// lib/review/fill-finding-ids.mjs
// Finding ids are computed by code, never by the coordinator.
//
// The review-coordinator agent has Read/Glob/Grep and no shell, so it cannot
// compute the SHA1 a finding id is. In the voyage-lekerepo trial (2026-10-06)
// it wrote `@@ID_1@@` placeholders and the orchestrator filled them by hand, a
// step no document named. Now the contract says it: the coordinator writes
// `@@ID_<n>@@` wherever finding n's id belongs (n = 1-based position in the
// trailing JSON block's `findings` array), and this tool replaces every
// placeholder with computeFindingId(file, line, rule_key) of that finding.
//
// Fail-closed: a placeholder with no JSON finding behind it, or a 40-hex id
// in the JSON block that is not the computed one, is an error -- never a guess.
// A review that is already correct passes unchanged (idempotent).
//
// CLI: node lib/review/fill-finding-ids.mjs <review.md>
//   exit 0 = filled (file rewritten in place) or already correct;
//   1 = unresolved placeholder / wrong id (errors on stderr, file untouched);
//   2 = could not run (unreadable file, no JSON block).

import { readFileSync, writeFileSync, renameSync } from 'node:fs';
import { computeFindingId } from '../parsers/finding-id.mjs';
import { extractFindingsBlock } from './findings-schema.mjs';
import { isMain } from '../util/is-main.mjs';

const PLACEHOLDER = /@@ID_(\d+)@@/g;
const HEX40 = /^[0-9a-f]{40}$/;

/**
 * @param {string} text - review.md content
 * @returns {{ ok: boolean, text: string, errors: string[], fatal?: boolean }}
 */
export function fillFindingIds(text) {
  const block = extractFindingsBlock(text);
  if (block === null) return { ok: false, fatal: true, text, errors: ['no trailing ```json block: nothing to compute ids from'] };
  let parsed;
  try {
    parsed = JSON.parse(block);
  } catch (e) {
    return { ok: false, fatal: true, text, errors: [`the JSON block did not parse: ${e.message}`] };
  }
  const findings = Array.isArray(parsed?.findings) ? parsed.findings : [];
  const errors = [];
  const ids = findings.map((f, i) => {
    try {
      return computeFindingId(f.file, f.line, f.rule_key);
    } catch (e) {
      errors.push(`findings[${i}]: cannot compute an id (${e.message})`);
      return null;
    }
  });
  findings.forEach((f, i) => {
    if (typeof f.id === 'string' && HEX40.test(f.id) && ids[i] && f.id !== ids[i]) {
      errors.push(`findings[${i}].id ${f.id} does not match the id computed over (file, line, rule_key): ${ids[i]}`);
    }
  });
  const out = text.replace(PLACEHOLDER, (m, n) => {
    const id = ids[Number(n) - 1];
    if (!id) {
      errors.push(`${m} has no JSON finding ${n} behind it (${findings.length} findings)`);
      return m;
    }
    return id;
  });
  if (errors.length > 0) return { ok: false, text, errors };
  return { ok: true, text: out, errors: [] };
}

if (isMain(import.meta.url)) {
  const path = process.argv[2];
  if (!path) {
    process.stderr.write('Usage: fill-finding-ids.mjs <review.md>\n');
    process.exit(2);
  }
  let text;
  try {
    text = readFileSync(path, 'utf-8');
  } catch (e) {
    process.stderr.write(`fill-finding-ids: cannot read ${path}: ${e.message}\n`);
    process.exit(2);
  }
  const r = fillFindingIds(text);
  if (!r.ok) {
    for (const e of r.errors) process.stderr.write(`fill-finding-ids: ${e}\n`);
    process.exit(r.fatal ? 2 : 1);
  }
  if (r.text !== text) {
    const tmp = `${path}.tmp-${process.pid}`;
    writeFileSync(tmp, r.text);
    renameSync(tmp, path);
  }
  process.stdout.write(`fill-finding-ids: ok ${path}\n`);
}