iona

defprotocol Iona.Input do
  @type t :: any

  @spec path?(input :: t) :: boolean
  def path?(input)

  @spec path(input :: t) :: Path.t() | nil
  def path(input)

  @spec content(input :: t) :: Iona.tex_t()
  def content(input)

  @spec included_files(input :: t) :: [Path.t()]
  def included_files(input)
end

defimpl Iona.Input, for: [Iona.Source, Iona.Template] do
  def path?(%{path: path}) when is_binary(path), do: true
  def path?(_), do: false

  def path(%{path: path}), do: path

  def content(%{content: content}), do: content

  def included_files(%{include: include}), do: include |> List.wrap()
  def included_files(%{}), do: []
end

defimpl Iona.Template.Safe, for: [Iona.Source, Iona.Template] do
  def to_iodata(input) do
    if Iona.Input.path?(input) do
      File.read!(Iona.Input.path(input))
    else
      Iona.Input.content(input)
    end
  end
end