#!/usr/bin/env node
// Real production-client migration through the unchanged Refresh UI flow.
import assert from 'node:assert/strict';
import { spawn, execFileSync } from 'node:child_process';
import { mkdtempSync, mkdirSync, symlinkSync, unlinkSync, writeFileSync, rmSync, readFileSync } from 'node:fs';
import { join, resolve } from 'node:path';
import { createServer } from 'node:net';
import { fileURLToPath } from 'node:url';
import { createThrottleProxy } from './proxy.mjs';
import { chromium, webkit } from 'playwright';

const repo = resolve(fileURLToPath(new URL('..', import.meta.url)));
const commit = 'b77938a', oldTag = '1175f1a1d2c1';
const args = process.argv.slice(2);
const profile = args.includes('--profile') ? args[args.indexOf('--profile')+1] : 'lossy';
const browserName = args.includes('--browser') ? args[args.indexOf('--browser') + 1] : 'all';
assert.ok(['all', 'chromium', 'webkit'].includes(browserName));
execFileSync('bash', [join(repo, 'perf/make-shell-fixture.sh'), commit, oldTag], { cwd: repo, stdio: 'inherit' });
const scratch = mkdtempSync(join(repo, 'perf/.tmp/migration-'));
const archive = join(scratch, 'old-server.tar');
writeFileSync(archive, execFileSync('git', ['archive', commit, 'server'], { cwd: repo, maxBuffer: 20 * 1024 * 1024 }));
execFileSync('tar', ['-xf', archive, '-C', scratch]);
symlinkSync(join(repo, 'server/node_modules'), join(scratch, 'server/node_modules'));
// Archived server modules resolve their Docker-style public imports relative
// to the module, while static routes resolve ./public relative to cwd.
symlinkSync(join(repo, `perf/fixtures/shell-${oldTag}`), join(scratch, 'server/public'));
const shell = [...readFileSync(join(repo, 'frontend/sw.js'), 'utf8').match(/const SHELL = \[([\s\S]*?)\n\];/)[1].matchAll(/['"](\/[^'"]+)['"]/g)].map(m => m[1]);
const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));
async function waitAsync(page,predicate,arg,timeout=90000) {
  const deadline=Date.now()+timeout;
  while(Date.now()<deadline) {
    if(await page.evaluate(predicate,arg)) return;
    await sleep(100);
  }
  throw new Error('Timed out waiting for asynchronous migration condition');
}
async function freePort() {
  const server = createServer();
  await new Promise(resolve => server.listen(0, '127.0.0.1', resolve));
  const port = server.address().port;
  await new Promise(resolve => server.close(resolve));
  return port;
}
async function run(name) {
  const cwd = join(scratch, name);
  mkdirSync(cwd);
  const port = await freePort();
  let child, output = '', browser, proxy;
  async function stop() {
    if (!child) return;
    const process = child; child = null;
    await new Promise(resolve => {
      if (process.exitCode !== null) return resolve();
      process.once('exit', resolve); process.kill('SIGTERM');
    });
  }
  async function start(old) {
    symlinkSync(old ? join(repo, `perf/fixtures/shell-${oldTag}`) : join(repo, 'frontend'), join(cwd, 'public'));
    output = '';
    child = spawn('bun', [old ? join(scratch, 'server/server.js') : join(repo, 'server/server.js')], {
      cwd, env: { ...process.env, BUILD_TAG: '', ASSET_HASHING: old ? '0' : '1', PORT: String(port),
        DATA_DIR: join(cwd, 'data'), DB_PATH: join(cwd, 'db.sqlite'), MEDIA_DIR: join(cwd, 'media'), UPLOAD_DIR: join(cwd, 'uploads') },
      stdio: ['ignore', 'pipe', 'pipe'],
    });
    for (const stream of [child.stdout, child.stderr]) stream.on('data', chunk => { output = (output + chunk).slice(-12000); });
    for (let i = 0; i < 200; i++) {
      if (child.exitCode !== null) throw new Error(`Bun server exited: ${output}`);
      try { if ((await fetch(`http://127.0.0.1:${port}/api/version`)).ok) return; } catch {}
      await sleep(100);
    }
    throw new Error(`Bun startup timeout: ${output}`);
  }
  try {
    await start(true);
    assert.equal((await (await fetch(`http://127.0.0.1:${port}/api/version`)).json()).buildTag, oldTag);
    proxy = createThrottleProxy({ targetPort: port, profile });
    const proxyPort = await proxy.listen();
    const origin = `http://127.0.0.1:${proxyPort}`;
    browser = await ({ chromium, webkit }[name]).launch({ headless: true });
    const context = await browser.newContext();
    // Keep this harness entirely local, including any UI third-party requests.
