/**
 * JS 取址链路（maidong-ktv/app/src/main/assets/mobile/ktv_api.js）**真实脚本**的
 * 127.0.0.1 stub 对照测量工具（优化前 / 优化后跑同一份脚本）。
 *
 * 为什么能这么测：ktv_api.js 走 `global.android.httpGet(url, headers, timeout)` 与
 * `global.android.appToken(host)`（Android JavascriptInterface 是**同步**调用），
 * 且 `android.appToken` 背后就是 Kotlin 的 `AppTokenClient`（按 host 缓存 10 分钟）。
 * Node 里把这两个方法换成"记录时间戳 + 同步 sleep(一次往返耗时) + 按 host 缓存"的 stub，
 * 就能在**不改一字**的真实脚本上量出：
 *   ① 点歌 → 首个请求发出；
 *   ② 点歌 → 拿到地址（= 用户在界面上"点了没反应"的时长）；
 *   ③ 每首歌实际打几次 /i.php、几次 /music/do.php。
 *
 * 用法：node maidong-ktv/tools/measure_ktv_js.js            （仓库内）
 *       STUB_LATENCY_MS=200 node maidong-ktv/tools/measure_ktv_js.js
 *       STUB_PREHEAT=1 node maidong-ktv/tools/measure_ktv_js.js  （额外模拟一轮后台预热）
 */
'use strict';

const fs = require('fs');
const path = require('path');
// 直接跑（仓库内 tools/measure_ktv_js.js）与从工作区根跑（tmp/measure_ktv_js.js）都要能找到脚本。
const JS_FILE = [
  path.resolve(__dirname, '../app/src/main/assets/mobile/ktv_api.js'),
  path.resolve(__dirname, '../maidong-ktv/app/src/main/assets/mobile/ktv_api.js'),
].find((candidate) => fs.existsSync(candidate));

function syncSleep(ms) {
  Atomics.wait(new Int32Array(new SharedArrayBuffer(4)), 0, 0, ms);
}

function hostOf(u) {
  const m = /^[a-z]+:\/\/([^/]+)/i.exec(String(u));
  return m ? m[1] : '';
}

const RTT_MS = Number(process.env.STUB_LATENCY_MS || 150);
const OFFICIAL = 'http://zk.ktv1.top:6677';
const SELF = 'https://mdmuse.kasugano.cn';
const MUSICNO = '7303235';
const SELF_URL = 'http://md.kasugano.cn/media/' + MUSICNO + '.ts';
const OFFICIAL_URL = 'http://txog.ktvsky.com/E/ts/xxx/' + MUSICNO + '.ts';

function makeScenarios() {
  const forbidden = { status: 200, body: JSON.stringify({ code: 403, msg: '请求被拒绝：检测到异常行为' }) };
  const adOnly = { status: 200, body: JSON.stringify({ code: 200, data: 'https://wb66.cn/f/d/7b7c9/' + MUSICNO + '.ts' }) };
  const notFound = { status: 200, body: JSON.stringify({ code: 404, msg: 'not in library' }) };
  return {
    forbidden: { officialOkTimes: 0, officialFail: forbidden },
    adOnly: { officialOkTimes: 0, officialFail: adOnly },
    notFound: { officialOkTimes: 0, officialFail: notFound },
    quota2: { officialOkTimes: 2, officialFail: forbidden },
  };
}

function newHarness(scenario) {
  const log = [];
  const calls = { iphp: 0, dophp: 0, appToken: 0, appTokenMisses: 0 };
  const tokenCache = new Map();
  let officialDoPhpCount = 0;
  const t0 = Date.now();
  const rel = () => Date.now() - t0;

