Introduce relay

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

lib/mobilizon/actors/follower.ex

@@ -7,9 +7,11 @@ defmodule Mobilizon.Actors.Follower do
   alias Mobilizon.Actors.Follower
   alias Mobilizon.Actors.Actor
 
+  @primary_key {:id, :binary_id, autogenerate: true}
+
   schema "followers" do
     field(:approved, :boolean, default: false)
-    field(:score, :integer, default: 1000)
+    field(:url, :string)
     belongs_to(:target_actor, Actor)
     belongs_to(:actor, Actor)
   end
@@ -17,8 +19,34 @@ defmodule Mobilizon.Actors.Follower do
   @doc false
   def changeset(%Follower{} = member, attrs) do
     member
-    |> cast(attrs, [:score, :approved, :target_actor_id, :actor_id])
-    |> validate_required([:score, :approved, :target_actor_id, :actor_id])
+    |> cast(attrs, [:url, :approved, :target_actor_id, :actor_id])
+    |> generate_url()
+    |> validate_required([:url, :approved, :target_actor_id, :actor_id])
     |> unique_constraint(:target_actor_id, name: :followers_actor_target_actor_unique_index)
   end
+
+  # If there's a blank URL that's because we're doing the first insert
+  defp generate_url(%Ecto.Changeset{data: %Follower{url: nil}} = changeset) do
+    case fetch_change(changeset, :url) do
+      {:ok, _url} -> changeset
+      :error -> do_generate_url(changeset)
+    end
+  end
+
+  # Most time just go with the given URL
+  defp generate_url(%Ecto.Changeset{} = changeset), do: changeset
+
+  defp do_generate_url(%Ecto.Changeset{} = changeset) do
+    uuid = Ecto.UUID.generate()
+
+    changeset
+    |> put_change(
+      :url,
+      "#{MobilizonWeb.Endpoint.url()}/follow/#{uuid}"
+    )
+    |> put_change(
+      :id,
+      uuid
+    )
+  end
 end