defimpl Altstd.Compact, for: Atom do
  @moduledoc since: "0.1.0"

  @doc since: "0.1.0"
  @spec resolve(atom(), keyword) :: Altstd.Compact.resolution_t()
  def resolve(object, opts \\ [])

  def resolve(nil, _opts) do
    {:reject, nil}
  end

  def resolve(false, _opts) do
    {:reject, false}
  end

  def resolve(:error, _opts) do
    {:reject, :error}
  end

  def resolve(:reject, _opts) do
    {:reject, :reject}
  end

  def resolve(object, _opts) do
    len =
      object
      |> Atom.to_string()
      |> String.length()

    case len do
      0 ->
        {:reject, object}

      _any ->
        {:resolve, object}
    end
  end

  @doc since: "0.1.0"
  @spec cast(atom(), keyword) :: Altstd.Compact.t()
  def cast(object, opts \\ []) do
    resolution =
      object
      |> Altstd.Compact.resolve(opts)

    case resolution do
      {:resolve, resolved_value} ->
        resolved_value
        |> List.wrap()

      {:reject, _any} ->
        []

      :reject ->
        []

      resolved_value ->
        resolved_value
        |> List.wrap()
    end
  end
end