class WebSocket::Driver::Client

def self.generate_key
  Base64.encode64((1..16).map { rand(255).chr } * '').strip
end

def fail_handshake(message)
  message = "Error during WebSocket handshake: #{message}"
  emit(:error, ProtocolError.new(message))
  @ready_state = 3
  emit(:close, CloseEvent.new(ERRORS[:protocol_error], message))
end

def handshake_request
  uri   = URI.parse(@socket.url)
  host  = uri.host + (uri.port ? ":#{uri.port}" : '')
  path  = (uri.path == '') ? '/' : uri.path
  query = uri.query ? "?#{uri.query}" : ''
  headers = [ "GET #{path}#{query} HTTP/1.1",
              "Host: #{host}",
              "Upgrade: websocket",
              "Connection: Upgrade",
              "Sec-WebSocket-Key: #{@key}",
              "Sec-WebSocket-Version: 13"
            ]
  if @protocols.size > 0
    headers << "Sec-WebSocket-Protocol: #{@protocols * ', '}"
  end
  (headers + [@headers.to_s, '']).join("\r\n")
end

def initialize(socket, options = {})
  super
  @ready_state = -1
  @key         = Client.generate_key
  @accept      = Hybi.generate_accept(@key)
  @http        = HTTP::Response.new
end

def parse(buffer)
  return super if @ready_state > 0
  @http.parse(buffer)
  return fail_handshake('Invalid HTTP response') if @http.error?
  validate_handshake if @http.complete?
  parse(@http.body) if @ready_state == 1
end

def start
  return false unless @ready_state == -1
  @socket.write(Driver.encode(handshake_request, :binary))
  @ready_state = 0
  true
end

def validate_handshake
  @status  = @http.code
  @headers = Headers.new(@http.headers)
  unless @http.code == 101
    return fail_handshake("Unexpected response code: #{@http.code}")
  end
  upgrade    = @http['Upgrade'] || ''
  connection = @http['Connection'] || ''
  accept     = @http['Sec-WebSocket-Accept'] || ''
  protocol   = @http['Sec-WebSocket-Protocol'] || ''
  if upgrade == ''
    return fail_handshake("'Upgrade' header is missing")
  elsif upgrade.downcase != 'websocket'
    return fail_handshake("'Upgrade' header value is not 'WebSocket'")
  end
  if connection == ''
    return fail_handshake("'Connection' header is missing")
  elsif connection.downcase != 'upgrade'
    return fail_handshake("'Connection' header value is not 'Upgrade'")
  end
  unless accept == @accept
    return fail_handshake('Sec-WebSocket-Accept mismatch')
  end
  unless protocol == ''
    if @protocols.include?(protocol)
      @protocol = protocol
    else
      return fail_handshake('Sec-WebSocket-Protocol mismatch')
    end
  end
  open
end

def version
  'hybi-13'
end