feat(F-102): completed feature

project/src/modules/checkout/api/checkout.routes.ts

@@ -57,6 +57,19 @@ export async function registerCheckoutRoutes(
     orderLookup,
     metrics,
     tracer,
+    getCartWeightKg: async (items) => {
+      if (items.length === 0) return 0;
+      const productIds = [...new Set(items.map((item) => item.productId))];
+      const result = await deps.pool.query<{ id: string; unit_weight_kg: string | number }>(
+        `SELECT id, unit_weight_kg FROM catalog_products WHERE id = ANY($1::uuid[])`,
+        [productIds],
+      );
+      const weights = new Map(result.rows.map((row) => [row.id, Number(row.unit_weight_kg ?? 1)]));
+      return items.reduce(
+        (total, item) => total + (weights.get(item.productId) ?? 1) * item.quantity,
+        0,
+      );
+    },
   });
 
   const checkoutSchema: FastifySchema = {

project/src/modules/checkout/application/checkout-service.ts

@@ -27,6 +27,10 @@ export interface CheckoutServiceDeps {
   orderLookup: CheckoutOrderLookup;
   metrics: CheckoutMetrics;
   tracer?: Tracer;
+  /** Peso total del carrito en kg (cantidad × peso unitario del producto). */
+  getCartWeightKg?: (
+    items: Array<{ productId: string; quantity: number }>,
+  ) => Promise<number>;
 }
 
 export interface CheckoutCommand {
@@ -132,8 +136,18 @@ export class CheckoutService {
         }
       }
 
+      const cartWeightKg = this.deps.getCartWeightKg
+        ? await this.deps.getCartWeightKg(
+            cart.items.map((item) => ({ productId: item.productId, quantity: item.quantity })),
+          ).catch(() => 0)
+        : 0;
+
       const shipping = await this.deps.shipping
-        .calculate(Math.max(0, netSubtotalCents + taxCents - discountCents), command.address)
+        .calculate(
+          Math.max(0, netSubtotalCents + taxCents - discountCents),
+          command.address,
+          cartWeightKg,
+        )
         .catch((error: unknown) => {
           if (error instanceof Error && error.name === 'ShippingZoneNotFoundError') return null;
           throw error;