package latest

import (
	"context"
	"crypto/sha256"
	"database/sql"
	"errors"
	"log"
	"os"
	"strings"
	"sync"
	"testing"
	"time"

	"bookmarkmanager/backend/internal/pgtest"
	"bookmarkmanager/backend/internal/store"
)

func TestMain(m *testing.M) { os.Exit(pgtest.Main(m)) }

// testOwner is the owner every test store seeds. A second reader, where a
// test needs one, is created by opening the same database as a second owner.
var testOwner = store.Owner{DiscordID: "test-owner", TokenHash: sha256.Sum256([]byte("owner-token-hash"))}

// testCoverBaseURL is the public origin every stored cover URL is built from.
const testCoverBaseURL = "https://bookmarks.test"

// newTestStore opens a store on a Postgres database of this test's own and
// returns the URL, for helpers that need a second connection to the same
// database (see TestRunOnceFetchesSharedSeriesOnce).
func newTestStore(t *testing.T) (*store.Store, string) {
	t.Helper()
	url := pgtest.URL(t)
	s, err := store.Open(url, testOwner, t.TempDir(), testCoverBaseURL)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	t.Cleanup(func() { s.Close() })
	return s, url
}

// seedForCheck inserts a bookmark (and with it its series) and forces the
// series' latest_checked_at.
func seedForCheck(t *testing.T, s *store.Store, key, seriesURL string, checkedAt int64) {
	t.Helper()
	site, seriesID, ok := strings.Cut(key, ":")
	if !ok {
		t.Fatalf("key %q: no ':' separator", key)
	}
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key:       key,
		Site:      site,
		SeriesID:  seriesID,
		SeriesURL: seriesURL,
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed %q: %v", key, err)
	}
	if err := s.MarkLatestChecked(site, seriesID, checkedAt); err != nil {
		t.Fatalf("seed mark %q: %v", key, err)
	}
}

func readLatestCheckedAt(t *testing.T, s *store.Store, key string) int64 {
	t.Helper()
	site, seriesID, ok := strings.Cut(key, ":")
	if !ok {
		t.Fatalf("key %q: no ':' separator", key)
	}
	ts, err := s.LatestCheckedAt(site, seriesID)
	if err != nil {
		t.Fatalf("LatestCheckedAt %q: %v", key, err)
	}
	return ts
}

// fakeFetcher stands in for the network. Every poller test uses it, so nothing
// in this file can reach tls-client or a real site.
type fakeFetcher struct {
	mu     sync.Mutex
	calls  []string
	body   string
	status int
	err    error
	// perURL overrides body/status/err for specific URLs.
	perURL map[string]fakeResponse
}

type fakeResponse struct {
	body   string
	status int
	err    error
}

func (f *fakeFetcher) Get(ctx context.Context, url string) (string, int, error) {
	f.mu.Lock()
	f.calls = append(f.calls, url)
	f.mu.Unlock()
	if r, ok := f.perURL[url]; ok {
		return r.body, r.status, r.err
	}
	return f.body, f.status, f.err
}

func (f *fakeFetcher) callCount() int {
	f.mu.Lock()
	defer f.mu.Unlock()
	return len(f.calls)
}

type fakeCoverFetcher struct {
	mu          sync.Mutex
	calls       []string
	body        []byte
	contentType string
	err         error
}

func (f *fakeCoverFetcher) Image(_ context.Context, imageURL string) ([]byte, string, error) {
	f.mu.Lock()
	f.calls = append(f.calls, imageURL)
	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)
}

type fakeBytesCoverFetcher struct {
	mu          sync.Mutex
	calls       []string
	body        []byte
	contentType string
	err         error
}

func (f *fakeBytesCoverFetcher) Fetch(_ context.Context, sourceURL string) ([]byte, string, error) {
	f.mu.Lock()
	f.calls = append(f.calls, sourceURL)
	f.mu.Unlock()
	if f.err != nil {
		return nil, "", f.err
	}
	return f.body, f.contentType, nil
}

func (f *fakeBytesCoverFetcher) 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 {
	t.Helper()
	return &Poller{
		Store:           s,
		Fetch:           f,
		Now:             func() time.Time { return at },
		Cooldown:        time.Hour,
		BrowserCooldown: 6 * time.Hour,
		Interval:        10 * time.Minute,
		Stagger:         0,
		Batch:           14,
	}
}

