#!/usr/bin/ruby

require 'net/smtp'

# Only reboot if these packages are updated
flagged = ['linux']

# Some required SMTP vars
smtp_server = ''
smtp_port = 25
smtp_helo = ''
smtp_username = ''
smtp_password = ''
email = ''
smtp_msg = <<EOF
From:
To:
Subject:

Updating via pacman failed. Investigate ASAP.
EOF

reboot = false

# See what packages have updates available
updates = `/usr/bin/pacman -Qu`

if $?.exitstatus == 0 # Perform updates if they're available
  # If any of our previously flagged packages have updates, schedule a reboot
  flagged.each do |pkg|
    reboot = true if updates =~ /^\b#{pkg}\b(?!-)/
  end

  # Perform the updates
  system('/usr/bin/pacman -Syu --noconfirm > /dev/null 2>&1')

  # Send out an email if anything went wrong
  if $?.exitstatus != 0
    Net::SMTP.start(smtp_server, smtp_port, smtp_helo, smtp_username, smtp_password, :plain) do |smtp|
      smtp.send_message smtp_msg, email, email
    end
  end

  # Reboot the host if any flagged packages were updated
  if reboot
    system('reboot')
  end
end