#!/usr/bin/env -S bun --no-env-file --config=/dev/null
/**
 * gstack-review-scope — the finding scope of /ship's review loop (docs/ship-policy.md#review-scope).
 *
 *   gstack-review-scope classify --base <ref> --pass <n> [--range-base <sha>] [--policy frozen|diff-plus-blocking|all] [--findings <file>|-] [--json]
 *   gstack-review-scope defer --findings <classified.json> [--out <deferred.json>] [--json]
 *   gstack-review-scope render --deferred <deferred.json> [--findings <classified.json>]
 *   gstack-review-scope summary --since <iso-timestamp> (--run <dir> | --ledger <f>... | --no-ledger) [--out <file>] [--json]
 *
 * `classify` reads a JSON array of findings (the Step 9.3 result) and stamps
 * each with `locus` (diff | fix-range | outside), `kind` (defect | test-gap |
 * advisory), `blocking` and `scope` (fix | defer | note); the loop fixes only
 * `fix` and writes `defer` and `note` into the PR body. `defer` records each
 * deferred finding for the PR and files no issue. `render` prints the PR-body
 * sections. `summary` reads this branch's review log for the invocation's
 * passes and prints the REVIEW_LOOP line the ship receipt carries.
 * Logic: lib/review-scope.ts.
 */
import { spawnSync } from 'node:child_process';
import * as fs from 'node:fs';
import * as os from 'node:os';
import * as path from 'node:path';
import { StringDecoder } from 'node:string_decoder';
import { EXIT, exitTableHelp } from '../lib/headless-artifacts';
import { resultLineWithDocs } from '../lib/result-codes';
import { runScriptSync } from '../lib/script-invocation';
import { isUnavailable, loadPolicyFromBase, policyUnavailableLine, resolveBaseBranch } from '../lib/ship-policy';
import {
  deferredRecord, ledgerPass, parseFixTrailers, parseHunks, renderDeferredSection, reviewLoopLine, scopeFindings, scopeLine, summarizeReviewLoop,
  REVIEW_SCOPE_POLICIES, type DeferredRecord, type ReviewScopePolicy, type ScopeFinding, type ScopedFinding,
} from '../lib/review-scope';
import { ledgerBlockers, type LedgerBlocker } from '../lib/review-ledger';

const HELP = `gstack-review-scope — finding scope for /ship's review loop (docs/ship-policy.md#review-scope)

  classify --base <ref> --pass <n> [--range-base <sha>] [--policy frozen|diff-plus-blocking|all] [--findings <file>|-]
                                      stamp each finding with locus, kind, blocking and scope (fix | defer | note);
                                      prints REVIEW_SCOPE: … and the classified JSON array (--json: JSON only)
  defer --findings <classified.json> [--out <file>]
                                      record each scope=defer finding for the PR body (no issue is filed);
                                      prints DEFERRED: lines and the deferred records
  render --deferred <file> [--findings <classified.json>]
                                      the PR-body sections: ## Deferred findings (references, never closing keywords)
                                      and ## Review notes (scope=note findings)
  summary --since <iso> (--run <dir> | --ledger <f>... | --no-ledger) [--out <file>]
                                      the invocation's passes from this branch's review log: REVIEW_LOOP: passes=…
                                      blocking_found=… deferred=… noted=… (the ship receipt's --review-loop input);
                                      blocking_found also counts every CRITICAL the dispatch ledgers collected or judged
                                      (--run finds each review-ledger.jsonl under the run directory); unrecorded=N names
                                      blockers no row disposes; a row finding's ledger_id (<pass dir>/<merged id>) and each
                                      fix commit's Review-Finding: <id> reader=<role> trailer bind by id, and what cannot bind
                                      prints REVIEW_SCOPE_UNBOUND: <what>: <why> (unbound=N). An unreadable ledger: REVIEW_SCOPE_LEDGER