// seedCoverSource writes a Series' cover source address without any stored
// bytes. Nothing in production produces that state any more — a client cover
// is discarded and an acquired one arrives with its bytes — but rows created
// before covers moved server-side still carry one, and the prefetch is what
// heals them.
func seedCoverSource(t *testing.T, dbURL, site, seriesID, coverURL string) {
	t.Helper()
	db, err := sql.Open("pgx", dbURL)
	if err != nil {
		t.Fatalf("open %s: %v", dbURL, err)
	}
	defer db.Close()
	if _, err := db.Exec(
		`UPDATE series SET cover = $3 WHERE site = $1 AND series_id = $2`,
		site, seriesID, coverURL); err != nil {
		t.Fatalf("seed cover source %s:%s: %v", site, seriesID, err)
	}
}

func TestRunOncePrefetchesPublicCover(t *testing.T) {
	s, dbURL := newTestStore(t)
	const (
		key       = "asura:chronicles-of-the-demon-faction-f886a8af"
		seriesURL = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
		coverURL  = "https://cdn.example/covers/chronicles.jpg"
	)
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "asura", SeriesID: "chronicles-of-the-demon-faction-f886a8af",
		SeriesURL: seriesURL, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "asura", "chronicles-of-the-demon-faction-f886a8af", coverURL)
	covers := &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/jpeg"}
	p := &Poller{
		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200}, CoverBytesFetch: covers,
		Now: func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	if got := covers.callCount(); got != 1 {
		t.Fatalf("cover fetch calls = %d, want 1", got)
	}
	body, contentType, found, err := s.GetCover(coverURL)
	if err != nil || !found {
		t.Fatalf("GetCover: %v found=%v", err, found)
	}
	if string(body) != "cover-bytes" || contentType != "image/jpeg" {
		t.Fatalf("stored cover = (%q, %q), want (cover-bytes, image/jpeg)", body, contentType)
	}
}

func TestRunOnceDoesNotStoreNonImagePublicCover(t *testing.T) {
	s, dbURL := newTestStore(t)
	const (
		key       = "asura:non-image-cover"
		seriesURL = "https://asurascans.com/comics/non-image-cover"
		coverURL  = "https://cdn.example/covers/challenge"
	)
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "asura", SeriesID: "non-image-cover", SeriesURL: seriesURL,
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "asura", "non-image-cover", coverURL)
	p := &Poller{
		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200},
		CoverBytesFetch: &fakeBytesCoverFetcher{body: []byte("challenge"), contentType: "text/html"},
		Now:             func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	if _, _, found, err := s.GetCover(coverURL); err != nil || found {
		t.Fatalf("non-image cover = found %v, err %v; want missing", found, err)
	}
}

func TestRunOnceRecordsLatestChapter(t *testing.T) {
	s, _ := newTestStore(t)
	const url = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
	seedForCheck(t, s, "asura:chronicles-of-the-demon-faction-f886a8af", url, 0)

	now := time.UnixMilli(5_000_000)
	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
	newTestPoller(t, s, f, now).runOnce(context.Background())

	b, ok, err := s.Get(s.OwnerID(), "asura:chronicles-of-the-demon-faction-f886a8af")
	if err != nil || !ok {
		t.Fatalf("Get: %v ok=%v", err, ok)
	}
	if b.LatestChapterNum == nil || *b.LatestChapterNum != 181 {
		t.Fatalf("LatestChapterNum = %v, want 181", b.LatestChapterNum)
	}
	if b.LatestChapter != "Chapter 181" {
		t.Fatalf("LatestChapter = %q, want %q", b.LatestChapter, "Chapter 181")
	}
	if got := readLatestCheckedAt(t, s, "asura:chronicles-of-the-demon-faction-f886a8af"); got != now.UnixMilli() {
		t.Fatalf("latest_checked_at = %d, want %d", got, now.UnixMilli())
	}
}

// The whole point of the updated_at CASE in Upsert: a newly published chapter is
// not reading progress and must not move the series up the list.
func TestRunOnceDoesNotReorderList(t *testing.T) {
	s, _ := newTestStore(t)
	const url = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
	const key = "asura:chronicles-of-the-demon-faction-f886a8af"

	// "other" is the most recently read, so it must stay at the top of List().
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: "asura:other", Site: "asura", SeriesID: "other",
		SeriesURL: "https://asurascans.com/comics/other", UpdatedAt: 9_000_000,
	}); err != nil {
		t.Fatalf("seed other: %v", err)
	}
	seedForCheck(t, s, key, url, 0)
	before, _, err := s.Get(s.OwnerID(), key)
	if err != nil {
		t.Fatalf("Get before: %v", err)
	}

	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
	newTestPoller(t, s, f, time.UnixMilli(9_999_999)).runOnce(context.Background())

	after, _, err := s.Get(s.OwnerID(), key)
	if err != nil {
		t.Fatalf("Get after: %v", err)
	}
	if after.UpdatedAt != before.UpdatedAt {
		t.Fatalf("updated_at moved from %d to %d on a latest-chapter bump",
			before.UpdatedAt, after.UpdatedAt)
	}
	list, err := s.List(s.OwnerID())
	if err != nil {
		t.Fatalf("List: %v", err)
	}
	if list[0].Key != "asura:other" {
		t.Fatalf("list reordered: head is %q, want asura:other", list[0].Key)
	}
}

