mangaBookmark/backend/internal/store/store_test.go

package store

import (
	"bytes"
	"crypto/sha256"
	"database/sql"
	"os"
	"strconv"
	"strings"
	"testing"
	"time"

	"bookmarkmanager/backend/internal/pgtest"
)

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

// testOwner is the owner every test store seeds. Tests that need a second
// reader register one (see secondReader).
var testOwner = Owner{DiscordID: "test-owner", TokenHash: sha256.Sum256([]byte("owner-token-hash"))}

func newTestStore(t *testing.T) *Store {
	t.Helper()
	store, err := Open(pgtest.URL(t), testOwner)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	t.Cleanup(func() { store.Close() })
	return store
}

// secondReader registers an extra reader through the same path a first login
// takes, and returns its id.
func secondReader(t *testing.T, s *Store) int64 {
	t.Helper()
	discordID := "second-" + strconv.FormatInt(time.Now().UnixNano(), 10)
	id, err := s.EnsureReader(discordID, sha256.Sum256([]byte("token-"+discordID)))
	if err != nil {
		t.Fatalf("register second reader: %v", err)
	}
	return id
}

// The migration runner runs on every start, so a second Open against a
// database it already built must be a no-op rather than a duplicate-table
// error, and must leave the rows alone.
func TestOpenIsIdempotent(t *testing.T) {
	url := pgtest.URL(t)
	first, err := Open(url, testOwner)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	if _, err := first.Upsert(first.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	first.Close()

	second, err := Open(url, testOwner)
	if err != nil {
		t.Fatalf("reopen: %v", err)
	}
	t.Cleanup(func() { second.Close() })

	list, err := second.List(second.OwnerID())
	if err != nil {
		t.Fatalf("List: %v", err)
	}
	if len(list) != 1 || list[0].Key != "asura:solo" {
		t.Fatalf("rows after reopen = %+v, want only the seeded one", list)
	}
}

// The hash lookup is the whole authentication path: the store resolves a
// Reader from the SHA-256 of their presented credential, and nothing else.
func TestReaderIDForTokenHash(t *testing.T) {
	store := newTestStore(t)
	ownerHash := sha256.Sum256([]byte("owner-token-hash"))

	id, ok, err := store.ReaderIDForTokenHash(ownerHash)
	if err != nil {
		t.Fatalf("ReaderIDForTokenHash: %v", err)
	}
	if !ok || id != store.OwnerID() {
		t.Fatalf("owner lookup = (%d, %v), want (%d, true)", id, ok, store.OwnerID())
	}

	if _, ok, err := store.ReaderIDForTokenHash(sha256.Sum256([]byte("nope"))); err != nil {
		t.Fatalf("miss: %v", err)
	} else if ok {
		t.Fatal("unknown hash resolved to a Reader")
	}
}

func TestReaderTokenInfo(t *testing.T) {
	store := newTestStore(t)
	discordID, epoch, err := store.ReaderTokenInfo(store.OwnerID())
	if err != nil {
		t.Fatalf("ReaderTokenInfo: %v", err)
	}
	if discordID != testOwner.DiscordID || epoch != 0 {
		t.Fatalf("ReaderTokenInfo = (%q, %d), want (%q, 0)", discordID, epoch, testOwner.DiscordID)
	}
}

// Rotation swaps the stored hash and bumps the epoch in one step, and the
// seed must not undo it: a restart re-runs seedOwner, which refreshes the
// epoch-0 hash only while the row has never been rotated.
func TestRotateTokenInvalidatesOldAndSurvivesRestart(t *testing.T) {
	url := pgtest.URL(t)
	store, err := Open(url, testOwner)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}

	oldHash := sha256.Sum256([]byte("owner-token-hash"))
	newHash := sha256.Sum256([]byte("rotated-token-hash"))
	if err := store.RotateToken(store.OwnerID(), 0, newHash); err != nil {
		t.Fatalf("RotateToken: %v", err)
	}
	// A second rotation against the stale epoch is refused: the stored hash
	// must never describe a different epoch than the column says.
	if err := store.RotateToken(store.OwnerID(), 0, sha256.Sum256([]byte("third-hash"))); err == nil {
		t.Fatal("stale-epoch rotation succeeded, want error")
	}
	if _, ok, err := store.ReaderIDForTokenHash(oldHash); err != nil {
		t.Fatalf("old lookup: %v", err)
	} else if ok {
		t.Fatal("old hash still resolves after rotation")
	}
	if id, ok, err := store.ReaderIDForTokenHash(newHash); err != nil {
		t.Fatalf("new lookup: %v", err)
	} else if !ok || id != store.OwnerID() {
		t.Fatalf("new hash resolved to (%d, %v), want owner", id, ok)
	}
	if _, epoch, err := store.ReaderTokenInfo(store.OwnerID()); err != nil {
		t.Fatalf("ReaderTokenInfo: %v", err)
	} else if epoch != 1 {
		t.Fatalf("epoch = %d after rotation, want 1", epoch)
	}
	store.Close()

	reopened, err := Open(url, testOwner)
	if err != nil {
		t.Fatalf("reopen: %v", err)
	}
	t.Cleanup(func() { reopened.Close() })
	if _, ok, err := reopened.ReaderIDForTokenHash(oldHash); err != nil {
		t.Fatalf("old lookup after reopen: %v", err)
	} else if ok {
		t.Fatal("restart resurrected the pre-rotation hash")
	}
	if _, ok, err := reopened.ReaderIDForTokenHash(newHash); err != nil {
		t.Fatalf("new lookup after reopen: %v", err)
	} else if !ok {
		t.Fatal("restart dropped the rotated hash")
	}
}

func TestStoreGet(t *testing.T) {
	store := newTestStore(t)
	if _, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", LastChapterNum: 45, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("Upsert: %v", err)
	}

