chan uint32, func(), error) {
+func (i *Device) WatchStepCount(ctx context.Context) (<-chan uint32, error) {
-	if err := i.checkStatus(i.stepCountChar); err != nil {
+	if err := i.checkStatus(i.stepCountChar, StepCountChar); err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Start notifications on step count characteristic
 	err := i.stepCountChar.StartNotify()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Watch properties of step count characteristic
 	ch, err := i.stepCountChar.WatchProperties()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out := make(chan uint32, 2)
 	currentStepCount, err := i.StepCount()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out <- currentStepCount
-	cancel, done := cancelFunc()
 	go func() {
 		// For every event
 		for {
 			select {
-			case <-done:
+			case <-ctx.Done():
 				log.Debug().Str("func", "WatchMotion").Msg("Received done signal")
 				close(out)
-				close(done)
 				i.stepCountChar.StopNotify()
 				return
 			case event := <-ch:
@@ -619,38 +643,36 @@ func (i *Device) WatchStepCount() (<-chan uint32, func(), error) {
 			}
 		}
 	}()
-	return out, cancel, nil
+	return out, nil
 }
 
-func (i *Device) WatchMotion() (<-chan MotionValues, func(), error) {
+func (i *Device) WatchMotion(ctx context.Context) (<-chan MotionValues, error) {
-	if err := i.checkStatus(i.motionValChar); err != nil {
+	if err := i.checkStatus(i.motionValChar, MotionValChar); err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Start notifications on motion characteristic
 	err := i.motionValChar.StartNotify()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	// Watch properties of motion characteristic
 	ch, err := i.motionValChar.WatchProperties()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out := make(chan MotionValues, 2)
 	motionVals, err := i.Motion()
 	if err != nil {
-		return nil, nil, err
+		return nil, err
 	}
 	out <- motionVals
-	cancel, done := cancelFunc()
 	go func() {
 		// For every event
 		for {
 			select {
-			case <-done:
+			case <-ctx.Done():
 				log.Debug().Str("func", "WatchMotion").Msg("Received done signal")
 				close(out)
-				close(done)
 				i.motionValChar.StopNotify()
 				return
 			case event := <-ch:
@@ -668,19 +690,12 @@ func (i *Device) WatchMotion() (<-chan MotionValues, func(), error) {
 
 		}
 	}()
-	return out, cancel, nil
+	return out, nil
-}
-
-func cancelFunc() (func(), chan struct{}) {
-	done := make(chan struct{}, 1)
-	return func() {
-		done <- struct{}{}
-	}, done
 }
 
 // SetTime sets the watch's time using the Current Time Service
 func (i *Device) SetTime(t time.Time) error {
-	if err := i.checkStatus(i.currentTimeChar); err != nil {
+	if err := i.checkStatus(i.currentTimeChar, CurrentTimeChar); err != nil {
 		return err
 	}
 	buf := &bytes.Buffer{}
@@ -699,7 +714,7 @@ func (i *Device) SetTime(t time.Time) error {
 // Notify sends a notification to InfiniTime via
 // the Alert Notification Service (ANS)
 func (i *Device) Notify(title, body string) error {
-	if err := i.checkStatus(i.newAlertChar); err != nil {
+	if err := i.checkStatus(i.newAlertChar, NewAlertChar); err != nil {
 		return err
 	}
 	return i.newAlertChar.WriteValue(
@@ -718,7 +733,7 @@ const (
 // NotifyCall sends a call notification to the PineTime and returns a channel.
 // This channel will contain the user's response to the call notification.
 func (i *Device) NotifyCall(from string) (<-chan uint8, error) {
-	if err := i.checkStatus(i.newAlertChar); err != nil {
+	if err := i.checkStatus(i.newAlertChar, NewAlertChar); err != nil {
 		return nil, err
 	}
 	// Write call notification to new alert characteristic
@@ -770,7 +785,7 @@ func (i *Device) initNotifEvent() error {
 
 // FS creates and returns a new filesystem from the device
 func (i *Device) FS() (*blefs.FS, error) {
-	if err := i.checkStatus(i.fsTransferChar); err != nil {
+	if err := i.checkStatus(i.fsTransferChar, FSTransferChar); err != nil {
 		return nil, err
 	}
 	return blefs.New(i.fsTransferChar)
@@ -780,7 +795,7 @@ func (i *Device) FS() (*blefs.FS, error) {
 // the weather package to the timeline. Input must be
 // a struct containing TimelineHeader.
 func (i *Device) AddWeatherEvent(event interface{}) error {
-	if err := i.checkStatus(i.weatherDataChar); err != nil {
+	if err := i.checkStatus(i.weatherDataChar, WeatherDataChar); err != nil {
 		return err
 	}
 	// Get type of input
@@ -803,7 +818,7 @@ func (i *Device) AddWeatherEvent(event interface{}) error {
 	return i.weatherDataChar.WriteValue(data, nil)
 }
 
-func (i *Device) checkStatus(char *gatt.GattCharacteristic1) error {
+func (i *Device) checkStatus(char *gatt.GattCharacteristic1, uuid string) error {
 	log.Debug().Msg("Checking characteristic status")
 	connected, err := i.device.GetConnected()
 	if err != nil {
@@ -814,8 +829,11 @@ func (i *Device) checkStatus(char *gatt.GattCharacteristic1) error {
 	}
 	if char == nil {
 		log.Debug().Msg("Characteristic not available (nil)")
-		return ErrCharNotAvail
+		return ErrCharNotAvail{uuid}
 	}
-	log.Debug().Str("uuid", char.Properties.UUID).Msg("Characteristic available")
+	log.Debug().
+		Str("uuid", char.Properties.UUID).
+		Str("name", charNames[char.Properties.UUID]).
+		Msg("Characteristic available")
 	return nil
 }