captoys/diigo-cache/CONTRIBUTING.md

# Contributing to diigo-cache

diigo-cache is a Cloudflare Worker cache over [the webapp factory](../webapp/README.md): session-cookie reads of diigo bookmarks, cached in Durable-Object SQLite storage. Evolved from the diigo-dump worker (provenance: [mm-diigo `projects/diigo-bak/`](https://github.com/dckc/mm-diigo)); the static API-key path is dead (see [the capsite checklist](../capsite-checklist.md), goal 2 preamble).

## What it holds

- **The create flow, on one port**: `/_connect` renders webapp's own mint form (diigo-prefilled, cookie blank) — wrangler multi-config dev doesn't serve aux workers' HTTP, so `/_mint` relays the form opaquely into the WEBAPP binding (the cookie crosses; nothing on this side opens or logs it). Mint → `/_wire` (webapp id pre-filled, mode public|private) → the created page, where the user saves the ids.
- **Two independent page caches** (`src/cache.ts`), one behavior: a page hit is served from storage with no diigo call; a miss asks the webapp instance in the cache's wiring and etches the page.
  - `DiigoCache` (binding `CACHE_DO`): every item. Addressed by its cache id.
  - `PublicCache` (binding `PUBLIC_DO`): shared items only — private rows are dropped *before* etching (`publicOnly`), so its storage holds nothing private. Same cookie webapp as the private cache. Public page n is diigo page n, filtered (may show fewer than `PAGE_SIZE`, 100: diigo's cap). `/public/<username>` resolves through the `idFromName("index")` registry, and reads through `viewer()`, a read-only facet: it shows stored pages and fill progress, and can't fetch from diigo or write.
- **Storage**: SQL lives in `src/cache-read.sql` (selects only) and `src/cache-write.sql`; `src/store.ts` turns them into a reader and a writer facet, so the cache logic holds no SQL text.
- **Pages**: home's dump form (cache id + page number, POST) shows raw dump rows; `/public/<username>?page=n` shows an HTML list with a page form (JSON for `Accept: application/json`). Both say `cache: HIT` or `MISS`; every page read also logs `{event: "cache", kind, page, outcome}`.
- **Filters on the public page** (`src/query.ts`): `days`, `after`, `before`, `in` (`2026`, `2026-03`, `2026-Q1`, `2026-W41`), `by=updated|created`, and `q` (words, `"phrases"`, `#tag`, `-` negation, gmail/Slack/GitHub date operators). UTC, half-open windows. The same fields work as a dev-side spec (`toQuery({ days: 7 })`). A filter queries the stored `items` table through `viewer()`, never diigo: results are as fresh as the cache, and JSON says `complete` when every diigo page is stored.
- **Publish later**: `POST /_publish` (cache id in the body) wires a public companion to a private-only cache.
- **The webkey page and Cap'n Web**: `/cache/#<cache id>` is a skeleton page, the same for every key; its script reads the key from the fragment and trades it in-band for a capability over [Cap'n Web](https://github.com/cloudflare/capnweb) at `/api` (`CacheApi.cache(key)` → a `CacheCap` facet: fill, status, the public companion; `src/api.ts`). The worker serves capnweb's browser build itself at `/_capnweb.js`.
- **Fill job**: walks every diigo page into a cache in the background — DO alarms, a few pages per step, progress stored in the DO (`startFill`/`fillStatus`/`stopFill`), driven from the webkey page; the public page shows progress. "Invalidate the last N days" there drops the cached pages holding anything updated that recently (`invalidateRecent`), so the next fill refetches them.
- The `DiigoBridge` entrypoint for other workers (its cache-id source is the goal-2 wiring TODO).

## State surface

Ids are **webkeys** ([the pattern](../docs/webkeys.md)): 256-bit bearer secrets that never ride a query string or path. The webkey page carries the cache id in the URL fragment (never sent to the server) and passes it in-band over Cap'n Web; forms carry ids in POST bodies; logs and pages show only a fingerprint (a prefix of the id's one-way hash).

- **The cache id**: the cache's read capability (bearer; not logged). Held by the user — saved to the password manager under a petname they choose (the username field; never sent to the server) — and passed per POST.
- **The webapp instance id**: the diigo-read capability; lives in each cache DO's wiring, arrives from the mint step.
- **The cookie**: lives **only in webapp's DO storage**; crosses the wire once, at mint time, as an opaque relay.
- **The public cache**: no capability — `/public/<username>` is public by design (a guessable URL; hiding the link doesn't hide the page).

Stored state is meant to be durable: see the breaking-change rule in [capsite AGENTS.md](../AGENTS.md).

## Deployment concern: rate-limit `/api`

Public pages only read storage, so strangers can't make the cache spend your diigo session. `/api` is keyed (a cache id is needed), but Cap'n Web pipelining makes calls cheap to send. Before exposing a deployment:

- rate-limit `/api` (and `/public/*`, which reads storage) — on Cloudflare, the [Workers rate-limit binding](https://developers.cloudflare.com/workers/runtime-apis/bindings/rate-limit/) (keyed by client and/or username); on other workerd hosts, a rate limit in the proxy in front;
- run the fill job (goal 1e): public pages show only what's stored.

## RPC use (from another worker, same account)

```jsonc
// wrangler.jsonc of the caller
"services": [{ "binding": "DIIGO", "service": "diigo-cache", "entrypoint": "DiigoBridge" }]
```

```ts
// cache ids ride goal-2's wiring; see the capsite checklist
const ndjson = await env.DIIGO.dumpNdjson(4); // 4 pages of PAGE_SIZE
```

## Test

    pnpm types  # regenerate worker-configuration.d.ts (after wrangler.jsonc changes)
    pnpm lint   # fails if those types are stale; tsc over src/ and tests/
    pnpm test   # vitest

Tests run the real worker and both DOs in the vitest pool, with `WEBAPP` bound to [a fake webapp](tests/fake-webapp.js) serving diigo-shaped items (`wrangler.tests.jsonc`).

## Run

[The README](README.md) gets a cache going in dev. The same create flow from a terminal:

    wid=$(curl -s -X POST http://localhost:8787/_mint --data-urlencode \
      'url=https://www.diigo.com/interact_api/' --data-urlencode \
      'headers={"user-agent":"Mozilla/5.0","x-requested-with":"XMLHttpRequest","cookie":"<paste>"}' \
      --data-urlencode 'msPerCall=500' -D - -o /dev/null | grep -i x-webapp-id)
    curl -s -X POST http://localhost:8787/_wire -H 'content-type: application/json' \
      -d "{\"webappId\":\"<from $wid>\",\"mode\":\"private\"}"

Check a filled cache against a diigo RSS export: `node scripts/compare-export.ts <cache.sqlite> <export.xml> <out-dir>`.

## Deploy

Not deployed yet; the order matters (goal 5 in [the capsite checklist](../capsite-checklist.md)): webapp first (`cd ../webapp && npx wrangler deploy`), then diigo-cache, after rate-limiting `/api` (above).