optimising and making it better

src/app/services/cart.service.ts

@@ -1,6 +1,7 @@
 import { Injectable, signal, computed, effect } from '@angular/core';
 import { ApiService } from './api.service';
 import { Item, CartItem } from '../models';
+import { getDiscountedPrice } from '../utils/item.utils';
 import { environment } from '../../environments/environment';
 import type { } from '../types/telegram.types';
 
@@ -11,6 +12,7 @@ export class CartService {
   private readonly STORAGE_KEY = `${environment.brandName.toLowerCase().replace(/\s+/g, '_')}_cart`;
   private cartItems = signal<CartItem[]>([]);
   private isTelegram = typeof window !== 'undefined' && !!window.Telegram?.WebApp;
+  private addingItems = new Set<number>();
   
   items = this.cartItems.asReadonly();
   itemCount = computed(() => {
@@ -22,8 +24,7 @@ export class CartService {
     const items = this.cartItems();
     if (!Array.isArray(items)) return 0;
     return items.reduce((total, item) => {
-      const price = item.price * (1 - item.discount / 100);
-      return total + (price * item.quantity);
+      return total + (getDiscountedPrice(item) * item.quantity);
     }, 0);
   });
 
@@ -40,8 +41,8 @@ export class CartService {
   private saveToStorage(items: CartItem[]): void {
     const data = JSON.stringify(items);
     
-    // Always save to sessionStorage
-    sessionStorage.setItem(this.STORAGE_KEY, data);
+    // Always save to localStorage
+    localStorage.setItem(this.STORAGE_KEY, data);
     
     // Also save to Telegram CloudStorage if available
     if (this.isTelegram) {
@@ -59,21 +60,21 @@ export class CartService {
       window.Telegram!.WebApp.CloudStorage.getItem(this.STORAGE_KEY, (err, value) => {
         if (err) {
           console.error('Error loading from Telegram CloudStorage:', err);
-          this.loadFromSessionStorage();
+          this.loadFromLocalStorage();
         } else if (value) {
-          this.parseAndSetCart(value) || this.loadFromSessionStorage();
+          this.parseAndSetCart(value) || this.loadFromLocalStorage();
         } else {
-          // No data in CloudStorage, try sessionStorage
-          this.loadFromSessionStorage();
+          // No data in CloudStorage, try localStorage
+          this.loadFromLocalStorage();
         }
       });
     } else {
-      this.loadFromSessionStorage();
+      this.loadFromLocalStorage();
     }
   }
 
-  private loadFromSessionStorage(): void {
-    const stored = sessionStorage.getItem(this.STORAGE_KEY);
+  private loadFromLocalStorage(): void {
+    const stored = localStorage.getItem(this.STORAGE_KEY);
     if (stored) {
       this.parseAndSetCart(stored);
     }
@@ -98,6 +99,9 @@ export class CartService {
   }
 
   addItem(itemID: number, quantity: number = 1): void {
+    // Prevent duplicate API calls for same item
+    if (this.addingItems.has(itemID)) return;
+    
     const currentItems = this.cartItems();
     const existingItem = currentItems.find(i => i.itemID === itemID);
     
@@ -106,14 +110,16 @@ export class CartService {
       this.updateQuantity(itemID, existingItem.quantity + quantity);
     } else {
       // Get item details from API and add to cart
+      this.addingItems.add(itemID);
       this.apiService.getItem(itemID).subscribe({
         next: (item) => {
           const cartItem: CartItem = { ...item, quantity };
           this.cartItems.set([...this.cartItems(), cartItem]);
+          this.addingItems.delete(itemID);
         },
         error: (err) => {
           console.error('Error adding to cart:', err);
-          alert('Ошибка добавления в корзину: ' + (err.error?.message || err.message));
+          this.addingItems.delete(itemID);
         }
       });
     }