// A failed fetch must still consume the cooldown, or a renamed series gets
// retried on every tick forever.
func TestRunOnceMarksCheckedOnFailure(t *testing.T) {
	tests := []struct {
		name string
		resp fakeResponse
	}{
		{"network error", fakeResponse{err: errors.New("dial tcp: refused")}},
		{"non-200", fakeResponse{body: "nope", status: 503}},
		{"challenge page", fakeResponse{body: challengeFixture, status: 200}},
		{"empty body", fakeResponse{body: "", status: 200}},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			s, _ := newTestStore(t)
			const url = "https://asurascans.com/comics/x"
			seedForCheck(t, s, "asura:x", url, 0)

			now := time.UnixMilli(7_000_000)
			f := &fakeFetcher{perURL: map[string]fakeResponse{url: tt.resp}}
			newTestPoller(t, s, f, now).runOnce(context.Background())

			if got := readLatestCheckedAt(t, s, "asura:x"); got != now.UnixMilli() {
				t.Fatalf("latest_checked_at = %d, want %d", got, now.UnixMilli())
			}
			b, _, err := s.Get(s.OwnerID(), "asura:x")
			if err != nil {
				t.Fatalf("Get: %v", err)
			}
			if b.LatestChapterNum != nil {
				t.Fatalf("LatestChapterNum = %v, want nil on a failed check", *b.LatestChapterNum)
			}
		})
	}
}

func TestRunOnceRespectsBatchLimit(t *testing.T) {
	s, _ := newTestStore(t)
	for i := 0; i < 20; i++ {
		key := "asura:s" + string(rune('a'+i))
		seedForCheck(t, s, key, "https://asurascans.com/comics/"+key, 0)
	}

	f := &fakeFetcher{body: "", status: 200}
	p := newTestPoller(t, s, f, time.UnixMilli(5_000_000))
	p.Batch = 5
	p.runOnce(context.Background())

	if got := f.callCount(); got != 5 {
		t.Fatalf("fetched %d series, want 5 (batch limit)", got)
	}
}

// The point of the split (ADR-0003): a series referenced by several bookmarks
// is fetched once per due cycle, not once per bookmark. Two bookmarks share a
// series when two readers track it (issue #22).
func TestRunOnceFetchesSharedSeriesOnce(t *testing.T) {
	s, url := newTestStore(t)
	// The slug must match the fixture's own anchors: asura's parser scopes
	// chapter links to the stored slug.
	const slug = "chronicles-of-the-demon-faction-f886a8af"
	const seriesURL = "https://asurascans.com/comics/" + slug
	seedForCheck(t, s, "asura:"+slug, seriesURL, 0)
	// A second reader tracks the same series. The seed is the only
	// reader-creation path, so a second Open as a different owner is how a
	// test gets a second reader on the same database.
	other, err := store.Open(url, store.Owner{DiscordID: "second-reader", TokenHash: sha256.Sum256([]byte("second-token-hash"))}, t.TempDir(), testCoverBaseURL)
	if err != nil {
		t.Fatalf("Open second reader: %v", err)
	}
	t.Cleanup(func() { other.Close() })
	if _, err := s.Upsert(other.OwnerID(), store.Bookmark{
		Key: "asura:" + slug, Site: "asura", SeriesID: slug, UpdatedAt: 2000,
	}); err != nil {
		t.Fatalf("seed second reader: %v", err)
	}

	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
	newTestPoller(t, s, f, time.UnixMilli(5_000_000)).runOnce(context.Background())

	if got := f.callCount(); got != 1 {
		t.Fatalf("fetched shared series %d times, want 1", got)
	}
	// Both bookmarks join to the same updated series row.
	for _, st := range []*store.Store{s, other} {
		b, ok, err := st.Get(st.OwnerID(), "asura:"+slug)
		if err != nil || !ok {
			t.Fatalf("Get: %v ok=%v", err, ok)
		}
		if b.LatestChapterNum == nil || *b.LatestChapterNum != 181 {
			t.Fatalf("LatestChapterNum = %v, want 181", b.LatestChapterNum)
		}
	}
}

// One unreachable series must not abandon the rest of the batch.
func TestRunOnceOneBadSeriesDoesNotStallBatch(t *testing.T) {
	s, _ := newTestStore(t)
	keys := []string{"asura:a", "asura:b", "asura:c", "asura:d", "asura:e"}
	for _, k := range keys {
		seedForCheck(t, s, k, "https://asurascans.com/comics/"+k, 0)
	}

	now := time.UnixMilli(6_000_000)
	f := &fakeFetcher{
		body: "", status: 200,
		perURL: map[string]fakeResponse{
			"https://asurascans.com/comics/asura:b": {err: errors.New("boom")},
		},
	}
	newTestPoller(t, s, f, now).runOnce(context.Background())

	if got := f.callCount(); got != 5 {
		t.Fatalf("fetched %d series, want all 5 attempted", got)
	}
	for _, k := range keys {
		if got := readLatestCheckedAt(t, s, k); got != now.UnixMilli() {
			t.Fatalf("%s latest_checked_at = %d, want %d", k, got, now.UnixMilli())
		}
	}
}

func TestRunLogsCooldowns(t *testing.T) {
	var logs strings.Builder
	previous := log.Writer()
	log.SetOutput(&logs)
	t.Cleanup(func() { log.SetOutput(previous) })

