// 通过 CDP 检查模拟器浏览器中页面的移动端布局
const wsUrl = process.argv[2] || "ws://127.0.0.1:9222/devtools/page/2";

const ws = new WebSocket(wsUrl);
let id = 0;
const pending = new Map();

function send(method, params = {}) {
  return new Promise((resolve, reject) => {
    const msgId = ++id;
    pending.set(msgId, { resolve, reject });
    ws.send(JSON.stringify({ id: msgId, method, params }));
  });
}

ws.onmessage = (event) => {
  const msg = JSON.parse(event.data);
  if (msg.id && pending.has(msg.id)) {
    const { resolve, reject } = pending.get(msg.id);
    pending.delete(msg.id);
    if (msg.error) reject(new Error(JSON.stringify(msg.error)));
    else resolve(msg.result);
  }
};

ws.onerror = (e) => {
  console.error("WS error:", e.message || e);
  process.exit(1);
};

ws.onopen = async () => {
  try {
    const expr = `JSON.stringify({
      viewport: { w: window.innerWidth, h: window.innerHeight, dpr: window.devicePixelRatio },
      doc: { scrollW: document.documentElement.scrollWidth, clientW: document.documentElement.clientWidth, scrollH: document.documentElement.scrollHeight },
      body: { scrollW: document.body.scrollWidth, clientW: document.body.clientWidth },
      overflowX: document.documentElement.scrollWidth > document.documentElement.clientWidth,
      title: document.title,
      url: location.href,
      navVisible: !!document.querySelector('nav, header'),
      bodyTextLen: document.body.innerText.length
    })`;
    const res = await send("Runtime.evaluate", { expression: expr, returnByValue: true });
    console.log(res.result.value);
  } catch (e) {
    console.error("Error:", e.message);
  } finally {
    ws.close();
    process.exit(0);
  }
};