require "fileutils"

module Cache
  DIR = File.join(ENV["HOME"], ".cache", "d20pfsrd")

  def cache(k, &block)
    FileUtils.mkdir_p(DIR)
    encoded_k = k.to_s.gsub(/\W/, "_")
    cache_file = File.join(DIR, encoded_k)
    if File.exist?(cache_file)
      File.read(cache_file)
    else
      out = block.call
      File.write(cache_file, out)
      out
    end
  end
end