package media

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

// The real thing, when ffmpeg is here: a generated clip goes through as H.264 and comes out
// as a playlist of segments, the status follows it to the end, and closing removes it all.
func TestStreamWithFFmpeg(t *testing.T) {
	if _, err := exec.LookPath("ffmpeg"); err != nil {
		t.Skip("no ffmpeg")
	}
	c := Probe(context.Background())
	if c.Error != "" {
		t.Skip(c.Error)
	}
	if EngineFor(c, "h264") == "" {
		t.Skip("nothing here encodes h264")
	}
	dir := t.TempDir()
	clip := filepath.Join(dir, "clip.mp4")
	out, err := exec.Command("ffmpeg", "-nostdin", "-v", "error", "-f", "lavfi", "-i", "testsrc=size=640x360:rate=25:duration=9", "-f", "lavfi", "-i", "sine=frequency=440:duration=9",
		"-c:v", "mpeg4", "-q:v", "5", "-c:a", "aac", "-shortest", clip).CombinedOutput()
	if err != nil {
		t.Skipf("could not make a clip: %s", out)
	}
	src, err := Inspect(context.Background(), c, clip, false)
	if err != nil || src.Video == nil || src.Audio == nil || src.Video.Codec != "mpeg4" || src.Duration < 8 {
		t.Fatalf("inspect: %+v %v", src, err)
	}
	m := NewStreamer(dir, "hamlab", 2)
	s, err := m.Open(context.Background(), c, false, clip, "h264", "480p", src)
	if err != nil {
		t.Fatal(err)
	}
	if s.Width != 640 || s.Height != 360 || s.Engine == "" {
		t.Fatalf("stream: %+v", s)
	}
	if p, ok := s.File("index.m3u8"); !ok {
		t.Fatal("no playlist")
	} else if !hasSegments(p) {
		t.Fatal("Open returned before the first segment")
	}
	for _, bad := range []string{"../x", "progress", "seg1.m4s", "index.m3u8/", "init.mp4.tmp"} {
		if _, ok := s.File(bad); ok {
			t.Fatalf("%q must not be served", bad)
		}
	}
	// the same request is the same stream
	if again, err := m.Open(context.Background(), c, false, clip, "h264", "480p", src); err != nil || again.ID != s.ID {
		t.Fatal("not reused")
	}
	var st StreamStatus
	for i := 0; i < 120; i++ {
		st = s.Status()
		if st.Done || st.Error != "" {
			break
		}
		time.Sleep(250 * time.Millisecond)
	}
	if !st.Done || st.Error != "" || st.Segments < 2 || st.Progress < 8 {
		t.Fatalf("status at the end: %+v", st)
	}
	if init, _ := s.File("init.mp4"); !exists(init) {
		t.Fatal("no init segment")
	}
	m.Close(s.ID)
	if _, ok := m.Find(s.ID); ok || exists(s.dir) {
		t.Fatal("close must forget and remove")
	}
	// an unplayable source is a DecodeError, and leaves nothing behind
	bad := filepath.Join(dir, "bad.mkv")
	_ = os.WriteFile(bad, []byte("not a video"), 0o644)
	if _, err := Inspect(context.Background(), c, bad, false); err == nil {
		t.Fatal("inspect of garbage")
	}
	if left, _ := os.ReadDir(m.dir); len(left) != 0 {
		t.Fatalf("left behind: %v", left)
	}
}