    await context.route('**/*', route => route.request().url().startsWith(origin) ? route.continue() : route.abort());
    let banners = 0, navigations = 0;
    const errors = [];
    const failedRequests = [];
    let disconnected = false;
    const page = await context.newPage();
    await page.exposeFunction('migrationBanner', () => { banners++; });
    await page.addInitScript(() => {
      let visible = false;
      new MutationObserver(() => {
        const modal = document.querySelector('#modal');
        const now = !!modal && !modal.classList.contains('hidden') && /Update available/.test(document.querySelector('#modalTitle')?.textContent || '');
        if (now && !visible) window.migrationBanner();
        visible = now;
      }).observe(document, { subtree: true, childList: true, attributes: true, characterData: true });
    });
    page.on('pageerror', error => errors.push({ message: error.message, disconnected }));
    page.on('requestfailed', request => failedRequests.push(request.url()));
    page.on('framenavigated', frame => { if (frame === page.mainFrame()) navigations++; });
    await page.goto(origin, { waitUntil: 'load', timeout: 90000 });
    await page.waitForFunction(() => !!navigator.serviceWorker.controller, { timeout: 90000 });
    assert.equal(await page.locator('meta[name="ytp-build"]').getAttribute('content'), oldTag);
    assert.equal(banners, 0, 'no first-install banner');
    await stop(); unlinkSync(join(cwd, 'public')); await start(false);
    const backend = `http://127.0.0.1:${port}`;
    const manifest = await (await fetch(`${backend}/api/manifest`)).json();
    assert.notEqual(manifest.buildTag, oldTag);
    // Old URLs must continue delivering actual NEW bytes, not error/fallback HTML.
    for (const path of ['/app.js', '/theme-glass.css', '/opfs-worker.js', '/sha256-wasm.js', '/manifest.webmanifest', '/icons/icon-192.png', '/fonts/HankenGrotesk-latin.woff2']) {
      for (const query of ['', '?__ytpfresh=migration', `?v=${oldTag}`]) {
        const response = await fetch(`${backend}${path}${query}`);
        assert.equal(response.status, 200);
        assert.equal(response.headers.get('x-asset-hash'), manifest.files[path].h);
        assert.deepEqual(Buffer.from(await response.arrayBuffer()), readFileSync(join(repo, 'frontend', path.slice(1))));
        if (query.includes('?v=')) assert.equal(response.headers.get('cache-control'), 'no-store');
      }
    }
    proxy.resetStats(); proxy.startTracking();
    const started = Date.now();
    // Use the old application's public functions; no simulated update helper.
    await page.evaluate(async () => {
      await checkBuildTag();
      await (await navigator.serviceWorker.getRegistration()).update();
    });
    await waitAsync(page,async () => !!(await navigator.serviceWorker.getRegistration())?.waiting);
    await page.waitForFunction(() => /Update available/.test(document.querySelector('#modalTitle')?.textContent || '') && !document.querySelector('#modal').classList.contains('hidden'));
    assert.equal(banners, 1, 'exactly one offer before refresh');
    const before = navigations;
    await sleep(4500);
    assert.equal(navigations,before,'legacy installation does not reload without Refresh UI');
    // A legacy startup update can still be in flight through the stall proxy.
