very first commit

src/app/services/cart.service.ts

@@ -0,0 +1,217 @@
+import { Injectable, signal, computed, effect } from '@angular/core';
+import { ApiService } from './api.service';
+import { Item, CartItem } from '../models';
+import type { } from '../types/telegram.types';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class CartService {
+  private readonly STORAGE_KEY = 'dexarmarket_cart';
+  private cartItems = signal<CartItem[]>([]);
+  private isTelegram = typeof window !== 'undefined' && !!window.Telegram?.WebApp;
+  
+  items = this.cartItems.asReadonly();
+  itemCount = computed(() => {
+    const items = this.cartItems();
+    if (!Array.isArray(items)) return 0;
+    return items.reduce((total, item) => total + item.quantity, 0);
+  });
+  totalPrice = computed(() => {
+    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);
+    }, 0);
+  });
+
+  constructor(private apiService: ApiService) {
+    this.loadCart();
+    
+    // Auto-save whenever cart changes
+    effect(() => {
+      const items = this.cartItems();
+      this.saveToStorage(items);
+    });
+  }
+
+  private saveToStorage(items: CartItem[]): void {
+    const data = JSON.stringify(items);
+    
+    // Always save to sessionStorage
+    sessionStorage.setItem(this.STORAGE_KEY, data);
+    
+    // Also save to Telegram CloudStorage if available
+    if (this.isTelegram) {
+      window.Telegram!.WebApp.CloudStorage.setItem(this.STORAGE_KEY, data, (err) => {
+        if (err) {
+          console.error('Error saving to Telegram CloudStorage:', err);
+        }
+      });
+    }
+  }
+
+  private loadCart(): void {
+    if (this.isTelegram) {
+      // Load from Telegram CloudStorage first
+      window.Telegram!.WebApp.CloudStorage.getItem(this.STORAGE_KEY, (err, value) => {
+        if (err) {
+          console.error('Error loading from Telegram CloudStorage:', err);
+          this.loadFromSessionStorage();
+        } else if (value) {
+          try {
+            const items = JSON.parse(value);
+            if (Array.isArray(items)) {
+              // Migrate old items without quantity field
+              const migratedItems: CartItem[] = items.map(item => ({
+                ...item,
+                quantity: item.quantity || 1
+              }));
+              this.cartItems.set(migratedItems);
+            } else {
+              this.cartItems.set([]);
+            }
+          } catch (parseErr) {
+            console.error('Error parsing cart data:', parseErr);
+            this.loadFromSessionStorage();
+          }
+        } else {
+          // No data in CloudStorage, try sessionStorage
+          this.loadFromSessionStorage();
+        }
+      });
+    } else {
+      // Load from sessionStorage
+      this.loadFromSessionStorage();
+    }
+
+    // API version (commented out)
+    // this.apiService.getCart().subscribe({
+    //   next: (items) => {
+    //     console.log('Cart response:', items);
+    //     if (Array.isArray(items)) {
+    //       this.cartItems.set(items);
+    //     } else {
+    //       console.error('Cart response is not an array:', items);
+    //       this.cartItems.set([]);
+    //     }
+    //   },
+    //   error: (err) => console.error('Error loading cart:', err)
+    // });
+  }
+
+  private loadFromSessionStorage(): void {
+    const stored = sessionStorage.getItem(this.STORAGE_KEY);
+    if (stored) {
+      try {
+        const items = JSON.parse(stored);
+        if (Array.isArray(items)) {
+          // Migrate old items without quantity field
+          const migratedItems: CartItem[] = items.map(item => ({
+            ...item,
+            quantity: item.quantity || 1
+          }));
+          this.cartItems.set(migratedItems);
+        } else {
+          this.cartItems.set([]);
+        }
+      } catch (err) {
+        console.error('Error parsing cart from sessionStorage:', err);
+        this.cartItems.set([]);
+      }
+    } else {
+      this.cartItems.set([]);
+    }
+  }
+
+  addItem(itemID: number, quantity: number = 1): void {
+    const currentItems = this.cartItems();
+    const existingItem = currentItems.find(i => i.itemID === itemID);
+    
+    if (existingItem) {
+      // Item exists, increase quantity
+      this.updateQuantity(itemID, existingItem.quantity + quantity);
+    } else {
+      // Get item details from API and add to cart
+      this.apiService.getItem(itemID).subscribe({
+        next: (item) => {
+          const cartItem: CartItem = { ...item, quantity };
+          this.cartItems.set([...this.cartItems(), cartItem]);
+        },
+        error: (err) => {
+          console.error('Error adding to cart:', err);
+          alert('Ошибка добавления в корзину: ' + (err.error?.message || err.message));
+        }
+      });
+    }
+
+    // API version (commented out)
+    // this.apiService.addToCart(itemID, quantity).subscribe({
+    //   next: (response) => {
+    //     console.log('Item added to cart:', response);
+    //     this.loadCart();
+    //   },
+    //   error: (err) => {
+    //     console.error('Error adding to cart:', err);
+    //     alert('Ошибка добавления в корзину: ' + (err.error?.message || err.message));
+    //   }
+    // });
+  }
+
+  updateQuantity(itemID: number, quantity: number): void {
+    if (quantity <= 0) {
+      this.removeItem(itemID);
+      return;
+    }
+    
+    const currentItems = this.cartItems();
+    const updatedItems = currentItems.map(item =>
+      item.itemID === itemID ? { ...item, quantity } : item
+    );
+    this.cartItems.set(updatedItems);
+
+    // API version (commented out)
+    // this.apiService.updateCartQuantity(itemID, quantity).subscribe({
+    //   next: (response) => {
+    //     console.log('Quantity updated:', response);
+    //     this.loadCart();
+    //   },
+    //   error: (err) => {
+    //     console.error('Error updating quantity:', err);
+    //   }
+    // });
+  }
+
+  removeItems(itemIDs: number[]): void {
+    const currentItems = this.cartItems();
+    const updatedItems = currentItems.filter(item => !itemIDs.includes(item.itemID));
+    this.cartItems.set(updatedItems);
+
+    // API version (commented out)
+    // this.apiService.removeFromCart(itemIDs).subscribe({
+    //   next: (response) => {
+    //     console.log('Items removed from cart:', response);
+    //     this.loadCart();
+    //   },
+    //   error: (err) => {
+    //     console.error('Error removing from cart:', err);
+    //     alert('Ошибка удаления из корзины: ' + (err.error?.message || err.message));
+    //   }
+    // });
+  }
+
+  removeItem(itemID: number): void {
+    this.removeItems([itemID]);
+  }
+
+  clearCart(): void {
+    this.cartItems.set([]);
+    
+    // API version (commented out)
+    // const itemIDs = this.cartItems().map(item => item.itemID);
+    // if (itemIDs.length > 0) {
+    //   this.removeItems(itemIDs);
+    // }
+  }
+}