#!/usr/bin/env node
/**
 * PoC H2: manifest 并发写入安全性
 *
 * 红队 red-team-logic A3 [HIGH]: 多 hook 并发 JSON.stringify 整文件写→撕裂
 * 方案对比:
 *   M1. JSON 整写 (当前多 hook 做法)       期望: 撕裂
 *   M2. JSONL append-only + proper-lockfile 期望: 无撕裂
 *   M3. fs.appendFileSync 原子(小于 PIPE_BUF=4096) 期望: Linux 原子, Windows 部分保证
 *
 * 测试: 10 个子进程并发写 100 条记录, 读回检查总条数和完整性
 * 产出: h2-report.json
 */
'use strict';

const fs = require('fs');
const os = require('os');
const path = require('path');
const { spawn } = require('child_process');

const SANDBOX = path.join(__dirname, '..', '..', 'ai-delivery-pipeline', '_poc-sandbox');
const WORKER = path.join(__dirname, 'poc-h2-worker.js');
const REPORT = path.join(SANDBOX, 'h2-report.json');

function makeWorkerIfMissing() {
  if (fs.existsSync(WORKER)) return;
  const src = `
'use strict';
const fs = require('fs');
const mode = process.argv[2];       // 'jsonl' | 'json-full'
const target = process.argv[3];
const workerId = process.argv[4];
const count = Number(process.argv[5]) || 100;

function writeJsonlRecord() {
  for (let i = 0; i < count; i++) {
    const rec = JSON.stringify({ worker: workerId, i, ts: Date.now() }) + '\\n';
    fs.appendFileSync(target, rec);
  }
}

function writeJsonFullRewrite() {
  for (let i = 0; i < count; i++) {
    let arr = [];
    try { arr = JSON.parse(fs.readFileSync(target, 'utf8') || '[]'); } catch { arr = []; }
    arr.push({ worker: workerId, i, ts: Date.now() });
    fs.writeFileSync(target, JSON.stringify(arr), 'utf8');
  }
}

if (mode === 'jsonl') writeJsonlRecord();
else writeJsonFullRewrite();
`;
  fs.writeFileSync(WORKER, src, 'utf8');
}

function runConcurrent(mode, target, workers = 10, perWorker = 100) {
  if (fs.existsSync(target)) fs.unlinkSync(target);
  if (mode === 'jsonl') fs.writeFileSync(target, '', 'utf8');

  return new Promise((resolve) => {
    let done = 0;
    const started = Date.now();
    for (let w = 0; w < workers; w++) {
      const proc = spawn(process.execPath, [WORKER, mode, target, 'w' + w, perWorker], {
        stdio: 'ignore', windowsHide: true,
      });
      proc.on('exit', () => {
        if (++done === workers) resolve(Date.now() - started);
      });
    }
  });
}

function verifyJsonl(target, expected) {
  const raw = fs.readFileSync(target, 'utf8');
  const lines = raw.split('\n').filter(Boolean);
  let parsed = 0, corrupt = 0;
  for (const L of lines) {
    try { JSON.parse(L); parsed++; } catch { corrupt++; }
  }
  return { total: lines.length, parsed, corrupt, expected };
}

function verifyJsonFull(target, expected) {
  let parsed = 0, corrupt = 0, final = null;
  try {
    final = JSON.parse(fs.readFileSync(target, 'utf8'));
    parsed = Array.isArray(final) ? final.length : 0;
  } catch (e) {
    corrupt = 1;
  }
  return { finalCount: parsed, corrupt, expected, lost: expected - parsed };
}

async function main() {
  fs.mkdirSync(SANDBOX, { recursive: true });
  makeWorkerIfMissing();

  const W = 10, P = 100, EXPECTED = W * P;

  const jsonlTarget = path.join(SANDBOX, 'h2-jsonl.log');
  const jsonFullTarget = path.join(SANDBOX, 'h2-jsonfull.log');

  console.log('[H2] running jsonl append-only with', W, 'workers x', P, 'records...');
  const t1 = await runConcurrent('jsonl', jsonlTarget, W, P);
  const jsonlResult = verifyJsonl(jsonlTarget, EXPECTED);
  console.log('[H2] jsonl elapsed', t1, 'ms', jsonlResult);

  console.log('[H2] running json full-rewrite (vulnerable pattern)...');
  const t2 = await runConcurrent('json-full', jsonFullTarget, W, P);
  const jsonResult = verifyJsonFull(jsonFullTarget, EXPECTED);
  console.log('[H2] json-full elapsed', t2, 'ms', jsonResult);

  const report = {
    hypothesis: 'H2 · manifest 并发写入安全性',
    platform: os.platform() + ' ' + os.release(),
    nodeVersion: process.version,
    timestamp: new Date().toISOString(),
    workers: W, perWorker: P, expected: EXPECTED,
    jsonl_append_only: { elapsedMs: t1, ...jsonlResult },
    json_full_rewrite: { elapsedMs: t2, ...jsonResult },
    verdict: {
      jsonlSafe: jsonlResult.corrupt === 0 && jsonlResult.parsed === EXPECTED,
      jsonFullSafe: jsonResult.corrupt === 0 && jsonResult.lost === 0,
    },
    recommendation: '',
  };
  report.recommendation = report.verdict.jsonlSafe && !report.verdict.jsonFullSafe
    ? '✅ manifest 必须用 JSONL append-only, 禁用 JSON 整文件写'
    : report.verdict.jsonlSafe
      ? '✅ JSONL 安全; 整写偶然未暴露但仍有风险, 强制 JSONL'
      : '❌ JSONL 也撕裂, 必须加 proper-lockfile';
  fs.writeFileSync(REPORT, JSON.stringify(report, null, 2), 'utf8');
  console.log('\n' + JSON.stringify(report, null, 2));
}

main();