class Faye::WebSocket::Draft76Parser

def big_endian(number)
  string = ''
  [24,16,8,0].each do |offset|
    string << (number >> offset & 0xFF).chr
  end
  string
end

def handshake_response
  env = @socket.env
  signature = handshake_signature(env['rack.input'].read)
  
  upgrade =  "HTTP/1.1 101 Web Socket Protocol Handshake\r\n"
  upgrade << "Upgrade: WebSocket\r\n"
  upgrade << "Connection: Upgrade\r\n"
  upgrade << "Sec-WebSocket-Origin: #{env['HTTP_ORIGIN']}\r\n"
  upgrade << "Sec-WebSocket-Location: #{@socket.url}\r\n"
  upgrade << "\r\n"
  upgrade << signature if signature
  upgrade
end

def handshake_signature(head)
  return nil if head.empty?
  @handshake_complete = true
  
  env = @socket.env
  
  key1   = env['HTTP_SEC_WEBSOCKET_KEY1']
  value1 = number_from_key(key1) / spaces_in_key(key1)
  
  key2   = env['HTTP_SEC_WEBSOCKET_KEY2']
  value2 = number_from_key(key2) / spaces_in_key(key2)
  
  Digest::MD5.digest(big_endian(value1) +
                     big_endian(value2) +
                     head)
end

def number_from_key(key)
  key.scan(/[0-9]/).join('').to_i(10)
end

def parse(data)
  return super if @handshake_complete
  handshake_signature(data)
end

def spaces_in_key(key)
  key.scan(/ /).size
end

def version
  'draft-76'
end