import { spawn } from 'child_process';
import { createServer } from 'http';
import WebSocket, { WebSocketServer } from 'ws';

const CHROME_PORT = 9222;
const PORT = 7860;
let chrome;

function startChrome() {
  if (chrome) chrome.kill();
  console.log('Starting Chrome...');
  chrome = spawn('chromium', [
    '--headless=new', '--no-sandbox', '--disable-gpu',
    `--remote-debugging-port=${CHROME_PORT}`,
    '--remote-debugging-address=127.0.0.1',
    '--disable-dev-shm-usage',
    '--no-zygote',
    '--window-size=1280,800',
    '--disable-breakpad',
    '--disable-backgrounding-occluded-windows',
    '--disable-renderer-backgrounding',
    '--disable-component-extensions-with-background-pages',
    '--no-first-run',
    '--no-default-browser-check',
    '--disable-sync',
    '--disable-component-update',
    '--disable-default-apps',
    '--disable-hang-monitor',
  ], { stdio: ['ignore', 'pipe', 'pipe'] });
  chrome.stderr.on('data', d => console.error('CHROME:', d.toString().trimEnd()));
  chrome.on('exit', (code, sig) => {
    console.error('Chrome died exit=' + code + ' sig=' + sig + ', restarting in 3s...');
    setTimeout(startChrome, 3000);
  });
}

async function waitForChrome(retries = 30) {
  for (let i = 0; i < retries; i++) {
    try {
      const r = await fetch(`http://127.0.0.1:${CHROME_PORT}/json/version`);
      if (r.ok) {
        const j = await r.json();
        console.log('Chrome ready, browser:', j.webSocketDebuggerUrl);
        return;
      }
    } catch {}
    await new Promise(r => setTimeout(r, 1000));
  }
  console.error('Chrome not ready after', retries, 'retries');
}

startChrome();

function wsProto(req) {
  return req.socket.encrypted || req.headers['x-forwarded-proto'] === 'https' ? 'wss' : 'ws';
}

const server = createServer(async (req, res) => {
  if (req.url === '/' || req.url === '/health') {
    res.writeHead(200, { 'content-type': 'application/json' });
    res.end(JSON.stringify({ status: 'ok', chrome: 'running' }));
    return;
  }
  try {
    const r = await fetch(`http://127.0.0.1:${CHROME_PORT}${req.url}`);
    const text = await r.text();
    const h = { 'content-type': r.headers.get('content-type') || 'application/json' };
    res.writeHead(r.status, h);
    res.end(text.replace(
      new RegExp(`ws://127\\.0\\.0\\.1:${CHROME_PORT}`, 'g'),
      `${wsProto(req)}://${req.headers.host}`
    ));
  } catch (e) {
    res.writeHead(502);
    res.end(JSON.stringify({ error: e.message }));
  }
});

new WebSocketServer({ server }).on('connection', (ws, req) => {
  const url = req.url || '/';
  const target = `ws://127.0.0.1:${CHROME_PORT}${url}`;
  const cws = new WebSocket(target);
  let cwsReady = false;
  const pending = [];

  ws.on('message', (d) => {
    const str = d.toString();
    if (cwsReady) { try { cws.send(str); } catch {} }
    else { pending.push(str); }
  });
  ws.on('close', () => { try { cws.close(); } catch {} });

  cws.on('open', () => {
    cwsReady = true;
    for (const s of pending) try { cws.send(s); } catch {}
    pending.length = 0;
    cws.on('message', d => { try { ws.send(d.toString()); } catch {} });
    cws.on('close', () => { try { ws.close(); } catch {} });
  });
  cws.on('error', () => { try { ws.close(1011); } catch {} });
});

await waitForChrome();
server.listen(PORT, '0.0.0.0', () => {
  console.log(`WSS proxy on 0.0.0.0:${PORT}`);
});