require 'rubygems'
require 'twitter'
require 'simple-rss'
require 'shorturl'
require 'open-uri'

### Section 1
username = 'your_username'
password = 'your_password'
twitter = Twitter::Base.new( username, password )

### Section 2
# If the rss_times file exists, unmarshal
# the rss_times hash, else create a new
# one.
rss_times = if File.exists?('rss_times')
  Marshal.load( File.read('rss_times') )
else
  Hash.new( Time.mktime('1970') )
end

### Section 3
# Connect to twitter and fetch RSS
rss = SimpleRSS.parse( open(ARGV[0]) )

### Section 4
rss.items.reverse.each_with_index do|i,idx|
  if i.pubDate > rss_times[ARGV[0]]
    link = ShortURL.shorten(i.link)
    text = "#{i.title} #{link}"

    puts text
    puts "=" * 50

    ### Section 5
    # Save the time of this update
    # and marshal the hash back to storage

    twitter.update text

    rss_times[ARGV[0]] = i.pubDate
    File.open( 'rss_times', 'w' ) do|f|
      f.write Marshal.dump(rss_times)
    end

    sleep 300
  end
end