/**
 * 回归：本轮 code review 修掉的 5 个 P0 缺陷
 *
 * 每条都锁死"修复后的语义"，并尽可能给出**反向证明**（展示修复前的写法会产出什么），
 * 防止将来有人"顺手简化"时把缺陷放回去。
 *
 * 红线：
 *   1. crypto 必须按**字节**做 XOR（UTF-8），非 ASCII 无损往返；失败不 fail-open
 *   2. addDevice 必须返回布尔，数量达上限时返回 false（调用方据此中断）
 *   3. publish 必须有超时出口，底层永不回调时也能结算
 *   4. subscriptions 的生命周期属于"业务意图"，只有 disconnect() 能清
 *   5. 产品ID 必须是正整数，NaN / 小数不得进入 topic
 *
 * 跑法：node tests/p0-regressions.test.js
 */
const fs = require('fs');
const path = require('path');
const { MINI_ROOT, loadRuntime, clearMiniCache } = require('./helpers/fake-wx.js');

/* ============================ 迷你断言器 ============================ */

let passed = 0;
let failed = 0;

function ok(cond, label, extra) {
  if (cond) {
    passed++;
    process.stdout.write(`  ✓ ${label}\n`);
  } else {
    failed++;
    process.stdout.write(`  ✗ ${label}${extra !== undefined ? `  ← ${JSON.stringify(extra)}` : ''}\n`);
  }
}

function eq(actual, expected, label) {
  ok(actual === expected, `${label} (期望 ${JSON.stringify(expected)}，实际 ${JSON.stringify(actual)})`);
}

/* ============================ 加载真实 MQTT 模块 ============================ */

/**
 * ⚠️ 必须在 loadRuntime() 之前调用：loadRuntime 会用假 mqtt-client 顶掉
 * services/mqtt-client.js，之后 require 拿到的是桩而不是被测实现
 */
function loadRealMqtt() {
  clearMiniCache();
  global.wx = {
    getNetworkType: (o = {}) => setTimeout(() => o.success && o.success({ networkType: 'wifi' }), 0),
    arrayBufferToBase64: () => '',
    base64ToArrayBuffer: () => new ArrayBuffer(0),
  };
  return require(path.join(MINI_ROOT, 'services/mqtt-client.js'));
}

const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

/* ============================ 用例 ============================ */

/** P0-5：publish 超时出口 */
async function casePublishTimeout() {
  process.stdout.write('\n[1] P0-5 publish 必须有超时出口（底层永不回调也能结算）\n');

  const { mqttClient } = loadRealMqtt();

  // 坏桩：publish 永不回调，模拟卡在在途队列里的 QoS1 消息
  mqttClient.client = { connected: true, publish: () => {} };
  const t0 = Date.now();
  let msg = null;
  try {
    await mqttClient.publish('/1/BT_01/001/measure/post', 'AABB', { publishTimeout: 120 });
  } catch (err) {
    msg = err.message;
  }
  const cost = Date.now() - t0;
  eq(msg, '发布超时', '超时后 reject');
  ok(cost >= 110 && cost < 1000, `约 120ms 内结算，不是永久挂起 (实际 ${cost}ms)`);

  // 未连接仍应立刻拒绝，不进超时路径
  mqttClient.client = null;
  let msg2 = null;
  try { await mqttClient.publish('/t', 'x'); } catch (err) { msg2 = err.message; }
  eq(msg2, 'MQTT 未连接', '未连接时立即 reject');

  // 成功路径不受影响
  mqttClient.client = { connected: true, publish: (t, m, o, cb) => cb && cb(null) };
  let resolved = false;
  await mqttClient.publish('/t', 'x').then(() => { resolved = true; }).catch(() => {});
  ok(resolved, '正常回调时仍然 resolve');
}

/** P0-4：订阅表不得随连接被清空 */
async function caseSubscriptions() {
  process.stdout.write('\n[2] P0-4 订阅表生命周期属于业务意图，只有 disconnect() 能清\n');

  const { mqttClient } = loadRealMqtt();

  mqttClient.subscriptions.set('/p/1/sn/function/get', () => {});
  mqttClient.client = { end: () => {} };
  mqttClient._teardownClient(mqttClient.client);
  eq(mqttClient.subscriptions.size, 1, '拆掉客户端后订阅表仍在（供 _resubscribe 恢复）');

  const SRC = fs.readFileSync(path.join(MINI_ROOT, 'services/mqtt-client.js'), 'utf8');
  const clears = SRC.match(/this\.subscriptions\.clear\(\)/g) || [];
  eq(clears.length, 1, 'subscriptions.clear() 全文件只允许 1 处');
  ok(SRC.indexOf('this.subscriptions.clear()') > SRC.indexOf('  disconnect()'),
    '唯一那处在 disconnect() 内（用户主动断开才清）');
  ok(SRC.includes('_resubscribe'), 'connect 成功后仍有 _resubscribe 恢复订阅');
}