	got, ok, err := store.Get(store.OwnerID(), "asura:solo")
	if err != nil {
		t.Fatalf("Get: %v", err)
	}
	if !ok {
		t.Fatal("Get ok = false, want true")
	}
	if got.Title != "Solo Leveling" || got.LastChapterNum != 45 {
		t.Fatalf("Get = %+v, want title/chapter preserved", got)
	}
}

func TestStoreGetMissing(t *testing.T) {
	store := newTestStore(t)
	_, ok, err := store.Get(store.OwnerID(), "asura:nope")
	if err != nil {
		t.Fatalf("Get missing returned error %v, want nil", err)
	}
	if ok {
		t.Fatal("Get ok = true for missing key, want false")
	}
}

func TestBookmarkHasNewChapter(t *testing.T) {
	num := func(f float64) *float64 { return &f }
	cases := []struct {
		name string
		b    Bookmark
		want bool
	}{
		{"latest ahead", Bookmark{LastChapterNum: 45, LatestChapterNum: num(47)}, true},
		{"latest equal", Bookmark{LastChapterNum: 45, LatestChapterNum: num(45)}, false},
		{"latest behind", Bookmark{LastChapterNum: 45, LatestChapterNum: num(44)}, false},
		{"latest unknown", Bookmark{LastChapterNum: 45}, false},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := tc.b.HasNewChapter(); got != tc.want {
				t.Fatalf("HasNewChapter() = %v, want %v", got, tc.want)
			}
		})
	}
}

func TestBookmarkContinueURL(t *testing.T) {
	cases := []struct {
		name string
		b    Bookmark
		want string
	}{
		{"chapter url present", Bookmark{LastChapterURL: "/ch/45", SeriesURL: "/series"}, "/ch/45"},
		{"falls back to series", Bookmark{SeriesURL: "/series"}, "/series"},
		{"both empty", Bookmark{}, ""},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := tc.b.ContinueURL(); got != tc.want {
				t.Fatalf("ContinueURL() = %q, want %q", got, tc.want)
			}
		})
	}
}

// readLatestCheckedAt reads the column directly. It is deliberately absent from
// Series (see Store.MarkLatestChecked), so tests cannot assert on it any other
// way. The key splits the same way the API handler derives site/series_id.
func readLatestCheckedAt(t *testing.T, s *Store, key string) int64 {
	t.Helper()
	site, seriesID, ok := strings.Cut(key, ":")
	if !ok {
		t.Fatalf("key %q: no ':' separator", key)
	}
	var ts int64
	if err := s.db.QueryRow(
		`SELECT latest_checked_at FROM series WHERE site = $1 AND series_id = $2`,
		site, seriesID).Scan(&ts); err != nil {
		t.Fatalf("read latest_checked_at %q: %v", key, err)
	}
	return ts
}

// seedForCheck inserts a bookmark (and with it its series) and forces the
// series' latest_checked_at.
func seedForCheck(t *testing.T, s *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(), 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 TestDueForLatestCheck(t *testing.T) {
	const hour = int64(3600_000)
	now := 10 * hour

	tests := []struct {
		name      string
		checkedAt int64
		seriesURL string
		wantDue   bool
	}{
		{"never checked", 0, "https://asurascans.com/comics/a", true},
		{"checked 30m ago", now - hour/2, "https://asurascans.com/comics/a", false},
		{"checked exactly at cutoff", now - hour, "https://asurascans.com/comics/a", true},
		{"checked 2h ago", now - 2*hour, "https://asurascans.com/comics/a", true},
		{"no series url", 0, "", false},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			s := newTestStore(t)
			seedForCheck(t, s, "asura:x", tt.seriesURL, tt.checkedAt)

			due, err := s.DueForLatestCheck(now-hour, 10)
			if err != nil {
				t.Fatalf("DueForLatestCheck: %v", err)
			}
			if got := len(due) == 1; got != tt.wantDue {
				t.Fatalf("due=%v, want %v (got %d rows)", got, tt.wantDue, len(due))
			}
		})
	}
}

func TestDueForLatestCheckOldestFirstAndLimited(t *testing.T) {
	s := newTestStore(t)
	// Insert newest-checked first so a correct ORDER BY has to reverse it.
	seedForCheck(t, s, "asura:c", "https://asurascans.com/comics/c", 300)
	seedForCheck(t, s, "asura:b", "https://asurascans.com/comics/b", 200)
	seedForCheck(t, s, "asura:a", "https://asurascans.com/comics/a", 100)

	due, err := s.DueForLatestCheck(1000, 2)
	if err != nil {
		t.Fatalf("DueForLatestCheck: %v", err)
	}
	if len(due) != 2 {
		t.Fatalf("got %d rows, want 2 (limit)", len(due))
	}
	if due[0].Key() != "asura:a" || due[1].Key() != "asura:b" {
		t.Fatalf("got %q,%q; want asura:a,asura:b (oldest first)", due[0].Key(), due[1].Key())
	}
}

func TestMarkLatestChecked(t *testing.T) {
	s := newTestStore(t)
	seedForCheck(t, s, "asura:x", "https://asurascans.com/comics/x", 0)

	if err := s.MarkLatestChecked("asura", "x", 4242); err != nil {
		t.Fatalf("MarkLatestChecked: %v", err)
	}
	if got := readLatestCheckedAt(t, s, "asura:x"); got != 4242 {
		t.Fatalf("latest_checked_at = %d, want 4242", got)
	}
	// A missing series is not an error: its bookmarks may have been deleted
	// mid-fetch.
	if err := s.MarkLatestChecked("asura", "gone", 1); err != nil {
		t.Fatalf("MarkLatestChecked on missing series: %v", err)
	}
}