    // Require the target candidate, not a transient earlier waiting worker.
    await waitAsync(page,async tag => {
      const reg=await navigator.serviceWorker.getRegistration();
      const cache=await caches.open('ytplayer-assets');
      return !reg.installing && reg.waiting?.state==='installed' &&
        !!await cache.match('/__ytp_candidate/'+tag);
    }, manifest.buildTag);
    const status = await page.evaluate(async()=>SwUpdate.askCacheStatus((await navigator.serviceWorker.getRegistration()).waiting,{timeoutMs:4000}));
    assert.equal(status?.ready,true,'new worker confirms persistent cache to old helper');
    assert.equal(status.version,manifest.buildTag,'status belongs to the target build');
    const oldTab = await context.newPage();
    await oldTab.goto(origin,{waitUntil:'load'});
    assert.equal(await oldTab.locator('meta[name="ytp-build"]').getAttribute('content'),oldTag);
    const oldBytes = await oldTab.evaluate(async()=>await (await fetch('/app.js')).text());
    await page.locator('#modal').getByRole('button', { name: 'Refresh UI', exact: true }).click();
    await page.waitForFunction(tag => document.querySelector('meta[name="ytp-build"]')?.content === tag && typeof checkBuildTag === 'function', manifest.buildTag, { timeout: 90000 });
    await page.waitForFunction(() => !sessionStorage.getItem('ytpUpdateAttempt'));
    await page.evaluate(async () => { await checkBuildTag(); await checkBuildTag(); await checkBuildTag(); });
    await sleep(2000);
    assert.equal(navigations - before, 1, 'one reload, no update loop');
    assert.equal(banners, 1, 'no banner after applying the current build');
    assert.equal(await oldTab.evaluate(async()=>await (await fetch('/app.js')).text()),oldBytes,'open legacy tab keeps N-1 plain assets');
    await oldTab.close();
    // Phase 3 commits core + layout first; idle warming must fill the retained full shell before offline feature checks.
    await page.evaluate(()=>Lazy.warm());
    await waitAsync(page,async files=>{const cache=await caches.open('ytplayer-assets');return (await Promise.all(Object.keys(files).map(async path=>{const response=await cache.match(path+'?v='+files[path].h);return !!response&&response.headers.get('X-Asset-Hash')===files[path].h;}))).every(Boolean);},Object.fromEntries(shell.map(path=>[path==='/'?'/index.html':path,manifest.files[path==='/'?'/index.html':path]])));
    const cacheResult = await page.evaluate(async ({ tag, shell, files }) => {
      const cache = await caches.open('ytplayer-assets');
      const missing = [], incorrect = [];
      for (const path of shell) {
        const p = path === '/' ? '/index.html' : path;
        const response = await cache.match(p+'?v='+files[p].h);
        if (!response) { missing.push(path); continue; }
        if (response.headers.get('x-asset-hash') !== files[path === '/' ? '/index.html' : path]?.h) incorrect.push(path);
      }
      return { missing, incorrect, count: (await cache.keys()).length };
    }, { tag: manifest.buildTag, shell, files: manifest.files });
    assert.deepEqual(cacheResult.missing, []);
    assert.deepEqual(cacheResult.incorrect, [], 'every cached shell asset belongs to the new build');
    proxy.stopTracking();
    const stats = proxy.getStats();
    assert.equal(stats.requests.filter(r=>r.url.includes('__ytpfresh')).length,0,'legacy helper skips its full download after ready:true');
    const durationMs = Date.now() - started;
    assert.deepEqual(errors, [], 'no script failures during installation and update');
    // Exercise the new helper's actual lexical Player guard, without starting
    // media or changing the production update/outcome code.
