Recursive URL looker-upper

gistfile1.rb

# recursively looks up a URL and returns a unicode
def self.lookup_url(uri_str, limit = 10, old_uri = nil)
  raise ArgumentError, 'too many HTTP redirects' if limit == 0
  response = Net::HTTP.get_response(URI(uri_str))

  case response
  when Net::HTTPSuccess then
    return self.unicode_parse(old_uri)
  when Net::HTTPRedirection then
    location = response['location']
    return self.lookup_url(location, limit - 1, location)
  else
    raise StandardError, "Could not determine qualified url, error: #{response.value}"
  end
end

# converts punycode to unicode if necessary
def self.unicode_parse(uri)
  if uri.match(/xn--/)
    if uri.match(/https?:\/\//)
     split_url = uri.split('://')
     split_url[1] = SimpleIDN.to_unicode(split_url.second)
     decoded_uri = split_url.join('://')
   else
    decoded_uri = SimpleIDN.to_unicode(uri)
   end
   return decoded_uri
  else
    # not punycoded
    return uri
  end
end