	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	(&Poller{
		Cooldown:        time.Hour,
		BrowserCooldown: 6 * time.Hour,
		Interval:        time.Hour,
	}).Run(ctx)

	if got := logs.String(); !strings.Contains(got, "cooldown=1h") ||
		!strings.Contains(got, "browser-cooldown=6h") {
		t.Fatalf("startup log = %q, want both cooldowns", got)
	}
}

// The cooldown is enforced by the due query, so a second immediate pass must do
// nothing at all — this is what makes the tick interval independent of it.
func TestRunOnceHonoursCooldownAcrossPasses(t *testing.T) {
	s, _ := newTestStore(t)
	const url = "https://asurascans.com/comics/x"
	seedForCheck(t, s, "asura:x", url, 0)

	now := time.UnixMilli(8_000_000)
	f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
	p := newTestPoller(t, s, f, now)

	p.runOnce(context.Background())
	if got := f.callCount(); got != 1 {
		t.Fatalf("first pass fetched %d, want 1", got)
	}
	// Same instant, and again 59 minutes later: both inside the 1h cooldown.
	p.runOnce(context.Background())
	p.Now = func() time.Time { return now.Add(59 * time.Minute) }
	p.runOnce(context.Background())
	if got := f.callCount(); got != 1 {
		t.Fatalf("fetched %d times inside the cooldown, want 1", got)
	}
	// Past the cooldown, it is due again.
	p.Now = func() time.Time { return now.Add(61 * time.Minute) }
	p.runOnce(context.Background())
	if got := f.callCount(); got != 2 {
		t.Fatalf("fetched %d times after the cooldown, want 2", got)
	}
}

func TestRunOnceUsesBrowserCooldown(t *testing.T) {
	s, _ := newTestStore(t)
	const browserKey = "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
	seedForCheck(t, s, "asura:plain", "https://asurascans.com/comics/plain", 0)
	seedForCheck(t, s, browserKey, "https://kagane.to/series/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b", 0)

	hour := time.Hour
	now := time.Unix(2*int64(hour/time.Second), 0)
	tls := &fakeFetcher{status: 200}
	browser := &fakeFetcher{status: 200}
	p := &Poller{
		Store:           s,
		Fetch:           tls,
		BrowserFetch:    browser,
		Now:             func() time.Time { return now },
		Cooldown:        hour,
		BrowserCooldown: 6 * hour,
		Batch:           10,
	}

	p.runOnce(context.Background())
	if got := tls.callCount(); got != 1 {
		t.Fatalf("plain-TLS fetches after 2h = %d, want 1", got)
	}
	if got := browser.callCount(); got != 0 {
		t.Fatalf("browser fetches after 2h = %d, want 0", got)
	}

	now = time.Unix(7*int64(hour/time.Second), 0)
	p.runOnce(context.Background())
	if got := tls.callCount(); got != 2 {
		t.Fatalf("plain-TLS fetches after 7h = %d, want 2", got)
	}
	if got := browser.callCount(); got != 1 {
		t.Fatalf("browser fetches after 7h = %d, want 1", got)
	}
}

// A site that retracts a chapter should correct the stored number downward,
// mirroring the userscript's equality check (L427) rather than a >.
func TestRunOnceCorrectsDownward(t *testing.T) {
	s, _ := newTestStore(t)
	const url = "https://demonicscans.org/manga/Catastrophic-Necromancer"
	const key = "demonic:Catastrophic-Necromancer"

	high := 400.0
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "demonic", SeriesID: "Catastrophic-Necromancer",
		SeriesURL: url, LatestChapter: "Chapter 400", LatestChapterNum: &high,
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}

	f := &fakeFetcher{body: demonicSeriesFixture, status: 200}
	newTestPoller(t, s, f, time.UnixMilli(5_000_000)).runOnce(context.Background())

	b, _, err := s.Get(s.OwnerID(), key)
	if err != nil {
		t.Fatalf("Get: %v", err)
	}
	if b.LatestChapterNum == nil || *b.LatestChapterNum != 296 {
		t.Fatalf("LatestChapterNum = %v, want 296", b.LatestChapterNum)
	}
}

// series_url is client-supplied via PUT /bookmarks/{key}, so checkOne must
// reject anything that is not a known site with an https URL before spending a
// request on it — the cooldown still gets consumed either way.
func TestCheckOneValidatesSeriesURLBeforeFetching(t *testing.T) {
	tests := []struct {
		name      string
		site      string
		seriesURL string
		wantCalls int
	}{
		{"unknown site", "mangadex", "https://mangadex.org/title/x", 0},
		{"http scheme", "asura", "http://asurascans.com/comics/x", 0},
		{"unparseable url", "asura", "http://[::1", 0},
		{"valid https asura", "asura", "https://asurascans.com/comics/x", 1},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			s, _ := newTestStore(t)
			key := tt.site + ":x"
			if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
				Key: key, Site: tt.site, SeriesID: "x", SeriesURL: tt.seriesURL,
				UpdatedAt: 1000,
			}); err != nil {
				t.Fatalf("seed: %v", err)
			}

			now := time.UnixMilli(4_000_000)
			f := &fakeFetcher{body: asuraSeriesFixture, status: 200}
			newTestPoller(t, s, f, now).checkOne(context.Background(), store.Series{
				Site: tt.site, SeriesID: "x", SeriesURL: tt.seriesURL,
			})

			if got := f.callCount(); got != tt.wantCalls {
				t.Fatalf("fetch calls = %d, want %d", got, tt.wantCalls)
			}
			if got := readLatestCheckedAt(t, s, key); got != now.UnixMilli() {
				t.Fatalf("latest_checked_at = %d, want %d (cooldown must be consumed regardless)", got, now.UnixMilli())
			}
		})
	}
}

