Vellum/internal/media/subtitles_test.go

package media

import (
	"database/sql"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/mithral/vellum/internal/auth"
)

// subtitleFixture builds a library rooted at a real temp dir, so a sidecar
// subtitle can be written to disk and read back through the route, plus a second
// item in a library the caller may not read.
type subtitleFixture struct {
	h         *Handlers
	db        *sql.DB
	root      string
	user      int64
	item      int64
	forbidden int64
}

func newSubtitleFixture(t *testing.T) subtitleFixture {
	t.Helper()
	db := testDB(t)
	root := t.TempDir()

	lib := newLibrary(t, db, "Video", "video", root)
	other := newLibrary(t, db, "Other", "video", t.TempDir())

	f := subtitleFixture{db: db, root: root}
	f.user = newUser(t, db, "watcher")
	grantRead(t, db, f.user, lib)

	const at = "2026-01-01T00:00:00.000Z"
	f.item = newItem(t, db, lib, "video", "movie.mkv", "Movie", "movie", false, at)
	f.forbidden = newItem(t, db, other, "video", "secret.mkv", "Secret", "secret", false, at)
	f.h = mediaHandlers(t, db)
	return f
}

// addTrack writes a sidecar file and the subtitles row that points at it.
func (f subtitleFixture) addTrack(t *testing.T, name, content, format, lang string) int64 {
	t.Helper()
	if err := os.WriteFile(filepath.Join(f.root, name), []byte(content), 0o640); err != nil {
		t.Fatalf("write %s: %v", name, err)
	}
	return mustQueryID(t, f.db, `
		INSERT INTO subtitles (item_id, source, path, stream_index, format, language, label)
		VALUES (?, 'sidecar', ?, -1, ?, ?, ?) RETURNING id`,
		f.item, name, format, lang, name)
}

func listSubtitleTracks(t *testing.T, h *Handlers, u auth.User, itemID int64) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodGet, "/api/v1/items/1/subtitles", nil)
	req.SetPathValue("id", itoa(itemID))
	rec := httptest.NewRecorder()
	h.handleSubtitles(rec, req, u)
	return rec
}

func getSubtitleTrack(t *testing.T, h *Handlers, u auth.User, itemID, trackID int64) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodGet, "/api/v1/items/1/subtitles/1", nil)
	req.SetPathValue("id", itoa(itemID))
	req.SetPathValue("trackID", itoa(trackID))
	rec := httptest.NewRecorder()
	h.handleSubtitleTrack(rec, req, u)
	return rec
}

// TestSubtitleSRTConvertsToVTT pins the SubRip rewrite: the WebVTT header, a dot
// in every timestamp, and the subtitle text left alone.
func TestSubtitleSRTConvertsToVTT(t *testing.T) {
	f := newSubtitleFixture(t)
	srt := "1\n00:00:01,000 --> 00:00:04,000\nHello, world\n\n2\n00:00:05,500 --> 00:00:06,000\nBye\n"
	id := f.addTrack(t, "movie.en.srt", srt, "srt", "en")

	rec := getSubtitleTrack(t, f.h, auth.User{ID: f.user}, f.item, id)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, body=%s", rec.Code, rec.Body.String())
	}
	if ct := rec.Header().Get("Content-Type"); ct != "text/vtt; charset=utf-8" {
		t.Errorf("content-type = %q, want text/vtt; charset=utf-8", ct)
	}

	body := rec.Body.String()
	if !strings.HasPrefix(body, "WEBVTT\n\n") {
		t.Errorf("body does not start with WEBVTT header: %q", body)
	}
	if !strings.Contains(body, "00:00:01.000 --> 00:00:04.000") ||
		!strings.Contains(body, "00:00:05.500 --> 00:00:06.000") {
		t.Errorf("timestamps not dot-separated: %q", body)
	}
	if strings.Contains(body, ",000") || strings.Contains(body, ",500") {
		t.Errorf("a comma survived in a timestamp: %q", body)
	}
	if !strings.Contains(body, "Hello, world") {
		t.Errorf("a comma in the subtitle text was rewritten: %q", body)
	}
}

// TestSubtitleVTTPassesThrough pins that an already-WebVTT sidecar is served
// byte for byte, with no header prepended and no timestamp touched.
func TestSubtitleVTTPassesThrough(t *testing.T) {
	f := newSubtitleFixture(t)
	vtt := "WEBVTT\n\n00:00:01.000 --> 00:00:04.000\nHi there\n"
	id := f.addTrack(t, "movie.en.vtt", vtt, "vtt", "en")

	rec := getSubtitleTrack(t, f.h, auth.User{ID: f.user}, f.item, id)
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, body=%s", rec.Code, rec.Body.String())
	}
	if got := rec.Body.String(); got != vtt {
		t.Errorf("body = %q, want unchanged %q", got, vtt)
	}
	if ct := rec.Header().Get("Content-Type"); ct != "text/vtt; charset=utf-8" {
		t.Errorf("content-type = %q, want text/vtt; charset=utf-8", ct)
	}
}

// TestSubtitleRoutesAreGrantScoped pins the access chokepoint on both routes: an
// item in a library the caller cannot read must answer with the same 404, byte
// for byte, as an item that does not exist.
func TestSubtitleRoutesAreGrantScoped(t *testing.T) {
	f := newSubtitleFixture(t)
	u := auth.User{ID: f.user}

	// The readable item lists, empty, with a 200.
	if rec := listSubtitleTracks(t, f.h, u, f.item); rec.Code != http.StatusOK {
		t.Errorf("readable list status = %d, want 200 (body %s)", rec.Code, rec.Body.String())
	}

	forbidden := listSubtitleTracks(t, f.h, u, f.forbidden)
	absent := listSubtitleTracks(t, f.h, u, 999999)
	if forbidden.Code != http.StatusNotFound || absent.Code != http.StatusNotFound {
		t.Fatalf("list statuses = %d/%d, want 404/404", forbidden.Code, absent.Code)
	}
	if forbidden.Body.String() != absent.Body.String() {
		t.Errorf("forbidden body %q != absent body %q", forbidden.Body.String(), absent.Body.String())
	}

	// The track route leaks nothing either: the item is rejected before the
	// track id is ever looked at.
	fb := getSubtitleTrack(t, f.h, u, f.forbidden, 1)
	ab := getSubtitleTrack(t, f.h, u, 999999, 1)
	if fb.Code != http.StatusNotFound || ab.Code != http.StatusNotFound {
		t.Fatalf("track statuses = %d/%d, want 404/404", fb.Code, ab.Code)
	}
	if fb.Body.String() != ab.Body.String() {
		t.Errorf("track forbidden body %q != absent body %q", fb.Body.String(), ab.Body.String())
	}

	// A user with no grants at all gets the same 404 on the readable item.
	none := listSubtitleTracks(t, f.h, auth.User{ID: newUser(t, f.db, "nobody")}, f.item)
	if none.Code != http.StatusNotFound {
		t.Errorf("no-grant list status = %d, want 404", none.Code)
	}
}