// Upsert must not touch latest_checked_at. If the column ever migrates into
// the client-visible write path, this fails and the cooldown is silently dead.
func TestUpsertPreservesLatestCheckedAt(t *testing.T) {
	s := newTestStore(t)
	seedForCheck(t, s, "asura:x", "https://asurascans.com/comics/x", 999)

	b, ok, err := s.Get(s.OwnerID(), "asura:x")
	if err != nil || !ok {
		t.Fatalf("Get: %v ok=%v", err, ok)
	}
	b.Title = "changed"
	if _, err := s.Upsert(s.OwnerID(), b); err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if got := readLatestCheckedAt(t, s, "asura:x"); got != 999 {
		t.Fatalf("latest_checked_at = %d after Upsert, want 999", got)
	}
}

func TestUpsertDefaultsStatusToReading(t *testing.T) {
	store := newTestStore(t)
	stored, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		UpdatedAt: time.Now().UnixMilli(),
	})
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if stored.Status != StatusReading {
		t.Fatalf("Status = %q, want %q", stored.Status, StatusReading)
	}
}

// An empty status means "no opinion" — a userscript build that predates the
// column must not reset the bucket on every progress PUT.
func TestUpsertEmptyStatusPreservesStored(t *testing.T) {
	store := newTestStore(t)
	base := Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Status: StatusArchived, UpdatedAt: time.Now().UnixMilli(),
	}
	if _, err := store.Upsert(store.OwnerID(), base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	base.Status = ""
	base.LastChapterNum = 12
	stored, err := store.Upsert(store.OwnerID(), base)
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if stored.Status != StatusArchived {
		t.Fatalf("Status = %q, want it preserved as %q", stored.Status, StatusArchived)
	}
}

// Mirrors the poller's read-modify-write in latest.go: Get the current row,
// mutate only the latest-chapter fields, and Upsert the whole struct back.
// cur.Status comes from Get (never empty — see scanBookmark), so it must
// round-trip through Upsert unchanged rather than being reset.
func TestLatestPollRoundTripPreservesArchived(t *testing.T) {
	store := newTestStore(t)
	base := Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Status: StatusArchived, UpdatedAt: time.Now().UnixMilli(),
	}
	if _, err := store.Upsert(store.OwnerID(), base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	cur, found, err := store.Get(store.OwnerID(), base.Key)
	if err != nil || !found {
		t.Fatalf("Get: found=%v err=%v", found, err)
	}

	num := 7.0
	cur.LatestChapter = "7"
	cur.LatestChapterNum = &num
	cur.UpdatedAt = time.Now().UnixMilli()

	stored, err := store.Upsert(store.OwnerID(), cur)
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if stored.Status != StatusArchived {
		t.Fatalf("Status = %q, want it preserved as %q", stored.Status, StatusArchived)
	}
}

func TestUpsertReplacesStatusWhenGiven(t *testing.T) {
	store := newTestStore(t)
	base := Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Status: StatusArchived, UpdatedAt: time.Now().UnixMilli(),
	}
	if _, err := store.Upsert(store.OwnerID(), base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	base.Status = StatusReading
	stored, err := store.Upsert(store.OwnerID(), base)
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if stored.Status != StatusReading {
		t.Fatalf("Status = %q, want %q", stored.Status, StatusReading)
	}
}

// A status change is not reading progress, so the list must not reorder.
func TestUpsertStatusChangeKeepsUpdatedAt(t *testing.T) {
	store := newTestStore(t)
	base := Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		LastChapter: "45", LastChapterNum: 45,
		UpdatedAt: time.Now().UnixMilli(),
	}
	first, err := store.Upsert(store.OwnerID(), base)
	if err != nil {
		t.Fatalf("seed: %v", err)
	}

	base.Status = StatusArchived
	base.UpdatedAt = first.UpdatedAt + 60_000
	stored, err := store.Upsert(store.OwnerID(), base)
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if stored.UpdatedAt != first.UpdatedAt {
		t.Fatalf("UpdatedAt = %d, want it frozen at %d", stored.UpdatedAt, first.UpdatedAt)
	}
}

// Archiving is the reason to keep polling — the point is to come back to a
// series that has moved on. A finished series has nothing left to publish.
func TestDueForLatestCheckSkipsFinishedKeepsArchived(t *testing.T) {
	store := newTestStore(t)
	for _, tc := range []struct{ key, status string }{
		{"asura:reading", StatusReading},
		{"asura:archived", StatusArchived},
		{"asura:finished", StatusFinished},
	} {
		if _, err := store.Upsert(store.OwnerID(), Bookmark{
			Key: tc.key, Site: "asura", SeriesID: strings.TrimPrefix(tc.key, "asura:"),
			SeriesURL: "https://asurascans.com/comics/" + tc.key,
			Status:    tc.status, UpdatedAt: time.Now().UnixMilli(),
		}); err != nil {
			t.Fatalf("seed %s: %v", tc.key, err)
		}
	}

	due, err := store.DueForLatestCheck(time.Now().UnixMilli(), 10)
	if err != nil {
		t.Fatalf("DueForLatestCheck: %v", err)
	}
	got := map[string]bool{}
	for _, sr := range due {
		got[sr.Key()] = true
	}
	if !got["asura:reading"] || !got["asura:archived"] {
		t.Fatalf("due = %v, want reading and archived present", got)
	}
	if got["asura:finished"] {
		t.Fatal("due included a finished series")
	}
}

func TestDisplayChapter(t *testing.T) {
	cases := []struct {
		name string
		raw  string
		num  float64
		want string
	}{
		{"userscript label", "Chapter 250", 250, "Ch 250"},
		{"abbreviated with dot", "Ch. 12", 12, "Ch 12"},
		{"lowercase abbreviation", "ch 3", 3, "Ch 3"},
		{"bare number from a manual edit", "45.5", 45.5, "Ch 45.5"},
		{"empty falls back to the number", "", 7, "Ch 7"},
		{"empty and zero", "", 0, "Ch 0"},
		{"label with no number passes through", "Prologue", 0, "Prologue"},
		{"title-like label keeps its words", "Chapter of the Sun", 0, "of the Sun"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := displayChapter(tc.raw, tc.num); got != tc.want {
				t.Errorf("displayChapter(%q, %v) = %q, want %q", tc.raw, tc.num, got, tc.want)
			}
		})
	}

