Fix remote group moderators managing event participations

Closes #827

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

lib/graphql/resolvers/event/utils.ex

@@ -0,0 +1,34 @@
+defmodule Mobilizon.GraphQL.Resolvers.Event.Utils do
+  @moduledoc """
+  Tools to test permission on events
+  """
+
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Events.Event
+  alias Mobilizon.Federation.ActivityPub.Permission
+
+  def can_event_be_updated_by?(
+        %Event{attributed_to: %Actor{type: :Group}} = event,
+        %Actor{} = actor_member
+      ) do
+    Permission.can_update_group_object?(actor_member, event)
+  end
+
+  def can_event_be_updated_by?(
+        %Event{} = event,
+        %Actor{id: actor_member_id}
+      ) do
+    Event.can_be_managed_by?(event, actor_member_id)
+  end
+
+  def can_event_be_deleted_by?(
+        %Event{attributed_to: %Actor{type: :Group}} = event,
+        %Actor{} = actor_member
+      ) do
+    Permission.can_delete_group_object?(actor_member, event)
+  end
+
+  def can_event_be_deleted_by?(%Event{} = event, %Actor{id: actor_member_id}) do
+    Event.can_be_managed_by?(event, actor_member_id)
+  end
+end