package store

import (
	"database/sql"
	"os"
	"strings"
	"testing"
	"time"

	"bookmarkmanager/backend/internal/pgtest"
)

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

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

// 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)
	if err != nil {
		t.Fatalf("Open: %v", err)
	}
	if _, err := first.Upsert(Bookmark{
		Key: "asura:solo", Site: "asura", SeriesID: "solo", UpdatedAt: 1000,
	}); err != nil {
		t.Fatalf("seed: %v", err)
	}
	first.Close()

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

	list, err := second.List()
	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)
	}
}

func TestStoreGet(t *testing.T) {
	store := newTestStore(t)
	if _, err := store.Upsert(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("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("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(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("asura:x")
	if err != nil || !ok {
		t.Fatalf("Get: %v ok=%v", err, ok)
	}
	b.Title = "changed"
	if _, err := s.Upsert(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(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(base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	base.Status = ""
	base.LastChapterNum = 12
	stored, err := store.Upsert(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(base); err != nil {
		t.Fatalf("seed: %v", err)
	}

	cur, found, err := store.Get(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(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(base); err != nil {
		t.Fatalf("seed: %v", err)
	}

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

	base.Status = StatusArchived
	base.UpdatedAt = first.UpdatedAt + 60_000
	stored, err := store.Upsert(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(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 TestUpsertKindDefaultsToManga(t *testing.T) {
	store := newTestStore(t)
	got, err := store.Upsert(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(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(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(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: 0002 must backfill the series row, not lose data.
	if err := migrate(db); err != nil {
		t.Fatalf("migrate: %v", err)
	}
	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)
	}
	if err := db.QueryRow(`SELECT favorite, last_chapter_num FROM bookmarks
		WHERE key = 'asura:solo'`).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)
	}

	// The migrated database opens as a normal store.
	st, err := Open(url)
	if err != nil {
		t.Fatalf("Open after migrate: %v", err)
	}
	defer st.Close()
}

// 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(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(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(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(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(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(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("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(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. Today the
// bookmark key is <site>:<series_id>, so two bookmarks can share a series only
// once keys stop being derived from the series identity (issue #22); the due
// queue's reader-count ordering must already be right for that world.
func seedSecondReader(t *testing.T, s *Store, key, site, seriesID string, updatedAt int64) {
	t.Helper()
	if _, err := s.Upsert(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)
	}
}