feat: add join form settings

lib/membership/setting/changes/normalize_join_form_settings.ex

@@ -0,0 +1,60 @@
+defmodule Mv.Membership.Setting.Changes.NormalizeJoinFormSettings do
+  @moduledoc """
+  Ash change that normalizes join form field settings before persist.
+
+  Applied on create and update actions whenever join form attributes are present.
+
+  Rules enforced:
+  - Email is always added to join_form_field_ids if not already present.
+  - Email is always marked as required (true) in join_form_field_required.
+  - Keys in join_form_field_required that are not in join_form_field_ids are dropped.
+
+  Only runs when join_form_field_ids is being changed; if only
+  join_form_field_required changes, normalization still uses the current
+  (possibly changed) field_ids to strip orphaned required flags.
+  """
+  use Ash.Resource.Change
+
+  def change(changeset, _opts, _context) do
+    changing_ids? = Ash.Changeset.changing_attribute?(changeset, :join_form_field_ids)
+    changing_required? = Ash.Changeset.changing_attribute?(changeset, :join_form_field_required)
+
+    if changing_ids? or changing_required? do
+      normalize(changeset)
+    else
+      changeset
+    end
+  end
+
+  defp normalize(changeset) do
+    field_ids = Ash.Changeset.get_attribute(changeset, :join_form_field_ids)
+    required_config = Ash.Changeset.get_attribute(changeset, :join_form_field_required)
+
+    field_ids = normalize_field_ids(field_ids)
+    required_config = normalize_required(field_ids, required_config)
+
+    changeset
+    |> Ash.Changeset.force_change_attribute(:join_form_field_ids, field_ids)
+    |> Ash.Changeset.force_change_attribute(:join_form_field_required, required_config)
+  end
+
+  defp normalize_field_ids(nil), do: ["email"]
+
+  defp normalize_field_ids(ids) when is_list(ids) do
+    if "email" in ids do
+      ids
+    else
+      ["email" | ids]
+    end
+  end
+
+  defp normalize_field_ids(_), do: ["email"]
+
+  defp normalize_required(field_ids, required_config) do
+    base = if is_map(required_config), do: required_config, else: %{}
+
+    base
+    |> Map.filter(fn {key, _} -> key in field_ids end)
+    |> Map.put("email", true)
+  end
+end