multicast ip music player

beat2beat.rb

#####################################################################################
#
#  Peer base
#
#####################################################################################

require 'socket'
require 'thread'
require 'ipaddr'
require 'json'

class Peer
  MULTICAST_ADDR = '224.5.3.209'
  BIND_ADDR = '0.0.0.0'
  PORT = 53209
  MULTICAST_BIND_ADDR = IPAddr.new(MULTICAST_ADDR).hton + IPAddr.new(BIND_ADDR).hton

  def initialize
    @user_info = {
      :user => ENV['USERNAME'] || ENV['USER'],
      :host => Socket.gethostname,
      :ip   => (Socket.ip_address_list.detect{|i| i.ipv4_private?}.ip_address rescue '?'),
      :pid  => $$
    }
    @handle    = [@user_info[:user], @user_info[:host], @user_info[:ip], @user_info[:pid]].join('/')
    @listeners = []
  end

  def add_message_listener(listener)
    listen unless @listening
    @listeners << listener
  end

  def send(data)
    data = {'message' => data} unless data.is_a?(Hash)
    data.merge!('handle' => @handle)
    puts "sending #{data}" if $DEBUG
    socket.send(data.to_json, 0, MULTICAST_ADDR, PORT)
    data
  end

  private

  def listen
    socket.bind(BIND_ADDR, PORT)
    Thread.new do
      loop do
        data, _ = socket.recvfrom(1024)
        data = JSON.parse(data)
        puts "received #{data}" if $DEBUG
        @listeners.each{|listener| listener.new_message(data) } unless data['handle'] == @handle
      end
    end
    @listening = true
  end

  def socket
    @socket ||= UDPSocket.open.tap do |socket|
      socket.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, MULTICAST_BIND_ADDR)
      socket.setsockopt(Socket::IPPROTO_IP, Socket::IP_MULTICAST_TTL, 3)
      socket.setsockopt(Socket::SOL_SOCKET, Socket::SO_REUSEADDR, 1)
    end
  end

end

#####################################################################################
#
#  Player
#
#####################################################################################

class MusicPlayer
  #MUSIC_PATH = File.expand_path(File.join(File.dirname(__FILE__),'music'))
  MUSIC_PATH = File.expand_path(File.dirname(__FILE__))

  def play(file)
    stop if @pid
    file = File.expand_path(File.join(MUSIC_PATH, file))
    return false unless File.exists? file
    @pid = fork do
      if RUBY_PLATFORM =~ /darwin/
        exec 'afplay', file
      else
        #exec 'mpg123','-T' ,'-q', file
        exec 'mpg123','-q', file
      end
    end
  end

  def say(text)
    stop if @pid
    @pid = fork do
      if RUBY_PLATFORM =~ /darwin/
        exec "say '#{text.tr("'","")}'"
      else
        exec "echo '#{text.tr("'","")}' | festival --tts"
      end
    end
  end

  def stop
    return unless @pid
    Process.kill 'TERM', @pid
    @pid = nil
  end

  def list
    Dir.entries(MUSIC_PATH).reject{|e|e.start_with? '.'}.sort
  end
end

#####################################################################################
#
#  Interface
#
#####################################################################################

require 'curses'

class Window
  include Curses

  def initialize(client)
    @client = client
    @messages = []
    @player = MusicPlayer.new
  end

  def start
    init_screen
    start_color
    init_pair(COLOR_WHITE, COLOR_BLACK, COLOR_WHITE)
    use_default_colors
    redraw

    @client.add_message_listener(self)

    loop do
      content = getstr
      if content.length > 0
        message = @client.send(content)
        new_message(message)
      end
    end
  end

  def new_message(message)
    if message['message'].start_with?('play ')
      @player.play(message['message'][5..-1])
    elsif message['message'] == 'stop'
      @player.stop
    elsif message['message'] == 'list'
      @player.list.each{|e| @client.send(e)}
    elsif message['message'].start_with?('say ')
      @player.say(message['message'][4..-1])
    end
    @messages << message
    redraw
  end

  private

  def redraw
    draw_text_field
    draw_messages
    cursor_to_input_line
    refresh
  end

  def draw_text_field
    setpos(divider_line, 0)
    attron(color_pair(COLOR_WHITE) | A_NORMAL){ addstr(" [beat2beat]" + " " * cols) }
    cursor_to_input_line
    clrtoeol
  end

  def draw_messages
    @messages.last(window_line_size).inject(0) do |line_number, message|
      setpos(line_number, 0)
      clrtoeol
      addstr("<#{message['handle']}> #{message['message']}")
      line_number + 1
    end
  end

  def input_line; lines - 1 end
  def divider_line; lines - 2 end
  def window_line_size; lines - 2 end
  def cursor_to_input_line; setpos(input_line, 0) end
end



Window.new(Peer.new).start