refactor: pass output options as single struct

output/driver-alsa.go

@@ -54,18 +54,18 @@ type alsaOutput struct {
 	err          chan error
 }
 
-func newAlsaOutput(reader librespot.Float32Reader, sampleRate int, channels int, device string, mixer string, control string, initialVolume float32, externalVolume bool, volumeUpdate chan float32) (*alsaOutput, error) {
+func newAlsaOutput(opts *NewOutputOptions) (*alsaOutput, error) {
 	out := &alsaOutput{
-		reader:         reader,
-		channels:       channels,
-		sampleRate:     sampleRate,
-		device:         device,
-		mixer:          mixer,
-		control:        control,
-		volume:         initialVolume,
+		reader:         opts.Reader,
+		channels:       opts.ChannelCount,
+		sampleRate:     opts.SampleRate,
+		device:         opts.Device,
+		mixer:          opts.Mixer,
+		control:        opts.Control,
+		volume:         opts.InitialVolume,
 		err:            make(chan error, 2),
-		externalVolume: externalVolume,
-		volumeUpdate:   volumeUpdate,
+		externalVolume: opts.ExternalVolume,
+		volumeUpdate:   opts.VolumeUpdate,
 	}
 
 	if err := out.setupMixer(); err != nil {

output/driver-pulseaudio.go

@@ -22,7 +22,7 @@ type pulseAudioOutput struct {
 	err                  chan error
 }
 
-func newPulseAudioOutput(reader librespot.Float32Reader, sampleRate int, channels int, externalVolumeUpdate chan float32) (*pulseAudioOutput, error) {
+func newPulseAudioOutput(opts *NewOutputOptions) (*pulseAudioOutput, error) {
 	// Initialize the PulseAudio client.
 	// The device name is shown by PulseAudio volume controls (usually built
 	// into a desktop environment), so we might want to use device_name here.
@@ -32,21 +32,21 @@ func newPulseAudioOutput(reader librespot.Float32Reader, sampleRate int, channel
 		return nil, err
 	}
 	out := &pulseAudioOutput{
-		sampleRate:           sampleRate,
-		reader:               reader,
+		sampleRate:           opts.SampleRate,
+		reader:               opts.Reader,
 		client:               client,
-		externalVolumeUpdate: externalVolumeUpdate,
+		externalVolumeUpdate: opts.VolumeUpdate,
 		err:                  make(chan error, 2),
 	}
 
 	// Create a new playback.
 	var channelOpt pulse.PlaybackOption
-	if channels == 1 {
+	if opts.ChannelCount == 1 {
 		channelOpt = pulse.PlaybackMono
-	} else if channels == 2 {
+	} else if opts.ChannelCount == 2 {
 		channelOpt = pulse.PlaybackStereo
 	} else {
-		return nil, fmt.Errorf("cannot play %d channels, pulse only supports mono and stereo", channels)
+		return nil, fmt.Errorf("cannot play %d channels, pulse only supports mono and stereo", opts.ChannelCount)
 	}
 	volumeUpdates := make(chan proto.ChannelVolumes, 1)
 	out.stream, err = out.client.NewPlayback(pulse.Float32Reader(out.float32Reader), pulse.PlaybackSampleRate(out.sampleRate), channelOpt, pulse.PlaybackVolumeChanges(volumeUpdates))
@@ -60,7 +60,7 @@ func newPulseAudioOutput(reader librespot.Float32Reader, sampleRate int, channel
 	// PulseAudio provided volume.
 	cvol, _ := out.stream.Volume()
 	out.volume = cvol.Avg()
-	sendVolumeUpdate(externalVolumeUpdate, float32(out.volume.Norm()))
+	sendVolumeUpdate(opts.VolumeUpdate, float32(out.volume.Norm()))
 
 	// Listen for volume changes (through the volume mixer application, usually
 	// built into the desktop environment), and send them back to Spotify.
@@ -70,7 +70,7 @@ func newPulseAudioOutput(reader librespot.Float32Reader, sampleRate int, channel
 
 			out.volumeLock.Lock()
 			if volume != out.volume {
-				sendVolumeUpdate(externalVolumeUpdate, float32(volume.Norm()))
+				sendVolumeUpdate(opts.VolumeUpdate, float32(volume.Norm()))
 				out.volume = volume
 			}
 			out.volumeLock.Unlock()

output/output.go

@@ -89,13 +89,13 @@ type NewOutputOptions struct {
 func NewOutput(options *NewOutputOptions) (Output, error) {
 	switch options.Backend {
 	case "alsa":
-		out, err := newAlsaOutput(options.Reader, options.SampleRate, options.ChannelCount, options.Device, options.Mixer, options.Control, options.InitialVolume, options.ExternalVolume, options.VolumeUpdate)
+		out, err := newAlsaOutput(options)
 		if err != nil {
 			return nil, err
 		}
 		return out, nil
 	case "pulseaudio":
-		out, err := newPulseAudioOutput(options.Reader, options.SampleRate, options.ChannelCount, options.VolumeUpdate)
+		out, err := newPulseAudioOutput(options)
 		if err != nil {
 			return nil, err
 		}