class WebSocket::Driver::Draft76

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

def close(reason = nil, code = nil)
  return false if @ready_state == 3
  @socket.write(Driver.encode("\xFF\x00", :binary))
  @ready_state = 3
  emit(:close, CloseEvent.new(nil, nil))
  true
end

def handshake_response
  start   = 'HTTP/1.1 101 WebSocket Protocol Handshake'
  headers = [start, @headers.to_s, '']
  headers.join("\r\n")
end

def handshake_signature
  return nil unless @body.bytesize >= BODY_SIZE
  head   = @body[0...BODY_SIZE]
  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 initialize(socket, options = {})
  super
  input  = @socket.env['rack.input']
  @stage = -1
  @body  = Driver.encode(input ? input.read : '', :binary)
  @headers.clear
  @headers['Upgrade'] = 'WebSocket'
  @headers['Connection'] = 'Upgrade'
  @headers['Sec-WebSocket-Origin'] = @socket.env['HTTP_ORIGIN']
  @headers['Sec-WebSocket-Location'] = @socket.url
end

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

def parse_leading_byte(data)
  return super unless data == 0xFF
  @closing = true
  @length = 0
  @stage = 1
end

def send_handshake_body
  return unless signature = handshake_signature
  @socket.write(Driver.encode(signature, :binary))
  @stage = 0
  open
  parse(@body[BODY_SIZE..-1]) if @body.bytesize > BODY_SIZE
end

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

def start
  return false unless super
  send_handshake_body
  true
end

def version
  'hixie-76'
end