feat(latest): prefetch kagane covers during polling

Add an optional cover fetcher to the latest-chapter poller and wire the shared browser into it. Each due Kagane series now checks persistent storage, fetches a missing cover once, and keeps chapter polling and cooldown bookkeeping independent when cover work fails.\n\nCentralize Kagane image-id and content-type validation so prefetched bytes cannot poison the on-first-view fallback, and cover the missing, cached, failure, nil-fetcher, invalid-type, and non-Kagane paths with deterministic poll-cycle tests.\n\nRefs #45
2026-08-09 07:50:55 +07:00
parent 84cfd1b2c1
commit 639ca6ffd1
5 changed files with 258 additions and 15 deletions
@@ -104,6 +104,30 @@ func (f *fakeFetcher) callCount() int {
 	return len(f.calls)
 }

+type fakeCoverFetcher struct {
+	mu          sync.Mutex
+	calls       []string
+	body        []byte
+	contentType string
+	err         error
+}
+
+func (f *fakeCoverFetcher) Image(_ context.Context, imageID string) ([]byte, string, error) {
+	f.mu.Lock()
+	f.calls = append(f.calls, imageID)
+	f.mu.Unlock()
+	if f.err != nil {
+		return nil, "", f.err
+	}
+	return f.body, f.contentType, nil
+}
+
+func (f *fakeCoverFetcher) callCount() int {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	return len(f.calls)
+}
+
 // newTestPoller wires a poller with a frozen clock and no stagger, so tests run
 // instantly and deterministically.
 func newTestPoller(t *testing.T, s *store.Store, f Fetcher, at time.Time) *Poller {
@@ -580,6 +604,171 @@ func TestKaganeUsesBrowserFetcher(t *testing.T) {
 	}
 }

