module R509
    module CertificateAuthority
        module Http
            class SubjectParser
                def parse(raw, name="subject")
                    if raw.nil?
                        raise ArgumentError, "Must provide a query string"
                    end

                    subject = R509::Subject.new
                    raw.split(/[&;] */n).each { |pair|
                        key, value = pair.split('=', 2).map { |data| unescape(data) }
                        match = key.match(/#{name}\[(.*)\]/)
                        if not match.nil? and not value.empty?
                            subject[match[1]] = value
                        end
                    }
                    subject
                end

                if defined?(::Encoding)
                    def unescape(s, encoding = Encoding::UTF_8)
                        URI.decode_www_form_component(s, encoding)
                    end
                else
                    def unescape(s, encoding = nil)
                        URI.decode_www_form_component(s, encoding)
                    end
                end
            end
        end
    end
end