let chunk = await req.into_body().concat2();
let update  = from_slice::<Update>(chunk.as_ref())?;
let chat_id = update.message.chat.id;
let message_id = update.message.message_id;
let processing_info = match (&update.message.from, &update.message.document, &update.message.photo) {
  (Some(ref from), Some(ref document), _) => Some((from, &document.file_id)),
  (Some(ref from), _, Some(ref photo)) => photo
    .iter()
    .max_by_key(|x| x.file_size.unwrap_or(0))
    .map(|x| (from, &x.file_id)),
  _ => None,
};
let file = await telegram_client.get_file(&file_id);
if let Some((file_path, ext)) = get_file_path_if_processable(file.file_path) {
  let image = Image::new(
    bytes.into_iter().collect(),
    ImageMetadata::new(format!("{}.{}", file_id, ext), user.id, message_id),
  );
   ....
}