Add the Publisher resource.

lib/decentralised_book_index/metadata.ex

@@ -88,5 +88,13 @@ defmodule DecentralisedBookIndex.Metadata do
       define :update_book_id, action: :update
       define :destroy_book_id, action: :destroy
     end
+
+    resource DecentralisedBookIndex.Metadata.Publisher do
+      define :create_publisher, action: :create, args: [:name]
+      define :list_publishers, action: :read
+      define :get_publisher_by_id, args: [:id], action: :by_id
+      define :update_publisher, action: :update
+      define :destroy_publisher, action: :destroy
+    end
   end
 end

lib/decentralised_book_index/metadata/book.ex

@@ -17,7 +17,7 @@ defmodule DecentralisedBookIndex.Metadata.Book do
 
     create :create do
       primary? true
-      accept [:title, :description, :book_editions_registry_id]
+      accept [:title, :description, :publisher_id, :book_editions_registry_id]
       argument :bids, {:array, :map}
       argument :author_roles, {:array, :map}
 
@@ -38,7 +38,7 @@ defmodule DecentralisedBookIndex.Metadata.Book do
     end
 
     create :add_book_to_related_editions_registry do
-      accept [:title, :description]
+      accept [:title, :description, :publisher_id]
 
       argument :related_book_id, :uuid do
         allow_nil? false
@@ -121,6 +121,8 @@ defmodule DecentralisedBookIndex.Metadata.Book do
   relationships do
     belongs_to :book_editions_registry, Metadata.BookEditionsRegistry
 
+    belongs_to :publisher, Metadata.Publisher
+
     has_many :author_roles, Metadata.AuthorRole do
       sort order: :asc
       public? true

lib/decentralised_book_index/metadata/publisher.ex

@@ -0,0 +1,44 @@
+defmodule DecentralisedBookIndex.Metadata.Publisher do
+  use Ash.Resource,
+    otp_app: :decentralised_book_index,
+    domain: DecentralisedBookIndex.Metadata,
+    data_layer: AshPostgres.DataLayer
+
+  require Ash.Query
+  alias DecentralisedBookIndex.Metadata
+
+  postgres do
+    table "publishers"
+    repo DecentralisedBookIndex.Repo
+  end
+
+  actions do
+    defaults [:read, :update, :destroy]
+
+    create :create do
+      primary? true
+      accept [:name]
+    end
+
+    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
+
+    attribute :name, :string do
+      allow_nil? false
+      public? true
+    end
+
+    timestamps()
+  end
+
+  relationships do
+    has_many :books, Metadata.Book
+  end
+end

priv/repo/migrations/20250315185359_add_publisher_and_update_book_relationship.exs

@@ -0,0 +1,44 @@
+defmodule DecentralisedBookIndex.Repo.Migrations.AddPublisherAndUpdateBookRelationship do
+  @moduledoc """
+  Updates resources based on their most recent snapshots.
+
+  This file was autogenerated with `mix ash_postgres.generate_migrations`
+  """
+
+  use Ecto.Migration
+
+  def up do
+    create table(:publishers, primary_key: false) do
+      add :id, :uuid, null: false, default: fragment("gen_random_uuid()"), primary_key: true
+      add :name, :text, null: false
+
+      add :inserted_at, :utc_datetime_usec,
+        null: false,
+        default: fragment("(now() AT TIME ZONE 'utc')")
+
+      add :updated_at, :utc_datetime_usec,
+        null: false,
+        default: fragment("(now() AT TIME ZONE 'utc')")
+    end
+
+    alter table(:books) do
+      add :publisher_id,
+          references(:publishers,
+            column: :id,
+            name: "books_publisher_id_fkey",
+            type: :uuid,
+            prefix: "public"
+          )
+    end
+  end
+
+  def down do
+    drop constraint(:books, "books_publisher_id_fkey")
+
+    alter table(:books) do
+      remove :publisher_id
+    end
+
+    drop table(:publishers)
+  end
+end

priv/resource_snapshots/repo/books/20250315185359.json

@@ -0,0 +1,127 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"gen_random_uuid()\")",
+      "generated?": false,
+      "primary_key?": true,
+      "references": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "title",
+      "type": "text"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "description",
+      "type": "text"
+    },
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"(now() AT TIME ZONE 'utc')\")",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "inserted_at",
+      "type": "utc_datetime_usec"
+    },
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"(now() AT TIME ZONE 'utc')\")",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "updated_at",
+      "type": "utc_datetime_usec"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "primary_key?": false,
+      "references": {
+        "deferrable": false,
+        "destination_attribute": "id",
+        "destination_attribute_default": null,
+        "destination_attribute_generated": null,
+        "index?": false,
+        "match_type": null,
+        "match_with": null,
+        "multitenancy": {
+          "attribute": null,
+          "global": null,
+          "strategy": null
+        },
+        "name": "books_book_editions_registry_id_fkey",
+        "on_delete": null,
+        "on_update": null,
+        "primary_key?": true,
+        "schema": "public",
+        "table": "book_editions_registries"
+      },
+      "size": null,
+      "source": "book_editions_registry_id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": true,
+      "default": "nil",
+      "generated?": false,
+      "primary_key?": false,
+      "references": {
+        "deferrable": false,
+        "destination_attribute": "id",
+        "destination_attribute_default": null,
+        "destination_attribute_generated": null,
+        "index?": false,
+        "match_type": null,
+        "match_with": null,
+        "multitenancy": {
+          "attribute": null,
+          "global": null,
+          "strategy": null
+        },
+        "name": "books_publisher_id_fkey",
+        "on_delete": null,
+        "on_update": null,
+        "primary_key?": true,
+        "schema": "public",
+        "table": "publishers"
+      },
+      "size": null,
+      "source": "publisher_id",
+      "type": "uuid"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "300A3E949AD533F77BA317D27879A00127B75EF995918F065811DB96ED1BC6F8",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.DecentralisedBookIndex.Repo",
+  "schema": null,
+  "table": "books"
+}

priv/resource_snapshots/repo/publishers/20250315185359.json

@@ -0,0 +1,59 @@
+{
+  "attributes": [
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"gen_random_uuid()\")",
+      "generated?": false,
+      "primary_key?": true,
+      "references": null,
+      "size": null,
+      "source": "id",
+      "type": "uuid"
+    },
+    {
+      "allow_nil?": false,
+      "default": "nil",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "name",
+      "type": "text"
+    },
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"(now() AT TIME ZONE 'utc')\")",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "inserted_at",
+      "type": "utc_datetime_usec"
+    },
+    {
+      "allow_nil?": false,
+      "default": "fragment(\"(now() AT TIME ZONE 'utc')\")",
+      "generated?": false,
+      "primary_key?": false,
+      "references": null,
+      "size": null,
+      "source": "updated_at",
+      "type": "utc_datetime_usec"
+    }
+  ],
+  "base_filter": null,
+  "check_constraints": [],
+  "custom_indexes": [],
+  "custom_statements": [],
+  "has_create_action": true,
+  "hash": "B93F1B7B70B8C5407B5E7CACF23275E9B054BCF49D147940480E54C08C69CB21",
+  "identities": [],
+  "multitenancy": {
+    "attribute": null,
+    "global": null,
+    "strategy": null
+  },
+  "repo": "Elixir.DecentralisedBookIndex.Repo",
+  "schema": null,
+  "table": "publishers"
+}