DS9

gem ds9

##
# ruby client.rb https://nghttp2.org/
# ruby client.rb https://www.google.com/

require 'ds9'
require 'socket'
require 'openssl'
require 'stringio'
require 'uri'
require 'thread'

class MySession < DS9::Client
  def initialize sock
    @sock      = sock
    @responses = Queue.new
    @requests  = []
    @in_flight = {}
    super()
  end

  def on_stream_close id, errcode
    @responses << @in_flight.delete(id)
    puts "FINISHED READING STREAM: #{id}"
    if @requests.any?
      submit_request @requests.pop
    else
      @responses << nil
      @thread.join
      terminate_session DS9::NO_ERROR
    end
  end

  def on_begin_headers frame
    @in_flight[frame.stream_id] = StringIO.new if frame.headers?
    @requests << [] if frame.push_promise?
  end

  def on_header name, value, frame, flags
    if frame.push_promise?
      @requests.last << [name, value]
    else
      puts "HEADER: #{name}: #{value}"
    end
  end

  def on_data_chunk_recv id, data, flags
    @in_flight[id] << data
  end

  def send_event string
    @sock.write_nonblock string
  end

  def recv_event length
    case data = @sock.read_nonblock(length, nil, exception: false)
    when :wait_readable then DS9::ERR_WOULDBLOCK
    when nil            then DS9::ERR_EOF
    else
      data
    end
  end

  def run
    @thread = Thread.new do
      while response = @responses.pop
        yield response
      end
    end

    while want_read? || want_write?
      rd, wr, _ = IO.select([@sock], [@sock])
      receive
      send
    end
  end
end

uri = URI.parse ARGV[0]
socket = TCPSocket.new uri.host, uri.port

ctx               = OpenSSL::SSL::SSLContext.new
ctx.npn_protocols = [DS9::PROTO_VERSION_ID]
ctx.alpn_protocols = [DS9::PROTO_VERSION_ID]
ctx.npn_select_cb = lambda do |protocols|
  if protocols.include?(DS9::PROTO_VERSION_ID)
    puts "The negotiated protocol: " + DS9::PROTO_VERSION_ID
    DS9::PROTO_VERSION_ID
  end
end

socket            = OpenSSL::SSL::SSLSocket.new socket, ctx
socket.hostname = uri.hostname
socket.connect
socket.sync_close = true

session = MySession.new socket
session.submit_settings []

path = uri.path == '' ? '/' : uri.path
session.submit_request [
  [':method', 'GET'],
  [':path', path],
  [':scheme', uri.scheme],
  [':authority', [uri.host, uri.port].join(':')],
  ['accept', '*/*'],
  ['user-agent', 'test'],
]

session.run do |res|
  p res.string
end