	b := Bookmark{LastChapter: "Chapter 9", LastChapterNum: 9}
	if got := b.DisplayChapter(); got != "Ch 9" {
		t.Errorf("DisplayChapter() = %q, want %q", got, "Ch 9")
	}
	if got := b.DisplayLatest(); got != "Ch 0" {
		t.Errorf("DisplayLatest() with nothing captured = %q, want %q", got, "Ch 0")
	}
	num := 11.0
	b.LatestChapter, b.LatestChapterNum = "Chapter 11", &num
	if got := b.DisplayLatest(); got != "Ch 11" {
		t.Errorf("DisplayLatest() = %q, want %q", got, "Ch 11")
	}
}

func TestCoverURL(t *testing.T) {
	cases := []struct {
		name  string
		cover string
		want  string
	}{
		{
			"kagane routes through the proxy",
			"https://kagane.to/api/v2/image/019fe11a-84c3-7fc3-a84b-88787374b617/compressed",
			"/img/kagane/019fe11a-84c3-7fc3-a84b-88787374b617",
		},
		{
			"another site is served as stored",
			"https://gg.asuracomic.net/storage/media/1/conversions/cover.webp",
			"https://gg.asuracomic.net/storage/media/1/conversions/cover.webp",
		},
		{
			"a lookalike host is not rewritten",
			"https://evil.example/api/v2/image/019fe11a-84c3-7fc3-a84b-88787374b617/compressed",
			"https://evil.example/api/v2/image/019fe11a-84c3-7fc3-a84b-88787374b617/compressed",
		},
		{"no cover stays empty", "", ""},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := (Bookmark{Cover: tc.cover}).CoverURL(); got != tc.want {
				t.Errorf("CoverURL() = %q, want %q", got, tc.want)
			}
		})
	}
}

func TestUpsertKindDefaultsToManga(t *testing.T) {
	store := newTestStore(t)
	got, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", UpdatedAt: 1000,
	})
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if got.Kind != KindManga {
		t.Fatalf("Kind = %q, want %q", got.Kind, KindManga)
	}
}

func TestUpsertKindRoundTrips(t *testing.T) {
	store := newTestStore(t)
	got, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "lightnovelworld:a-will-eternal", Site: "lightnovelworld",
		SeriesID: "a-will-eternal", Kind: KindNovel, UpdatedAt: 1000,
	})
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if got.Kind != KindNovel {
		t.Fatalf("Kind = %q, want %q", got.Kind, KindNovel)
	}
}

// The real hazard: a client that predates the column sends no kind at all. That
// must keep the stored library, not silently demote a novel to manga.
func TestUpsertEmptyKindKeepsStoredValue(t *testing.T) {
	store := newTestStore(t)
	if _, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "lightnovelworld:a-will-eternal", Site: "lightnovelworld",
		SeriesID: "a-will-eternal", Kind: KindNovel, LastChapterNum: 10, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}

	got, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "lightnovelworld:a-will-eternal", Site: "lightnovelworld",
		SeriesID: "a-will-eternal", Kind: "", LastChapterNum: 11, UpdatedAt: 2000,
	})
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if got.Kind != KindNovel {
		t.Fatalf("Kind = %q, want %q — an empty kind must not reset the library", got.Kind, KindNovel)
	}
	if got.LastChapterNum != 11 {
		t.Fatalf("LastChapterNum = %v, want 11 — progress in the same request must still land", got.LastChapterNum)
	}
}

// The 0002 backfill must survive a database that already ran 0001 with real
// rows: one series row per distinct (site, series_id) carrying the moved
// columns, and the bookmark keeping the rest. That is the upgrade path for
// every deployed database, so it is exercised rather than trusted.
func TestMigration0002BackfillsExistingBookmarks(t *testing.T) {
	url := pgtest.URL(t)
	db, err := sql.Open("pgx", url)
	if err != nil {
		t.Fatalf("open: %v", err)
	}
	t.Cleanup(func() { db.Close() })

	// Run only 0001, as a database created before this change would have.
	// migrate() normally creates the version table first; do the same here.
	if _, err := db.Exec(`CREATE TABLE IF NOT EXISTS schema_migrations (
		version    bigint PRIMARY KEY,
		applied_at timestamptz NOT NULL DEFAULT now())`); err != nil {
		t.Fatalf("create version table: %v", err)
	}
	body, err := migrations.ReadFile("migrations/0001_bookmarks.sql")
	if err != nil {
		t.Fatalf("read 0001: %v", err)
	}
	if err := applyMigration(db, 1, string(body)); err != nil {
		t.Fatalf("apply 0001: %v", err)
	}
	if _, err := db.Exec(`
		INSERT INTO bookmarks (key, site, series_id, title, series_url, cover,
			last_chapter, last_chapter_num, last_chapter_url, favorite, latest_chapter,
			latest_chapter_num, latest_checked_at, status, kind, updated_at)
		VALUES ('asura:solo', 'asura', 'solo', 'Solo Leveling',
			'https://asurascans.com/comics/solo', 'https://asurascans.com/covers/solo.jpg',
			'Chapter 10', 10, 'https://asurascans.com/comics/solo/ch/10', true,
			'Chapter 11', 11, 123456, 'reading', 'manga', 1000)`); err != nil {
		t.Fatalf("seed legacy row: %v", err)
	}

