//go:build linux

package audio

import (
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
)

// pwEngine plays pre-rendered WAVs by spawning pw-play per effect
type pwEngine struct {
	dir   string
	files [EffectCount]string
}

// NewEngine synthesizes effect WAVs into a temp dir. Falls back to a silent
// engine when pw-play is unavailable — game remains playable without audio
func NewEngine() Engine {
	if _, err := exec.LookPath("pw-play"); err != nil {
		return nullEngine{}
	}
	dir, err := os.MkdirTemp("", "symph-sfx-")
	if err != nil {
		return nullEngine{}
	}
	e := &pwEngine{dir: dir}
	for fx := EffectNone + 1; fx < EffectCount; fx++ {
		path := filepath.Join(dir, fmt.Sprintf("fx-%d.wav", fx))
		if err := os.WriteFile(path, wavBytes(synth(effectSegs[fx])), 0o644); err != nil {
			os.RemoveAll(dir)
			return nullEngine{}
		}
		e.files[fx] = path
	}
	return e
}

// Play spawns pw-play detached; process reaped asynchronously
func (e *pwEngine) Play(fx Effect) {
	if fx == EffectNone || fx >= EffectCount || e.files[fx] == "" {
		return
	}
	cmd := exec.Command("pw-play", "--volume", "0.7", e.files[fx])
	if err := cmd.Start(); err == nil {
		go cmd.Wait()
	}
}

func (e *pwEngine) Close() {
	os.RemoveAll(e.dir)
}