Store original file size and filename to Model about arc_ecto HOT 1 OPEN

  def create_changeset(relationship_attachment, attrs) do
    upload = Map.get(attrs, "attachment")

    relationship_attachment
    |> changeset(attrs)
    |> put_file_size(upload) # or we could just send this from the JavaScript File API?
    |> validate_required([:file_size])
    |> put_mime_type(upload)
    |> validate_required([:mime_type])
    |> cast_attachments(attrs, [:attachment])
    |> validate_required([:attachment])
  end

  defp put_mime_type(changeset, %Plug.Upload{} = upload) do
    put_change(changeset, :mime_type, upload.content_type)
  end
  defp put_mime_type(changeset, _), do: changeset

  defp put_file_size(changeset, %Plug.Upload{} = upload) do
    put_change(changeset, :file_size, file_size(upload))
  end
  defp put_file_size(changeset, _), do: changeset

  defp file_size(%Plug.Upload{} = upload) do
    case File.stat(upload.path) do
      {:ok, stats} ->
        stats.size
      {:error, _} ->
        nil
    end
  end