Add the book eidtions registry to manage book editions.

lib/decentralised_book_index/metadata.ex

@@ -24,5 +24,7 @@ defmodule DecentralisedBookIndex.Metadata do
       define :update_author_alias_registry, action: :update
       define :destroy_author_alias_registry, action: :destroy
     end
+
+    resource DecentralisedBookIndex.Metadata.BookEditionsRegistry
   end
 end

lib/decentralised_book_index/metadata/book.ex

@@ -33,4 +33,8 @@ defmodule DecentralisedBookIndex.Metadata.Book do
 
     timestamps()
   end
+
+  relationships do
+    belongs_to :book_editions_registry, DecentralisedBookIndex.Metadata.BookEditionsRegistry
+  end
 end

lib/decentralised_book_index/metadata/book_editions_registry.ex

@@ -0,0 +1,31 @@
+defmodule DecentralisedBookIndex.Metadata.BookEditionsRegistry do
+  use Ash.Resource,
+    otp_app: :decentralised_book_index,
+    domain: DecentralisedBookIndex.Metadata,
+    data_layer: AshPostgres.DataLayer
+
+  postgres do
+    table "book_editions_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.Book
+  end
+end