Introduce registerPerson mutation

To register a profile from an unactivated user

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

👤 Fix Person interface use

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

Change host function for data property

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

lib/mobilizon/actors/actor.ex

@@ -103,6 +103,8 @@ defmodule Mobilizon.Actors.Actor do
       :user_id
     ])
     |> build_urls()
+    # Needed because following constraint can't work for domain null values (local)
+    |> unique_username_validator()
     |> unique_constraint(:preferred_username, name: :actors_preferred_username_domain_type_index)
     |> unique_constraint(:url, name: :actors_url_index)
     |> validate_required([:preferred_username, :keys, :suspended, :url, :type])
@@ -177,6 +179,16 @@ defmodule Mobilizon.Actors.Actor do
     |> put_change(:local, true)
   end
 
+  def unique_username_validator(
+        %Ecto.Changeset{changes: %{preferred_username: username}} = changeset
+      ) do
+    if Actors.get_local_actor_by_name(username) do
+      changeset |> add_error(:preferred_username, "Username is already taken")
+    else
+      changeset
+    end
+  end
+
   @spec build_urls(Ecto.Changeset.t(), atom()) :: Ecto.Changeset.t()
   defp build_urls(changeset, type \\ :Person)