import { cache } from "react";
import type { Paths } from "yt-dlp-transcript-common/lib/paths";
import { listChannelBriefs } from "yt-dlp-transcript-common/controller/channels";
import { readDuplicateReport } from "yt-dlp-transcript-common/controller/duplicateShorts";
import { getSettings } from "yt-dlp-transcript-common/lib/settings";

// Per-REQUEST memoization for loaders that more than one component on the same
// page reaches for. The dashboard derives the channel list three separate ways
// in a single render (the layout's reclaimable-disk badge, the actionable
// census and buildWidgetSyncPayload); without this it reads the same 65 files
// each time.
//
// `React.cache` is scoped to one request, so there is no staleness risk here by
// construction — the request boundary is already the consistency boundary, and
// two components rendering the same page should see the same numbers anyway.
//
// This lives in editor/app rather than common/ deliberately, on both counts:
// common/ is shared with the export, MCP and CLI packages and must not import
// react. And no cache with a LONGER life than a request belongs on this data —
// no `unstable_cache`, no `use cache`, no module-level map. The snapshot
// scheduler rewrites these files on a ~1 s debounce from job runners inside
// common/, which cannot import next/cache to invalidate anything. A cache
// nothing can invalidate is just a stale number with extra steps.
// ONE EXCEPTION, bounded: the operations status poll's 3-second memo of the
// lanes' pending counts (operations/status.ts, `autoQueueStatusMemo`), keyed by
// the settings it is folded from and otherwise expired by time.
// Keyed on the `paths` argument by identity, which works because getPaths()
// memoizes its result at module scope and hands back the same object every
// call. Pass it straight through; don't spread or rebuild it.
//
// (loadActionableSummary gets the same treatment, but its cached wrapper lives
// beside it in ./actionable/loadActionable — this module deliberately imports
// nothing from app/ so those loaders can import IT.)
export const getChannelBriefs = cache((paths: Paths) =>
  listChannelBriefs(paths),
);

// The duplicates report is a 6.7 MB JSON parse. It measures at ~65 ms. Only
// /review reads it now — the dashboard and the widget poll used to pay for it
// through loadActionableSummary and never showed a cluster.
export const getDuplicateReport = cache((paths: Paths) =>
  readDuplicateReport(paths),
);

export const getSettingsCached = cache(() => getSettings());