// A cancelled context must abandon the batch rather than run it to completion.
func TestRunOnceStopsOnCancelledContext(t *testing.T) {
	s, _ := newTestStore(t)
	for _, k := range []string{"asura:a", "asura:b", "asura:c"} {
		seedForCheck(t, s, k, "https://asurascans.com/comics/"+k, 0)
	}

	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	f := &fakeFetcher{body: "", status: 200}
	newTestPoller(t, s, f, time.UnixMilli(5_000_000)).runOnce(ctx)

	if got := f.callCount(); got != 0 {
		t.Fatalf("fetched %d series with a cancelled context, want 0", got)
	}
}

func TestFetchableSeriesURL(t *testing.T) {
	tests := []struct {
		name      string
		site      string
		seriesURL string
		want      bool
	}{
		{"asura https", "asura", "https://asurascans.com/comics/x-aabbccdd", true},
		{"demonic https", "demonic", "https://demonicscans.org/manga/X", true},
		{"comix https", "comix", "https://comix.to/title/n8we-dungeons-and-crayons", true},
		{"kagane on its own host", "kagane", "https://kagane.to/series/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b", true},
		// The browser fetcher runs JavaScript and carries cookies, so a
		// client-supplied series_url must not be able to aim it anywhere else.
		{"kagane on a foreign host", "kagane", "https://evil.example/series/x", false},
		{"kagane on a lookalike host", "kagane", "https://kagane.to.evil.example/series/x", false},
		{"unknown site", "mangadex", "https://mangadex.org/title/x", false},
		{"non-https", "comix", "http://comix.to/title/x", false},
		{"no host", "comix", "https:///title/x", false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := fetchableSeriesURL(tt.site, tt.seriesURL); got != tt.want {
				t.Errorf("fetchableSeriesURL(%q, %q) = %v, want %v",
					tt.site, tt.seriesURL, got, tt.want)
			}
		})
	}
}

// A kagane row must not be handed to the plain TLS fetcher: it would only ever
// receive a challenge page, and the browser fetcher is the whole reason kagane
// is pollable at all.
func TestKaganeSkippedWhenNoBrowserFetcher(t *testing.T) {
	s, _ := newTestStore(t)
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key:       "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b",
		Site:      "kagane",
		SeriesID:  "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b",
		SeriesURL: "https://kagane.to/series/019f84bc-9ba0-7ed9-86f5-8b905ec7c28b",
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	f := &fakeFetcher{body: kaganeAPIFixture, status: 200}

	p := &Poller{
		Store:    s,
		Fetch:    f,
		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
		Cooldown: time.Hour, BrowserCooldown: time.Hour,
		Interval: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	if len(f.calls) != 0 {
		t.Errorf("TLS fetcher was called for kagane: %v", f.calls)
	}
}

// novelfull without a browser is not skipped outright: its challenge is a
// live time-varying fact, so the plain-TLS page fetch is attempted and — when
// the body answers — fills both the chapter and the Cover, exactly the
// client-scraped rows #62 wants healed.
func TestNovelfullUsesTLSWhenNoBrowserFetcher(t *testing.T) {
	s, _ := newTestStore(t)
	key := "novelfull:reverend-insanity"
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key:       key,
		Site:      "novelfull",
		SeriesID:  "reverend-insanity",
		SeriesURL: "https://novelfull.com/reverend-insanity.html",
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}

	tlsF := &fakeFetcher{body: novelfullSeriesFixture + novelfullCoverFixture, status: 200}
	covers := &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/webp"}
	p := &Poller{
		Store: s, Fetch: tlsF, CoverBytesFetch: covers,
		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
		Cooldown: time.Hour, BrowserCooldown: time.Hour,
		Interval: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	if len(tlsF.calls) != 1 {
		t.Fatalf("TLS fetcher calls = %d, want 1", len(tlsF.calls))
	}
	if got := covers.callCount(); got != 1 {
		t.Fatalf("cover fetches = %d, want 1", got)
	}
	got, found, err := s.Get(s.OwnerID(), key)
	if err != nil || !found {
		t.Fatalf("Get: %v found=%v", err, found)
	}
	if want := testCoverBaseURL + "/covers/" + store.CoverAddress(novelfullCoverURL); got.Cover != want {
		t.Fatalf("Cover = %q, want %q", got.Cover, want)
	}
	if got.LatestChapterNum == nil || *got.LatestChapterNum != 2334 {
		t.Fatalf("LatestChapterNum = %v, want 2334", got.LatestChapterNum)
	}
}

