回答

代码如下：

addEventListener('fetch', event => {
  event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) {
  if (request.headers.get('Upgrade') !== 'websocket') {
    return new Response('Expected Upgrade: websocket', { status: 426 })
  }

  const targetUrl = 'wss://openai websocket 的api网关地址'
  const [client, server] = Object.values(new WebSocketPair())

  await server.accept()

  const targetWebSocket = new WebSocket(targetUrl)

  targetWebSocket.addEventListener('open', () => {
    console.log('Connected to target WebSocket server')
  })

  server.addEventListener('message', event => {
    console.log('Message from client:', event.data)
    if (targetWebSocket.readyState === WebSocket.OPEN) {
      targetWebSocket.send(event.data)
    }
  })

  targetWebSocket.addEventListener('message', event => {
    console.log('Message from target:', event.data)
    if (server.readyState === WebSocket.OPEN) {
      server.send(event.data)
    }
  })

  server.addEventListener('close', () => {
    console.log('Client connection closed')
    targetWebSocket.close()
  })

  targetWebSocket.addEventListener('close', () => {
    console.log('Target connection closed')
    server.close()
  })

  // 错误处理
  server.addEventListener('error', error => {
    console.error('Server WebSocket error:', error)
  })

  targetWebSocket.addEventListener('error', error => {
    console.error('Target WebSocket error:', error)
  })

  // 保持连接活跃
  const keepAlive = setInterval(() => {
    if (server.readyState === WebSocket.OPEN) {
      server.send('ping')
    }
  }, 25000)

  server.addEventListener('close', () => {
    clearInterval(keepAlive)
  })

  return new Response(null, {
    status: 101,
    webSocket: client,
  })
}