wire Printful shipping rates into cart calculation

Add blueprint_id and print_provider_id to Printful provider_data so the
generic shipping calculator can look up rates. Fix v2 API request format
(order_items key) and response field names. Fetch one representative
variant per product to get accurate per-item rates.

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

lib/simpleshop_theme/clients/printful.ex

@@ -187,7 +187,7 @@ defmodule SimpleshopTheme.Clients.Printful do
       )
   """
   def calculate_shipping(recipient, items) do
-    post("/v2/shipping-rates", %{recipient: recipient, items: items})
+    post("/v2/shipping-rates", %{recipient: recipient, order_items: items})
   end
 
   # =============================================================================

lib/simpleshop_theme/providers/printful.ex

@@ -168,19 +168,22 @@ defmodule SimpleshopTheme.Providers.Printful do
 
     with api_key when is_binary(api_key) <- ProviderConnection.get_api_key(conn),
          :ok <- set_credentials(api_key, store_id) do
-      variant_ids = extract_catalog_variant_ids(products)
+      # Build per-product items: one representative variant per product
+      product_items = extract_per_product_items(products)
 
       Logger.info(
-        "Fetching Printful shipping rates for #{length(variant_ids)} catalogue variants"
+        "Fetching Printful shipping rates for #{length(product_items)} product(s), " <>
+          "#{length(target_countries())} countries"
       )
 
       rates =
-        target_countries()
+        for {catalog_product_id, variant_id} <- product_items,
-        |> Enum.with_index()
+            {country_code, _index} <- Enum.with_index(target_countries()),
-        |> Enum.flat_map(fn {country_code, index} ->
+            reduce: [] do
-          if index > 0, do: Process.sleep(100)
+          acc ->
-          fetch_rates_for_country(variant_ids, country_code, products)
+            if acc != [], do: Process.sleep(100)
-        end)
+            acc ++ fetch_rate_for_product(catalog_product_id, variant_id, country_code)
+        end
 
       {:ok, rates}
     else
@@ -193,30 +196,23 @@ defmodule SimpleshopTheme.Providers.Printful do
     ["GB", "US", "DE", "FR", "CA", "AU", "IE", "NL", "AT", "BE"]
   end
 
-  defp fetch_rates_for_country(variant_ids, country_code, products) do
+  defp fetch_rate_for_product(catalog_product_id, variant_id, country_code) do
-    items =
+    items = [%{source: "catalog", catalog_variant_id: variant_id, quantity: 1}]
-      Enum.map(variant_ids, fn vid ->
-        %{source: "catalog", catalog_variant_id: vid, quantity: 1}
-      end)
 
     case Client.calculate_shipping(%{country_code: country_code}, items) do
       {:ok, rates} when is_list(rates) ->
-        # Take the STANDARD rate (cheapest)
+        standard = Enum.find(rates, &(&1["shipping"] == "STANDARD")) || List.first(rates)
-        standard = Enum.find(rates, &(&1["id"] == "STANDARD")) || List.first(rates)
 
         if standard do
-          catalog_product_id = extract_first_catalog_product_id(products)
-          rate_cents = parse_price(standard["rate"])
-
           [
             %{
               blueprint_id: catalog_product_id,
               print_provider_id: 0,
               country_code: country_code,
-              first_item_cost: rate_cents,
+              first_item_cost: parse_price(standard["rate"]),
               additional_item_cost: 0,
               currency: String.upcase(standard["currency"] || "USD"),
-              handling_time_days: standard["maxDeliveryDays"]
+              handling_time_days: standard["max_delivery_days"]
             }
           ]
         else
@@ -232,33 +228,24 @@ defmodule SimpleshopTheme.Providers.Printful do
     end
   end
 
-  defp extract_catalog_variant_ids(products) do
+  # Returns {catalog_product_id, first_catalog_variant_id} per product
+  defp extract_per_product_items(products) do
     products
     |> Enum.flat_map(fn product ->
       provider_data = product[:provider_data] || %{}
 
+      catalog_product_id =
+        provider_data[:catalog_product_id] || provider_data["catalog_product_id"]
+
       catalog_variant_ids =
         provider_data[:catalog_variant_ids] || provider_data["catalog_variant_ids"] || []
 
-      if catalog_variant_ids == [] do
+      case {catalog_product_id, catalog_variant_ids} do
-        # Fall back to extracting from raw data
+        {nil, _} -> []
-        raw = provider_data[:raw] || provider_data["raw"] || %{}
+        {_, []} -> []
-        sync_variants = raw["sync_variants"] || raw[:sync_variants] || []
+        {cpid, [vid | _]} -> [{cpid, vid}]
-        Enum.map(sync_variants, fn sv -> sv["variant_id"] || sv[:variant_id] end)
-      else
-        catalog_variant_ids
       end
     end)
-    |> Enum.reject(&is_nil/1)
-    |> Enum.uniq()
-  end
-
-  defp extract_first_catalog_product_id(products) do
-    products
-    |> Enum.find_value(fn product ->
-      provider_data = product[:provider_data] || %{}
-      provider_data[:catalog_product_id] || provider_data["catalog_product_id"]
-    end) || 0
   end
 
   # =============================================================================
@@ -310,6 +297,9 @@ defmodule SimpleshopTheme.Providers.Printful do
       provider_data: %{
         catalog_product_id: catalog_product_id,
         catalog_variant_ids: catalog_variant_ids,
+        # Shipping calc uses these generic keys (shared with Printify)
+        blueprint_id: catalog_product_id,
+        print_provider_id: 0,
         thumbnail_url: sync_product["thumbnail_url"],
         options: build_option_types(sync_variants),
         raw: %{sync_product: sync_product}

test/simpleshop_theme/providers/printful_test.exs

@@ -178,6 +178,8 @@ defmodule SimpleshopTheme.Providers.PrintfulTest do
 
       # Provider data
       assert normalized.provider_data.catalog_product_id == 71
+      assert normalized.provider_data.blueprint_id == 71
+      assert normalized.provider_data.print_provider_id == 0
       assert is_list(normalized.provider_data.options)
       assert length(normalized.provider_data.catalog_variant_ids) == 4
     end
@@ -357,6 +359,8 @@ defmodule SimpleshopTheme.Providers.PrintfulTest do
       provider_data: %{
         catalog_product_id: catalog_product_id,
         catalog_variant_ids: catalog_variant_ids,
+        blueprint_id: catalog_product_id,
+        print_provider_id: 0,
         thumbnail_url: sync_product["thumbnail_url"],
         options: build_option_types(sync_variants),
         raw: %{sync_product: sync_product}