// With a browser fetcher wired up, kagane goes to it and not to the TLS one.
func TestKaganeUsesBrowserFetcher(t *testing.T) {
	s, _ := newTestStore(t)
	key := "kagane:019f84bc-9ba0-7ed9-86f5-8b905ec7c28b"
	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",
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}

	tlsF := &fakeFetcher{body: "", status: 200}
	browserF := &fakeFetcher{body: kaganeAPIFixture, status: 200}
	p := &Poller{
		Store: s, Fetch: tlsF, BrowserFetch: browserF,
		Now:      func() time.Time { return time.UnixMilli(5_000_000) },
		Cooldown: time.Hour, BrowserCooldown: time.Hour,
		Interval: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	if len(tlsF.calls) != 0 {
		t.Errorf("TLS fetcher was called for kagane: %v", tlsF.calls)
	}
	if len(browserF.calls) != 1 {
		t.Fatalf("browser fetcher calls = %v, want 1", browserF.calls)
	}
	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.Errorf("LatestChapterNum = %v, want 41", got.LatestChapterNum)
	}
}

func TestRunOncePrefetchesKaganeCover(t *testing.T) {
	s, dbURL := 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",
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "kagane", "019f84bc-9ba0-7ed9-86f5-8b905ec7c28b", coverURL)
	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.CoverByAddress(store.CoverAddress(coverURL))
	if err != nil || !ok {
		t.Fatalf("CoverByAddress: %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)
	}
	if got := readBookmark(t, s, key); got.Cover != testCoverBaseURL+"/covers/"+store.CoverAddress(coverURL) {
		t.Fatalf("wire Cover = %q, want content-addressed URL", got.Cover)
	}
}

func TestRunOnceDoesNotRefetchKaganeCover(t *testing.T) {
	s, dbURL := 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, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "kagane", seriesID, coverURL)
	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, dbURL := 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, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "kagane", seriesID, coverURL)
	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, dbURL := 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, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "kagane", seriesID, coverURL)
	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.CoverByAddress(store.CoverAddress(coverURL)); err != nil || found {
		t.Fatalf("invalid cover persisted = %v, err %v; want missing", found, err)
	}
}

func TestRunOnceWithoutCoverFetcherStillPollsKagane(t *testing.T) {
	s, dbURL := 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, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "kagane", seriesID, coverURL)
	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.CoverByAddress(store.CoverAddress(coverURL)); err != nil || found {
		t.Fatalf("cover after nil CoverFetch = found %v, err %v; want missing", found, err)
	}
}

func TestRunOnceRoutesNonKaganeCoverToPublicFetcher(t *testing.T) {
	s, dbURL := newTestStore(t)
	const key = "asura:solo"
	const coverURL = "https://asurascans.com/covers/solo.jpg"
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "asura", SeriesID: "solo", SeriesURL: "https://asurascans.com/comics/solo",
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	seedCoverSource(t, dbURL, "asura", "solo", coverURL)
	browserCovers := &fakeCoverFetcher{body: []byte("must not be fetched"), contentType: "image/webp"}
	publicCovers := &fakeBytesCoverFetcher{body: []byte("public cover"), contentType: "image/webp"}
	p := &Poller{
		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture, status: 200}, CoverFetch: browserCovers,
		CoverBytesFetch: publicCovers,
		Now:             func() time.Time { return time.UnixMilli(5_000_000) }, Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	if got := publicCovers.callCount(); got != 1 {
		t.Fatalf("public cover fetch calls = %d, want 1", got)
	}
	if got := browserCovers.callCount(); got != 0 {
		t.Fatalf("browser cover fetch calls for asura = %d, want 0", got)
	}
}

func TestFetcherForRoutesNovelSites(t *testing.T) {
	tls := &fakeFetcher{}
	browser := &fakeFetcher{}

	cases := []struct {
		site    string
		browser Fetcher
		tls     Fetcher
		want    Fetcher
	}{
		{"asura", browser, tls, tls},
		{"lightnovelworld", browser, tls, tls},
		{"kagane", browser, tls, browser},
		{"novelfull", browser, tls, browser},
		// browser-less deployment: kagane is nothing, novelfull degrades to TLS
		{"kagane", nil, tls, nil},
		{"novelfull", nil, tls, tls},
	}
	for _, tc := range cases {
		t.Run(tc.site, func(t *testing.T) {
			if got := fetcherFor(tc.site, tc.browser, tc.tls); got != tc.want {
				t.Fatalf("fetcherFor(%q) = %v, want %v", tc.site, got, tc.want)
			}
		})
	}
}

func TestFetchableSeriesURLPinsNovelHosts(t *testing.T) {
	cases := []struct {
		name string
		site string
		url  string
		want bool
	}{
		{"novelfull on its own host", "novelfull", "https://novelfull.com/reverend-insanity.html", true},
		{"novelfull on a foreign host", "novelfull", "https://evil.example/x.html", false},
		{"novelfull over http", "novelfull", "http://novelfull.com/x.html", false},
		{"lightnovelworld on its own host", "lightnovelworld", "https://lightnovelworld.net/novel/a-will-eternal/", true},
		{"lightnovelworld on a foreign host", "lightnovelworld", "https://evil.example/novel/x/", false},
		{"unknown site", "webnovel", "https://webnovel.com/x", false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := fetchableSeriesURL(tc.site, tc.url); got != tc.want {
				t.Fatalf("fetchableSeriesURL(%q, %q) = %v, want %v", tc.site, tc.url, got, tc.want)
			}
		})
	}
}

