#!/usr/bin/env ruby

# checksd.rb: Periodically check Slickdeals RSS feed, and notify when a new post appears
# Set this up to run periodically in your crontab
# By: Pete Kruckenberg (pete@kruckenberg.com)
#
# Version: 0.1 September 6, 2005: first deployment
#
# License and warranty: This program is copyrighted by the author. Permission is granted 
# to use it for any lawful use. No warranty of usability, implied or otherwise, is made.

# Configuration items you will want to change

# Where to keep track of Slickdeals URLs we've already seen
URLfile = "/home/pete/slickdeals/sdurls.txt"

# Where to send an email when we find a new Slickdeal
EmailAddr = "5015551212@vtext.com"

# What command (including path, arguments) to execute to send notification
# Note that EmailAddr must be included in the right place
EmailCmd = "/bin/mail -s \"SlickDeal\" #{EmailAddr}"

# This should only change if Slickdeals changes their RSS feed URL
SlickRSS = "http://www.slickdeals.net/rss.php"

# End of configuration items, rest shouldn't need to change

# You'll need (besides Ruby) to install RubyGems and the 'simple-rss' gem
require 'rubygems'
require 'simple-rss'
require 'open-uri'

# Get the RSS feed
rss = SimpleRSS.parse open(SlickRSS)

# Initialize a few hashes to track and report on new Slickdeals
matches = Hash.new()
titles = Hash.new()
rss.items.each do |item|
  matches[item.link] = 0
  titles[item.link] = item.title
end

# This is really ineffecient, but it's good enough for now
# Load the URLs from URLfile, and then compare each to each URL in the RSS feed
newlines = Array.new()
if (File.readable?(URLfile))
  file = File.open(URLfile,"r")
  while file.gets # Get a URL from the URLfile
    chomp
    rss.items.each do |item| # Now see if it matches any URLs from the RSS feed
      if ($_ == item.link)
        matches[item.link] = 1 # If it does, remember that
      end
    end
  end
  file.close
end

# Now, go through all of the RSS feed URLs, and if we find one that didn't match
# the URLs in URLfile, that's a new Slickdeal. Notify using EmailCmd, and add the URL
# to URLfile
mail_open = 0
file = File.new(URLfile,"a+")
matches.each do |key, value|
  if (value == 0)
    file.puts key + "\n" # Add the URL to URLfile
    # Only open the mail program once, allows us to send multiple updates in one notice
    if (mail_open == 0) 
      $mail = IO.popen(EmailCmd,"w")
      mail_open = 1
    end
    $mail.puts titles[key] + "\n"
  end
end
if (mail_open == 1)
  $mail.close
end
file.close