#!/usr/bin/env node
// 🤖 Verify a ledger stream end-to-end (issue #1224): fetch HEAD, walk the
// prev-hash chain newest→oldest re-hashing every entry's exact bytes, and
// fail loudly on the first broken link. Needs no credentials — the whole
// walk rides the bucket's public https door, so anyone can run it.
//
//   node tools/ledger-verify.mjs <ledger>
import { fetchPublic, getHead } from "./ledgerstream.mjs";
import { verifyLink } from "./ledgerchain.mjs";

const ledger = process.argv[2];
if (!ledger) { console.error("usage: node tools/ledger-verify.mjs <ledger>"); process.exit(1); }

const head = await getHead(ledger);
if (!head) { console.error(ledger + ": no HEAD — stream doesn't exist"); process.exit(1); }

let key = head.head_key, claimedSha = head.head_sha256, walked = 0;
while (key) {
  const bytes = await fetchPublic(key);
  if (!bytes) { console.error("BROKEN: " + key + " is missing"); process.exit(1); }
  const v = verifyLink({ bytes, key, claimedSha });
  if (!v.ok) { console.error("BROKEN at " + key + ": " + v.reason); process.exit(1); }
  walked++;
  key = v.entry.prev_key;
  claimedSha = v.entry.prev_sha256;
}
if (walked !== head.count) {
  console.error("BROKEN: HEAD counts " + head.count + " but the chain walks " + walked);
  process.exit(1);
}
console.log(ledger + ": chain OK — " + walked + " entr" + (walked === 1 ? "y" : "ies") + ", head " + head.head_sha256.slice(0, 12) + "…");