Introduce the group activity section

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

lib/service/activity/discussion.ex

@@ -0,0 +1,51 @@
+defmodule Mobilizon.Service.Activity.Discussion do
+  @moduledoc """
+  Insert a discussion activity
+  """
+  alias Mobilizon.Actors
+  alias Mobilizon.Discussions.Discussion
+  alias Mobilizon.Service.Activity
+  alias Mobilizon.Service.Workers.ActivityBuilder
+
+  @behaviour Activity
+
+  @impl Activity
+  def insert_activity(discussion, options \\ [])
+
+  def insert_activity(
+        %Discussion{creator_id: creator_id, actor_id: actor_id} = discussion,
+        options
+      )
+      when not is_nil(creator_id) do
+    creator = Actors.get_actor(creator_id)
+    group = Actors.get_actor(actor_id)
+    subject = Keyword.fetch!(options, :subject)
+    author = Keyword.get(options, :moderator, creator)
+    author_id = Keyword.get(options, :actor_id, author.id)
+    old_discussion = Keyword.get(options, :old_discussion)
+
+    ActivityBuilder.enqueue(:build_activity, %{
+      "type" => "discussion",
+      "subject" => subject,
+      "subject_params" => subject_params(discussion, subject, old_discussion),
+      "group_id" => group.id,
+      "author_id" => author_id,
+      "object_type" => "discussion",
+      "object_id" => if(subject != "discussion_deleted", do: to_string(discussion.id), else: nil),
+      "inserted_at" => DateTime.utc_now()
+    })
+  end
+
+  def insert_activity(_, _), do: {:ok, nil}
+
+  @spec subject_params(Discussion.t(), String.t() | nil, Discussion.t() | nil) :: map()
+  defp subject_params(%Discussion{} = discussion, "discussion_renamed", old_discussion) do
+    discussion
+    |> subject_params(nil, nil)
+    |> Map.put(:old_discussion_title, old_discussion.title)
+  end
+
+  defp subject_params(%Discussion{} = discussion, _, _) do
+    %{discussion_slug: discussion.slug, discussion_title: discussion.title}
+  end
+end