+func TestRunOncePrefetchesKaganeCover(t *testing.T) {
+	s, _ := newTestStore(t)
+	const (
+		key      = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		coverURL = "https://kagane.to/api/v2/image/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b/compressed"
+	)
+	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+		Key: key, Site: "kagane", SeriesID: "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b",
+		SeriesURL: "https://kagane.to/series/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b",
+		Cover:     coverURL, UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	covers := &fakeCoverFetcher{body: []byte("cover-bytes"), contentType: "image/webp"}
+	p := &Poller{
+		Store: s, Fetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
+		BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200}, CoverFetch: covers,
+		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
+		Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+	}
+	p.runOnce(context.Background())
+
+	body, contentType, ok, err := s.GetKaganeCover("019f84bc-9ba0-7ed9-86f5-8b905ec7c28b")
+	if err != nil || !ok {
+		t.Fatalf("GetKaganeCover: %v found=%v", err, ok)
+	}
+	if string(body) != "cover-bytes" || contentType != "image/webp" {
+		t.Fatalf("stored cover = (%q, %q), want (cover-bytes, image/webp)", body, contentType)
+	}
+	if got := covers.callCount(); got != 1 {
+		t.Fatalf("cover fetch calls = %d, want 1", got)
+	}
+}
+
+func TestRunOnceDoesNotRefetchKaganeCover(t *testing.T) {
+	s, _ := newTestStore(t)
+	const (
+		key      = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		seriesID = "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		coverURL = "https://kagane.to/api/v2/image/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b/compressed"
+	)
+	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+		Key: key, Site: "kagane", SeriesID: seriesID,
+		SeriesURL: "https://kagane.to/series/" + seriesID, Cover: coverURL, UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	at := time.UnixMilli(5_000_000)
+	covers := &fakeCoverFetcher{body: []byte("cover-bytes"), contentType: "image/webp"}
+	p := &Poller{
+		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200}, CoverFetch: covers,
+		Now: func() time.Time { return at }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+	}
+	p.runOnce(context.Background())
+	at = at.Add(2 * time.Hour)
+	p.runOnce(context.Background())
+
+	if got := covers.callCount(); got != 1 {
+		t.Fatalf("cover fetch calls = %d, want 1 after two due cycles", got)
+	}
+}
+
+func TestRunOnceCoverFailureDoesNotBlockChapter(t *testing.T) {
+	s, _ := newTestStore(t)
+	const (
+		key      = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		seriesID = "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		coverURL = "https://kagane.to/api/v2/image/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b/compressed"
+	)
+	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+		Key: key, Site: "kagane", SeriesID: seriesID,
+		SeriesURL: "https://kagane.to/series/" + seriesID, Cover: coverURL, UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	now := time.UnixMilli(5_000_000)
+	p := &Poller{
+		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
+		CoverFetch: &fakeCoverFetcher{err: errors.New("browser unavailable")},
+		Now:        func() time.Time { return now }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+	}
+	p.runOnce(context.Background())
+
+	got, found, err := s.Get(s.OwnerID(), key)
+	if err != nil || !found {
+		t.Fatalf("Get: %v found=%v", err, found)
+	}
+	if got.LatestChapterNum == nil || *got.LatestChapterNum != 41 {
+		t.Fatalf("LatestChapterNum = %v, want 41", got.LatestChapterNum)
+	}
+	if checked := readLatestCheckedAt(t, s, key); checked != now.UnixMilli() {
+		t.Fatalf("latest_checked_at = %d, want %d", checked, now.UnixMilli())
+	}
+}
+
+func TestRunOnceRejectsInvalidKaganeCover(t *testing.T) {
+	s, _ := newTestStore(t)
+	const (
+		key      = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		seriesID = "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		coverURL = "https://kagane.to/api/v2/image/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b/compressed"
+	)
+	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+		Key: key, Site: "kagane", SeriesID: seriesID,
+		SeriesURL: "https://kagane.to/series/" + seriesID, Cover: coverURL, UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	p := &Poller{
+		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
+		CoverFetch: &fakeCoverFetcher{body: []byte("not an image"), contentType: "text/html"},
+		Now:        func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+	}
+	p.runOnce(context.Background())
+
+	if _, _, found, err := s.GetKaganeCover("019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"); err != nil || found {
+		t.Fatalf("invalid cover persisted = %v, err %v; want missing", found, err)
+	}
+}
+
+func TestRunOnceWithoutCoverFetcherStillPollsKagane(t *testing.T) {
+	s, _ := newTestStore(t)
+	const (
+		key      = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		seriesID = "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
+		coverURL = "https://kagane.to/api/v2/image/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b/compressed"
+	)
+	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+		Key: key, Site: "kagane", SeriesID: seriesID,
+		SeriesURL: "https://kagane.to/series/" + seriesID, Cover: coverURL, UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	p := &Poller{
+		Store: s, BrowserFetch: &fakeFetcher{body: kaganeAPIFixture, status: 200},
+		Now: func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+	}
+	p.runOnce(context.Background())
+
+	if _, _, found, err := s.GetKaganeCover("019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"); err != nil || found {
+		t.Fatalf("cover after nil CoverFetch = found %v, err %v; want missing", found, err)
+	}
+}
+
+func TestRunOnceDoesNotPrefetchNonKaganeCover(t *testing.T) {
+	s, _ := newTestStore(t)
+	const key = "asura:solo"
+	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
+		Key: key, Site: "asura", SeriesID: "solo", SeriesURL: "https://asurascans.com/comics/solo",
+		Cover: "https://asurascans.com/covers/solo.jpg", UpdatedAt: 1000,
+	}); err != nil {
+		t.Fatalf("seed: %v", err)
+	}
+	covers := &fakeCoverFetcher{body: []byte("must not be fetched"), contentType: "image/webp"}
+	p := &Poller{
+		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200}, CoverFetch: covers,
+		Now: func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
+	}
+	p.runOnce(context.Background())
+
+	if got := covers.callCount(); got != 0 {
+		t.Fatalf("cover fetch calls for asura = %d, want 0", got)
+	}
+}
+
 func TestFetcherForRoutesNovelSites(t *testing.T) {
 	tls := &fakeFetcher{}
 	browser := &fakeFetcher{}