Add the author alias registry to manage alias relationship.

Add datalayer and migrations.

lib/decentralised_book_index/metadata/author.ex

@@ -10,7 +10,17 @@ defmodule DecentralisedBookIndex.Metadata.Author do
   end
 
   actions do
-    defaults [:read]
+    defaults [:read, :update, :destroy]
+
+    update :add_author_to_alias_registry do
+      accept [:author_alias_registry_id]
+    end
+
+    create :create do
+      primary? true
+      accept [:name, :description, :author_alias_registry_id]
+
+    end
   end
 
   attributes do
@@ -28,4 +38,10 @@ defmodule DecentralisedBookIndex.Metadata.Author do
 
     timestamps()
   end
+
+  relationships do
+    belongs_to :author_alias_registry, DecentralisedBookIndex.Metadata.AuthorAliasRegistry do
+      attribute_writable? true
+    end
+  end
 end

lib/decentralised_book_index/metadata/author_alias_registry.ex

@@ -0,0 +1,31 @@
+defmodule DecentralisedBookIndex.Metadata.AuthorAliasRegistry do
+  use Ash.Resource,
+    otp_app: :decentralised_book_index,
+    domain: DecentralisedBookIndex.Metadata,
+    data_layer: AshPostgres.DataLayer
+
+  postgres do
+    table "author_alias_registries"
+    repo DecentralisedBookIndex.Repo
+  end
+
+  actions do
+    defaults [:read, :create, :update, :destroy]
+
+    read :by_id do
+      argument :id, :uuid, allow_nil?: false
+      get? true
+      filter expr(id == ^arg(:id))
+    end
+  end
+
+  attributes do
+    uuid_primary_key :id
+
+    timestamps()
+  end
+
+  relationships do
+    has_many :authors, DecentralisedBookIndex.Metadata.Author
+  end
+end