/** P0-3：crypto 字节级编解码 */
async function caseCrypto() {
  process.stdout.write('\n[3] P0-3 crypto 按字节做 XOR，非 ASCII 无损往返\n');

  const rt = loadRuntime();
  const { encrypt, decrypt, encryptFields, decryptFields } = require(path.join(MINI_ROOT, 'utils/crypto.js'));
  const KEY = 'fastbee-mini-2026';

  // 修复前的写法（按 UTF-16 charCode XOR + setUint8 截断），用于兼容性与反向证明
  const oldEncrypt = (text, key = KEY) => {
    let s = '';
    for (let i = 0; i < text.length; i++) s += String.fromCharCode(text.charCodeAt(i) ^ key.charCodeAt(i % key.length));
    const bytes = [];
    for (let i = 0; i < s.length; i++) bytes.push(s.charCodeAt(i) & 0xFF);
    return rt.wx.arrayBufferToBase64(new Uint8Array(bytes).buffer);
  };

  // 存量兼容：纯 ASCII 的新密文必须与旧实现逐字节一致，老数据才能继续解开
  for (const s of ['secret', 'fastbee', 'Abc123!@#', '0123456789abcdefXYZ']) {
    eq(encrypt(s), oldEncrypt(s), `新密文与旧实现一致（存量可解）: ${s}`);
    eq(decrypt(oldEncrypt(s)), s, `新实现能解开旧密文: ${s}`);
  }

  // 非 ASCII：修复前会静默损坏，修复后必须无损
  for (const s of ['密钥中文', '密码abc中文', '测点·2026', '🔧扳手', 'Ünïcödé']) {
    eq(decrypt(encrypt(s)), s, `往返无损: ${s}`);
  }
  ok(decrypt(oldEncrypt('密钥中文')) !== '密钥中文',
    '反向证明：旧实现对中文确实不可逆损坏', decrypt(oldEncrypt('密钥中文')));

  // 不得 fail-open（旧实现异常时返回明文/密文本身）
  eq(encrypt(''), '', 'encrypt("") 返回空串');
  eq(decrypt(''), '', 'decrypt("") 返回空串');
  const realDecode = global.wx.base64ToArrayBuffer;
  global.wx.base64ToArrayBuffer = () => { throw new Error('decode boom'); };
  eq(decrypt('anycipher'), '', '解码异常时返回空串，不拿密文冒充明文');
  global.wx.base64ToArrayBuffer = realDecode;

  // 字段级
  const enc = encryptFields({ productSecret: '我的密钥123', serialNumber: 'BT_01' }, ['productSecret']);
  ok(enc.productSecret !== '我的密钥123' && enc._productSecret_encrypted === true, '敏感字段已加密并打标记');
  eq(enc.serialNumber, 'BT_01', '非敏感字段不受影响');
  const dec = decryptFields(enc, ['productSecret']);
  eq(dec.productSecret, '我的密钥123', '字段级往返无损');
  eq(dec._productSecret_encrypted, undefined, '解密后清除标记');
}

/** P0-2：addDevice 返回值 */
async function caseAddDevice() {
  process.stdout.write('\n[4] P0-2 addDevice 数量达上限必须返回 false（供调用方中断）\n');

  const rt = loadRuntime();
  let added = 0;
  for (let i = 0; i < 60; i++) {
    const sn = 'DEV_' + String(i).padStart(3, '0');
    if (rt.storage.addDevice({ deviceId: 'ID_' + i, serialNumber: sn, name: sn, enabled: false }) === true) added++;
  }
  eq(added, 50, '恰好写入 50 台后开始返回 false');
  eq(rt.storage.addDevice({ serialNumber: 'DEV_OVER', deviceId: 'X' }), false, '第 51 台返回 false');
  eq(rt.storage.getDeviceList().length, 50, '列表未被超限写入污染');
  eq(rt.storage.addDevice({ serialNumber: 'DEV_000', deviceId: 'ID_0', name: '改名' }), true, '覆盖既有编号仍返回 true');

