// 无浏览器依赖的页面逻辑回归；使用 DOM/网络替身，不操作用户界面或真实串口。
const assert = require('node:assert/strict');
const fs = require('node:fs');
const path = require('node:path');
const vm = require('node:vm');

async function main() {
  const elements = new Map();
  function element(id) {
    if (!elements.has(id)) {
      const classes = new Set();
      elements.set(id, {
        value: '', textContent: '', checked: true, style: {}, dataset: {},
        scrollTop: 0, scrollHeight: 1000, clientHeight: 200,
        selectionStart: 0, selectionEnd: 0, handlers: {},
        classList: {
          toggle(name, active) { if (active) classes.add(name); else classes.delete(name); },
          remove(name) { classes.delete(name); },
          contains(name) { return classes.has(name); }
        },
        addEventListener(name, callback) { this.handlers[name] = callback; },
        focus() {},
        setSelectionRange(start, end) { this.selectionStart = start; this.selectionEnd = end; }
      });
    }
    return elements.get(id);
  }
  const windows = {};
  const sources = [];
  const calls = [];
  const timeouts = new Map();
  let nextTimer = 1;
  let log = '[2026-10-21 16:00:00] localhost login:';
  let hangStatusBody = false;
  let selectedLog = false;
  let selectedElsewhere = false;
  let failLog = false;
  let onLogBody = null;
  let deferFrame = false;
  const frames = [];
  const bytes = text => new TextEncoder().encode(text).buffer;
  const sandbox = {
    console, TextDecoder, TextEncoder, AbortController,
    document: {
      body: { dataset: { token: 'test-token', port: 'COM-TEST' } },
      querySelector: element, querySelectorAll: () => []
    },
    window: {
      crypto: { randomUUID: () => 'test-page' },
      getSelection: () => ({
        isCollapsed: !selectedLog && !selectedElsewhere, rangeCount: 1,
        getRangeAt: () => ({ intersectsNode: node => selectedLog && node === element('#log') })
      }),
      addEventListener(name, callback) { windows[name] = callback; }
    },
    navigator: { sendBeacon: () => true },
    EventSource: class {
      constructor(url) { this.url = url; this.closed = false; sources.push(this); }
      close() { this.closed = true; }
    },
    requestAnimationFrame(callback) { if (deferFrame) frames.push(callback); else callback(); },
    setInterval() {},
    setTimeout(callback) { const id = nextTimer++; timeouts.set(id, callback); return id; },
    clearTimeout(id) { timeouts.delete(id); },
    async fetch(url, options = {}) {
      calls.push({ url, options });
      if (options.method === 'POST') return { ok: true, json: async () => ({ status: 'written' }) };
      if (url.startsWith('/api/status')) {
        return {
          ok: true,
          arrayBuffer: () => hangStatusBody
            ? new Promise((resolve, reject) => options.signal.addEventListener('abort', () => reject(new Error('aborted'))))
            : Promise.resolve(bytes(JSON.stringify({ isOpen: true, port: 'COM-TEST', receivedBytes: 10 })))
        };
      }
      if (failLog) throw new Error('test log failure');
      return { ok: true, arrayBuffer: async () => { if (onLogBody) onLogBody(); return bytes(log); } };
    }
  };
  const context = vm.createContext(sandbox);
  const html = fs.readFileSync(path.join(__dirname, '../assets/serial-console.html'), 'utf8');
  const source = html.match(/<script>([\s\S]*?)<\/script>/)[1];
  vm.runInContext(source, context);
  const run = text => vm.runInContext(text, context);
  const flush = () => new Promise(resolve => setImmediate(resolve));
  await flush();
  assert.equal(sources.length, 1);
  assert.match(sources[0].url, /client=test-page&token=test-token/);
  assert.equal(element('#log').scrollTop, 1000, '首次显示最新日志');
  element('#log').scrollTop = 0;
  log += '\nnew line';
  await run('refreshLog()');
  assert.equal(element('#log').scrollTop, 0, '用户向上查看时不抢滚动位置');
  element('#follow').handlers.change();
  assert.equal(element('#log').scrollTop, 1000);