  const api = {
    httpGet(url) {
      const u = String(url);
      const at = rel();
      if (u.indexOf('/i.php') >= 0) {
        calls.iphp++;
        log.push({ t: at, kind: 'i.php', host: hostOf(u) });
        syncSleep(RTT_MS);
        return JSON.stringify({ status: 200, body: JSON.stringify({ code: 200, token: 'tok-' + hostOf(u), heart_time: 5400 }) });
      }
      if (u.indexOf('/music/do.php') >= 0) {
        calls.dophp++;
        const host = hostOf(u);
        log.push({ t: at, kind: 'do.php', host: host });
        syncSleep(RTT_MS);
        if (host === hostOf(OFFICIAL)) {
          officialDoPhpCount++;
          if (officialDoPhpCount <= scenario.officialOkTimes) {
            return JSON.stringify({ status: 200, body: JSON.stringify({ code: 200, msg: 'SUCCESS', data: OFFICIAL_URL }) });
          }
          const r = scenario.officialFail;
          return JSON.stringify({ status: r.status, body: r.body });
        }
        return JSON.stringify({ status: 200, body: JSON.stringify({ code: 200, msg: 'SUCCESS', data: SELF_URL }) });
      }
      throw new Error('unexpected url ' + u);
    },
    appToken(host) {
      const key = String(host);
      calls.appToken++;
      if (tokenCache.has(key)) return tokenCache.get(key);
      calls.appTokenMisses++;
      log.push({ t: rel(), kind: 'appToken(首次)', host: key });
      syncSleep(RTT_MS);
      tokenCache.set(key, 'app-token');
      return 'app-token';
    },
    invalidateAppToken(host) { tokenCache.delete(String(host)); },
    onSongSource() {},
    reportSongResult() {},
    log() {},
  };
  return { api, log, calls, rel };
}

async function runScenario(name, scenario, songs) {
  delete require.cache[require.resolve(JS_FILE)];
  const fakeWindow = {};
  const prev = global.window;
  global.window = fakeWindow;
  const mod = require(JS_FILE);
  if (prev === undefined) delete global.window; else global.window = prev;

  const KtvApi = fakeWindow.KtvApi || mod.KtvApi;
  const h = newHarness(scenario);
  fakeWindow.android = h.api;
  mod.android = h.api;

  const api = new KtvApi({
    mac: '1ca410000001', sn: 'aabbccddeeff', maxDeviceRetries: 0, debug: false,
    hosts: [OFFICIAL, SELF],
  });

  // 可选：模拟 App 启动 / 进入点歌列表时的**后台预热**（SourcePreheat 在 JS 路径上做的事）：
  //   ① 构造 window.api 并逐个源取一次 /i.php token（同时热好 DNS/TCP/TLS）；
  //   ② 逐个源问一次 App 令牌（android.appToken → Kotlin 侧按 host 缓存）。
  // 用 STUB_PREHEAT=1 打开，用于量"预热把首次点歌的哪些往返省掉了"。
  let preheatMs = null;
  if (process.env.STUB_PREHEAT) {
    const preheatAt = h.rel();
    const warmHosts = [OFFICIAL, SELF];
    for (const host of warmHosts) {
      await api.getToken(host, false);
      h.api.appToken(host);
    }
    preheatMs = h.rel() - preheatAt;
  }

  const songsOut = [];
  for (let i = 0; i < songs; i++) {
    const start = h.rel();
    const before = h.log.length;
    const url = await api.getSongUrl(MUSICNO, '720', false);
    const end = h.rel();
    const reqs = h.log.slice(before);
    const okReq = reqs.filter(r => r.kind === 'do.php' && r.host === hostOf(SELF))[0];
    songsOut.push({
      song: i + 1,
      totalMs: end - start,
      firstRequestSentAtMs: reqs.length ? reqs[0].t - start : null,
      successSourceRequestSentAtMs: okReq ? okReq.t - start : null,
      url: url,
      requests: reqs.map(r => ((r.t - start) + 'ms ' + r.kind + ' ' + r.host)),
    });
  }
  return {
    scenario: name,
    stub: { httpRoundTripMs: RTT_MS, preheat: !!process.env.STUB_PREHEAT, preheatMs: preheatMs },
    totals: h.calls,
    songs: songsOut,
  };
}

(async () => {
  const scenarios = makeScenarios();
  const out = [];
  for (const name of Object.keys(scenarios)) out.push(await runScenario(name, scenarios[name], 4));
  console.log(JSON.stringify({ jsFile: JS_FILE, results: out }, null, 2));
})();