// A Series that has been blank since creation has no source URL to refetch.
// The poll extracts the Cover from the same series page it already fetched
// for the chapter signal and stores the bytes — every Site, both Libraries.
func TestRunOnceFillsBlankCoverFromSeriesPage(t *testing.T) {
	cases := []struct {
		name      string
		key       string
		site      string
		seriesID  string
		seriesURL string
		kind      string
		body      string
		wantCover string
		browser   bool
	}{
		{
			name: "asura manga",
			key:  "asura:chronicles-of-the-demon-faction-f886a8af", site: "asura",
			seriesID:  "chronicles-of-the-demon-faction-f886a8af",
			seriesURL: "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af",
			kind:      store.KindManga, body: asuraSeriesFixture + asuraCoverFixture,
			wantCover: "https://cdn.asurascans.com/asura-images/covers/chronicles-of-the-demon-faction.d4dcb8.webp",
		},
		{
			name: "lightnovelworld novel",
			key:  "lightnovelworld:a-will-eternal", site: "lightnovelworld",
			seriesID: "a-will-eternal", seriesURL: "https://lightnovelworld.net/novel/a-will-eternal/",
			kind: store.KindNovel, body: lnwSeriesFixture + lnwCoverFixture,
			wantCover: "https://lightnovelworld.net/wp-content/uploads/2026/03/a-will-eternal-1.webp",
		},
		{
			name: "kagane manga",
			key:  "kagane:019fe11a-8670-7cf3-8343-0b02057d3787", site: "kagane",
			seriesID:  "019fe11a-8670-7cf3-8343-0b02057d3787",
			seriesURL: "https://kagane.to/series/019fe11a-8670-7cf3-8343-0b02057d3787",
			kind:      store.KindManga, body: kaganeAPIFixtureWithCover, browser: true,
			wantCover: "https://kagane.to/api/v2/image/019fe11a-84c3-7fc3-a84b-88787374b617/compressed",
		},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			s, _ := newTestStore(t)
			if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
				Key: tc.key, Site: tc.site, SeriesID: tc.seriesID,
				SeriesURL: tc.seriesURL, Kind: tc.kind, UpdatedAt: 1000,
			}); err != nil {
				t.Fatalf("seed: %v", err)
			}
			page := &fakeFetcher{body: tc.body, status: 200}
			public := &fakeBytesCoverFetcher{body: []byte("cover-bytes"), contentType: "image/jpeg"}
			browser := &fakeCoverFetcher{body: []byte("cover-bytes"), contentType: "image/webp"}
			p := &Poller{
				Store: s, Fetch: page, BrowserFetch: page,
				CoverBytesFetch: public, CoverFetch: browser,
				Now:      func() time.Time { return time.UnixMilli(5_000_000) },
				Cooldown: time.Hour, BrowserCooldown: time.Hour, Batch: 10,
			}
			p.runOnce(context.Background())

			got := readBookmark(t, s, tc.key)
			wantWire := testCoverBaseURL + "/covers/" + store.CoverAddress(tc.wantCover)
			if got.Cover != wantWire {
				t.Fatalf("Cover = %q, want %q", got.Cover, wantWire)
			}
			if tc.browser {
				if got := browser.callCount(); got != 1 {
					t.Fatalf("browser cover fetches = %d, want 1", got)
				}
				if got := public.callCount(); got != 0 {
					t.Fatalf("public cover fetches = %d, want 0", got)
				}
			} else {
				if got := public.callCount(); got != 1 {
					t.Fatalf("public cover fetches = %d, want 1", got)
				}
				if got := browser.callCount(); got != 0 {
					t.Fatalf("browser cover fetches = %d, want 0", got)
				}
			}
		})
	}
}

// Once a Cover exists the poll must leave it alone: refetching every cycle is
// noise for the Reader and a request per Series against Sites that already
// bot-score the deployment's single IP.
func TestRunOnceDoesNotReplaceExistingCover(t *testing.T) {
	s, _ := newTestStore(t)
	const (
		key       = "asura:chronicles-of-the-demon-faction-f886a8af"
		seriesID  = "chronicles-of-the-demon-faction-f886a8af"
		seriesURL = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
		first     = "https://cdn.example/covers/first.jpg"
	)
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "asura", SeriesID: seriesID, SeriesURL: seriesURL, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	if err := s.SetSeriesCover("asura", seriesID, first, []byte("first"), "image/jpeg"); err != nil {
		t.Fatalf("seed cover: %v", err)
	}
	public := &fakeBytesCoverFetcher{body: []byte("second"), contentType: "image/jpeg"}
	at := time.UnixMilli(5_000_000)
	p := &Poller{
		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture + asuraCoverFixture, status: 200},
		CoverBytesFetch: public,
		Now:             func() time.Time { return at }, Cooldown: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())
	at = at.Add(2 * time.Hour)
	p.runOnce(context.Background())

	if got := public.callCount(); got != 0 {
		t.Fatalf("cover fetch calls = %d, want 0", got)
	}
	got := readBookmark(t, s, key)
	if want := testCoverBaseURL + "/covers/" + store.CoverAddress(first); got.Cover != want {
		t.Fatalf("Cover = %q, want the first one %q", got.Cover, want)
	}
}

