Introduce the group activity section

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

lib/service/activity/member.ex

@@ -0,0 +1,97 @@
+defmodule Mobilizon.Service.Activity.Member do
+  @moduledoc """
+  Insert a member activity
+  """
+  alias Mobilizon.Actors
+  alias Mobilizon.Actors.{Actor, Member}
+  alias Mobilizon.Service.Activity
+  alias Mobilizon.Service.Workers.ActivityBuilder
+
+  @behaviour Activity
+
+  @impl Activity
+  def insert_activity(member, options \\ [])
+
+  def insert_activity(
+        %Member{parent_id: parent_id, id: member_id} = new_member,
+        options
+      ) do
+    subject = Keyword.get(options, :subject)
+
+    with author_id <- get_author(new_member, options),
+         object_id <- if(subject == "member_removed", do: nil, else: to_string(member_id)) do
+      ActivityBuilder.enqueue(:build_activity, %{
+        "type" => "member",
+        "subject" => subject,
+        "subject_params" => get_subject_params(new_member, options),
+        "group_id" => parent_id,
+        "author_id" => author_id,
+        "object_type" => "member",
+        "object_id" => object_id,
+        "inserted_at" => DateTime.utc_now()
+      })
+    end
+  end
+
+  def insert_activity(_, _), do: {:ok, nil}
+
+  @spec get_author(Member.t(), Member.t() | nil) :: String.t() | integer()
+  defp get_author(%Member{actor_id: actor_id}, options) do
+    moderator = Keyword.get(options, :moderator)
+
+    if is_nil(moderator) do
+      actor_id
+    else
+      moderator.id
+    end
+  end
+
+  @spec get_subject_params(Member.t(), Keyword.t()) :: map()
+  defp get_subject_params(%Member{actor: actor, role: role, id: member_id}, options) do
+    # We may need to preload the member to make sure the actor exists
+    actor =
+      case actor do
+        %Actor{} = actor ->
+          actor
+
+        _ ->
+          case Actors.get_member(member_id) do
+            %Member{actor: actor} -> actor
+            _ -> nil
+          end
+      end
+
+    moderator = Keyword.get(options, :moderator)
+    old_member = Keyword.get(options, :old_member)
+
+    subject_params = %{
+      member_role: String.upcase(to_string(role))
+    }
+
+    subject_params =
+      if(is_nil(actor),
+        do: subject_params,
+        else:
+          Map.put(
+            subject_params,
+            :member_preferred_username,
+            Actor.preferred_username_and_domain(actor)
+          )
+      )
+
+    subject_params =
+      if(is_nil(old_member),
+        do: subject_params,
+        else: Map.put(subject_params, :old_role, String.upcase(to_string(old_member.role)))
+      )
+
+    if is_nil(moderator),
+      do: subject_params,
+      else:
+        Map.put(
+          subject_params,
+          :moderator_preferred_username,
+          Actor.preferred_username_and_domain(moderator)
+        )
+  end
+end