Defaults: --policy from the base branch's .gstack/ship-policy.json review_scope (frozen); an unresolvable base refuses
  (POLICY_SOURCE_UNAVAILABLE) unless --policy is passed; --findings - reads stdin.
${exitTableHelp()}`;

function flag(args: string[], name: string): string | undefined {
  const i = args.indexOf(name);
  return i >= 0 ? args[i + 1] : undefined;
}
const DIFF_ARGS = ['-U0', '--no-color', '--no-ext-diff', '--no-textconv', '--src-prefix=a/', '--dst-prefix=b/'];
function git(args: string[], cwd: string): { ok: boolean; out: string; err: string } {
  // quotePath off: a non-ASCII path must come back as itself, not as "caf\303\251.ts", or the hunk map never matches the finding.
  const r = spawnSync('git', ['-c', 'core.quotePath=false', ...args], { cwd, encoding: 'utf8', timeout: 60_000, maxBuffer: 64 * 1024 * 1024 });
  return { ok: r.status === 0, out: r.stdout ?? '', err: (r.stderr ?? '').trim() };
}
const HUNK_LINE = /^(diff --git |--- |\+\+\+ |@@)/;
/**
 * `git diff <from>` reduced to the lines parseHunks reads (file headers and @@ lines). git writes the diff to a scratch file that
 * is read back a megabyte at a time, so no pipe buffer bounds the diff's size (GST-1855: harness-evals #320's 67 MB results diff
 * passed the 64 MB buffer and classify refused with an empty reason). A failure names git's stderr, its error code or the timeout.
 */
function diffHunkLines(from: string, cwd: string): { ok: boolean; out: string; err: string } {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'gstack-review-scope-'));
  try {
    const file = path.join(dir, 'diff');
    const r = spawnSync('git', ['-c', 'core.quotePath=false', 'diff', ...DIFF_ARGS, `--output=${file}`, from], { cwd, encoding: 'utf8', timeout: 120_000 });
    const code = (r.error as NodeJS.ErrnoException | undefined)?.code;
    if (r.status !== 0) return { ok: false, out: '', err: (r.stderr ?? '').trim() || (code === 'ETIMEDOUT' ? 'timed out after 120 s' : code ?? `exit ${r.status ?? r.signal}`) };
    const keep: string[] = [];
    const decoder = new StringDecoder('utf8');
    const buf = Buffer.alloc(1024 * 1024);
    const fd = fs.openSync(file, 'r');
    let rest = '';
    try {
      for (let n = fs.readSync(fd, buf); n > 0; n = fs.readSync(fd, buf)) {
        const lines = (rest + decoder.write(buf.subarray(0, n))).split('\n');
        rest = lines.pop()!;
        for (const l of lines) if (HUNK_LINE.test(l)) keep.push(l);
      }
    } finally { fs.closeSync(fd); }
    rest += decoder.end();
    if (HUNK_LINE.test(rest)) keep.push(rest);
    return { ok: true, out: keep.join('\n'), err: '' };
  } finally { fs.rmSync(dir, { recursive: true, force: true }); }
}
function readFindings(spec: string | undefined, what: string): ScopeFinding[] {
  const text = spec === undefined || spec === '-' ? fs.readFileSync(0, 'utf8') : fs.readFileSync(spec, 'utf8');
  const parsed = JSON.parse(text.trim() || '[]');
  const list = Array.isArray(parsed) ? parsed : Array.isArray(parsed.findings) ? parsed.findings : null;
  if (!list || !list.every((f: unknown) => f && typeof f === 'object' && !Array.isArray(f))) throw new Error(`${what}: expected a JSON array of finding objects`);
  return list as ScopeFinding[];
}
function refuse(cmd: string, code: 'REVIEW_SCOPE_INPUT' | 'REVIEW_SCOPE_RANGE' | 'REVIEW_SCOPE_LEDGER', detail: string): number {
  process.stderr.write(resultLineWithDocs(`gstack-review-scope ${cmd}`, code, detail) + '\n');
  return EXIT.fail;
}