	// Bring it current through the production path: Open runs the schema to
	// 0003, seeds the owner, then applies 0004 which attaches this row. 0002
	// must have backfilled the series row, not lost data.
	st, err := Open(url, testOwner)
	if err != nil {
		t.Fatalf("Open after migrate: %v", err)
	}
	defer st.Close()
	var (
		title   string
		checked int64
		fav     bool
		lastNum float64
	)
	if err := db.QueryRow(`SELECT title, latest_checked_at FROM series
		WHERE site = 'asura' AND series_id = 'solo'`).Scan(&title, &checked); err != nil {
		t.Fatalf("series row missing after migration: %v", err)
	}
	if title != "Solo Leveling" || checked != 123456 {
		t.Fatalf("series = (%q, %d), want backfilled title and latest_checked_at", title, checked)
	}
	// The key column is gone; the bookmark is read by its composite key.
	if err := db.QueryRow(`SELECT favorite, last_chapter_num FROM bookmarks
		WHERE reader_id = $1 AND site = 'asura' AND series_id = 'solo'`,
		st.OwnerID()).Scan(&fav, &lastNum); err != nil {
		t.Fatalf("bookmark row missing after migration: %v", err)
	}
	if !fav || lastNum != 10 {
		t.Fatalf("bookmark = (%v, %v), want favorite and progress kept", fav, lastNum)
	}
}

// readSeries reads the series row directly, for asserting on what Upsert
// actually stored rather than what the joined Bookmark reports.
func readSeries(t *testing.T, s *Store, site, seriesID string) Series {
	t.Helper()
	sr, err := scanSeries(s.db.QueryRow(
		`SELECT `+seriesColumns+`, 0 AS reader_count FROM series s
		 WHERE s.site = $1 AND s.series_id = $2`, site, seriesID).Scan)
	if err != nil {
		t.Fatalf("read series %s:%s: %v", site, seriesID, err)
	}
	return sr
}

// The first PUT for a series creates its row from the client's title, cover
// and URL — there is no other source for them (ADR-0003).
func TestUpsertCreatesSeriesFromClient(t *testing.T) {
	store := newTestStore(t)
	if _, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", SeriesURL: "https://asurascans.com/comics/solo",
		Cover: "https://asurascans.com/covers/solo.jpg", Kind: KindManga,
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("Upsert: %v", err)
	}

	sr := readSeries(t, store, "asura", "solo")
	if sr.Title != "Solo Leveling" || sr.SeriesURL != "https://asurascans.com/comics/solo" ||
		sr.Cover != "https://asurascans.com/covers/solo.jpg" {
		t.Fatalf("series = %+v, want client title/url/cover stored", sr)
	}
}

// A PUT naming an existing series must not overwrite its title, cover or URL:
// the row is shared, and those values are scraped page content (ADR-0003).
func TestUpsertExistingSeriesIgnoresClientTitleCoverURL(t *testing.T) {
	store := newTestStore(t)
	base := Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", SeriesURL: "https://asurascans.com/comics/solo",
		Cover: "https://asurascans.com/covers/solo.jpg", LastChapterNum: 10,
		UpdatedAt: 1000,
	}
	if _, err := store.Upsert(store.OwnerID(), base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	// Same series, hostile/compromised values, real progress advance.
	base.Title = "Scraped Rename"
	base.SeriesURL = "https://evil.example/solo"
	base.Cover = "https://evil.example/solo.jpg"
	base.LastChapterNum = 11
	got, err := store.Upsert(store.OwnerID(), base)
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if got.Title != "Solo Leveling" || got.SeriesURL != "https://asurascans.com/comics/solo" ||
		got.Cover != "https://asurascans.com/covers/solo.jpg" {
		t.Fatalf("stored = %+v, want original title/url/cover kept", got)
	}
	if got.LastChapterNum != 11 {
		t.Fatalf("LastChapterNum = %v, want 11 — progress in the same request must still land", got.LastChapterNum)
	}
}

// Kind and latest-chapter are last-write-wins even on an existing series: the
// poller and the userscript both report the latest chapter, and kind is only
// known to whichever client created the row.
func TestUpsertExistingSeriesAcceptsKindAndLatest(t *testing.T) {
	store := newTestStore(t)
	base := Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", Kind: KindManga,
		UpdatedAt: 1000,
	}
	if _, err := store.Upsert(store.OwnerID(), base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	num := 12.0
	base.Kind = KindNovel
	base.LatestChapter = "Chapter 12"
	base.LatestChapterNum = &num
	got, err := store.Upsert(store.OwnerID(), base)
	if err != nil {
		t.Fatalf("Upsert: %v", err)
	}
	if got.Kind != KindNovel || got.LatestChapter != "Chapter 12" ||
		got.LatestChapterNum == nil || *got.LatestChapterNum != 12 {
		t.Fatalf("stored = %+v, want kind and latest chapter updated", got)
	}
}

// Deleting the last bookmark must leave the series row behind, so a later
// re-bookmark shows title and cover immediately instead of waiting for a poll.
func TestDeleteKeepsSeriesRow(t *testing.T) {
	store := newTestStore(t)
	if _, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", Cover: "https://asurascans.com/covers/solo.jpg",
		UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	if err := store.Delete(store.OwnerID(), "asura:solo"); err != nil {
		t.Fatalf("Delete: %v", err)
	}

	sr := readSeries(t, store, "asura", "solo")
	if sr.Title != "Solo Leveling" {
		t.Fatalf("series = %+v, want it kept after the last bookmark is deleted", sr)
	}

	// Re-bookmark with nothing but progress: the stored title/cover come back.
	stored, err := store.Upsert(store.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		LastChapterNum: 5, UpdatedAt: 2000,
	})
	if err != nil {
		t.Fatalf("re-upsert: %v", err)
	}
	if stored.Title != "Solo Leveling" || stored.Cover != "https://asurascans.com/covers/solo.jpg" {
		t.Fatalf("re-bookmark = %+v, want title/cover from the surviving series row", stored)
	}
}

