# Implementation plan: bookmark reorder, latest-chapter tracking, favorites

## Context

Design already approved and committed at
`plans/2026-07-25-bookmark-list-favorites-design.md` on branch
`feat/bookmark-list-favorites-latest`. It covers three requested userscript
features plus one incidental bug found while verifying feasibility live via
Playwright:

1. Bookmark list reordered so the most-recently-progressed manga is first.
2. Show the latest *available* chapter for a manga, not just the last one
   read — including a background same-origin refresh mechanism to get closer
   to "live" without server-side polling (Cloudflare blocks that; confirmed
   live, and confirmed no JSON API / RSS exists on either site to poll
   instead).
3. A favorites mechanism (star toggle + tabs) that doesn't remove a manga
   from the normal list.
4. `asuracomic.net` deep links now 301-redirect straight to the
   `asurascans.com` homepage (path discarded) — a Cloudflare-edge redirect
   confirmed live, with no client-side fix possible. Doc-only correction.

This plan turns that design into concrete code changes against the actual
current backend (Go/SQLite) and userscript, informed by full reads of
`backend/store.go`, `backend/handlers.go`, `backend/store_test.go`,
`backend/main.go`, and the full 782-line
`userscript/manga-bookmark.user.js`.

## Key design decision surfaced during planning

Today `handlers.go`'s `put()` echoes back the client's decoded request
struct as the API response, not what was actually persisted. Once
`updated_at` is sometimes *not* bumped (this whole feature's core mechanic),
echoing the request struct back would return a **wrong** `updated_at` to the
caller on every no-bump write — silently breaking the ordering guarantee the
entire feature depends on, since the userscript's `syncUpsert`/mutation
helpers adopt whatever the server echoes back (`upsertLocal(saved)`) as the
new source of truth. **`Store.Upsert` must therefore return the row as
actually written (read back inside the same transaction), and `handlers.go`
must respond with that**, not the client's payload. This is a correctness
fix required by the design, not a new decision to re-litigate.

Confirmed via the user: background latest-chapter refresh should fire on
Asura's SPA in-app navigation too (`onNavigate()`), not only true browser
page loads (`init()`) — more refresh opportunities on a client-routed site
that rarely does full reloads, still bounded by the same throttle/batch
limits.

## Phase 1 — Backend (`backend/`), TDD

### 1.1 Tests first — `backend/store_test.go`

Add four tests (all go through the existing `newTestServer(t)` /
`httptest` pattern already used in this file, since there are no direct
`Store`-level unit tests in the current style):

- **`TestUpsertConditionalUpdatedAt`** — table-driven: new bookmark (bumps),
  unchanged progress (no bump), changed progress (bumps), favorite-only
  change (no bump), latest-chapter-only change (no bump). Assert on the
  `updated_at` returned by each PUT response.
- **`TestFavoriteRoundTrip`** — PUT `favorite: true`, GET list, assert it
  round-trips.
- **`TestLatestChapterNullable`** — PUT without `latest_chapter_num`, assert
  JSON response has `"latest_chapter_num":null`; PUT again with a value,
  assert it round-trips.
- **`TestOpenStoreMigratesLegacySchema`** — hand-create the *old* (10-column)
  schema in a temp DB file, seed one row, then call `OpenStore` on it and
  assert the row survives with the new columns defaulting cleanly
  (`favorite=false`, `latest_chapter=""`, `latest_chapter_num=nil`). This is
  the safety net for the already-deployed production DB.

Run `cd backend && go test ./...` — expect compile failures (red state is
correct/expected before 1.2).

### 1.2 `backend/store.go`

- **`Bookmark` struct**: add `Favorite bool `json:"favorite"``,
  `LatestChapter string `json:"latest_chapter"``,
  `LatestChapterNum *float64 `json:"latest_chapter_num"`` (nullable — only
  this one needs to be a pointer, per the design doc's data-model table).
- **`schema`**: extend `CREATE TABLE IF NOT EXISTS` with
  `favorite INTEGER NOT NULL DEFAULT 0`,
  `latest_chapter TEXT NOT NULL DEFAULT ''`, `latest_chapter_num REAL`
  (covers fresh installs only).
- **Idempotent migration for the already-deployed DB**: add a
  `migrateColumns(db)` helper using `PRAGMA table_info(bookmarks)` to check
  each new column's existence before running its `ALTER TABLE ... ADD
  COLUMN` (SQLite has no `ADD COLUMN IF NOT EXISTS`). Call it in
  `OpenStore` right after the existing `schema` exec succeeds, same
  error-wrapping style as today.
- **Shared `scanBookmark` helper**: centralizes converting the `favorite`
  `INTEGER` (0/1) to `bool` and the nullable `latest_chapter_num` `REAL` to
  `*float64` via `sql.NullFloat64`, used by both `List()` and `Upsert()`'s
  read-back.
- **`List()`**: extend the `SELECT` to the new columns, scan via
  `scanBookmark`.
- **`Upsert(b Bookmark) (Bookmark, error)`** — signature changes to return
  the stored row. Implementation: wrap in `db.Begin()`/`tx.Commit()`
  (explicit "read exactly what I just wrote" guarantee rather than relying
  on `SetMaxOpenConns(1)` staying 1 forever). The `INSERT ... ON CONFLICT
  DO UPDATE SET` gets a `CASE` expression for `updated_at`:
  ```sql
  updated_at = CASE
    WHEN bookmarks.last_chapter_num IS NOT excluded.last_chapter_num
    THEN excluded.updated_at
    ELSE bookmarks.updated_at
  END
  ```
  This is valid SQLite upsert syntax (bare column = pre-update row value,
  `excluded.col` = proposed new row) and naturally handles "new row" for
  free — `ON CONFLICT DO UPDATE` only fires on the update path, so a
  genuinely new row goes through the plain `INSERT ... VALUES` and always
  gets the fresh `updated_at`. After the exec, `SELECT` the row back inside
  the same transaction and return it via `scanBookmark`.

