samly

defmodule Samly.Assertion do
  @moduledoc """
  SAML assertion returned from IDP upon successful user authentication.

  The assertion attributes returned by the IdP are available in `attributes` field
  as a map. Any computed attributes (using a Plug Pipeline by way of configuration)
  are available in `computed` field as map.

  The attributes can be accessed directly from `attributes` or `computed` maps.
  The `Samly.get_attribute/2` function can be used as well. This function will
  first look at the `computed` attributes. If the request attribute is not present there,
  it will check in `attributes` next.
  """

  require Samly.Esaml
  alias Samly.Esaml
  alias Samly.Subject

  defstruct [
    version: "2.0",
    issue_instant: "",
    recipient: "",
    issuer: "",
    subject: %Subject{},
    conditions: %{},
    attributes: %{},
    authn: %{},
    computed: %{}
  ]

  @type t :: %__MODULE__{
    version: String.t,
    issue_instant: String.t,
    recipient: String.t,
    issuer: String.t,
    subject: Subject.t,
    conditions: map,
    attributes: map,
    authn: map,
    computed: map
  }

  @doc false
  def from_rec(assertion_rec) do
    Esaml.esaml_assertion(
      version: version,
      issue_instant: issue_instant,
      recipient: recipient,
      issuer: issuer,
      subject: subject_rec,
      conditions: conditions,
      attributes: attributes,
      authn: authn
    ) = assertion_rec

    %__MODULE__{
      version: List.to_string(version),
      issue_instant: List.to_string(issue_instant),
      recipient: List.to_string(recipient),
      issuer: List.to_string(issuer),
      subject: Subject.from_rec(subject_rec),
      conditions: conditions |> stringize(),
      attributes: attributes |> stringize(),
      authn: authn |> stringize()
    }
  end

  defp stringize(proplist) do
    proplist |> Enum.map(fn {k, v} -> {k, List.to_string(v)} end) |> Enum.into(%{})
  end
end