defmodule Carny do
  alias Carny.{Identifier, Policy}

  def require_permission(privilege, %Identifier{} = id, %Policy{} = policy, f) do
    case Policy.authorized?(privilege, id, policy) do
      true -> f.()
      false -> {:error, :unauthorized}
    end
  end

  def require_permission(privilege, id, policy, f) do
    id = id |> atom_map() |> Identifier.from_map()

    require_permission(privilege, id, Policy.from_map(policy), f)
  end

  defp atom_map(t), do: Map.new(t, fn {k, v} -> {String.to_atom(k), v} end)
end