#!/usr/bin/env node
// report-verified-staleness.mjs — Spor 3 Port 3, INCREMENTAL cadence pass.
// Compares each tracked source's sitemap_lastmod to the reference file's
// **Verified:** header (the Port 1 born-verified stamp) and reports the files
// whose source changed AFTER they were last verified — the cheap, lastmod-
// visible drift the periodic full-pass (P3d) complements.
//
// Run on the KB-refresh cadence, NOT on SessionStart (the SessionStart hook
// only READS the cached report this writes — the reporting floor, P3b). All
// logic lives in lib/verified-staleness.mjs (pure, unit-tested); this file is
// I/O glue mirroring report-changes.mjs.
//
// Usage: node report-verified-staleness.mjs [--json]

import { readFileSync, existsSync } from 'node:fs';
import { join, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';
import { loadRegistry, saveReport } from './lib/registry-io.mjs';
import { parseTypeHeader, parseVerifiedHeader } from './lib/kb-headers.mjs';
import { buildStalenessReport } from './lib/verified-staleness.mjs';

const __dirname = dirname(fileURLToPath(import.meta.url));
const PLUGIN_ROOT = join(__dirname, '..', '..');
const DATA_DIR = join(__dirname, 'data');
const jsonOnly = process.argv.includes('--json');

// Read a reference file's Port 1 headers, or null if the file is gone on disk
// (registry hygiene, not a staleness signal — buildStalenessReport skips it).
// Only the top 500 bytes are read; both header parsers scan that region.
function headerReader(refFile) {
  const full = join(PLUGIN_ROOT, refFile);
  if (!existsSync(full)) return null;
  const head = readFileSync(full, 'utf8').slice(0, 500);
  return { type: parseTypeHeader(head), verified: parseVerifiedHeader(head) };
}

const registry = loadRegistry(DATA_DIR);
if (!registry.last_poll) {
  console.error('Registry has not been polled yet. Run poll-sitemaps.mjs first.');
  process.exit(1);
}

const today = new Date().toISOString().split('T')[0];
const report = buildStalenessReport(registry, headerReader, { today });
saveReport('verified-staleness-report.json', report, DATA_DIR);

if (jsonOnly) {
  process.stdout.write(JSON.stringify(report, null, 2) + '\n');
} else {
  const c = report.counts;
  console.log(`\n=== Verified-staleness Report (${report.generated_at}) — incremental ===`);
  console.log(`Sources last polled: ${report.last_poll}`);
  console.log(
    `Reference files w/ tracked sources: ${c.total} ` +
      `(fresh: ${c.fresh}, stale-since-verified: ${c.stale}, unverified: ${c.unverified}, unmigrated: ${c.unmigrated}, out-of-scope: ${c.outOfScope})`,
  );
  if (report.flagged.length > 0) {
    console.log(`\nFlagged for re-judge (${report.flagged.length}):`);
    for (const f of report.flagged.slice(0, 30)) {
      console.log(`  [${f.reason}] ${f.path}`);
      console.log(`    verified: ${f.verified ?? '—'}  source changed: ${f.newestSourceLastmod ?? '—'}`);
    }
    if (report.flagged.length > 30) console.log(`  ... and ${report.flagged.length - 30} more`);
    console.log('\nNext: human-confirm each flag against its source, fix, then bump **Verified:** (never auto-fix).');
  } else {
    console.log('\nNo lastmod-visible drift since last verification.');
  }
}