defmodule DockerizeElixir.Path do
  # For some reason Path.relative_to/2 doesn't actually do anything if the given path is absolute
  def relative_to(path, from) do
    [relative_path, relative_from] = remove_same_prefix(Path.split(path), Path.split(from))

    relative_from
    |> Enum.map(fn _ -> ".." end)
    |> Enum.concat(relative_path)
    |> Path.join()
  end

  defp remove_same_prefix([head | tail1], [head | tail2]) do
    remove_same_prefix(tail1, tail2)
  end

  defp remove_same_prefix(list1, list2), do: [list1, list2]
end