  // 即使没有新增日志，也不能无条件替换文本节点。
  let displayed = element('#log').textContent;
  let replacements = 0;
  Object.defineProperty(element('#log'), 'textContent', {
    get() { return displayed; },
    set(value) { displayed = value; replacements++; }
  });
  await run('refreshLog()');
  assert.equal(replacements, 0, '相同正文不重建文本节点');
  const heldText = displayed;
  selectedLog = true;
  log += '\narrived while selected';
  await run('refreshLog()');
  assert.equal(displayed, heldText, '选中日志时保留文本节点');
  assert.equal(run('logPolling'), false, '暂停绘制不阻塞下一次轮询');
  element('#log').scrollTop = 20;
  element('#follow').handlers.change();
  assert.equal(element('#log').scrollTop, 20, '有选区时不能自动滚动');
  failLog = true;
  await run('refreshLog()');
  assert.equal(displayed, heldText, '读取失败也不能破坏选区');
  failLog = false;
  selectedLog = false;
  element('#log').handlers.pointerdown({ button: 0 });
  await run('refreshLog()');
  assert.equal(displayed, heldText, '拖选尚未形成非空选区时也保护文本');
  windows.pointerup();
  await run('refreshLog()');
  assert.equal(displayed, log, '松开且取消选区后恢复最新日志');
  selectedElsewhere = true;
  log += '\nselected outside log';
  await run('refreshLog()');
  assert.equal(displayed, log, '选择其他区域不能暂停日志');
  selectedElsewhere = false;
  const beforeRace = displayed;
  log += '\nselection during response';
  onLogBody = () => { selectedLog = true; };
  await run('refreshLog()');
  assert.equal(displayed, beforeRace, '响应等待期间形成的选区也受保护');
  onLogBody = null;
  selectedLog = false;
  element('#log').scrollTop = 1000;
  deferFrame = true;
  await run('refreshLog()');
  assert.ok(frames.length > 0);
  selectedLog = true;
  element('#log').scrollTop = 30;
  for (const callback of frames.splice(0)) callback();
  assert.equal(element('#log').scrollTop, 30, '布局帧等待期间开始选择也不能抢滚动');
  selectedLog = false;
  deferFrame = false;
  element('#log').handlers.pointerdown({ button: 0 });
  windows.blur();
  assert.equal(run('isLogSelectionActive()'), false, '窗口失焦不遗留拖选锁');

  // 正文读取也必须在超时保护范围内，而不只是拿到响应头。
  hangStatusBody = true;
  const hung = run('refreshStatus()');
  await flush();
  for (const callback of [...timeouts.values()]) callback();
  await hung;
  assert.equal(run('statusPolling'), false);
  hangStatusBody = false;
  await run('refreshStatus()');
  assert.equal(run('serialOpen'), true, '超时后能再次请求并恢复连接状态');

  log = 'Password:';
  await run('refreshLog()');
  assert.equal(element('#command').classList.contains('masked'), true);
  element('#command').value = 'fake-test-secret';
  await run('sendCommand()');
  assert.equal(run('commandHistory.length'), 0, '密码不进入页面历史');
  log = 'localhost login:';
  await run('refreshLog()');
  element('#command').value = '';
  const commandCalls = () => calls.filter(call => call.url === '/api/send?ending=CR');
  const before = commandCalls().length;
  element('#command').handlers.keydown({ key: 'Enter', isComposing: true });
  assert.equal(commandCalls().length, before, '输入法候选确认不能发送');
  element('#command').handlers.keydown({ key: 'Enter', repeat: true, preventDefault() {} });
  assert.equal(commandCalls().length, before, '长按 Enter 不能重复空发');
  await run('sendCommand()');
  assert.equal(commandCalls().at(-1).options.body, '', '空输入按 CR 接口发送');
  element('#command').value = 'test-command';
  await run('sendCommand()');
  assert.equal(commandCalls().at(-1).options.body, 'test-command');
  assert.equal(element('#command').value, '');
  element('#command').handlers.keydown({ key: 'ArrowUp', preventDefault() {} });
  assert.equal(element('#command').value, 'test-command');
  element('#command').handlers.keydown({ key: 'Escape', preventDefault() {} });
  assert.equal(element('#command').value, '');

  windows.pagehide();
  assert.equal(sources[0].closed, true);
  const count = calls.length;
  await run('refreshStatus(); refreshLog()');
  assert.equal(calls.length, count, '离页后不能继续轮询把已关闭页面重新登记');
  windows.pageshow();
  await flush();
  assert.equal(sources.length, 2, '从页面缓存恢复时重建当前页面连接');
  assert.equal(sources[1].closed, false);
  windows.pageshow();
  assert.equal(sources.length, 2, '重复 pageshow 不得创建重复连接');
  console.log(JSON.stringify({ passed: true, checks: [
    'liveness lifecycle', 'poll timeout recovery', 'initial/follow scroll',
    'password history exclusion', 'IME/Enter guard', 'empty CR request',
    'command request/history', 'pagehide/pageshow', 'unchanged log DOM retention',
    'selection/drag protection', 'selection during response/frame', 'selection resume'
  ] }));
}

main().catch(error => { console.error(error); process.exitCode = 1; });