// seedSecondReader inserts an extra bookmark on an existing series, owned by a
// second reader. Two bookmarks can share a series only across readers now
// (issue #22); the due queue's reader-count ordering counts them all.
func seedSecondReader(t *testing.T, s *Store, key, site, seriesID string, updatedAt int64) {
	t.Helper()
	if _, err := s.Upsert(secondReader(t, s), Bookmark{
		Key: key, Site: site, SeriesID: seriesID, UpdatedAt: updatedAt,
	}); err != nil {
		t.Fatalf("seed second reader %q: %v", key, err)
	}
}

// The whole point of the split: a shared series is due once, ordered ahead of
// single-reader series by how many bookmarks reference it.
func TestDueForLatestCheckOrdersByReaderCountThenAge(t *testing.T) {
	s := newTestStore(t)
	// "pop" has two bookmarks but was checked most recently; "solo" has one and
	// was checked long ago. Reader count must win over age.
	seedForCheck(t, s, "asura:pop", "https://asurascans.com/comics/pop", 900)
	seedSecondReader(t, s, "asura:pop:2", "asura", "pop", 1001)
	seedForCheck(t, s, "asura:solo", "https://asurascans.com/comics/solo", 100)

	due, err := s.DueForLatestCheck(1000, 10)
	if err != nil {
		t.Fatalf("DueForLatestCheck: %v", err)
	}
	if len(due) != 2 {
		t.Fatalf("due = %d rows, want 2", len(due))
	}
	if due[0].Key() != "asura:pop" || due[1].Key() != "asura:solo" {
		t.Fatalf("due order = %q, %q; want asura:pop (2 readers), asura:solo (1)",
			due[0].Key(), due[1].Key())
	}
}

// A series with no bookmarks must never appear in the due queue, and nothing
// in the store ever deletes it (see TestDeleteKeepsSeriesRow).
func TestDueForLatestCheckExcludesOrphanSeries(t *testing.T) {
	s := newTestStore(t)
	seedForCheck(t, s, "asura:kept", "https://asurascans.com/comics/kept", 0)
	if _, err := s.db.Exec(`
		INSERT INTO series (site, series_id, title, series_url, cover, kind,
		                    latest_chapter, latest_chapter_num, latest_checked_at)
		VALUES ('asura', 'orphan', 'Orphan', 'https://asurascans.com/comics/orphan',
		        '', 'manga', '', NULL, 0)`); err != nil {
		t.Fatalf("seed orphan series: %v", err)
	}

	due, err := s.DueForLatestCheck(1000, 10)
	if err != nil {
		t.Fatalf("DueForLatestCheck: %v", err)
	}
	if len(due) != 1 || due[0].Key() != "asura:kept" {
		t.Fatalf("due = %+v, want only the bookmarked series", due)
	}
	var n int
	if err := s.db.QueryRow(
		`SELECT count(*) FROM series WHERE site = 'asura' AND series_id = 'orphan'`).Scan(&n); err != nil {
		t.Fatalf("count orphan series: %v", err)
	}
	if n != 1 {
		t.Fatalf("orphan series count = %d, want 1 (never deleted)", n)
	}
}

// The seed must never multiply the owner row: reopening the same database with
// a different token hash refreshes the stored hash, not the row. That is what
// keeps the readers table at exactly one row across restarts and token
// rotations.
func TestSeedOwnerIdempotentAndRefreshesTokenHash(t *testing.T) {
	url := pgtest.URL(t)
	first, err := Open(url, Owner{DiscordID: "owner", TokenHash: sha256.Sum256([]byte("hash-v1"))})
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	ownerID := first.OwnerID()
	first.Close()

	second, err := Open(url, Owner{DiscordID: "owner", TokenHash: sha256.Sum256([]byte("hash-v2"))})
	if err != nil {
		t.Fatalf("reopen: %v", err)
	}
	defer second.Close()
	if second.OwnerID() != ownerID {
		t.Fatalf("owner id = %d after reopen, want %d (same row)", second.OwnerID(), ownerID)
	}
	var (
		n    int
		hash []byte
	)
	if err := second.db.QueryRow(`SELECT count(*), (SELECT token_sha256 FROM readers LIMIT 1) FROM readers`).Scan(&n, &hash); err != nil {
		t.Fatalf("read readers: %v", err)
	}
	if n != 1 {
		t.Fatalf("readers count = %d, want 1", n)
	}
	want := sha256.Sum256([]byte("hash-v2"))
	if !bytes.Equal(hash, want[:]) {
		t.Fatalf("token hash = %x, want the refreshed sha256", hash)
	}
}

// The upgrade path for a deployed database: bookmarks created before readers
// existed must all land on the seeded owner, the key column must be gone, and
// the same database must be able to hold two readers' bookmarks for one series.
func TestMigration0004AttachesBookmarksToOwner(t *testing.T) {
	url := pgtest.URL(t)
	db, err := sql.Open("pgx", url)
	if err != nil {
		t.Fatalf("open: %v", err)
	}
	t.Cleanup(func() { db.Close() })

