Introduce group basic federation, event new page and notifications

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

lib/mobilizon/storage/ecto.ex

@@ -4,6 +4,9 @@ defmodule Mobilizon.Storage.Ecto do
   """
 
   import Ecto.Query, warn: false
+  import Ecto.Changeset, only: [fetch_change: 2, put_change: 3]
+  alias Mobilizon.Web.Endpoint
+  alias Mobilizon.Web.Router.Helpers, as: Routes
 
   @doc """
   Adds sort to the query.
@@ -12,4 +15,35 @@ defmodule Mobilizon.Storage.Ecto do
   def sort(query, sort, direction) do
     from(query, order_by: [{^direction, ^sort}])
   end
+
+  @doc """
+  Ensure changeset contains an URL
+
+  If there's a blank URL that's because we're doing the first insert.
+  Most of the time just go with the given URL.
+  """
+  @spec ensure_url(Ecto.Changeset.t(), atom()) :: Ecto.Changeset.t()
+  def ensure_url(%Ecto.Changeset{data: %{url: nil}} = changeset, route) do
+    case fetch_change(changeset, :url) do
+      {:ok, _url} ->
+        changeset
+
+      :error ->
+        generate_url(changeset, route)
+    end
+  end
+
+  def ensure_url(%Ecto.Changeset{} = changeset, _route), do: changeset
+
+  @spec generate_url(Ecto.Changeset.t(), atom()) :: Ecto.Changeset.t()
+  defp generate_url(%Ecto.Changeset{} = changeset, route) do
+    uuid = Ecto.UUID.generate()
+
+    changeset
+    |> put_change(:id, uuid)
+    |> put_change(
+      :url,
+      apply(Routes, String.to_existing_atom("#{to_string(route)}_url"), [Endpoint, route, uuid])
+    )
+  end
 end