package app

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

func TestFFmpegArgs(t *testing.T) {
	args := ffmpegArgs("/in/a.flac", "/out/a.mp3", "128k", "Neon Rain", "AI Radio")
	joined := ""
	for _, a := range args {
		joined += a + " "
	}
	for _, want := range []string{
		"-i /in/a.flac",
		"libmp3lame",
		"-b:a 128k",
		"-ar 44100",
		"-ac 2",
		"-id3v2_version 3",
		"-write_id3v1 1",
		"-metadata title=Neon Rain",
		"-metadata album=AI Radio",
		"/out/a.mp3",
	} {
		if !contains(joined, want) {
			t.Fatalf("args missing %q:\n%s", want, joined)
		}
	}
}

func contains(hay, needle string) bool {
	return len(hay) >= len(needle) && (func() bool {
		for i := 0; i+len(needle) <= len(hay); i++ {
			if hay[i:i+len(needle)] == needle {
				return true
			}
		}
		return false
	})()
}

// TestTranscodeReal actually runs ffmpeg if present; skips otherwise.
func TestTranscodeReal(t *testing.T) {
	if _, err := exec.LookPath("ffmpeg"); err != nil {
		t.Skip("ffmpeg not installed")
	}
	dir := t.TempDir()
	src := filepath.Join(dir, "s.flac")
	// generate a 1s sine flac
	cmd := exec.Command("ffmpeg", "-y", "-hide_banner", "-loglevel", "error",
		"-f", "lavfi", "-i", "sine=frequency=440:duration=1", "-c:a", "flac", src)
	if err := cmd.Run(); err != nil {
		t.Fatalf("fixture gen: %v", err)
	}
	dst := filepath.Join(dir, "s.mp3")
	if err := Transcode(src, dst, "128k", "Test", "Station"); err != nil {
		t.Fatalf("Transcode: %v", err)
	}
	st, err := os.Stat(dst)
	if err != nil || st.Size() == 0 {
		t.Fatal("mp3 not produced")
	}
}