function cmdClassify(rest: string[], json: boolean): number {
  const repoRoot = git(['rev-parse', '--show-toplevel'], process.cwd()).out.trim() || process.cwd();
  const base = flag(rest, '--base') ?? resolveBaseBranch(repoRoot);
  const pass = Number(flag(rest, '--pass') ?? '1');
  if (!Number.isInteger(pass) || pass < 1) return refuse('classify', 'REVIEW_SCOPE_INPUT', '--pass must be a positive integer');
  const policyFlag = flag(rest, '--policy');
  let policy: ReviewScopePolicy;
  if (policyFlag !== undefined) {
    if (!REVIEW_SCOPE_POLICIES.includes(policyFlag as ReviewScopePolicy)) return refuse('classify', 'REVIEW_SCOPE_INPUT', `--policy must be one of ${REVIEW_SCOPE_POLICIES.join(' | ')}, got ${JSON.stringify(policyFlag)}`);
    policy = policyFlag;
  } else {
    const load = loadPolicyFromBase(repoRoot, base);
    // The reviewed policy is the base's; the working tree's copy is never read silently (pass --policy to override).
    if (isUnavailable(load)) { process.stderr.write(policyUnavailableLine('gstack-review-scope classify', base, `${load.detail}; pass --policy to classify without the base`) + '\n'); return EXIT.refused; }
    policy = load.policy.review_scope;
  }
  let findings: ScopeFinding[];
  try { findings = readFindings(flag(rest, '--findings'), 'findings'); } catch (e: any) { return refuse('classify', 'REVIEW_SCOPE_INPUT', e.message); }
  const baseRef = /^[0-9a-f]{7,64}$/i.test(base) ? base : `origin/${base.replace(/^origin\//, '')}`;
  const mergeBase = git(['merge-base', baseRef, 'HEAD'], repoRoot);
  if (!mergeBase.ok) return refuse('classify', 'REVIEW_SCOPE_RANGE', `cannot resolve the merge base of ${baseRef} and HEAD: ${mergeBase.err}`);
  // Prefixes pinned as lib/pregate/checks/secrets.ts pins them: diff.mnemonicPrefix would print c/ and w/ and nothing would match a finding.
  const diff = diffHunkLines(mergeBase.out.trim(), repoRoot);
  if (!diff.ok) return refuse('classify', 'REVIEW_SCOPE_RANGE', `git diff ${mergeBase.out.trim()} failed: ${diff.err}`);
  const untracked = git(['ls-files', '--others', '--exclude-standard'], repoRoot).out.split('\n').filter(Boolean);
  const diffHunks = parseHunks(diff.out, untracked);
  let rangeHunks = null;
  const rangeBase = flag(rest, '--range-base');
  if (rangeBase !== undefined && !/^[0-9a-f]{7,64}$/i.test(rangeBase)) return refuse('classify', 'REVIEW_SCOPE_INPUT', `--range-base must be a commit id, got ${JSON.stringify(rangeBase.slice(0, 40))}`);
  if (pass > 1) {
    if (!rangeBase) return refuse('classify', 'REVIEW_SCOPE_INPUT', '--range-base <sha> (HEAD at the start of the previous pass) is required from pass 2 on');
    const ancestor = git(['merge-base', '--is-ancestor', rangeBase, 'HEAD'], repoRoot);
    if (!ancestor.ok) return refuse('classify', 'REVIEW_SCOPE_RANGE', `--range-base ${rangeBase.slice(0, 12)} is not an ancestor of HEAD (rewritten history? start a full pass)`);
    const range = diffHunkLines(rangeBase, repoRoot);
    if (!range.ok) return refuse('classify', 'REVIEW_SCOPE_RANGE', `git diff ${rangeBase.slice(0, 12)} failed: ${range.err}`);
    rangeHunks = parseHunks(range.out, untracked);
  }
  const scoped = scopeFindings(findings, { policy, pass, diffHunks, rangeHunks });
  const line = scopeLine(policy, pass, scoped);
  process.stderr.write(line + '\n');
  process.stdout.write(json ? JSON.stringify({ policy, pass, range_base: pass > 1 ? rangeBase : null, findings: scoped }) + '\n' : line + '\n' + JSON.stringify(scoped, null, 2) + '\n');
  return EXIT.ok;
}

