// WAYBACK PROVENANCE ON DISK — the `wayback.json` sidecar.
//
// A record downloaded from a Wayback Machine capture (lib/wayback.ts) carries
// what it is a copy of: the original URL, the capture's timestamp, the capture
// as a page that plays and as its raw bytes. Built from the capture URL alone
// — no request — so it is written on every download of one
// (ytdlp/downloadOneManaged.ts) and by `archilyzer wayback refresh` for a
// record imported before this existed (controller/waybackRefresh.ts).

import {
  WAYBACK_PROVENANCE_FILENAME,
  buildWaybackProvenance,
  coerceWaybackProvenance,
  sameWaybackProvenance,
  type WaybackProvenance,
} from "./wayback";
import { sidecar, sidecarField } from "./sidecar-server";

export const waybackProvenanceSidecar = sidecar(
  WAYBACK_PROVENANCE_FILENAME,
  sidecarField(coerceWaybackProvenance),
);

export const { load: loadWaybackProvenance, write: writeWaybackProvenance } =
  waybackProvenanceSidecar;

// The sidecar for a record fetched by `url`: written when the URL is a
// capture and the one on disk is absent or says otherwise. Returns what the
// record now carries (null for a URL that is not a capture) and whether it was
// (or, with `dryRun`, would be) written.
export async function ensureWaybackProvenance(
  videoDir: string,
  url: string,
  opts: { dryRun?: boolean; onLog?: (line: string) => void } = {},
): Promise<{ provenance: WaybackProvenance | null; written: boolean }> {
  const next = buildWaybackProvenance(url);
  if (!next) return { provenance: null, written: false };
  const prev = await loadWaybackProvenance(videoDir);
  if (prev && sameWaybackProvenance(prev, next)) return { provenance: prev, written: false };
  if (!opts.dryRun) await writeWaybackProvenance(videoDir, next);
  opts.onLog?.(`Wayback provenance: a capture of ${next.originalUrl} (${next.captureTs}).\n`);
  return { provenance: next, written: true };
}