    let guardText='';
    page.once('dialog',async dialog=>{guardText=dialog.message();await dialog.dismiss();});
    const guard=await page.evaluate(async()=>{
      const saved=Player._wantsPlaying;Player._wantsPlaying=true;let reloads=0;
      try { await SwUpdate.applyUpdate({reg:null,container:navigator.serviceWorker,reload:()=>reloads++});return {reloads,blocked:false}; }
      catch(e){return {reloads,blocked:/Playing/.test(e.message)};}
      finally{Player._wantsPlaying=saved;}
    });
    assert.match(guardText,/Playing - update after this song \/ when paused/);
    assert.deepEqual(guard,{reloads:0,blocked:true});
    const refresh=await page.evaluate(async files=>{
      const cache=await caches.open('ytplayer-assets');
      const key='/async-guard.js?v='+files['/async-guard.js'].h;
      await cache.delete(key);
      const requests=[];
      const result=await SwUpdate.refreshShellInPlace({cachesApi:caches,
        fetchFn:(url,init)=>{requests.push(url);return fetch(url,init)},isShellCache:()=>true});
      if(!await cache.match(key)) throw Error('Refresh did not repair missing asset');
      // Independently test the worker's plain-URL eviction repair.
      const other='/visible-timer.js?v='+files['/visible-timer.js'].h;
      await cache.delete(other);
      const r=await fetch('/visible-timer.js');
      if(r.headers.get('X-Asset-Hash')!==files['/visible-timer.js'].h || !await cache.match(other)) throw Error('Evicted asset did not self-heal');
      return {result,requests};
    },manifest.files);
    assert.equal(refresh.result.refreshed,1,'thin refresh downloads only its missing asset');
    assert.deepEqual(refresh.requests,['/api/manifest','/async-guard.js?v='+manifest.files['/async-guard.js'].h]);
    disconnected = true;
    // Match baseline.mjs: Linux WebKit's setOffline breaks even SW navigation.
    // Cut the proxy AND stop Bun so offline boot cannot use network bytes.
    if (name !== 'webkit') await context.setOffline(true);
    proxy.setOffline(true);
    await stop();
    await page.reload({ waitUntil: 'load', timeout: 60000 });
    assert.equal(await page.locator('meta[name="ytp-build"]').getAttribute('content'), manifest.buildTag);
    await page.waitForFunction(() => typeof checkBuildTag === 'function' && !!document.querySelector('#cards')?.dataset.view);
    assert.equal(banners, 1);
    // WebKit surfaces rejected SW network fetches as pageerrors even when the
    // app catches them. Check only the exact, intentional offline API failures;
    // syntax/reference/runtime exceptions must still fail this harness.
    for (const error of errors) {
      assert.equal(name, 'webkit', 'only WebKit has offline transport pageerrors');
      assert.equal(error.disconnected, true, 'transport errors only after disconnection');
      assert.ok(error.message === 'TypeError: Load failed' || /\/api\/(?:recommendations\?[^\s]*|version)\.$/.test(error.message), `unexpected offline error: ${error.message}`);
    }
    if (errors.length) assert.ok(failedRequests.some(url => /\/api\/(?:recommendations|version)/.test(url)), 'transport errors correspond to disconnected API requests');
    const result = { browser: name, oldTag, newTag: manifest.buildTag, banners, updateReloads: 1, cachedFiles: cacheResult.count, durationMs, wireBytes: stats.totalWireBytes, offline: true, legacyURLs: 21, profile, userInitiatedOnly: true, playbackGuard: true, evictionRepair: true, incrementalRefresh: true, offlineTransportErrors: errors.length };
    console.log(JSON.stringify(result));
    return result;
  } finally {
    await browser?.close();
    if (proxy) { proxy.server.closeAllConnections(); await proxy.close(); }
    await stop();
  }
}
try {
  const results = [];
  for (const name of browserName === 'all' ? ['chromium', 'webkit'] : [browserName]) results.push(await run(name));
  writeFileSync(args.includes('--out') ? resolve(args[args.indexOf('--out')+1]) : join(repo, `perf/results/phase3-migration-${profile}-2026-10-08.json`), JSON.stringify({ commit, results }, null, 2) + '\n');
} finally { rmSync(scratch, { recursive: true, force: true }); }