### 1.3 `backend/handlers.go`

In `put()`: keep `b.UpdatedAt = time.Now().UnixMilli()` as a *candidate*
value (update its comment — it's no longer unconditionally authoritative),
then:
```go
stored, err := h.store.Upsert(b)
...
writeJSON(w, http.StatusOK, stored)
```
No other changes — `Favorite`/`LatestChapter`/`LatestChapterNum` already
flow through untouched from the decoded body, which is correct (they're
fully client-set synced fields). `list()`/`delete()` unchanged.

### 1.4 Green + build

```bash
cd backend && go test ./...          # all pass, including pre-existing TestBookmarkRoundTrip unmodified
cd backend && CGO_ENABLED=0 go build  # static binary still builds
```

## Phase 2 — Userscript (`userscript/manga-bookmark.user.js`)

No JS test harness in this repo — verification is manual (Phase 4).

1. **Config constants** (near `CACHE_KEY`, ~line 24): `LASTCHECKED_KEY =
   "mangabm:lastchecked"`, `LATEST_CHECK_THROTTLE_MS = 4 * 60 * 60 * 1000`
   (4h), `LATEST_CHECK_BATCH = 1`.

2. **Shared anchor extraction** so the exact same per-site chapter-matching
   rule runs against both the live DOM and raw fetched HTML text (no HTML
   parser available for the fetch path): `anchorsFromDocument(doc)` (via
   `querySelectorAll("a[href]")`) and `anchorsFromHTML(html)` (regex-based
   `<a href="...">...</a>` extraction). Add near `meta()` (~line 34).

3. **Per-adapter `latestChapterFromAnchors(anchors)`** added to both `asura`
   and `demonic` adapter objects, implementing the regex rules from the
   design doc (Asura: href matches `/chapter/([\d.]+)$/` AND text matches
   `/Chapter\s+[\d.]+/i`, excluding the "First Chapter" quick-jump button;
   Demonic: all `chaptered.php?manga=\d+&chapter=([\d.]+)` matches, take
   max — no order assumption). Plus a `computeLatestChapter(site, anchors)`
   dispatcher near `keyOf()`.

4. **`mangabm:lastchecked` local helpers**: `loadLastChecked()` /
   `saveLastChecked(map)`, parallel to existing `loadCache`/`saveCache`
   (~line 154), storing `{ [bookmarkKey]: timestampMs }`. Client-local only,
   never synced.

5. **`applyLatestChapterIfChanged(existing, latest)`** (~near `syncUpsert`,
   line 295): if `latest.num` differs from the bookmark's stored
   `latest_chapter_num`, optimistically update local cache + render, then
   `apiPut` with `updated_at: Date.now()` as a *candidate* — the backend
   (Phase 1) decides whether to actually apply it, and the client adopts
   whatever comes back via `upsertLocal(saved)`, same pattern the rest of
   the file already uses. No client-side "don't reorder" logic needed
   beyond that — the server is the single source of truth for it. Silent
   on failure (no toast), per the design doc.

6. **Live-page capture**: `maybeCaptureLatestOnSeriesPage()` — on a
   `type: "series"` page for an already-bookmarked series, scan the live
   DOM via `anchorsFromDocument` + `computeLatestChapter`, then
   `applyLatestChapterIfChanged`. Hooked into `onNavigate()` (~line 633),
   after the existing `maybeAutoUpdate()` call.

7. **Background opportunistic refresh**: `backgroundRefreshLatest()` — get
   `currentSite()` (which adapter matches `window.location`), pick
   same-site bookmarks not checked within `LATEST_CHECK_THROTTLE_MS`
   (oldest-checked-first), fetch+parse at most `LATEST_CHECK_BATCH` of them
   via `fetch(bm.series_url).then(r => r.text())` → `anchorsFromHTML` →
   `computeLatestChapter` → `applyLatestChapterIfChanged`. Mark each
   attempted bookmark's `lastchecked` timestamp regardless of success/failure
   (advances the throttle window either way, avoiding hammering a
   consistently-failing fetch). Silent on failure.
   **Hook into both `init()` and `onNavigate()`** (per user's confirmed
   preference — more refresh opportunities on Asura's SPA navigation, same
   throttle/batch caps prevent request bursts either way).

