94 lines
2.7 KiB
TypeScript
94 lines
2.7 KiB
TypeScript
import { Injectable } from '@nestjs/common';
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import { CacheService } from 'src/modules/utils/cache.service';
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import { roundQuantity } from 'src/modules/products/utils/quantity.utils';
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import { Cart } from '../interfaces/cart.interface';
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@Injectable()
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export class CartRepository {
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private readonly CART_TTL = 3600; // 1 hour in seconds
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private readonly CART_KEY_PREFIX = 'cart';
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constructor(private readonly cacheService: CacheService) { }
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/**
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* Get cart by user and shop
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*/
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async findByUserAndShop(userId: string, shopId: string): Promise<Cart | null> {
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const cacheKey = this.getCacheKey(userId, shopId);
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const cachedCart = await this.cacheService.get<string>(cacheKey);
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if (cachedCart) {
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try {
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const parsed: unknown = JSON.parse(cachedCart);
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if (this.isCart(parsed) && parsed.userId === userId && parsed.shopId === shopId) {
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return this.normalizeCartQuantities(parsed);
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}
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} catch {
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// If parsing fails, return null
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}
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}
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return null;
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}
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/**
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* Save cart to cache
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*/
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async save(cart: Cart): Promise<void> {
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const cacheKey = this.getCacheKey(cart.userId, cart.shopId);
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await this.cacheService.set(cacheKey, JSON.stringify(cart), this.CART_TTL);
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}
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/**
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* Delete cart from cache
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*/
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async delete(userId: string, shopId: string): Promise<void> {
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const cacheKey = this.getCacheKey(userId, shopId);
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await this.cacheService.del(cacheKey);
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}
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/**
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* Generate cache key for cart
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*/
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private getCacheKey(userId: string, shopId: string): string {
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return `${this.CART_KEY_PREFIX}:${userId}:${shopId}`;
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}
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/**
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* Coerce cached item quantities to numbers (guards against string concat bugs).
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*/
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private normalizeCartQuantities(cart: Cart): Cart {
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for (const item of cart.items) {
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item.quantity = roundQuantity(item.quantity);
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}
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cart.totalItems = roundQuantity(cart.totalItems);
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return cart;
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}
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/**
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* Type guard to check if an object is a Cart
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*/
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private isCart(obj: unknown): obj is Cart {
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if (typeof obj !== 'object' || obj === null) {
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return false;
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}
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const cart = obj as Record<string, unknown>;
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return (
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typeof cart.userId === 'string' &&
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typeof cart.shopId === 'string' &&
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Array.isArray(cart.items) &&
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typeof cart.subTotal === 'number' &&
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typeof cart.itemsDiscount === 'number' &&
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typeof cart.couponDiscount === 'number' &&
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typeof cart.totalDiscount === 'number' &&
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typeof cart.tax === 'number' &&
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typeof cart.deliveryFee === 'number' &&
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typeof cart.total === 'number' &&
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typeof cart.totalItems === 'number' &&
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typeof cart.createdAt === 'string' &&
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typeof cart.updatedAt === 'string'
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);
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}
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}
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