#!/usr/bin/env node
// build-gold-set.mjs — Fase 0, steg 2/3 glue: assemble the gold correctness set.
//
// Consolidates the per-batch verification returns (scripts/kb-eval/data/
// fase0-returns/batch-*.json — produced by Opus 4.8 subagents that checked each
// volatile claim against live MS Learn) into a single, reusable gold set, and
// joins the DETERMINISTIC lastmod_changed signal in code (never an LLM call):
// for each file, did any cited source change on the MS Learn sitemap after the
// file's own "last updated" date? That is exactly what the existing KB staleness
// loop sees, so it tells us which genuine errors a correctness judge would catch
// that the staleness loop would miss.
//
// The non-trivial logic (date parse, lastmod comparison) lives in tested
// lib/base-rate.mjs; this CLI is thin wiring over it.
//
// Usage:  node scripts/kb-eval/build-gold-set.mjs [--write]
//   (default: print summary; --write: persist gold-correctness-set.json)

import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { parseLastUpdated, fileLastmodChanged } from './lib/base-rate.mjs';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.resolve(__dirname, '..', '..');
const DATA = path.join(__dirname, 'data');
const RETURNS = path.join(DATA, 'fase0-returns');

const frame = JSON.parse(fs.readFileSync(path.join(DATA, 'fase0-sample-frame.json'), 'utf8'));
const registry = JSON.parse(
  fs.readFileSync(path.join(ROOT, 'scripts/kb-update/data/url-registry.json'), 'utf8'),
);

// file -> citedUrls (from the deterministic sample frame)
const citedByFile = {};
for (const e of [...frame.volatile, ...frame.control]) citedByFile[e.file] = e.citedUrls;

// file -> { date, lastmod_changed } (read each file once)
const fileMeta = {};
function metaFor(file) {
  if (fileMeta[file]) return fileMeta[file];
  let date = null;
  try {
    date = parseLastUpdated(fs.readFileSync(path.join(ROOT, file), 'utf8'));
  } catch {
    date = null;
  }
  const changed = fileLastmodChanged(citedByFile[file] || [], registry, date);
  return (fileMeta[file] = { date, lastmod_changed: changed });
}

// relpath after skills/<skill>/references/ for a compact, stable claim id
function relOf(file, skill) {
  const prefix = `skills/${skill}/references/`;
  return file.startsWith(prefix) ? file.slice(prefix.length) : file;
}

const claims = [];
const batchFiles = fs.readdirSync(RETURNS).filter((f) => /^batch-\d+\.json$/.test(f)).sort();
for (const bf of batchFiles) {
  const batch = JSON.parse(fs.readFileSync(path.join(RETURNS, bf), 'utf8'));
  for (const c of batch.claims) {
    const meta = metaFor(c.file);
    claims.push({
      id: `${c.skill}/${relOf(c.file, c.skill)}#${c.n}`,
      file: c.file,
      skill: c.skill,
      stratum: c.stratum,
      claim: c.claim,
      claim_type: c.claim_type,
      verdict: c.verdict,
      evidence_url: c.evidence_url ?? null,
      lastmod_changed: meta.lastmod_changed,
      file_last_updated: meta.date,
      notes: c.notes ?? '',
    });
  }
}

const goldSet = {
  _meta: {
    created: '2026-06-26',
    method:
      'Per-file volatile-claim verification against live MS Learn by Opus 4.8 subagents (strict v2 evidence rule: correct/outdated/wrong require a fetched learn.microsoft.com quote; otherwise unsourced). lastmod_changed joined deterministically in code from url-registry sitemap_lastmod vs the file last-updated date.',
    sample_frame: 'fase0-sample-frame.json',
    raw_returns: 'fase0-returns/batch-*.json',
    note_evidence_quote:
      'Per-claim evidence_quote omitted here to bound size; full verbatim quotes live in the session transcript. notes + evidence_url capture each verdict basis.',
    claim_count: claims.length,
  },
  claims,
};

if (process.argv.includes('--write')) {
  const out = path.join(DATA, 'gold-correctness-set.json');
  fs.writeFileSync(out, JSON.stringify(goldSet, null, 2) + '\n');
  console.log(`wrote ${out} (${claims.length} claims)`);
} else {
  const filesWithChange = Object.entries(fileMeta).filter(([, m]) => m.lastmod_changed === true).length;
  const filesNoChange = Object.entries(fileMeta).filter(([, m]) => m.lastmod_changed === false).length;
  const filesUnknown = Object.entries(fileMeta).filter(([, m]) => m.lastmod_changed === null).length;
  console.log(`claims: ${claims.length} | files: ${Object.keys(fileMeta).length}`);
  console.log(`file lastmod_changed: true=${filesWithChange} false=${filesNoChange} unknown(null date)=${filesUnknown}`);
  console.log('(dry run — pass --write to persist gold-correctness-set.json)');
}