  // 调用方确实检查了返回值：scan.js 里 addDevice 之后不得无条件继续激活+启动
  const SCAN = fs.readFileSync(path.join(MINI_ROOT, 'pages/device/scan/scan.js'), 'utf8');
  ok(/if\s*\(\s*!storage\.addDevice\(/.test(SCAN), 'scan.js 对 addDevice 的返回值做了失败分支');
  ok(!/^\s*storage\.addDevice\(deviceConfig\);\s*$/m.test(SCAN), '不再有「无视返回值直接调用」的写法');
}

/** P0-1：产品ID 必须是正整数 */
async function caseProductId() {
  process.stdout.write('\n[5] P0-1 产品ID 必须校验为整数，NaN/小数不得进入 topic\n');

  const rt = loadRuntime();
  // 必须种进 storage：auth.getMqttCredentials 读的是存储里的用户信息，不是页面 data。
  // 不种的话合法用例会走到"未登录"分支而失败，非法用例也会因提前 return 而假绿
  rt.storage.setUserInfo({ userId: 1, userName: 'tester' });

  const toasts = [];
  global.wx.showToast = (o) => toasts.push(o.title);
  global.wx.showModal = (o) => toasts.push('MODAL:' + o.title);
  global.wx.showLoading = () => {};
  global.wx.hideLoading = () => {};

  global.getApp = () => ({ globalData: {} });
  let cfg = null;
  global.Page = (c) => { cfg = c; };
  require(path.join(MINI_ROOT, 'pages/mine/mine.js'));
  if (!cfg) throw new Error('mine.js 未调用 Page()，加载失败');

  const page = Object.assign({}, cfg);
  page.data = JSON.parse(JSON.stringify(cfg.data));
  page.setData = function (patch) { Object.assign(this.data, patch); };
  page.setData({ userInfo: { userId: 1 } });

  const auth = require(path.join(MINI_ROOT, 'utils/auth.js'));

  // 反向证明：修复前的 parseInt 会产出 NaN，而网关的判空两道都挡不住它
  eq(auth.buildMeasurePostTopic(parseInt('abc'), 'BT_01', '001'), '/NaN/BT_01/001/measure/post',
    '反向证明：parseInt("abc") 会造出 /NaN/ 脏 topic');
  eq(auth.buildMeasurePostTopic(parseInt('12.5'), 'BT_01', '001'), '/12/BT_01/001/measure/post',
    '反向证明：parseInt("12.5") 会静默截断成 12');

  for (const bad of ['abc', '12.5', '0', '-3', '']) {
    rt.storage.removeMqttConfig();
    toasts.length = 0;
    page.setData({ mqttConnectingLocal: false });
    page.data.mqttForm = { serialNumber: 'BT_01', productId: bad, productSecret: 'sec' };
    await page.handleMqttConnect();
    eq(rt.storage.getMqttConfig(), null, `非法产品ID "${bad}" 不落盘`);
  }

  // 合法输入仍正常
  rt.storage.removeMqttConfig();
  toasts.length = 0;
  page.setData({ mqttConnectingLocal: false });
  page.data.mqttForm = { serialNumber: 'BT_01', productId: '12', productSecret: 'sec' };
  await page.handleMqttConnect();
  const saved = rt.storage.getMqttConfig();
  ok(saved !== null, '合法产品ID 正常保存');
  eq(saved && saved.productId, 12, '保存为数字 12（不是字符串）');
  eq(auth.buildMeasurePostTopic(saved.productId, saved.serialNumber, '001'), '/12/BT_01/001/measure/post',
    '构造出的 topic 正确');
}

/* ============================ 执行 ============================ */

(async () => {
  process.stdout.write('\n===== P0 缺陷回归 =====\n');
  // 顺序敏感：[1][2] 必须先加载真实 mqtt-client，之后 loadRuntime 才会注入假模块
  await casePublishTimeout();
  await caseSubscriptions();
  await caseCrypto();
  await caseAddDevice();
  await caseProductId();

  process.stdout.write(`\n===== 通过 ${passed} / 失败 ${failed} =====\n`);
  process.exit(failed === 0 ? 0 : 1);
})();