// A blank Cover whose byte fetch fails is retried the next time the Series is
// polled. There is no separate retry queue — the due cycle is the queue.
func TestRunOnceRetriesFailedBlankCoverOnNextPoll(t *testing.T) {
	s, _ := newTestStore(t)
	const (
		key       = "asura:chronicles-of-the-demon-faction-f886a8af"
		seriesID  = "chronicles-of-the-demon-faction-f886a8af"
		seriesURL = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
		coverURL  = "https://cdn.asurascans.com/asura-images/covers/chronicles-of-the-demon-faction.d4dcb8.webp"
	)
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "asura", SeriesID: seriesID, SeriesURL: seriesURL, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	public := &fakeBytesCoverFetcher{err: errors.New("cdn down")}
	at := time.UnixMilli(5_000_000)
	p := &Poller{
		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture + asuraCoverFixture, status: 200},
		CoverBytesFetch: public,
		Now:             func() time.Time { return at }, Cooldown: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())
	if got := readBookmark(t, s, key); got.Cover != "" {
		t.Fatalf("Cover after failed fetch = %q, want blank", got.Cover)
	}
	if got := public.callCount(); got != 1 {
		t.Fatalf("cover fetch calls after fail = %d, want 1", got)
	}

	public.err = nil
	public.body = []byte("cover-bytes")
	public.contentType = "image/jpeg"
	at = at.Add(2 * time.Hour)
	p.runOnce(context.Background())

	if got := public.callCount(); got != 2 {
		t.Fatalf("cover fetch calls after retry = %d, want 2", got)
	}
	got := readBookmark(t, s, key)
	if want := testCoverBaseURL + "/covers/" + store.CoverAddress(coverURL); got.Cover != want {
		t.Fatalf("Cover after retry = %q, want %q", got.Cover, want)
	}
}

// Cover work is cosmetic: a failed blank fill must leave the chapter poll's
// result intact for every Site, not only kagane.
func TestRunOnceBlankCoverFailureDoesNotBlockChapter(t *testing.T) {
	s, _ := newTestStore(t)
	const (
		key       = "asura:chronicles-of-the-demon-faction-f886a8af"
		seriesID  = "chronicles-of-the-demon-faction-f886a8af"
		seriesURL = "https://asurascans.com/comics/chronicles-of-the-demon-faction-f886a8af"
	)
	if _, err := s.Upsert(s.OwnerID(), store.Bookmark{
		Key: key, Site: "asura", SeriesID: seriesID, SeriesURL: seriesURL, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	now := time.UnixMilli(5_000_000)
	var logs strings.Builder
	prev := log.Writer()
	log.SetOutput(&logs)
	t.Cleanup(func() { log.SetOutput(prev) })

	p := &Poller{
		Store: s, Fetch: &fakeFetcher{body: asuraSeriesFixture + asuraCoverFixture, status: 200},
		CoverBytesFetch: &fakeBytesCoverFetcher{err: errors.New("cdn down")},
		Now:             func() time.Time { return now }, Cooldown: time.Hour, Batch: 10,
	}
	p.runOnce(context.Background())

	got := readBookmark(t, s, key)
	if got.LatestChapterNum == nil || *got.LatestChapterNum != 181 {
		t.Fatalf("LatestChapterNum = %v, want 181", got.LatestChapterNum)
	}
	if got.Cover != "" {
		t.Fatalf("Cover = %q, want blank after failed fetch", got.Cover)
	}
	if !strings.Contains(logs.String(), key) {
		t.Fatalf("cover failure log missing series key %q; got %q", key, logs.String())
	}
}

// kaganeAPIFixture carries chapter data only. The blank-fill path needs a
// cover image id in the same body the chapter poll already retrieved.
const kaganeAPIFixtureWithCover = `
{"series_id":"019fe11a-8670-7cf3-8343-0b02057d3787","title":"Infinite Decryption",
"series_covers":[{"cover_id":"019fe11a-84d1-714b-9cf4-2827f277f3c0","language":"en","volume_number":"1","chapter_number":null,"note":null,"image_id":"019fe11a-84c3-7fc3-a84b-88787374b617"}],
"series_books":[{"book_id":"a","title":"Episode 1","chapter_no":"1","sort_no":1},
{"book_id":"b","title":"Episode 41","chapter_no":"41","sort_no":41},
{"book_id":"c","title":"Episode 40.5","chapter_no":"40.5","sort_no":40}]}
`