feat: implement catalog service and product attribute selector component for product details

src/app/core/services/api-response.interface.ts

@@ -1,3 +1,5 @@
 export interface ApiResponse<T> {
   data: T;
+  message?: string;
+  errors?: Record<string, string[]>;
 }

src/app/core/services/catalog/catalog.service.ts

@@ -35,9 +35,14 @@ export class CatalogService {
     );
   }
 
-  getProducto(id: number): Observable<ProductDetail> {
+  getProducto(id: number, variantId?: number): Observable<ProductDetail> {
+    let params = new HttpParams();
+    if (variantId) {
+      params = params.set('variant_id', variantId);
+    }
+    
     return this.http
-      .get<ApiResponse<ProductDetail>>(`${this.tenantApiUrl}/productos/${id}`)
+      .get<ApiResponse<ProductDetail>>(`${this.tenantApiUrl}/productos/${id}`, { params })
       .pipe(map((response) => response.data));
   }
 

src/app/features/store/components/product-attribute-selector/product-attribute-selector.component.ts

@@ -77,6 +77,10 @@ export class ProductAttributeSelectorComponent {
     return availability;
   });
 
+  public reset(): void {
+    this.initializeSelections(this.attributes(), this.defaultVariant());
+  }
+
   constructor() {
     effect(() => {
       const attributes = this.attributes();

src/app/features/store/pages/product-detail-page/product-detail-page.component.html

@@ -81,13 +81,21 @@
                     class="product-detail__cta"
                     variant="secondary"
                     type="button"
-                    [disabled]="!selectedVariant()"
+                    [disabled]="!selectedVariant() || variantLoading()"
                   >
-                    Agregar al carrito
+                    @if (variantLoading()) {
+                      <div class="spinner-border spinner-border-sm" role="status"></div>
+                    } @else {
+                      Agregar al carrito
+                    }
                   </app-button>
 
-                  <app-button class="product-detail__cta" type="button" [disabled]="!selectedVariant()">
-                    Comprar
+                  <app-button class="product-detail__cta" type="button" [disabled]="!selectedVariant() || variantLoading()">
+                    @if (variantLoading()) {
+                      <div class="spinner-border spinner-border-sm" role="status"></div>
+                    } @else {
+                      Comprar
+                    }
                   </app-button>
                 </div>
               </div>

src/app/features/store/pages/product-detail-page/product-detail-page.component.ts

@@ -12,10 +12,12 @@ import {
   PLATFORM_ID
 } from '@angular/core';
 import { CommonModule, isPlatformBrowser } from '@angular/common';
+import { HttpErrorResponse } from '@angular/common/http';
 import { ActivatedRoute, Router, RouterModule } from '@angular/router';
 import { Subscription } from 'rxjs';
 
 import { CatalogService } from '../../../../core/services/catalog/catalog.service';
+import { ToastService } from '../../../../core/services/toast.service';
 import {
   ProductAttribute,
   ProductAttributeOption,
@@ -39,6 +41,8 @@ export class ProductDetailPageComponent implements OnInit, OnDestroy {
   private readonly route = inject(ActivatedRoute);
   private readonly router = inject(Router);
   private readonly catalogService = inject(CatalogService);
+  private readonly toastService = inject(ToastService);
+  private readonly attributeSelector = viewChild(ProductAttributeSelectorComponent);
   private readonly carouselHost = viewChild<ElementRef<HTMLElement>>('carouselHost');
   private readonly descriptionBody = viewChild<ElementRef<HTMLElement>>('descriptionBody');
   private readonly platformId = inject(PLATFORM_ID);
@@ -63,6 +67,7 @@ export class ProductDetailPageComponent implements OnInit, OnDestroy {
     return [];
   });
   protected readonly loading = signal(false);
+  protected readonly variantLoading = signal(false);
   protected readonly error = signal<string | null>(null);
   protected readonly selectedVariant = signal<ProductVariantMap | null>(null);
   protected readonly quantity = signal(1);
@@ -136,6 +141,39 @@ export class ProductDetailPageComponent implements OnInit, OnDestroy {
     });
   }
 
+  private loadProductVariant(productId: number, variantId: number): void {
+    this.variantLoading.set(true);
+
+    this.productSub?.unsubscribe();
+    this.productSub = this.catalogService.getProducto(productId, variantId).subscribe({
+      next: (prod) => {
+        this.product.set(prod);
+        this.variantLoading.set(false);
+      },
+      error: (err: HttpErrorResponse) => {
+        const errorMessage = err.error?.message || 'No pudimos cargar la variante seleccionada.';
+        this.toastService.danger(errorMessage);
+        this.variantLoading.set(false);
+
+        this.product.update((currentProduct) => {
+          if (!currentProduct) return null;
+          const updatedVariantsMap = currentProduct.variants_map.map((v) => {
+            if (v.variant_id === variantId) {
+              return { ...v, stock: 0 };
+            }
+            return v;
+          });
+          return {
+            ...currentProduct,
+            variants_map: updatedVariantsMap
+          };
+        });
+
+        this.attributeSelector()?.reset();
+      }
+    });
+  }
+
   protected goBack(): void {
     this.router.navigate(['/']);
   }
@@ -151,10 +189,19 @@ export class ProductDetailPageComponent implements OnInit, OnDestroy {
   }
 
   protected onVariantChange(variant: ProductVariantMap | null): void {
+    if (this.selectedVariant()?.variant_id === variant?.variant_id) {
+      return;
+    }
+
     this.selectedVariant.set(variant);
     if (variant && this.quantity() > variant.stock) {
       this.quantity.set(Math.max(1, variant.stock));
     }
+
+    const currentProduct = this.product();
+    if (variant && currentProduct && currentProduct.variant?.id !== variant.variant_id) {
+      this.loadProductVariant(currentProduct.id, variant.variant_id);
+    }
   }
 
   protected increaseQuantity(): void {