/**
 * One-shot backfill — write `token` into every PurchaseOrderDocumentEntry
 * in `purchase_orders.documents_history` that doesn't have one yet.
 *
 * Why this exists
 * ────────────────
 * The PO PDF route used to store the human-readable filename in
 * `documents_history[i].token`, which then 404'd when PB's file proxy
 * was asked to resolve it. The fix in the route handler stores the
 * real on-disk token (the slug PB returns from the upload) instead —
 * but legacy rows created before that change still have `file` and no
 * `token`, so the new GET handler would 404 on them.
 *
 * Strategy:
 *   - For each PO row, read `documents_history` and `documents`.
 *   - For each entry missing `token`, look up `documents[idx]` (or
 *     `documents[0]` as a fallback). The two arrays are kept in sync
 *     by the POST handler, so index alignment is correct.
 *   - Patch the row with the new history array.
 *
 * Idempotent — re-running this script is a no-op once every entry has
 * a token.
 *
 * Run with (from WFDASH_NEXTJS so .env.local is found):
 *   npx tsx scripts/migrations/2026-07-09-po-pdf-tokens.ts
 */
import { getAdminPocketBase } from "@/lib/server/pocketbase-admin";

type Entry = {
  version: number;
  file: string;
  token?: string;
  generatedAt: string;
  generatedBy: string;
  reason: string;
  status: "current" | "superseded";
};

type PoRow = {
  id: string;
  documents?: string[] | string;
  documents_history?: Entry[];
};

async function main() {
  const pb = await getAdminPocketBase();
  let patchedRows = 0;
  let patchedEntries = 0;
  let unresolvable = 0;

  const list = await pb.collection("purchase_orders").getList<PoRow>(1, 500, {
    fields: "id,documents,documents_history",
    filter: "documents_history != null",
  });

  for (const po of list.items) {
    const history = po.documents_history ?? [];
    if (history.length === 0) continue;

    const docsRaw = po.documents ?? [];
    const docs = Array.isArray(docsRaw) ? docsRaw : docsRaw ? [docsRaw] : [];

    let changed = false;
    const newHistory = history.map((entry, idx) => {
      if (entry.token) return entry;
      const token = docs[idx] || docs[0] || "";
      if (!token) {
        unresolvable += 1;
        return entry;
      }
      changed = true;
      return { ...entry, token };
    });

    if (changed) {
      await pb.collection("purchase_orders").update(po.id, {
        documents_history: newHistory,
      });
      patchedRows += 1;
      patchedEntries += newHistory.filter((e) => e.token).length - history.filter((e) => e.token).length;
    }
  }

  console.log(
    `[po-pdf-tokens] rows patched=${patchedRows} entries patched=${patchedEntries} unresolvable=${unresolvable}`,
  );
}

main().catch((err) => {
  console.error("[po-pdf-tokens] failed:", err);
  process.exit(1);
});