gistfile1.rb

require 'rubygems'
require 'eventmachine'
require 'em-http' # gem install em-http-request
require 'yajl'    # gem install yajl-ruby

module ChatClient
  def post_init
    @name = "anonymous_#{ChatClient.client_num+=1}"
    @sid = ChatClient.channel.subscribe(method(:send_msg))
    @buf = ''

    send_data "\033[2;23r"
    send_data "\033[2J"
    send_data "\033[1H"
    header = "Welcome to the EventMachine MWRC Demo (/say, /nick, /quit)".center(80)
    send_data "\033[32m#{header}\033[0m"
    send_prompt

    ChatClient.channel << "\033[1m#{@name}\033[0m has joined.\n"
  end

  def unbind
    ChatClient.channel.unsubscribe(@sid)
    ChatClient.channel << "\033[1m#{@name}\033[0m has left.\n"
  end

  def receive_data data
    @buf << data
    quit and return if @buf =~ /(\006|\004)/ # ctrl+c or ctrl+d

    while line = @buf.slice!(/(.+)\r?\n/)
      send_prompt

      if line =~ %r|^/nick (.+)|
        new_name = $1.strip[0..12]
        ChatClient.channel << "\033[1m#{@name}\033[0m is now known as \033[1m#{new_name}\033[0m\n"
        @name = new_name
        send_prompt

      elsif line =~ %r|^/say (.+)|
        ChatClient.say_queue.push "#{@name} said #{$1.strip}"

      elsif line =~ %r|^/quit|
        quit

      elsif line =~ /^\e/ # ignore escape sequences
        send_prompt

      elsif !line.strip.empty?
        ChatClient.channel << "\033[1m#{@name}\033[0m: #{line}"
      end
    end
  end

  private

  def send_msg msg
    send_data "\0337"
    send_data "\033M"
    send_data "\033[23;1H"
    send_data msg
    send_data "\0338"
  end

  def send_prompt
    send_data "\033[24H"
    send_data "\033[2K"
    send_data "\033[1m"
    send_data @name
    send_data "\033[0m: "
  end

  def quit
    send_data "\033[2J"
    send_data "\033[1;1H"
    header = "Check out http://gist.github.com/329682 for the source to the EM chat server".center(80)
    send_data "\033[32m#{header}\033[0m"
    send_data "\033[r"
    send_data "\033[3;1H"
    close_connection_after_writing
  end

  @client_num = 0
  class << self
    attr_accessor :client_num
  end

  def self.channel
    @channel ||= EM::Channel.new
  end

  def self.say_queue
    unless @say_queue
      @say_queue = EM::Queue.new

      # pop off items from the queue one at a time, and pass them to `say`
      processor = proc{ |msg|
        EM.system("say", msg) do |out, status|
          p [msg, out, status]
          @say_queue.pop(&processor)
        end
      }

      # pop off the first item
      @say_queue.pop(&processor)
    end

    @say_queue
  end
end

EM.run{
  EM.start_server '0.0.0.0', 1337, ChatClient

  http = EM::HttpRequest.new(
   "http://stream.twitter.com/1/statuses/filter.json?track=mwrc,eventmachine" 
  ).get(
    :head => {
      'authorization' => ['eventmachine', 'eventm4chine']
    }
  )

  parser = Yajl::Parser.new(:symbolize_keys => true)
  parser.on_parse_complete = proc{ |item|
    name = item[:user][:screen_name]
    tweet = item[:text]
    p [:twitter, name, tweet]
    ChatClient.channel << "\033[34;1m@#{name}\033[0m: #{tweet}\n"    
  }
  http.stream &parser.method(:<<)
}