dilbert.rb

require 'open-uri'
require 'hpricot'
require 'tempfile'


class Dilbert < CampfireBot::Plugin
  BASE_URL   = 'http://dilbert.com/'
  START_DATE = Date.parse('1996-01-01')
  
  on_command 'dilbert', :dilbert
  
  def dilbert(msg)
    comic = case msg[:message].split(/\s+/)[0]
    when 'latest'
      fetch_latest
    when 'random'
      fetch_random
    when /d+/
      fetch_comic(msg[:message].split(/\s+/)[1])
    else
      fetch_random
    end
    
    msg.speak(BASE_URL + comic['src'])

  end
  
  private
  
  def fetch_latest
    fetch_comic
  end
  
  def fetch_random
    fetch_comic(rand(number_of_comics))
  end
  
  def fetch_comic(id = nil)
    # Rely on the comic being the last image on the page not nested
    (Hpricot(open("#{BASE_URL}fast#{'/' + id_to_date(id) + '/' if id}"))/'//img').last
  end
  
  def id_to_date(id)
    (START_DATE + id.days).to_date.to_s(:db)
  end
  
  def number_of_comics
    (Date.today - START_DATE).to_i
  end
  
end