Introduce group basic federation, event new page and notifications

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

lib/federation/activity_stream/converter/todo.ex

@@ -0,0 +1,70 @@
+defmodule Mobilizon.Federation.ActivityStream.Converter.Todo do
+  @moduledoc """
+  TodoList converter.
+
+  This module allows to convert todo lists from ActivityStream format to our own
+  internal one, and back.
+  """
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Federation.ActivityPub
+  alias Mobilizon.Federation.ActivityStream.{Converter, Convertible}
+  alias Mobilizon.Todos
+  alias Mobilizon.Todos.{Todo, TodoList}
+
+  @behaviour Converter
+
+  defimpl Convertible, for: Todo do
+    alias Mobilizon.Federation.ActivityStream.Converter.Todo, as: TodoConverter
+
+    defdelegate model_to_as(todo), to: TodoConverter
+  end
+
+  @doc """
+  Convert an todo list struct to an ActivityStream representation
+  """
+  @impl Converter
+  @spec model_to_as(Todo.t()) :: map
+  def model_to_as(
+        %Todo{
+          todo_list: %TodoList{actor: %Actor{url: group_url} = _group, url: todo_list_url},
+          creator: %Actor{url: creator_url}
+        } = todo
+      ) do
+    %{
+      "type" => "Todo",
+      "actor" => creator_url,
+      "attributedTo" => group_url,
+      "id" => todo.url,
+      "name" => todo.title,
+      "status" => todo.status,
+      "todoList" => todo_list_url
+    }
+  end
+
+  @doc """
+  Converts an AP object data to our internal data structure.
+  """
+  @impl Converter
+  @spec as_to_model_data(map) :: {:ok, map} | {:error, any()}
+  def as_to_model_data(
+        %{"type" => "Todo", "actor" => actor_url, "todoList" => todo_list_url} = object
+      ) do
+    with {:ok, %Actor{id: creator_id} = _creator} <-
+           ActivityPub.get_or_fetch_actor_by_url(actor_url),
+         {:todo_list, %TodoList{id: todo_list_id}} <-
+           {:todo_list, Todos.get_todo_list_by_url(todo_list_url)} do
+      %{
+        title: object["name"],
+        status: object["status"],
+        url: object["id"],
+        todo_list_id: todo_list_id,
+        creator_id: creator_id
+      }
+    else
+      {:todo_list, nil} ->
+        with {:ok, %TodoList{}} <- ActivityPub.fetch_object_from_url(todo_list_url) do
+          as_to_model_data(object)
+        end
+    end
+  end
+end