feat: Add option to link an external registration provider for events

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

priv/repo/migrations/20230901160000_add_external_url_for_events.exs

@@ -0,0 +1,33 @@
+defmodule Mobilizon.Storage.Repo.Migrations.AddExternalUrlForEvents do
+  use Ecto.Migration
+  alias Mobilizon.Events.JoinOptions
+
+  def up do
+    alter table(:events) do
+      add(:external_participation_url, :string)
+    end
+
+    reset_join_options_enum()
+  end
+
+  def down do
+    alter table(:events) do
+      remove(:external_participation_url, :string)
+    end
+
+    reset_join_options_enum()
+  end
+
+  defp reset_join_options_enum do
+    execute("ALTER TABLE events ALTER COLUMN join_options TYPE VARCHAR USING join_options::text")
+    execute("ALTER TABLE events ALTER COLUMN join_options DROP DEFAULT")
+    JoinOptions.drop_type()
+    JoinOptions.create_type()
+
+    execute(
+      "ALTER TABLE events ALTER COLUMN join_options TYPE join_options USING join_options::join_options"
+    )
+
+    execute("ALTER TABLE events ALTER COLUMN join_options SET DEFAULT 'free'::join_options")
+  end
+end