hash image file name arc uploader

image.ex

defmodule HeraCore.Uploader.AttachmentImage do
  use Arc.Definition.Versioning
  use Arc.Definition.Storage

  # use Arc.Actions.Store
  use Arc.Actions.Delete
  use Arc.Actions.Url
  use Arc.Ecto.Definition

  # @versions [:original]
  # @cwd File.cwd!()

  # function override to store images locally.
  def __storage do
    Application.get_env(:arc, :storage)
  end

  # Whitelist file extensions:
  def validate({file, _}) do
    file_extension = file.file_name |> Path.extname() |> String.downcase()
    ~w(.jpg .jpeg .gif .png) |> Enum.member?(file_extension)
  end

  def storage_dir(_version, _) do
    "images/attachments"
  end

  # Provide a default URL if there hasn't been a file uploaded
  # def default_url(version, scope) do
  #   "/images/avatars/default_#{version}.png"
  # end

  def s3_object_headers(_version, {file, _scope}) do
    # for "image.png", would produce: "image/png"
    [content_type: MIME.from_path(file.file_name)]
  end

  def store(args) do
    args = fix_filename(args)
    Arc.Actions.Store.store(__MODULE__, args)
  end

  defp fix_filename(%{filename: filename} = file) do
    file_name =
      filename
      |> Path.basename(Path.extname(filename))
      |> Slugger.slugify_downcase()

    file_name = "#{file_name}-#{Nanoid.generate(4)}#{Path.extname(filename)}"

    %{file | filename: file_name}
  end

  defp fix_filename({file, scope}) do
    {fix_filename(file), scope}
  end

  defp fix_filename(args), do: args
end