package audio

import (
	"context"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"
)

type Recorder struct {
	Input string
}

type RecordResult struct {
	WavPath string
	TempDir string
}

func (r Recorder) Start(ctx context.Context) (*exec.Cmd, *RecordResult, error) {
	tmpdir, err := os.MkdirTemp("", "lel-")
	if err != nil {
		return nil, nil, err
	}
	wav := filepath.Join(tmpdir, "mic.wav")

	args := []string{"-hide_banner", "-loglevel", "error"}
	args = append(args, ffmpegInputArgs(r.Input)...)
	args = append(args, "-ac", "1", "-ar", "16000", "-c:a", "pcm_s16le", wav)

	cmd := exec.CommandContext(ctx, "ffmpeg", args...)
	if err := cmd.Start(); err != nil {
		_ = os.RemoveAll(tmpdir)
		return nil, nil, err
	}

	return cmd, &RecordResult{WavPath: wav, TempDir: tmpdir}, nil
}

func WaitWithTimeout(cmd *exec.Cmd, timeout time.Duration) error {
	done := make(chan error, 1)
	go func() {
		done <- cmd.Wait()
	}()

	select {
	case err := <-done:
		return err
	case <-time.After(timeout):
		if cmd.Process != nil {
			_ = cmd.Process.Kill()
		}
		return fmt.Errorf("process timeout after %s", timeout)
	}
}

func ffmpegInputArgs(spec string) []string {
	if spec == "" {
		spec = "pulse:default"
	}
	kind := spec
	name := "default"
	if idx := strings.Index(spec, ":"); idx != -1 {
		kind = spec[:idx]
		name = spec[idx+1:]
	}
	return []string{"-f", kind, "-i", name}
}