Split Federation as separate context

lib/federation/activity_pub/visibility.ex

@@ -0,0 +1,28 @@
+# Portions of this file are derived from Pleroma:
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social>
+# SPDX-License-Identifier: AGPL-3.0-only
+# Upstream: https://git.pleroma.social/pleroma/pleroma/blob/develop/lib/pleroma/web/activity_pub/visibility.ex
+
+defmodule Mobilizon.Federation.ActivityPub.Visibility do
+  @moduledoc """
+  Utility functions related to content visibility
+  """
+
+  alias Mobilizon.Events.Comment
+
+  alias Mobilizon.Federation.ActivityPub.Activity
+
+  @public "https://www.w3.org/ns/activitystreams#Public"
+
+  @spec is_public?(Activity.t() | map()) :: boolean()
+  def is_public?(%{data: %{"type" => "Tombstone"}}), do: false
+  def is_public?(%{data: data}), do: is_public?(data)
+  def is_public?(%Activity{data: data}), do: is_public?(data)
+
+  def is_public?(data) when is_map(data) do
+    @public in (Map.get(data, "to", []) ++ Map.get(data, "cc", []))
+  end
+
+  def is_public?(%Comment{deleted_at: deleted_at}), do: !is_nil(deleted_at)
+  def is_public?(err), do: raise(ArgumentError, message: "Invalid argument #{inspect(err)}")
+end