feat: add join form settings

lib/membership/setting.ex

@@ -15,6 +15,12 @@ defmodule Mv.Membership.Setting do
     (e.g., `%{"first_name" => true, "last_name" => true}`). Email is always required; other fields default to optional.
   - `include_joining_cycle` - Whether to include the joining cycle in membership fee generation (default: true)
   - `default_membership_fee_type_id` - Default membership fee type for new members (optional)
+  - `join_form_enabled` - Whether the public /join page is active (default: false)
+  - `join_form_field_ids` - Ordered list of field IDs shown on the join form. Each entry is
+    either a member field name string (e.g. "email") or a custom field UUID. Email is always
+    included and always required; normalization enforces this automatically.
+  - `join_form_field_required` - Map of field ID => required boolean for the join form.
+    Email is always forced to true.
 
   ## Singleton Pattern
   This resource uses a singleton pattern - there should only be one settings record.
@@ -86,8 +92,13 @@ defmodule Mv.Membership.Setting do
         :oidc_client_secret,
         :oidc_admin_group_name,
         :oidc_groups_claim,
-        :oidc_only
+        :oidc_only,
+        :join_form_enabled,
+        :join_form_field_ids,
+        :join_form_field_required
       ]
+
+      change Mv.Membership.Setting.Changes.NormalizeJoinFormSettings
     end
 
     update :update do
@@ -110,8 +121,13 @@ defmodule Mv.Membership.Setting do
         :oidc_client_secret,
         :oidc_admin_group_name,
         :oidc_groups_claim,
-        :oidc_only
+        :oidc_only,
+        :join_form_enabled,
+        :join_form_field_ids,
+        :join_form_field_required
       ]
+
+      change Mv.Membership.Setting.Changes.NormalizeJoinFormSettings
     end
 
     update :update_member_field_visibility do
@@ -232,6 +248,39 @@ defmodule Mv.Membership.Setting do
              end,
              on: [:create, :update]
 
+    # Validate join_form_field_ids: each entry must be a known member field name
+    # or a UUID-format string (custom field ID). Normalization (NormalizeJoinFormSettings
+    # change) runs before validations, so email is already present when this runs.
+    validate fn changeset, _context ->
+               field_ids = Ash.Changeset.get_attribute(changeset, :join_form_field_ids)
+
+               if is_list(field_ids) and field_ids != [] do
+                 valid_member_fields =
+                   Mv.Constants.member_fields() |> Enum.map(&Atom.to_string/1)
+
+                 uuid_pattern =
+                   ~r/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i
+
+                 invalid_ids =
+                   Enum.reject(field_ids, fn id ->
+                     is_binary(id) and
+                       (id in valid_member_fields or Regex.match?(uuid_pattern, id))
+                   end)
+
+                 if Enum.empty?(invalid_ids) do
+                   :ok
+                 else
+                   {:error,
+                    field: :join_form_field_ids,
+                    message:
+                      "Invalid field identifiers: #{inspect(invalid_ids)}. Use member field names or custom field UUIDs."}
+                 end
+               else
+                 :ok
+               end
+             end,
+             on: [:create, :update]
+
     # Validate default_membership_fee_type_id exists if set
     validate fn changeset, context ->
                fee_type_id =
@@ -382,6 +431,29 @@ defmodule Mv.Membership.Setting do
       description "When true and OIDC is configured, sign-in shows only OIDC (password login hidden)"
     end
 
+    # Join form (Beitrittsformular) settings
+    attribute :join_form_enabled, :boolean do
+      allow_nil? false
+      default false
+      public? true
+
+      description "When true, the public /join page is active and new members can submit a request."
+    end
+
+    attribute :join_form_field_ids, {:array, :string} do
+      allow_nil? true
+      public? true
+
+      description "Ordered list of field IDs shown on the join form. Each entry is a member field name (e.g. 'email') or a custom field UUID. Email is always present after normalization."
+    end
+
+    attribute :join_form_field_required, :map do
+      allow_nil? true
+      public? true
+
+      description "Map of field ID => required boolean for the join form. Email is always true after normalization."
+    end
+
     timestamps()
   end