#!/usr/bin/env ruby
require 'logger'
require 'rake'
require 'fileutils'

# apt install ruby genisoimage
# mkdir -p /opt/backup/isoupload && touch /opt/backup/backup.log

# Store all backup files
$backup_dir = '/opt/backup/isoupload'

# Delete all backup files older than $keep_days
$keep_days = 14

# Generate missing backup files newer than $check_days
$check_days = 7

# Path to pack
$pack_path = '/var/www/%<year>d/%<month>02d/%<day>02d'

# Path in ISO
$path_in_iso = '/%<year>d/%<month>02d/%<day>02d'

# ISO file name
$iso_name = '%<year>d/%<month>02d/%<year>d-%<month>02d-%<day>02d.iso'

# ISO volume name (CD label)
$iso_volume = '%<year>d-%<month>02d-%<day>02d'

$s3_subdir = ''

$log_file = '/opt/backup/backup.log'
# $log_file = STDOUT

# Generate backup file for given date
def generate(date)
  date_info = {
    year: date.year,
    month: date.month,
    day: date.day,
    hour: date.hour,
    min: date.min
  }

  pack_path = $pack_path % date_info
  path_in_iso = $path_in_iso % date_info
  iso_name = $iso_name % date_info
  iso_volume = $iso_volume % date_info

  if !File.exist?(pack_path)
    $logger.warn "#{pack_path} is missing, skipping."
    return
  end

  Dir.chdir($backup_dir) do
    if File.exist?(iso_name)
      $logger.info "#{iso_name} exists, skipping."
      return
    end

    FileUtils.mkdir_p(File.dirname(iso_name))
    Rake.sh 'ionice', 'genisoimage', '-U', '-J', '-quiet',
      '-dir-mode', '555', '-file-mode', '444',
      '-uid', '0', '-gid', '0',
      '-o', iso_name,
      '-V', iso_volume,
      '-graft-points', "#{path_in_iso}=#{pack_path}"

    if File.exist?(iso_name)
      $logger.info "#{iso_name} generated."
    end
  end
end

def upload
  # Pre-configure /root/.rclone.conf file
  Rake.sh 'ionice', 'rclone', 'copy', $backup_dir, "scaleway:#{$s3_subdir}", '--transfers', '1'
end

def purge
  purge_time = Time.now - 86400 * $keep_days
  Dir.chdir($backup_dir) do
    # Strict to only *.iso and *.xz
    Dir.glob('**/{*.iso,*.xz}') do |file|
      mtime = File.mtime(file)
      mtime_string = mtime.strftime('%Y-%m-%d %H:%M:%S')
      if mtime < purge_time
        $logger.info "Deleting #{file} (#{mtime_string})"
        # File.unlink(file)
      end
    end
  end
end

raise "check_days must be smaller than keep_days" unless $check_days < $keep_days
raise "check_days must be greater than 0" unless $check_days > 0

$logger = Logger.new($log_file)

$logger.info "Keep #{$keep_days} days, check #{$check_days} days"

# Loop through days
now = Time.now
$check_days.downto(1) do |day|
  generate(now - 86400 * day)
end

upload
purge