module DkimParse

# File lib/dkim_parse.rb, line 6
def self.check_host(host, resolver=Resolv::DNS.new)
  begin
    host_without_tld = host[0...host.rindex('.')]
  rescue
    raise StandardError.new('host'), "invalid hostname"
  end
  defaults = %W[default dkim google #{host_without_tld}]
  defaults.uniq!
  puts "  - using selectors: #{defaults}"
  dkim = nil
  defaults.each do |selector|
    record_path = "#{selector}._domainkey.#{host.downcase}"
    begin
      dkim = resolver.getresource(record_path, Resolv::DNS::Resource::IN::TXT).strings.join
      dkim = {:record =>dkim, :record_path=>record_path}
      break
    rescue Resolv::ResolvError
    end
  end
  dkim
end