#!/usr/bin/ruby

target_dirs = []

Dir::open('.').each{|f|
  next unless f =~ /^\d+$/
  target_dirs << f
}

dir_flist = []

target_dirs.sort{|a, b| a <=> b}.each{|dir|
  dir_flist << [dir, Dir::open(dir).reject{|f| f !~ /^img_\d+.jpg$/}.sort{|x, y| x <=> y}]
}

out_dir = ARGV.shift || "out"

unless FileTest::directory?(out_dir) then
  Dir::mkdir(out_dir)
end

offset = 0
dir_flist.each{|dir, flist|
  $stderr.puts "#{dir} => offset:#{offset}"
  flist.each{|f|
    f =~ /^img_(\d+).jpg$/
    new_f = sprintf("img_%05d.jpg", $1.to_i + offset)
    command = "cp #{dir}/#{f} #{out_dir}/#{new_f}"
    $stderr.puts command
    `#{command}`
  }
  offset += flist.size
}