	// A database at the state before #21 shipped: 0001 applied, bookmarks
	// keyed by <site>:<series_id>, no series table. Rows land before 0002, the
	// way a real deployment's data did.
	if err := migrate(db, 1); err != nil {
		t.Fatalf("migrate to 0001: %v", err)
	}
	for _, key := range []string{"asura:solo", "demonic:catastrophic-necromancer"} {
		site, seriesID, ok := strings.Cut(key, ":")
		if !ok {
			t.Fatalf("key %q: no ':' separator", key)
		}
		if _, err := db.Exec(`
			INSERT INTO bookmarks (key, site, series_id, updated_at)
			VALUES ($1, $2, $3, 1000)`, key, site, seriesID); err != nil {
			t.Fatalf("seed legacy row %q: %v", key, err)
		}
	}
	// 0002 backfills the series rows, as it did in the real upgrade.
	if err := migrate(db, 2); err != nil {
		t.Fatalf("migrate to 0002: %v", err)
	}

	st, err := Open(url, testOwner)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	defer st.Close()

	var (
		attached int
		readers  int
	)
	if err := st.db.QueryRow(
		`SELECT count(*) FROM bookmarks WHERE reader_id = $1`, st.OwnerID()).Scan(&attached); err != nil {
		t.Fatalf("count attached bookmarks: %v", err)
	}
	if attached != 2 {
		t.Fatalf("bookmarks attached to owner = %d, want all 2", attached)
	}
	if err := st.db.QueryRow(`SELECT count(*) FROM readers`).Scan(&readers); err != nil {
		t.Fatalf("count readers: %v", err)
	}
	if readers != 1 {
		t.Fatalf("readers = %d, want 1", readers)
	}
	// The surrogate key column is gone; only the composite key remains.
	if _, err := st.db.Query(`SELECT key FROM bookmarks`); err == nil {
		t.Fatal("bookmarks.key still exists after the migration")
	}
}

// One Reader and Series pair must admit at most one bookmark, enforced by the
// primary key itself — a raw INSERT that skips the upsert must fail.
func TestBookmarkDuplicateImpossibleAtDatabaseLevel(t *testing.T) {
	st := newTestStore(t)
	// A series row on its own, no bookmark: the raw inserts below must only
	// ever collide on the bookmark primary key.
	if _, err := st.db.Exec(
		`INSERT INTO series (site, series_id) VALUES ('asura', 'solo')`); err != nil {
		t.Fatalf("seed series: %v", err)
	}
	insert := func() error {
		_, err := st.db.Exec(`
			INSERT INTO bookmarks (reader_id, site, series_id, updated_at)
			VALUES ($1, 'asura', 'solo', 1000)`, st.OwnerID())
		return err
	}
	if err := insert(); err != nil {
		t.Fatalf("first insert: %v", err)
	}
	if err := insert(); err == nil {
		t.Fatal("duplicate bookmark for the same reader and series was accepted")
	}
}

// Every read and write is scoped to the reader it names: a second reader sees
// an empty list, cannot read or delete the owner's row, and a delete by the
// wrong reader leaves the row alone.
func TestStoreScopesBookmarksToReader(t *testing.T) {
	st := newTestStore(t)
	other := secondReader(t, st)
	if _, err := st.Upsert(st.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed owner bookmark: %v", err)
	}

	otherList, err := st.List(other)
	if err != nil {
		t.Fatalf("List(other): %v", err)
	}
	if len(otherList) != 0 {
		t.Fatalf("other reader's list = %+v, want empty", otherList)
	}
	if _, ok, err := st.Get(other, "asura:solo"); err != nil || ok {
		t.Fatalf("Get(other, asura:solo) = ok:%v err:%v, want not found", ok, err)
	}
	if err := st.Delete(other, "asura:solo"); err != nil {
		t.Fatalf("Delete(other): %v", err)
	}
	ownerList, err := st.List(st.OwnerID())
	if err != nil {
		t.Fatalf("List(owner): %v", err)
	}
	if len(ownerList) != 1 || ownerList[0].Key != "asura:solo" {
		t.Fatalf("owner's list after other's delete = %+v, want the row intact", ownerList)
	}

	// The same key under a second reader is an independent bookmark.
	if _, err := st.Upsert(other, Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", UpdatedAt: 2000,
	}); err != nil {
		t.Fatalf("upsert other's bookmark: %v", err)
	}
	if got, err := st.List(other); err != nil || len(got) != 1 {
		t.Fatalf("other's list after own upsert = %+v err:%v, want 1 row", got, err)
	}
}

// Deleting a reader must take their bookmarks with them (ON DELETE CASCADE)
// while leaving the shared series row behind.
func TestDeleteReaderCascadesToBookmarks(t *testing.T) {
	st := newTestStore(t)
	other := secondReader(t, st)
	if _, err := st.Upsert(other, Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed other's bookmark: %v", err)
	}

	if _, err := st.db.Exec(`DELETE FROM readers WHERE id = $1`, other); err != nil {
		t.Fatalf("delete reader: %v", err)
	}
	var n int
	if err := st.db.QueryRow(`SELECT count(*) FROM bookmarks`).Scan(&n); err != nil {
		t.Fatalf("count bookmarks: %v", err)
	}
	if n != 0 {
		t.Fatalf("bookmarks after reader delete = %d, want 0 (cascade)", n)
	}
	sr := readSeries(t, st, "asura", "solo")
	if sr.Title != "Solo Leveling" {
		t.Fatalf("series = %+v, want it kept after its only reader was deleted", sr)
	}
}

// Registration is one code path: the first sight of a Discord identity creates
// the Reader, every later one returns the same row. The epoch-0 hash argument
// is for creation only — a returning Reader who has rotated must not have that
// rotation undone by logging in again.
func TestEnsureReaderCreatesOnceAndNeverClobbersARotation(t *testing.T) {
	s := newTestStore(t)
	first, err := s.EnsureReader("new-member", sha256.Sum256([]byte("cred-epoch-0")))
	if err != nil {
		t.Fatalf("EnsureReader: %v", err)
	}
	if first == s.OwnerID() {
		t.Fatal("a new Discord identity resolved to the owner Reader")
	}
	if id, ok, err := s.ReaderIDForTokenHash(sha256.Sum256([]byte("cred-epoch-0"))); err != nil || !ok || id != first {
		t.Fatalf("new Reader's credential resolved to (%d, %v, %v), want (%d, true, nil)", id, ok, err, first)
	}

	rotated := sha256.Sum256([]byte("cred-epoch-1"))
	if err := s.RotateToken(first, 0, rotated); err != nil {
		t.Fatalf("RotateToken: %v", err)
	}

	again, err := s.EnsureReader("new-member", sha256.Sum256([]byte("cred-epoch-0")))
	if err != nil {
		t.Fatalf("second EnsureReader: %v", err)
	}
	if again != first {
		t.Fatalf("second login returned Reader %d, want the existing %d", again, first)
	}
	if _, ok, err := s.ReaderIDForTokenHash(sha256.Sum256([]byte("cred-epoch-0"))); err != nil {
		t.Fatalf("stale lookup: %v", err)
	} else if ok {
		t.Fatal("logging in again revived the pre-rotation credential")
	}
	if id, ok, err := s.ReaderIDForTokenHash(rotated); err != nil || !ok || id != first {
		t.Fatalf("rotated credential resolved to (%d, %v, %v), want the same Reader", id, ok, err)
	}

