require 'rubygems'
require 'net/imap'
require 'tmail'
require 'parsedate'

# NOTE: Set these values before you run the script

# Your gmail username
USERNAME = "YOUR_USERNAME"
# Your gmail password
PASSWORD = "YOUR_PASSWORD"
# Set this to true if you want a system beep to signal a new message in the inbox
BEEP = true
# This is the interval in minutes between inbox checks
INTERVAL = 1

class GmailCheck

  def initialize(username, password, interval=5, beep=true)
    @beep = beep
    @username, @password = username, password
    @interval = interval * 60
    @seen_ids = []
  end

  def run
    loop do
      check_inbox @username, @password
      @update_loop ||= true
      sleep @interval
    end
  end

  def fetch_email(imap, message_id)
    begin
      email = imap.fetch(message_id, "RFC822")[0].attr["RFC822"]
    rescue
      puts "Error fetching message #{message_id}. Skipping"
      nil
    end
  end

  def check_inbox(username, password)
    imap = Net::IMAP.new('imap.gmail.com', 993, true)

    imap.login(username, password)

    imap.select('INBOX')

    imap.search(["ALL"])[-5,5].each do |message_id|

      next if @seen_ids.include? message_id
      # beep
      if @update_loop && @beep
        print 7.chr
      end
      @seen_ids << message_id

      email = fetch_email(imap, message_id)
      next if email.nil?
      x = TMail::Mail.parse(email)
      puts "time:    #{x.date.strftime("%I:%M %p %a %b %d")}"
      puts "from:    #{x.from}"
      puts "subject: #{x.subject}"
      puts "excerpt: #{x.body.split(/\s+/)[0,10].join(' ')}"
      puts
    end

  rescue Exception => ex
    puts "Error: #{ex.message}"
  ensure
    if imap
      imap.close
      imap.disconnect
    end
  end
end

if __FILE__ == $0
  gmailcheck = GmailCheck.new(USERNAME, PASSWORD, INTERVAL, BEEP)
  gmailcheck.run
end