function cmdDefer(rest: string[], json: boolean): number {
  let findings: ScopedFinding[];
  try { findings = readFindings(flag(rest, '--findings'), 'classified findings') as ScopedFinding[]; } catch (e: any) { return refuse('defer', 'REVIEW_SCOPE_INPUT', e.message); }
  const records: DeferredRecord[] = findings.filter(f => f.scope === 'defer').map(deferredRecord);
  for (const r of records) process.stderr.write(`DEFERRED: ${r.severity} ${r.path}\n`);
  if (!records.length) process.stderr.write('DEFERRED: none\n');
  const out = flag(rest, '--out');
  if (out) fs.writeFileSync(out, JSON.stringify(records, null, 2) + '\n');
  process.stdout.write(json ? JSON.stringify(records) + '\n' : renderDeferredSection(records));
  return EXIT.ok;
}

function cmdRender(rest: string[]): number {
  const deferredFile = flag(rest, '--deferred');
  let deferred: DeferredRecord[] = [];
  let noted: ScopedFinding[] = [];
  try {
    if (deferredFile) deferred = JSON.parse(fs.readFileSync(deferredFile, 'utf8'));
    const wrapped = deferred as unknown as { deferred?: unknown };
    if (!Array.isArray(deferred) && Array.isArray(wrapped?.deferred)) deferred = wrapped.deferred as DeferredRecord[];
    const findingsFile = flag(rest, '--findings');
    if (findingsFile) noted = (readFindings(findingsFile, 'classified findings') as ScopedFinding[]).filter(f => f.scope === 'note');
  } catch (e: any) { return refuse('render', 'REVIEW_SCOPE_INPUT', e.message); }
  if (!Array.isArray(deferred)) return refuse('render', 'REVIEW_SCOPE_INPUT', `${deferredFile}: expected the JSON array defer --out writes`);
  process.stdout.write(renderDeferredSection(deferred, noted));
  return EXIT.ok;
}

