class Middleman::CoreExtensions::Internationalization

def known_locales
  if options[:locales]
    Array(options[:locales]).map(&:to_sym)
  else
    known_locales = app.files.by_type(:locales).files.select do |p|
      p[:relative_path].to_s.split(File::SEPARATOR).length == 1
    end
    known_locales.map do |p|
      File.basename(p[:relative_path].to_s).sub(/\.ya?ml$/, '').sub(/\.rb$/, '')
    end.sort.map(&:to_sym)
  end
end