module Roda::RodaPlugins::Assets::ClassMethods

def compile_assets_files(files, type, dirs)
  dirs = nil if dirs && dirs.empty?
  o = assets_opts
  app = allocate
  content = files.map do |file|
    file = "#{dirs.join('/')}/#{file}" if dirs && o[:group_subdirs]
    file = "#{o[:"#{type}_path"]}#{file}"
    app.read_asset_file(file, type)
  end.join("\n")
  unless o[:concat_only]
    content = compress_asset(content, type)
  end
  suffix = ".#{dirs.join('.')}" if dirs
  key = "#{type}#{suffix}"
  unique_id = o[:compiled][key] = asset_digest(content)
  path = "#{o[:"compiled_#{type}_path"]}#{suffix}.#{unique_id}.#{type}"
  ::FileUtils.mkdir_p(File.dirname(path))
  ::File.open(path, 'wb'){|f| f.write(content)}
  if o[:gzip]
    require 'zlib'
    Zlib::GzipWriter.open("#{path}.gz") do |gz|
      gz.write(content)
    end
  end
  nil
end