class AttachTag

def render(context)
  super
  return unless argv1
  message = context.registers["message"]
  if argv1.is_a? String
    message.add_attachment({url: argv1})
  elsif argv1.instance_of?(ActiveStorageAttachedOneDrop) || argv1.instance_of?(ActiveStorage::AttachmentDrop)
    io = StringIO.new(argv1.download)
    io.rewind
    content_type = argv1.content_type
    filename = argv1.filename
    if arg(:convert) == "pdf" && content_type != "application/pdf"
      content_type = "application/pdf"
      pdf = Labelary::Label.render(zpl: io.read,
        content_type: content_type,
        dpmm: 8,
        width: arg(:width).blank? ? 4 : arg(:width),
        height: arg(:height).blank? ? 6 : arg(:height))
      io = StringIO.new(pdf)
      filename = "#{filename}.pdf"
    end
    message.add_attachment({content: io, filename: filename, content_type: content_type})
  end
  ""
end