Feat: Adding Backfill Skus to the Migrate Import Job

src/Catalog/Services/SkuBackfillService.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace Modules\Core\Catalog\Services;
+
+use Lunar\Models\ProductVariant;
+
+/**
+ * Generates a SKU for every ProductVariant missing one — extracted out of
+ * Command\BackfillMissingSkusCommand (which becomes a thin CLI wrapper
+ * around this, keeping --dry-run/progress-bar concerns out of the
+ * reusable logic) so MigrateImport\RunMigrateImportJob can also call it
+ * directly, right after a Shopify import, with no CLI concerns at all.
+ *
+ * Format is "SKU-P{product_id}-V{variant_id}": deterministic and
+ * guaranteed unique without a uniqueness check, since product_id/
+ * variant_id already are. Only variants with a null `sku` are touched —
+ * not an importer bug when one shows up after a Shopify import, the
+ * source CSV rows genuinely had no `Variant SKU` value (see
+ * MigrateImport\Shopify\ShopifyExportImporter).
+ */
+class SkuBackfillService
+{
+    /**
+     * @param  ?callable(ProductVariant, string): void  $onEach  invoked
+     *   once per variant with the sku about to be written (or, when
+     *   $dryRun is true, that WOULD be written) — the command's own
+     *   --dry-run listing and progress bar hook in here without this
+     *   service knowing anything about console output.
+     * @return int the number of variants processed
+     */
+    public function backfill(bool $dryRun = false, ?callable $onEach = null): int
+    {
+        $query = ProductVariant::query()->whereNull('sku');
+        $total = $query->count();
+
+        if ($total === 0) {
+            return 0;
+        }
+
+        $query->chunkById(500, function ($variants) use ($dryRun, $onEach) {
+            foreach ($variants as $variant) {
+                $sku = "SKU-P{$variant->product_id}-V{$variant->id}";
+
+                if (! $dryRun) {
+                    $variant->update(['sku' => $sku]);
+                }
+
+                if ($onEach !== null) {
+                    $onEach($variant, $sku);
+                }
+            }
+        });
+
+        return $total;
+    }
+}