Add webpush front-end support

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/service/activity/utils.ex

@@ -0,0 +1,30 @@
+defmodule Mobilizon.Service.Activity.Utils do
+  @moduledoc """
+  Utils for activities
+  """
+
+  alias Mobilizon.Activities.Activity
+  alias Mobilizon.Service.Activity, as: ActivityService
+
+  def transform_activity(%Activity{} = activity) do
+    activity
+    |> Map.update(:subject_params, %{}, &transform_params/1)
+    |> add_activity_object()
+  end
+
+  @spec add_activity_object(Activity.t()) :: Activity.t()
+  def add_activity_object(%Activity{} = activity) do
+    Map.put(activity, :object, ActivityService.object(activity))
+  end
+
+  @spec transform_params(map()) :: list()
+  defp transform_params(params) do
+    Enum.map(params, fn {key, value} -> %{key: key, value: transform_value(value)} end)
+  end
+
+  defp transform_value(value) when is_list(value) do
+    Enum.join(value, ",")
+  end
+
+  defp transform_value(value), do: value
+end