class WebSocket::Driver::Hybi

def handshake_response
  sec_key = @socket.env['HTTP_SEC_WEBSOCKET_KEY']
  return '' unless String === sec_key
  accept    = Hybi.generate_accept(sec_key)
  protos    = @socket.env['HTTP_SEC_WEBSOCKET_PROTOCOL']
  supported = @protocols
  proto     = nil
  headers = [
    "HTTP/1.1 101 Switching Protocols",
    "Upgrade: websocket",
    "Connection: Upgrade",
    "Sec-WebSocket-Accept: #{accept}"
  ]
  if protos
    protos = protos.split(/\s*,\s*/) if String === protos
    proto = protos.find { |p| supported.include?(p) }
    if proto
      @protocol = proto
      headers << "Sec-WebSocket-Protocol: #{proto}"
    end
  end
  (headers + [@headers.to_s, '']).join("\r\n")
end