function cmdSummary(rest: string[], json: boolean): number {
  const since = flag(rest, '--since');
  if (!since || !Number.isFinite(Date.parse(since))) return refuse('summary', 'REVIEW_SCOPE_INPUT', '--since <ISO-8601 timestamp> (the invocation\'s first Step 9 entry) is required');
  const read = runScriptSync(path.join(path.dirname(Bun.fileURLToPath(import.meta.url)), 'gstack-review-read'), [], { encoding: 'utf8', timeout: 60_000, maxBuffer: 64 * 1024 * 1024 });
  if (read.status !== 0) return refuse('summary', 'REVIEW_SCOPE_INPUT', `gstack-review-read failed: ${read.error?.message ?? (read.stderr ?? '').trim().split('\n')[0] ?? ''}`);
  const rows: Record<string, unknown>[] = [];
  for (const line of (read.stdout ?? '').split('---CONFIG---')[0]!.split('\n')) {
    if (!line.trim() || line === 'NO_REVIEWS') continue;
    try { rows.push(JSON.parse(line)); } catch { /* malformed row: gstack-review-read already warned */ }
  }
  const files: string[] = [];
  for (let i = 0; i < rest.length; i++) {
    if (rest[i] !== '--ledger') continue;
    if (!rest[i + 1] || rest[i + 1]!.startsWith('--')) return refuse('summary', 'REVIEW_SCOPE_INPUT', '--ledger needs a file');
    files.push(rest[++i]!);
  }
  const run = flag(rest, '--run');
  if (run) {
    let found: string[];
    try { found = (fs.readdirSync(run, { recursive: true }) as string[]).filter(p => path.basename(p) === 'review-ledger.jsonl').sort().map(p => path.join(run, p)); } catch (e: any) { return refuse('summary', 'REVIEW_SCOPE_LEDGER', `--run ${run}: ${e.code ?? e.message}`); }
    if (!found.length) return refuse('summary', 'REVIEW_SCOPE_LEDGER', `--run ${run} holds no review-ledger.jsonl: name the run directory the passes wrote, or each --ledger`);
    files.push(...found);
  }
  const noLedger = rest.includes('--no-ledger');
  if (noLedger && files.length) return refuse('summary', 'REVIEW_SCOPE_INPUT', '--no-ledger contradicts --run and --ledger');
  // The ledgers hold every reader's findings, the voices' too, before any row classifies them; a summary without them can undercount.
  if (!noLedger && !files.length) return refuse('summary', 'REVIEW_SCOPE_LEDGER', 'name the review\'s dispatch ledgers (--run <run dir> or --ledger <f>), or --no-ledger when no reader ran through gstack-review-dispatch');
  // A row's ledger_id and a fix trailer name a finding as <pass dir>/<merged id>: the ids restart in every pass's ledger.
  const keyOf = (file: string) => (id: string) => `${path.basename(path.dirname(path.resolve(file)))}/${id}`;
  let ledgers: LedgerBlocker[][];
  try { ledgers = files.map(f => ledgerBlockers(f).map(b => ({ ...b, key: keyOf(f)(b.id) }))); } catch (e: any) { return refuse('summary', 'REVIEW_SCOPE_LEDGER', e.message); }
  const log = spawnSync('git', ['log', '--first-parent', '--no-merges', `--since=${since}`, '--format=%H%x00%(trailers:key=Review-Finding,valueonly,separator=%x1f)%x1e', 'HEAD'], { encoding: 'utf8', timeout: 60_000, maxBuffer: 64 * 1024 * 1024 });
  if (log.status !== 0) return refuse('summary', 'REVIEW_SCOPE_INPUT', `git log for Review-Finding trailers failed: ${(log.stderr ?? '').trim().split('\n')[0] ?? ''}`);
  const trailers = log.stdout.split('\x1e').flatMap(rec => { const [sha, values] = rec.trim().split('\0'); return sha && values ? parseFixTrailers(sha, values.split('\x1f').map(v => v.trim()).filter(Boolean)) : []; });
  const summary = summarizeReviewLoop(rows, since, ledgers, files.map(f => ledgerPass(f, keyOf(f))), trailers);
  for (const u of summary.unbound ?? []) process.stderr.write(`REVIEW_SCOPE_UNBOUND: ${u}\n`);
  for (const v of summary.voided ?? []) process.stderr.write(`REVIEW_SCOPE_VOIDED: ${v}\n`);
  const line = reviewLoopLine(summary);
  // A /ship invocation always runs Step 9 once; zero matching rows means the wrong --since or a review log written elsewhere, never a loop to record.
  if (summary.passes === 0) return refuse('summary', 'REVIEW_SCOPE_INPUT', `no review-log row of this branch is a via:ship review at or after ${since}; check REVIEW_SINCE (${line})`);
  process.stderr.write(line + '\n');
  const out = flag(rest, '--out');
  if (out) fs.writeFileSync(out, JSON.stringify(summary) + '\n');
  process.stdout.write(json ? JSON.stringify(summary) + '\n' : line + '\n');
  return EXIT.ok;
}

function main(argv: string[]): number {
  const [cmd, ...rest] = argv;
  const json = rest.includes('--json');
  if (!cmd || cmd === '--help' || cmd === '-h' || cmd === 'help') { process.stdout.write(HELP + '\n'); return cmd ? EXIT.ok : EXIT.usage; }
  try {
    if (cmd === 'classify') return cmdClassify(rest, json);
    if (cmd === 'defer') return cmdDefer(rest, json);
    if (cmd === 'render') return cmdRender(rest);
    if (cmd === 'summary') return cmdSummary(rest, json);
  } catch (e: any) { process.stderr.write(`gstack-review-scope ${cmd}: ${e.message}\n`); return EXIT.fail; }
  process.stderr.write(`gstack-review-scope: unknown command ${cmd}\n${HELP}\n`);
  return EXIT.usage;
}

process.exitCode = main(process.argv.slice(2));