8. **`toggleFavorite(key)`** (~near `setChapterManual`, line 293): flips
   `favorite`, optimistic update, `apiPut` with `Date.now()` candidate
   timestamp (again, backend decides), toast on success/failure (consistent
   with other explicit user-initiated actions like bookmark/remove).

9. **Tabs**: new module state `let activeTab = "all";` (~near `panelOpen`,
   line 374; not persisted, defaults to "all"). Wire click handlers in
   `buildUI()` for new `#tabAll`/`#tabFav` elements. In `render()` (~line
   568), toggle each tab's `.active` class and filter which array feeds the
   list-building loop (`activeTab === "favorites" ? state.list.filter(b =>
   b.favorite) : state.list`) — `state.list` itself is never mutated/filtered,
   so a favorited manga always still appears in "All".

10. **`renderItem(b)`** (~line 579): add a star toggle button (☆/★,
    `onclick: () => toggleFavorite(b.key)`) alongside the existing
    Continue/Edit/Remove buttons, and change the subtitle line to
    `"Read: " + last_chapter + " · Latest: " + latest_chapter` when
    `latest_chapter_num` is known and strictly greater than
    `last_chapter_num` (avoids showing "Latest: Chapter 12" next to "Read:
    Chapter 12" when they're numerically equal); otherwise keep today's
    `"<last_chapter> · <site>"` text.

11. **`TEMPLATE`** (~line 679): insert a tabs bar
    (`<div id="tabs"><button id="tabAll" class="tab active">All</button>
    <button id="tabFav" class="tab">★ Favorites</button></div>`) between
    `#context` and `#list`.

12. **`CSS`** (~near `.ctx-sub`/`.btn.danger`): add `.tab`/`.tab.active` and
    `.btn.star`/`.btn.star.active` rules following the existing dark-theme
    `.btn` modifier convention (`.btn.primary`, `.btn.small`, `.btn.danger`).

13. **Fix the misleading redirect comment** (line 41, in the `asura`
    adapter object): replace "asuracomic.net currently 301s to
    asurascans.com; match both." with an accurate note that the redirect
    now discards the path (goes straight to the asurascans.com root),
    happens at the Cloudflare edge before any JS runs, so no client-side
    fix is possible, and the user should navigate via asurascans.com links
    directly. No change to the `matches()` regex itself.

14. **`@version`**: bump `1.1.0` → `1.2.0`.

## Phase 3 — Documentation

- **`CLAUDE.md`**: update the `PUT /bookmarks/{key}` endpoint description
  (currently "upsert, server sets updated_at") to describe the new
  conditional rule, referencing
  `plans/2026-07-25-bookmark-list-favorites-design.md` §4.
- **`README.md`**: update the matching endpoint-table row, and correct the
  "Adapter reference" section's Asura row to note `asuracomic.net` deep
  links currently 301 to the asurascans.com root (broken/path discarded) —
  use `asurascans.com` links directly. While touching this, also fix
  `CLAUDE.md`'s intro line ("asuracomic.net (formerly asurascans.com)"),
  which has the relationship backwards and is inconsistent with README's
  own phrasing ("asurascans.com (a.k.a. asuracomic.net)") — bundle this
  small adjacent correction in since it's directly related to the same
  finding.

## Verification

**Backend (automated):**
```bash
cd backend && go test ./...
cd backend && CGO_ENABLED=0 go build
```

**Backend (manual smoke test, extends the existing curl convention in
CLAUDE.md/README.md):** PUT a new bookmark, then PUT again changing only
`favorite`, then only `latest_chapter*`, then a real `last_chapter_num`
advance — confirm via `jq .updated_at` that only the first and last calls
change `updated_at`.

**Userscript (manual — no JS test harness exists in this repo, matching
existing project convention):**
- List reorders only on a genuine progress advance, not on plain re-visit,
  favorite toggle, or latest-chapter capture.
- Latest-chapter capture fires when visiting a bookmarked series page on
  both sites and displays the "Read: X · Latest: Y" subtitle correctly.
- Background refresh: check `localStorage['mangabm:lastchecked']` in
  devtools to confirm throttling behavior; confirm via the Network tab that
  it never fires a cross-site request (only same-origin as the currently
  loaded site).
- Favorite toggle persists across a panel close/reopen and a `refresh()`
  round-trip through the backend; favorited manga still shows in "All".
- Fastest iteration path: desktop Tampermonkey/Violentmonkey first (script
  stays `GM_*`-free), then confirm on Bromite per existing project
  convention.

## Critical files
- `backend/store.go`
- `backend/handlers.go`
- `backend/store_test.go`
- `userscript/manga-bookmark.user.js`
- `CLAUDE.md`
- `README.md`