class HTTP::Request::Writer

def add_body_type_headers
  return if @headers[Headers::CONTENT_LENGTH] || chunked?
  @request_header << "#{Headers::CONTENT_LENGTH}: #{@body.size}"
end

def add_headers
  @headers.each do |field, value|
    @request_header << "#{field}: #{value}"
  end
end

def chunked?
  @headers[Headers::TRANSFER_ENCODING] == CHUNKED
end

def connect_through_proxy
  add_headers
  write(join_headers)
end

def encode_chunk(chunk)
  if chunked?
    chunk.bytesize.to_s(16) << CRLF << chunk << CRLF
  else
    chunk
  end
end

def initialize(socket, body, headers, headline)
  @body           = body
  @socket         = socket
  @headers        = headers
  @request_header = [headline]
end

def join_headers
  # join the headers array with crlfs, stick two on the end because
  # that ends the request header
  @request_header.join(CRLF) + CRLF * 2
end

def send_request
  # It's important to send the request in a single write call when
  # possible in order to play nicely with Nagle's algorithm. Making
  # two writes in a row triggers a pathological case where Nagle is
  # expecting a third write that never happens.
  data = join_headers
  @body.each do |chunk|
    data << encode_chunk(chunk)
    write(data)
    data.clear
  end
  write(data) unless data.empty?
  write(CHUNKED_END) if chunked?
end

def stream
  add_headers
  add_body_type_headers
  send_request
end

def write(data)
  until data.empty?
    length = @socket.write(data)
    break unless data.bytesize > length
    data = data.byteslice(length..-1)
  end
end