filter Printify options to enabled variants and order by hero colour

Printify's API returns all blueprint option values (e.g. 21 colours)
even when only a few are enabled as variants. This caused the PDP to
show phantom colour swatches with no images or purchasable variants.

Now filter_options_by_variants strips option values to only those with
enabled variants, ordered by first appearance so the hero/default
colour leads the swatch list.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/simpleshop_theme/providers/printify.ex

@@ -338,6 +338,7 @@ defmodule SimpleshopTheme.Providers.Printify do
     options = raw["options"] || []
     raw_variants = raw["variants"] || []
     color_lookup = build_image_color_lookup(raw_variants, options)
+    filtered_options = filter_options_by_variants(options, raw_variants)
 
     %{
       provider_product_id: to_string(raw["id"]),
@@ -350,7 +351,7 @@ defmodule SimpleshopTheme.Providers.Printify do
         blueprint_id: raw["blueprint_id"],
         print_provider_id: raw["print_provider_id"],
         tags: raw["tags"] || [],
-        options: options,
+        options: filtered_options,
         raw: raw
       }
     }
@@ -382,6 +383,59 @@ defmodule SimpleshopTheme.Providers.Printify do
     end)
   end
 
+  # Filter blueprint options to only include values present in enabled variants,
+  # ordered to match variant ordering (so the default variant's colour comes first).
+  defp filter_options_by_variants(options, raw_variants) do
+    enabled_order = enabled_option_value_order(options, raw_variants)
+
+    Enum.map(options, fn opt ->
+      name = opt["name"]
+
+      case Map.get(enabled_order, name) do
+        nil ->
+          opt
+
+        ordered_values ->
+          values_by_title = Map.new(opt["values"] || [], fn v -> {v["title"], v} end)
+
+          sorted =
+            ordered_values
+            |> Enum.map(&Map.get(values_by_title, &1))
+            |> Enum.reject(&is_nil/1)
+
+          Map.put(opt, "values", sorted)
+      end
+    end)
+  end
+
+  # Returns %{"Colors" => ["Dark Heather", "Navy", ...], "Sizes" => ["S", "2XL"]}
+  # preserving first-seen order from enabled variants.
+  defp enabled_option_value_order(options, raw_variants) do
+    option_names = Enum.map(options, & &1["name"])
+
+    raw_variants
+    |> Enum.filter(& &1["is_enabled"])
+    |> Enum.reduce(%{}, fn var, acc ->
+      parts = String.split(var["title"] || "", " / ")
+
+      option_names
+      |> Enum.with_index()
+      |> Enum.reduce(acc, fn {name, idx}, inner_acc ->
+        case Enum.at(parts, idx) do
+          nil ->
+            inner_acc
+
+          val ->
+            existing = Map.get(inner_acc, name, [])
+
+            if val in existing,
+              do: inner_acc,
+              else: Map.put(inner_acc, name, existing ++ [val])
+        end
+      end)
+    end)
+  end
+
   defp build_image_color_lookup(raw_variants, options) do
     option_names = Enum.map(options, & &1["name"])
     color_index = Enum.find_index(option_names, &(&1 in ["Colors", "Color"]))