#!/usr/bin/env ruby

require "ec2_snapshot"
require "optparse"
require "date"

options = Hash.new

optparse = OptionParser.new do |opts|
  opts.banner = "Usage: ec2-snapshot [options]"

  options[:volume_type] = :all
  opts.on("--volume-type TYPE", [:all, :root, :data], "Volume types that need to be snapshotted (all/root/data). Defaults to all.") do |volume_type|
    options[:volume_type] = volume_type
  end

  options[:aws_access_key] = ENV["AWS_ACCESS_KEY_ID"]
  opts.on("--aws-access-key KEY", "AWS Access Key.Either set ENV[\"AWS_ACCESS_KEY_ID\"] or provide it as an option.") do |access_key|
    options[:aws_access_key] = access_key
  end

  options[:aws_secret_access_key] = ENV["AWS_SECRET_ACCESS_KEY"]
  opts.on("--aws-secret-access-key KEY", "AWS Secret Access Key. Either set ENV[\"AWS_SECRET_ACCESS_KEY\"] or provide it as an option.") do |secret_access_key|
    options[:aws_secret_access_key] = secret_access_key
  end

  opts.on("--aws-region REGION", "AWS Region. Mandatory. Example regions are eu-west-1 and us-west-1") do |region|
    options[:aws_region] = region
  end

  opts.on("--before BEFORE", "Shell command to run before volume is snapshotted. Optional.") do |before|
    options[:before] = before
  end

  opts.on("--after AFTER", "Shell command to run after volume is snapshotted. Optional.") do |after|
    options[:after] = after
  end

  opts.on("--delete-older-than MONTHS", "Delete snapshots for this instance that are older than # months. Optional.") do |months|
    options[:delete_older_than] = months.to_i
  end

  options[:verbose] = false
  opts.on("-v", "--verbose", "Display progress output.") do |verbose|
    options[:verbose] = verbose
  end

  opts.on("-h", "--help", "Display this screen.") do
    puts opts
    exit
  end
end

optparse.parse!

if options[:aws_access_key].nil? or options[:aws_secret_access_key].nil? or options[:aws_region].nil?
  Kernel.abort("Not all mandatory options have been provided. Exiting.")
end

instance = Ec2Snapshot::Instance.new(options)
instance.enable_rootvol_snapshot if [:all, :root].include?(options[:volume_type])
instance.enable_datavol_snapshot if [:all, :data].include?(options[:volume_type])
instance.create_snapshots
instance.delete_snapshots(Date.today << options[:delete_older_than]) if options.include?(:delete_older_than)