+ |> Enum.filter(& &1)
+ end
+
+ @spec get_to_and_cc(
+ User.t(),
+ list(String.t()),
+ Activity.t() | nil,
+ String.t(),
+ Participation.t() | nil
+ ) :: {list(String.t()), list(String.t())}
+
+ def get_to_and_cc(_, _, _, _, %Participation{} = participation) do
+ participation = Repo.preload(participation, :recipients)
+ {Enum.map(participation.recipients, & &1.ap_id), []}