#!/usr/bin/env node
/**
 * PoC H1: Windows fs.renameSync 跨目录原子性验证
 *
 * 验证 4 种场景:
 *  A. 同分区同目录 rename      (期望: 原子)
 *  B. 同分区跨目录 rename      (期望: 原子)
 *  C. 跨分区 rename            (期望: Node 自动 copy+unlink, 非原子)
 *  D. 目标文件存在时 rename    (期望: 覆盖, Windows >=10 支持)
 *
 * 红队 red-team-logic A1 [CRITICAL]: 跨卷 rename 非原子 → 本测试量化验证
 * 产出: ai-delivery-pipeline/_poc-sandbox/h1-report.json
 */
'use strict';

const fs = require('fs');
const os = require('os');
const path = require('path');

const SANDBOX = path.join(__dirname, '..', '..', 'ai-delivery-pipeline', '_poc-sandbox');
const REPORT = path.join(SANDBOX, 'h1-report.json');

function mk(subdir) {
  const d = path.join(SANDBOX, subdir);
  fs.mkdirSync(d, { recursive: true });
  return d;
}

function scenarioA_sameDir() {
  const d = mk('h1-a');
  const a = path.join(d, 'src.txt');
  const b = path.join(d, 'dst.txt');
  fs.writeFileSync(a, 'A-content', 'utf8');
  const t0 = process.hrtime.bigint();
  fs.renameSync(a, b);
  const dt = Number(process.hrtime.bigint() - t0) / 1e6;
  const ok = !fs.existsSync(a) && fs.readFileSync(b, 'utf8') === 'A-content';
  return { name: 'A-sameDir', ok, ms: dt.toFixed(3) };
}

function scenarioB_crossDir() {
  const d1 = mk('h1-b/src');
  const d2 = mk('h1-b/dst');
  const a = path.join(d1, 'foo.txt');
  const b = path.join(d2, 'foo.txt');
  fs.writeFileSync(a, 'B-content', 'utf8');
  const t0 = process.hrtime.bigint();
  fs.renameSync(a, b);
  const dt = Number(process.hrtime.bigint() - t0) / 1e6;
  const ok = !fs.existsSync(a) && fs.readFileSync(b, 'utf8') === 'B-content';
  return { name: 'B-crossDir-sameVolume', ok, ms: dt.toFixed(3) };
}

function scenarioC_crossVolume() {
  // 探测系统是否有第二卷; 无则跳过
  const drives = [];
  for (const d of ['D:', 'E:', 'F:']) {
    try { fs.accessSync(d + '\\', fs.constants.W_OK); drives.push(d); } catch {}
  }
  if (drives.length === 0) {
    return { name: 'C-crossVolume', ok: null, skip: '未检测到第二可写卷' };
  }
  const otherVol = drives[0];
  const tmpOther = path.join(otherVol + '\\', 'bookworm-poc-' + Date.now());
  try {
    fs.mkdirSync(tmpOther, { recursive: true });
    const a = path.join(SANDBOX, 'h1-c-src.txt');
    const b = path.join(tmpOther, 'dst.txt');
    fs.writeFileSync(a, 'C-content', 'utf8');
    const t0 = process.hrtime.bigint();
    fs.renameSync(a, b);
    const dt = Number(process.hrtime.bigint() - t0) / 1e6;
    const ok = !fs.existsSync(a) && fs.readFileSync(b, 'utf8') === 'C-content';
    fs.unlinkSync(b);
    fs.rmdirSync(tmpOther);
    return { name: 'C-crossVolume', ok, ms: dt.toFixed(3), targetVol: otherVol };
  } catch (e) {
    return { name: 'C-crossVolume', ok: false, error: e.message, targetVol: otherVol };
  }
}

function scenarioD_overwrite() {
  const d = mk('h1-d');
  const a = path.join(d, 'src.txt');
  const b = path.join(d, 'dst.txt');
  fs.writeFileSync(a, 'D-new', 'utf8');
  fs.writeFileSync(b, 'D-old', 'utf8');
  try {
    fs.renameSync(a, b);
    const content = fs.readFileSync(b, 'utf8');
    const ok = !fs.existsSync(a) && content === 'D-new';
    return { name: 'D-overwrite', ok, note: 'overwrote existing' };
  } catch (e) {
    return { name: 'D-overwrite', ok: false, error: e.code + ': ' + e.message };
  }
}

function main() {
  fs.mkdirSync(SANDBOX, { recursive: true });
  const results = [
    scenarioA_sameDir(),
    scenarioB_crossDir(),
    scenarioC_crossVolume(),
    scenarioD_overwrite(),
  ];
  const report = {
    hypothesis: 'H1 · Windows fs.renameSync 跨目录原子性',
    platform: os.platform() + ' ' + os.release(),
    nodeVersion: process.version,
    timestamp: new Date().toISOString(),
    results,
    verdict: (() => {
      const a = results[0].ok === true;
      const b = results[1].ok === true;
      const d = results[3].ok === true;
      const c = results[2];
      if (a && b && d) {
        const cState = c.ok === null ? '无法测试(无第二卷)' :
                       c.ok === true ? '跨卷也可 rename(Node 自动 copy)' :
                       '跨卷 rename 失败: ' + (c.error || 'unknown');
        return { pass: true, summary: '同卷原子 ✅, 覆盖 ✅, ' + cState };
      }
      return { pass: false, summary: 'A/B/D 有失败场景, 不可用于生产' };
    })(),
    recommendation: '',
  };
  report.recommendation = report.verdict.pass
    ? '✅ 采用同卷 rename 作为 staging→delivery 主路径; 跨卷场景须 fallback 到 copy+fsync+unlink(非原子, 需上层补偿)'
    : '❌ 方案不可行, 需重新设计';
  fs.writeFileSync(REPORT, JSON.stringify(report, null, 2), 'utf8');
  console.log(JSON.stringify(report, null, 2));
}

main();