standup.rb

#!/usr/bin/env ruby

require 'highline/system_extensions'
include HighLine::SystemExtensions

module Standup
  module Control
    extend self

    def play
      `osascript -e 'tell application "iTunes" to play'`
    end

    def pause
      `osascript -e 'tell application "iTunes" to pause'`
    end

    def set_volume(level)
      `osascript -e 'tell application "iTunes" to set sound volume to #{level}'`
    end
  end

  class Timer
    def initialize(length = 50, initial_volume = 20)
      @length, @initial_volume = length.to_i, initial_volume.to_i
      Control.set_volume(@initial_volume)
      Control.pause
      start
    end

    def start
      @countdown = Thread.new do
        countdown
        fade_in
      end
    end

    def stop
      @countdown.kill
      Control.pause
    end

    def restart
      stop; start
    end

    def countdown
      @length.downto(1) do |i|
        p i
        sleep 1
      end
      Control.play
    end

    def fade_in
      @initial_volume.upto 100 do |i|
        Control.set_volume(i)
        sleep 0.05
        i += 1
      end
    end
  end

  def self.Timer(length, initial_volume)
    timer = Standup::Timer.new(length, initial_volume)
    begin
      loop do
        character = get_character
        if [32, 13].include? character # Restart on space bar or enter
          timer.restart
        elsif character == 27 # Exit on escape
          raise Interrupt
        end
      end
    rescue Interrupt
      Control.pause
      exit
    end
  end
end

if $0 == __FILE__
  length, initial_volume = ARGV
  Standup::Timer(length, initial_volume)
end