Add roles for users.

lib/decentralised_book_index/accounts/role.ex

@@ -0,0 +1,11 @@
+defmodule DecentralisedBookIndex.Accounts.Role do
+  use Ash.Type.Enum, values: [:user, :moderator, :admin]
+
+  def can_moderate?(role) when is_atom(role) do
+    role in [:moderator, :admin]
+  end
+
+  def can_administrate?(role) when is_atom(role) do
+    role == :admin
+  end
+end

lib/decentralised_book_index/accounts/user.ex

@@ -242,6 +242,11 @@ defmodule DecentralisedBookIndex.Accounts.User do
       allow_nil? false
       sensitive? true
     end
+
+    attribute :role, DecentralisedBookIndex.Accounts.Role do
+      allow_nil? false
+      default :user
+    end
   end
 
   identities do