chore: import upstream snapshot with attribution

player/audio_device_linux.go

@@ -0,0 +1,132 @@
+//go:build linux
+
+package player
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// ListAudioDevices returns available output sinks via pactl.
+// Works on PulseAudio and PipeWire (via pipewire-pulse).
+func ListAudioDevices() ([]AudioDevice, error) {
+	defaultSink := ""
+	if out, err := exec.Command("pactl", "get-default-sink").Output(); err == nil {
+		defaultSink = strings.TrimSpace(string(out))
+	}
+
+	out, err := exec.Command("pactl", "list", "sinks").Output()
+	if err != nil {
+		return nil, fmt.Errorf("pactl: %w (is PulseAudio/PipeWire running?)", err)
+	}
+
+	var devices []AudioDevice
+	var cur *AudioDevice
+
+	for _, line := range strings.Split(string(out), "\n") {
+		line = strings.TrimSpace(line)
+		if strings.HasPrefix(line, "Sink #") {
+			idx, _ := strconv.Atoi(strings.TrimPrefix(line, "Sink #"))
+			devices = append(devices, AudioDevice{Index: idx})
+			cur = &devices[len(devices)-1]
+		} else if cur != nil {
+			if key, val, ok := strings.Cut(line, ": "); ok {
+				switch key {
+				case "Name":
+					cur.Name = val
+					cur.Active = val == defaultSink
+				case "Description":
+					cur.Description = val
+				}
+			}
+		}
+	}
+
+	return devices, nil
+}
+
+// PrepareAudioDevice sets PIPEWIRE_NODE so the PipeWire ALSA plugin
+// routes this process's audio to the named device.
+// Must be called before player.New(). Returns a cleanup that restores the env.
+func PrepareAudioDevice(device string) func() {
+	prev, hadPrev := os.LookupEnv("PIPEWIRE_NODE")
+	os.Setenv("PIPEWIRE_NODE", device)
+	return func() {
+		if hadPrev {
+			os.Setenv("PIPEWIRE_NODE", prev)
+		} else {
+			os.Unsetenv("PIPEWIRE_NODE")
+		}
+	}
+}
+
+// SwitchAudioDevice moves cliamp's audio stream to a different sink.
+// Falls back to changing the system default if the stream can't be found.
+func SwitchAudioDevice(deviceName string) error {
+	out, err := exec.Command("pactl", "list", "sink-inputs").Output()
+	if err != nil {
+		return fmt.Errorf("pactl: %w", err)
+	}
+
+	pidStr := strconv.Itoa(os.Getpid())
+	sinkInputIdx := -1
+	currentIdx := 0
+	props := map[string]string{}
+
+	// Parse all sink-inputs, collecting properties per entry.
+	lines := strings.Split(string(out), "\n")
+	for _, line := range lines {
+		line = strings.TrimSpace(line)
+		if strings.HasPrefix(line, "Sink Input #") {
+			// Check previous entry before moving on.
+			if sinkInputIdx < 0 {
+				sinkInputIdx = matchCliamp(props, pidStr, currentIdx)
+			}
+			if sinkInputIdx >= 0 {
+				break
+			}
+			currentIdx, _ = strconv.Atoi(strings.TrimPrefix(line, "Sink Input #"))
+			props = map[string]string{}
+			continue
+		}
+		if key, val, ok := strings.Cut(line, "="); ok {
+			props[strings.TrimSpace(key)] = strings.Trim(strings.TrimSpace(val), `"`)
+		}
+	}
+	// Check the last entry.
+	if sinkInputIdx < 0 {
+		sinkInputIdx = matchCliamp(props, pidStr, currentIdx)
+	}
+
+	if sinkInputIdx >= 0 {
+		cmd := exec.Command("pactl", "move-sink-input",
+			strconv.Itoa(sinkInputIdx), deviceName)
+		if out, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("move-sink-input: %s (%w)", strings.TrimSpace(string(out)), err)
+		}
+		return nil
+	}
+
+	// Fallback: change the system default sink.
+	if out, err := exec.Command("pactl", "set-default-sink", deviceName).CombinedOutput(); err != nil {
+		return fmt.Errorf("set-default-sink: %s (%w)", strings.TrimSpace(string(out)), err)
+	}
+	return nil
+}
+
+// matchCliamp checks if a sink-input's properties belong to cliamp.
+func matchCliamp(props map[string]string, pidStr string, idx int) int {
+	if props["application.process.id"] == pidStr {
+		return idx
+	}
+	if strings.EqualFold(props["application.process.binary"], "cliamp") {
+		return idx
+	}
+	if strings.Contains(strings.ToLower(props["application.name"]), "cliamp") {
+		return idx
+	}
+	return -1
+}