	// Signing in as the owner's own Discord identity reuses the seeded row
	// rather than minting a duplicate library.
	if id, err := s.EnsureReader(testOwner.DiscordID, sha256.Sum256([]byte("ignored"))); err != nil {
		t.Fatalf("EnsureReader(owner): %v", err)
	} else if id != s.OwnerID() {
		t.Fatalf("owner login returned Reader %d, want the seeded owner %d", id, s.OwnerID())
	}
}

// The owner's administration view: who exists and how many live sessions each
// holds. Revocation drops all of one Reader's sessions and nobody else's.
func TestReadersAndSessionRevocation(t *testing.T) {
	s := newTestStore(t)
	other := secondReader(t, s)
	for _, id := range []string{"own-1", "own-2"} {
		if _, err := s.CreateSession(id, s.OwnerID(), time.Hour); err != nil {
			t.Fatalf("CreateSession(%s): %v", id, err)
		}
	}
	if _, err := s.CreateSession("other-1", other, time.Hour); err != nil {
		t.Fatalf("CreateSession(other): %v", err)
	}
	// An expired row must not be counted as a session the owner can revoke.
	if _, err := s.CreateSession("other-dead", other, -time.Minute); err != nil {
		t.Fatalf("CreateSession(expired): %v", err)
	}

	readers, err := s.Readers()
	if err != nil {
		t.Fatalf("Readers: %v", err)
	}
	if len(readers) != 2 || readers[0].ID != s.OwnerID() || readers[1].ID != other {
		t.Fatalf("readers = %+v, want the owner then the second Reader", readers)
	}
	if readers[0].DiscordID != testOwner.DiscordID {
		t.Fatalf("owner discord id = %q, want %q", readers[0].DiscordID, testOwner.DiscordID)
	}
	if readers[0].Sessions != 2 || readers[1].Sessions != 1 {
		t.Fatalf("session counts = %d, %d; want 2 and 1 live", readers[0].Sessions, readers[1].Sessions)
	}

	if err := s.DeleteReaderSessions(other); err != nil {
		t.Fatalf("DeleteReaderSessions: %v", err)
	}
	if _, ok, err := s.GetSession("other-1", time.Now()); err != nil || ok {
		t.Fatalf("revoked session still resolves: ok=%v err=%v", ok, err)
	}
	if _, ok, err := s.GetSession("own-1", time.Now()); err != nil || !ok {
		t.Fatalf("owner's session was collateral: ok=%v err=%v", ok, err)
	}
}

// Two Readers on one Series: one series row, two independent progresses. The
// second Reader starts at zero however far the first has read, and the shared
// row is still due exactly once.
func TestTwoReadersShareOneSeriesWithIndependentProgress(t *testing.T) {
	s := newTestStore(t)
	other := secondReader(t, s)
	if _, err := s.Upsert(s.OwnerID(), Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo",
		Title: "Solo Leveling", SeriesURL: "https://asurascans.com/comics/solo",
		LastChapter: "Chapter 200", LastChapterNum: 200, UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed owner: %v", err)
	}
	theirs, err := s.Upsert(other, Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", UpdatedAt: 2000,
	})
	if err != nil {
		t.Fatalf("seed other: %v", err)
	}
	if theirs.LastChapterNum != 0 || theirs.LastChapter != "" {
		t.Fatalf("second Reader's progress = %+v, want zero regardless of the first's 200", theirs)
	}
	// The shared facts are still shared: the series row it joined to is the
	// one the first Reader created.
	if theirs.Title != "Solo Leveling" {
		t.Fatalf("second Reader's title = %q, want the shared series title", theirs.Title)
	}
	var series int
	if err := s.db.QueryRow(`SELECT count(*) FROM series`).Scan(&series); err != nil {
		t.Fatalf("count series: %v", err)
	}
	if series != 1 {
		t.Fatalf("series rows = %d, want 1 shared row for two bookmarks", series)
	}

	due, err := s.DueForLatestCheck(time.Now().UnixMilli(), 10)
	if err != nil {
		t.Fatalf("DueForLatestCheck: %v", err)
	}
	if len(due) != 1 || due[0].Key() != "asura:solo" {
		t.Fatalf("due = %+v, want the shared series exactly once per cycle", due)
	}

	// One Reader dropping their bookmark leaves the other's intact and the
	// series still polled.
	if err := s.Delete(other, "asura:solo"); err != nil {
		t.Fatalf("Delete(other): %v", err)
	}
	if b, ok, err := s.Get(s.OwnerID(), "asura:solo"); err != nil || !ok || b.LastChapterNum != 200 {
		t.Fatalf("owner's bookmark after the other's delete = %+v ok=%v err=%v, want it intact", b, ok, err)
	}
	due, err = s.DueForLatestCheck(time.Now().UnixMilli(), 10)
	if err != nil {
		t.Fatalf("DueForLatestCheck after delete: %v", err)
	}
	if len(due) != 1 || due[0].Key() != "asura:solo" {
		t.Fatalf("due after one Reader left = %+v, want the series still polled", due)
	}
}