Unique slugs. Revert standard attribute definition to macro

Author: dev-guy

lib/geo/geography/country.ex

@@ -2,13 +2,13 @@ defmodule Geo.Geography.Country do
   use Ash.Resource,
     otp_app: :geo,
     domain: Geo.Geography,
-    data_layer: AshPostgres.DataLayer,
-    extensions: [Geo.Resources.Attributes.Id]
+    data_layer: AshPostgres.DataLayer
 
   # === Attributes ===
+  use Geo.Resources.Attributes.Id
+  use Geo.Resources.Attributes.Timestamps
   use Geo.Resources.Attributes.Name, allow_nil?: false, unique?: true
   use Geo.Resources.Attributes.Slug, allow_nil?: false, unique?: true
-  use Geo.Resources.Attributes.Timestamps
 
   attributes do
     attribute :iso_code, :ci_string do

lib/geo/resources/attributes/id.ex

@@ -1,32 +1,12 @@
 defmodule Geo.Resources.Attributes.Id do
   @moduledoc """
-  An Ash extension that adds a UUID v7 primary key attribute to a resource.
   """
 
-  use Spark.Dsl.Extension,
-    transformers: [
-      __MODULE__.Transformer
-    ]
-
-  defmodule Transformer do
-    @moduledoc false
-    use Spark.Dsl.Transformer
-
-    def before?(Ash.Resource.Transformers.BelongsToAttribute), do: true
-    def before?(_), do: false
-
-    def transform(dsl_state) do
-      attribute = %Ash.Resource.Attribute{
-        name: :id,
-        type: :uuid_v7,
-        allow_nil?: false,
-        writable?: false,
-        public?: true,
-        primary_key?: true,
-        default: &Ash.UUIDv7.generate/0
-      }
-
-      {:ok, Spark.Dsl.Transformer.add_entity(dsl_state, [:attributes], attribute)}
+  defmacro __using__(_opts) do
+    quote do
+      attributes do
+        uuid_v7_primary_key :id
+      end
     end
   end
 end

lib/geo/resources/changes/slugify_name.ex

@@ -28,15 +28,72 @@ defmodule Geo.Resources.Changes.SlugifyName do
 
       # If we have a name but no slug, generate one
       not is_nil(name) ->
-        generated_slug = slugify(name)
-        Ash.Changeset.force_change_attribute(changeset, :slug, generated_slug)
+        base_slug = slugify(name)
+        unique_slug = ensure_unique_slug(changeset, base_slug)
+        Ash.Changeset.force_change_attribute(changeset, :slug, unique_slug)
 
       # Otherwise, leave as is
       true ->
         changeset
     end
   end
 
+  defp ensure_unique_slug(changeset, base_slug) do
+    # Try base slug first
+    if !slug_exists?(changeset, base_slug) do
+      base_slug
+    else
+      find_unique_slug_with_number(changeset, base_slug)
+    end
+  end
+
+  defp find_unique_slug_with_number(changeset, base_slug) do
+    # Range 1: 1-9
+    case find_in_range(changeset, base_slug, 1..9) do
+      {:found, number} -> "#{base_slug}-#{number}"
+      :not_found ->
+        # Range 2: 1-99  
+        case find_in_range(changeset, base_slug, 1..99) do
+          {:found, number} -> "#{base_slug}-#{number}"
+          :not_found ->
+            # Range 3: 1-9999
+            case find_in_range(changeset, base_slug, 1..9999) do
+              {:found, number} -> "#{base_slug}-#{number}"
+              :not_found -> raise "Could not find unique slug after trying up to 9999"
+            end
+        end
+    end
+  end
+
+  defp find_in_range(changeset, base_slug, range) do
+    Enum.find_value(range, :not_found, fn number ->
+      slug_candidate = "#{base_slug}-#{number}"
+      if !slug_exists?(changeset, slug_candidate) do
+        {:found, number}
+      end
+    end)
+  end
+
+  defp slug_exists?(changeset, slug) do
+    resource = changeset.resource
+    query = Ash.Query.filter(resource, slug: slug)
+    
+    # Exclude the current record if it's an update
+    query =
+      case changeset.data do
+        %{id: id} when not is_nil(id) ->
+          Ash.Query.filter(query, id != ^id)
+        _ ->
+          query
+      end
+    
+    case Ash.read(query) do
+      {:ok, []} -> false
+      {:ok, _} -> true
+      {:error, _} -> false
+    end
+  end
+
   defp slugify(text) when is_binary(text) do
     text
     |> String.downcase()