package probe

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

// TestAvailable never skips: the answer is a plain bool and must not panic on a
// host without ffprobe.
func TestAvailable(t *testing.T) {
	_ = Available()
}

// TestFile probes a fixture generated on the fly. It skips cleanly when ffprobe
// or ffmpeg is missing, so the suite passes on a machine with neither.
func TestFile(t *testing.T) {
	if !Available() {
		t.Skip("ffprobe not on PATH; skipping probe test")
	}
	ffmpeg, err := exec.LookPath("ffmpeg")
	if err != nil {
		t.Skip("ffmpeg not on PATH; cannot generate a fixture")
	}

	path := filepath.Join(t.TempDir(), "clip.mp4")
	// One second of H.264 video and AAC audio in an MP4.
	gen := exec.Command(ffmpeg, "-v", "error", "-y",
		"-f", "lavfi", "-i", "testsrc=size=64x48:rate=10:duration=1",
		"-f", "lavfi", "-i", "sine=frequency=440:duration=1",
		"-c:v", "libx264", "-c:a", "aac", "-shortest", path,
	)
	if out, err := gen.CombinedOutput(); err != nil {
		t.Skipf("ffmpeg cannot produce a fixture here: %v\n%s", err, out)
	}

	info, err := File(context.Background(), path)
	if err != nil {
		t.Fatalf("File: %v", err)
	}
	if info.VCodec != "h264" {
		t.Errorf("VCodec = %q, want h264", info.VCodec)
	}
	if info.ACodec != "aac" {
		t.Errorf("ACodec = %q, want aac", info.ACodec)
	}
	if info.Width != 64 || info.Height != 48 {
		t.Errorf("dimensions = %dx%d, want 64x48", info.Width, info.Height)
	}
	if info.DurationMS < 500 || info.DurationMS > 2000 {
		t.Errorf("DurationMS = %d, want ~1000", info.DurationMS)
	}
}

// TestFileAudioOnly confirms an audio file reports no video codec, so a client
// does not mistake an mp3 for a video with a missing track.
func TestFileAudioOnly(t *testing.T) {
	if !Available() {
		t.Skip("ffprobe not on PATH; skipping probe test")
	}
	ffmpeg, err := exec.LookPath("ffmpeg")
	if err != nil {
		t.Skip("ffmpeg not on PATH; cannot generate a fixture")
	}

	path := filepath.Join(t.TempDir(), "tone.m4a")
	gen := exec.Command(ffmpeg, "-v", "error", "-y",
		"-f", "lavfi", "-i", "sine=frequency=440:duration=1",
		"-c:a", "aac", path,
	)
	if out, err := gen.CombinedOutput(); err != nil {
		t.Skipf("ffmpeg cannot produce a fixture here: %v\n%s", err, out)
	}

	info, err := File(context.Background(), path)
	if err != nil {
		t.Fatalf("File: %v", err)
	}
	if info.VCodec != "" {
		t.Errorf("VCodec = %q, want empty for audio-only", info.VCodec)
	}
	if info.ACodec != "aac" {
		t.Errorf("ACodec = %q, want aac", info.ACodec)
	}
}

// TestFileMissing confirms a missing file is an error, not a silent zero Info.
func TestFileMissing(t *testing.T) {
	if !Available() {
		t.Skip("ffprobe not on PATH; skipping probe test")
	}
	if _, err := File(context.Background(), filepath.Join(t.TempDir(), "nope.mp4")); err == nil {
		t.Fatal("File on a missing path: want error, got nil")
	}
}