better

cmd/cart/mutation_add_item.go

@@ -20,63 +20,57 @@ import (
 // NOTE: Any future field additions in messages.AddItem that affect pricing / tax
 // must keep this handler in sync.
 
-func init() {
-	RegisterMutation[messages.AddItem](
-		"AddItem",
-		func(g *CartGrain, m *messages.AddItem) error {
-			if m == nil {
-				return fmt.Errorf("AddItem: nil payload")
-			}
-			if m.Quantity < 1 {
-				return fmt.Errorf("AddItem: invalid quantity %d", m.Quantity)
-			}
+func AddItem(g *CartGrain, m *messages.AddItem) error {
+	if m == nil {
+		return fmt.Errorf("AddItem: nil payload")
+	}
+	if m.Quantity < 1 {
+		return fmt.Errorf("AddItem: invalid quantity %d", m.Quantity)
+	}
 
-			// Fast path: merge with existing item having same SKU
-			if existing, found := g.FindItemWithSku(m.Sku); found {
-				existing.Quantity += int(m.Quantity)
-				return nil
-			}
+	// Fast path: merge with existing item having same SKU
+	if existing, found := g.FindItemWithSku(m.Sku); found {
+		existing.Quantity += int(m.Quantity)
+		return nil
+	}
 
-			g.mu.Lock()
-			defer g.mu.Unlock()
+	g.mu.Lock()
+	defer g.mu.Unlock()
 
-			g.lastItemId++
-			taxRate := 2500
-			if m.Tax > 0 {
-				taxRate = int(m.Tax)
-			}
-			taxAmountPerUnit := GetTaxAmount(m.Price, taxRate)
+	g.lastItemId++
+	taxRate := 2500
+	if m.Tax > 0 {
+		taxRate = int(m.Tax)
+	}
+	taxAmountPerUnit := GetTaxAmount(m.Price, taxRate)
 
-			g.Items = append(g.Items, &CartItem{
-				Id:          g.lastItemId,
-				ItemId:      int(m.ItemId),
-				Quantity:    int(m.Quantity),
-				Sku:         m.Sku,
-				Name:        m.Name,
-				Price:       m.Price,
-				TotalPrice:  m.Price * int64(m.Quantity),
-				TotalTax:    int64(taxAmountPerUnit * int64(m.Quantity)),
-				Image:       m.Image,
-				Stock:       StockStatus(m.Stock),
-				Disclaimer:  m.Disclaimer,
-				Brand:       m.Brand,
-				Category:    m.Category,
-				Category2:   m.Category2,
-				Category3:   m.Category3,
-				Category4:   m.Category4,
-				Category5:   m.Category5,
-				OrgPrice:    m.OrgPrice,
-				ArticleType: m.ArticleType,
-				Outlet:      m.Outlet,
-				SellerId:    m.SellerId,
-				SellerName:  m.SellerName,
-				Tax:         int(taxAmountPerUnit),
-				TaxRate:     taxRate,
-				StoreId:     m.StoreId,
-			})
+	g.Items = append(g.Items, &CartItem{
+		Id:          g.lastItemId,
+		ItemId:      int(m.ItemId),
+		Quantity:    int(m.Quantity),
+		Sku:         m.Sku,
+		Name:        m.Name,
+		Price:       m.Price,
+		TotalPrice:  m.Price * int64(m.Quantity),
+		TotalTax:    int64(taxAmountPerUnit * int64(m.Quantity)),
+		Image:       m.Image,
+		Stock:       StockStatus(m.Stock),
+		Disclaimer:  m.Disclaimer,
+		Brand:       m.Brand,
+		Category:    m.Category,
+		Category2:   m.Category2,
+		Category3:   m.Category3,
+		Category4:   m.Category4,
+		Category5:   m.Category5,
+		OrgPrice:    m.OrgPrice,
+		ArticleType: m.ArticleType,
+		Outlet:      m.Outlet,
+		SellerId:    m.SellerId,
+		SellerName:  m.SellerName,
+		Tax:         int(taxAmountPerUnit),
+		TaxRate:     taxRate,
+		StoreId:     m.StoreId,
+	})
 
-			return nil
-		},
-		WithTotals(), // Recalculate totals after successful mutation
-	)
+	return nil
 }