// lib/review/engine-findings.mjs
// Claude Code's review as the engine (ordre 5, P11 — wrap, not a new engine).
//
// /trekreview Phase 4.7 starts Claude Code's own `/code-review` and
// `/security-review` through the Skill tool (never with `--fix`, never anything
// that edits code). Their findings come back as text: per finding a file
// location, a one-sentence summary, a failure scenario and an optional category
// slug (code.claude.com/docs/en/tools-reference.md, `ReportFindings`). The
// orchestrator transcribes them into a small JSON list; THIS module turns that
// list into a reviewer payload the coordinator already understands, so the
// engine's findings meet Voyage's brief control in the same dedup + verdict.
//
// Input (one engine per call):
//   { "engine": "code-review" | "security-review",
//     "findings": [ { "file": "...", "line": 12, "summary": "...",
//                     "failure_scenario": "...", "category": "correctness",
//                     "rule_key": "<optional narrower catalogue key>" } ] }
//
// Output: { reviewer, findings: [...catalogue-conformant...], out_of_scope: [...] }
//   - rule_key: the given one when it is in the catalogue AND at least as
//     severe as the engine's own key, else CODE_REVIEW_DEFECT (MAJOR) /
//     SECURITY_REVIEW_VULNERABILITY (BLOCKER). A "narrower" key can never
//     lower an engine finding's tier.
//   - File paths are made repo-relative (an absolute path under `repoRoot`
//     loses that prefix) before they are compared with the scope.
//   - A finding on a file outside the review scope is NOT dropped silently: it
//     lands in `out_of_scope`, which the coordinator counts as unverified
//     (`engine:out-of-scope`) — it forbids ALLOW and is listed under
//     Declined to Judge (`/security-review` diffs against origin's default
//     branch, which can be wider than the review's SHA range).
//   - An empty scope list is an error, never "everything is out of scope".
//
// CLI: node lib/review/engine-findings.mjs [--scope <file-list.txt>] [--repo-root <dir>] <engine-findings.json>
//   exit 0 = payload on stdout; 1 = input invalid (errors on stderr); 2 = could not run.

import { readFileSync, existsSync, realpathSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import { computeFindingId } from '../parsers/finding-id.mjs';
import { RULE_KEYS, getRule, SEVERITY_VALUES } from './rule-catalogue.mjs';
import { validateFindings } from './findings-schema.mjs';

export const ENGINES = Object.freeze({
  'code-review': Object.freeze({
    reviewer: 'claude-code-review',
    rule_key: 'CODE_REVIEW_DEFECT',
    brief_ref: 'NFR — code correctness (Claude Code /code-review)',
  }),
  'security-review': Object.freeze({
    reviewer: 'claude-security-review',
    rule_key: 'SECURITY_REVIEW_VULNERABILITY',
    brief_ref: 'NFR — security (Claude Code /security-review)',
  }),
});

function normPath(p, repoRoot) {
  let out = String(p ?? '').trim().replace(/\\/g, '/');
  if (repoRoot) {
    const root = String(repoRoot).replace(/\\/g, '/').replace(/\/+$/, '') + '/';
    if (out.startsWith(root)) out = out.slice(root.length);
  }
  return out.replace(/^(\.\/)+/, '');
}

function parseLine(v) {
  if (Number.isInteger(v) && v >= 0) return v;
  if (typeof v === 'string' && /^\d+$/.test(v.trim())) return Number(v.trim());
  return 0;
}

const tier = (key) => SEVERITY_VALUES.indexOf(getRule(key).severity);

