/*
  Does the documentation still match the code?

  ── Why a script and not a habit ──

  "Update the docs before a deploy" is a step that gets skipped at two in the morning, and its absence is
  invisible. Every piece of drift found on 2026-08-22 was MECHANICAL — a count, a route name, a process
  list — so it is checkable, and a check that exits non-zero cannot be quietly not done.

  What it will not do is read prose and judge it. It looks only at claims with a machine-checkable
  counterpart, which is a small fraction of the documentation and the fraction that rots fastest, because a
  number is exactly the thing nobody re-derives while editing a sentence around it.

  Real examples this was written from, both live at the time:

    platform/CLAUDE.md   "27 entries as of 2026-08-13"   → the registry held 18
    officer-dev/CLAUDE.md "Officer is twenty PM2 entries" → there were 13
    Spotlight's settings list  9 rows against 21 sections, and one route that does not exist

  ── The rule for adding a check ──

  A check must compare a documented claim against a value DERIVED AT RUN TIME, never against a second
  hard-coded copy. A check with the answer written into it is one more place to drift, and it will drift in
  the same edit that misses the doc.
*/

import { readFileSync, existsSync } from 'node:fs';
import { join, resolve } from 'node:path';

type Finding = { file: string; claim: string; documented: string; actual: string };
type CheckResult = { findings: Finding[]; skipped?: string };

const ROOT = resolve(import.meta.dir, '..');
const WORKSPACE = resolve(ROOT, '..');

const read = (path: string): string | null => (existsSync(path) ? readFileSync(path, 'utf-8') : null);

/** Spelled-out numbers appear in prose more often than digits, and both need catching. */
const WORDS: Record<string, number> = {
  ten: 10,
  eleven: 11,
  twelve: 12,
  thirteen: 13,
  fourteen: 14,
  fifteen: 15,
  sixteen: 16,
  seventeen: 17,
  eighteen: 18,
  nineteen: 19,
  twenty: 20,
  'twenty-one': 21,
  'twenty-two': 22,
  'twenty-three': 23,
  'twenty-four': 24,
  'twenty-five': 25,
};
const asNumber = (raw: string): number | null => {
  const digits = Number(raw);
  if (Number.isFinite(digits)) return digits;
  return WORDS[raw.toLowerCase()] ?? null;
};

/**
 * A documented count, found by a pattern with one capture group, compared to the live value.
 *
 * Returns a finding per MISMATCH, not per occurrence: a doc stating the right number twice is fine.
 */
function checkCount(file: string, pattern: RegExp, actual: number, claim: string): CheckResult {
  const body = read(file);
  if (!body) return { findings: [], skipped: `${file} not found` };
  const findings: Finding[] = [];
  for (const match of body.matchAll(pattern)) {
    const stated = asNumber(match[1] ?? '');
    if (stated === null || stated === actual) continue;
    findings.push({ file, claim, documented: String(stated), actual: String(actual) });
  }
  return { findings };
}

async function main(): Promise<void> {
  const all: Finding[] = [];
  const skipped: string[] = [];
  const record = (r: CheckResult) => {
    all.push(...r.findings);
    if (r.skipped) skipped.push(r.skipped);
  };

  // 1. How many permissions the registry holds. The number appears in prose and is never recomputed.
  const { PERMISSIONS } = await import('../src/servers/permissions/registry');
  record(
    checkCount(
      join(ROOT, 'AGENTS.md'),
      /([0-9]+|[a-z-]+) entries as of/gi,
      PERMISSIONS.length,
      'permission registry entries',
    ),
  );

  // 2. How many PM2 entries Officer is. Documented as going stale "every time a sidecar lands", which is an
  //    admission that it needs a check rather than a caveat.
  const pm2 = Bun.spawnSync([process.env.SHELL || '/bin/sh', '-ic', 'pm2 jlist'], { stdout: 'pipe', stderr: 'pipe' });
  if (pm2.exitCode === 0) {
    try {
      const list = JSON.parse(pm2.stdout.toString()) as Array<{ name: string }>;
      const officer = list.filter((p) => p.name === 'officer' || p.name.startsWith('officer-')).length;
      record(
        checkCount(
          join(WORKSPACE, 'CLAUDE.md'),
          /Officer is ([a-z-]+|[0-9]+) PM2 entries/gi,
          officer,
          'officer PM2 entries',
        ),
      );
    } catch {
      skipped.push('pm2 jlist did not parse');
    }
  } else {
    // Honest rather than silent: a machine with no pm2 cannot check this, and saying so is the point.
    skipped.push('pm2 unavailable — PM2 entry count unchecked');
  }

  // 3. Every settings path Spotlight offers must exist as a declared section. This is the drift that shipped
  //    a dead link to /settings/users, and it is the class the other two cannot catch: a name, not a count.
  const { SPOTLIGHT_SETTINGS_PATHS } = await import('./docs-check-settings');
  const declared = await SPOTLIGHT_SETTINGS_PATHS();
  for (const bad of declared.missing) {
    all.push({
      file: 'Spotlight/useSpotlightItems.ts',
      claim: 'settings route offered by Spotlight',
      documented: bad,
      actual: 'no screen declares that section',
    });
  }

  // 4. The generated platform skill must match its generator. A stale SKILL.md is worse than a stale doc:
  //    an agent quotes it to a user with no way to tell it is out of date.
  const { renderPlatformSkill, SKILL_PATH } = await import('./gen-platform-skill');
  const expected = await renderPlatformSkill();
  const onDisk = read(SKILL_PATH);
  if (onDisk === null) {
    all.push({
      file: 'capabilities/skills/platform/SKILL.md',
      claim: 'generated platform skill',
      documented: 'missing',
      actual: 'run `bun run skills:platform`',
    });
  } else if (onDisk !== expected) {
    all.push({
      file: 'capabilities/skills/platform/SKILL.md',
      claim: 'generated platform skill is stale',
      documented: `${onDisk.split('\n').length} lines on disk`,
      actual: `${expected.split('\n').length} lines from the generator — run \`bun run skills:platform\``,
    });
  }

  for (const note of skipped) console.log(`  skipped: ${note}`);
  if (all.length === 0) {
    console.log('docs:check — every checkable claim matches the code');
    return;
  }
  console.log(`\ndocs:check — ${all.length} claim(s) no longer match the code:\n`);
  for (const f of all) {
    console.log(`  ${f.file}`);
    console.log(`    ${f.claim}: says ${f.documented}, actually ${f.actual}\n`);
  }
  process.exit(1);
}

await main();