class WebSocket::Driver

def self.client(socket, options = {})
  Client.new(socket, options.merge(:masking => true))
end

def self.encode(data, encoding = nil)
  if Array === data
    encoding ||= Encoding::BINARY
    return data.pack('C*').force_encoding(encoding)
  end
  encoding ||= Encoding::UTF_8
  return data if data.encoding == encoding
  return data.encode(encoding) unless data.encoding == Encoding::BINARY
  data = data.dup if data.frozen?
  data.force_encoding(encoding)
end

def self.rack(socket, options = {})
  env     = socket.env
  version = env['HTTP_SEC_WEBSOCKET_VERSION']
  key     = env['HTTP_SEC_WEBSOCKET_KEY']
  key1    = env['HTTP_SEC_WEBSOCKET_KEY1']
  key2    = env['HTTP_SEC_WEBSOCKET_KEY2']
  if version or key
    Hybi.new(socket, options.merge(:require_masking => true))
  elsif key1 or key2
    Draft76.new(socket, options)
  else
    Draft75.new(socket, options)
  end
end

def self.server(socket, options = {})
  Server.new(socket, options.merge(:require_masking => true))
end

def self.validate_options(options, valid_keys)
  options.keys.each do |key|
    unless valid_keys.include?(key)
      raise ConfigurationError, "Unrecognized option: #{ key.inspect }"
    end
  end
end

def self.websocket?(env)
  connection = env['HTTP_CONNECTION'] || ''
  upgrade    = env['HTTP_UPGRADE']    || ''
  env['REQUEST_METHOD'] == 'GET' and
  connection.downcase.split(/ *, */).include?('upgrade') and
  upgrade.downcase == 'websocket'
end

def add_extension(extension)
  false
end

def binary(message)
  false
end

def close(reason = nil, code = nil)
  return false unless @ready_state == 1
  @ready_state = 3
  emit(:close, CloseEvent.new(nil, nil))
  true
end

def fail(type, message)
  @ready_state = 2
  emit(:error, ProtocolError.new(message))
  close
end

def fail_handshake(error)
  headers = Headers.new
  headers['Content-Type'] = 'text/plain'
  headers['Content-Length'] = error.message.bytesize
  headers = ['HTTP/1.1 400 Bad Request', headers.to_s, error.message]
  @socket.write(headers.join("\r\n"))
  fail(:protocol_error, error.message)
  false
end

def initialize(socket, options = {})
  super()
  Driver.validate_options(options, [:max_length, :masking, :require_masking, :protocols])
  @socket      = socket
  @reader      = StreamReader.new
  @options     = options
  @max_length  = options[:max_length] || MAX_LENGTH
  @headers     = Headers.new
  @queue       = []
  @ready_state = 0
end

def open
  @ready_state = 1
  @queue.each { |message| frame(*message) }
  @queue = []
  emit(:open, OpenEvent.new)
end

def ping(*args)
  false
end

def pong(*args)
  false
end

def queue(message)
  @queue << message
  true
end

def set_header(name, value)
  return false unless @ready_state <= 0
  @headers[name] = value
  true
end

def start
  return false unless @ready_state == 0
  unless Driver.websocket?(@socket.env)
    return fail_handshake(ProtocolError.new('Not a WebSocket request'))
  end
  begin
    response = handshake_response
  rescue => error
    return fail_handshake(error)
  end
  @socket.write(response)
  open unless @stage == -1
  true
end

def state
  return nil unless @ready_state >= 0
  STATES[@ready_state]
end

def text(message)
  message = Driver.encode(message, Encoding::UTF_8)
  frame(message, :text)
end