/**
 * Convert one engine's transcribed findings into a coordinator payload.
 * @param {{ engine: string, findings: object[] }} input
 * @param {{ scopeFiles?: string[], repoRoot?: string }} [opts]
 * @returns {{ ok: boolean, errors: string[], payload?: { reviewer: string, findings: object[] }, out_of_scope?: object[] }}
 */
export function toReviewerPayload(input, opts = {}) {
  const errors = [];
  const spec = ENGINES[input?.engine];
  if (!spec) return { ok: false, errors: [`engine must be one of ${Object.keys(ENGINES).join('|')}, got ${JSON.stringify(input?.engine)}`] };
  if (!Array.isArray(input.findings)) return { ok: false, errors: ['findings must be an array'] };
  if (opts.scopeFiles && opts.scopeFiles.length === 0) {
    return { ok: false, errors: ['scope list is empty — the review scope is unknown, so no engine finding can be placed'] };
  }
  const scope = opts.scopeFiles ? new Set(opts.scopeFiles.map((f) => normPath(f, opts.repoRoot))) : null;

  const findings = [];
  const out_of_scope = [];
  input.findings.forEach((f, i) => {
    const file = normPath(f?.file, opts.repoRoot);
    const summary = String(f?.summary ?? '').trim();
    if (!file) errors.push(`findings[${i}].file is empty`);
    if (!summary) errors.push(`findings[${i}].summary is empty`);
    if (!file || !summary) return;
    const line = parseLine(f.line);
    const narrower = typeof f.rule_key === 'string' && RULE_KEYS.has(f.rule_key)
      && tier(f.rule_key) <= tier(spec.rule_key);
    const rule_key = narrower ? f.rule_key : spec.rule_key;
    const out = {
      id: computeFindingId(file, line, rule_key),
      severity: getRule(rule_key).severity,
      rule_key,
      file,
      line,
      brief_ref: spec.brief_ref,
      title: summary,
      detail: [String(f.failure_scenario ?? '').trim(), f.category ? `(engine category: ${f.category})` : '']
        .filter(Boolean).join(' ') || summary,
      recommended_action: `Resolve: ${summary}`,
      engine: input.engine,
    };
    if (scope && !scope.has(file)) out_of_scope.push(out);
    else findings.push(out);
  });
  if (errors.length > 0) return { ok: false, errors };

  const payload = { reviewer: spec.reviewer, findings };
  const v = validateFindings(payload);
  if (!v.valid) return { ok: false, errors: v.errors.map((e) => `${e.code}: ${e.message}`) };
  return { ok: true, errors: [], payload, out_of_scope };
}

function isMain() {
  try {
    return realpathSync(process.argv[1]) === realpathSync(fileURLToPath(import.meta.url));
  } catch {
    return false;
  }
}

if (isMain()) {
  const args = process.argv.slice(2);
  const valueOf = (name) => { const i = args.indexOf(name); return i === -1 ? null : args[i + 1]; };
  const scopePath = valueOf('--scope');
  const repoRoot = valueOf('--repo-root');
  const flagValues = new Set([scopePath, repoRoot].filter(Boolean));
  const filePath = args.find((a) => !a.startsWith('--') && !flagValues.has(a));
  if (!filePath || !existsSync(filePath) || (scopePath && !existsSync(scopePath))) {
    process.stderr.write('Usage: engine-findings.mjs [--scope <file-list.txt>] [--repo-root <dir>] <engine-findings.json>\n');
    process.exit(2);
  }
  let input;
  let scopeFiles;
  try {
    input = JSON.parse(readFileSync(filePath, 'utf-8'));
    if (scopePath) scopeFiles = readFileSync(scopePath, 'utf-8').split('\n').map((l) => l.trim()).filter(Boolean);
  } catch (e) {
    process.stderr.write(`engine-findings: could not read input: ${e.message}\n`);
    process.exit(2);
  }
  const r = toReviewerPayload(input, { scopeFiles, repoRoot: repoRoot ?? undefined });
  if (!r.ok) {
    for (const e of r.errors) process.stderr.write(`  ERROR  ${e}\n`);
    process.exit(1);
  }
  process.stdout.write(JSON.stringify({ ...r.payload, out_of_scope: r.out_of_scope }, null, 2) + '\n');
  process.exit(0);
}