Feature Built: Authentication, Cart, Product Catalog, Coupons and Sponsored Ads

[prabhu30]

Implements five Valkey-powered backend subsystems with matching frontend integration for the Build Beyond Limits hackathon.

Challenge 1: User Authentication

• Session tokens stored in Valkey (SET session:{token} {userId} EX 86400)
• Passwords hashed with bcrypt (cost 12); user docs via JSON.SET
• Rate limiting on failed logins (INCR login_attempts:{email})
• Concurrent session tracking with SADD; POST /api/auth/refresh extends TTL
• Frontend: AuthContext, login/register/profile UI in Account.jsx, headers show logged-in user

Challenge 2: Product Catalog

• Products, categories, vendors stored as JSON docs (JSON.SET product:{id})
• Sorted sets for price index and category membership; sets for brand/vendor indexes
• 12 products × 4 root categories (17 total with 2-level nesting) seeded via POST /api/seed
• Filtering by category, price range, brand; cursor-based pagination
• Frontend: all product listing components fetch live catalog data

Challenge 3: Shopping Cart with Coupons

• Cart as Valkey Hash (HSET cart:{userId} {productId} {qty}) with 7-day TTL
• Guest carts via X-Guest-Id header; merge on login (POST /api/cart/merge)
• 4 coupons seeded with full validation: expiry, min order, per-user usage (SISMEMBER coupon_used:{code}),
  category restrictions
• Global usage count via JSON.NUMINCRBY
• Frontend: CartContext with auto-merge on login; live cart badge in both headers

Challenge 4: Trending Products

• Weighted event scoring: view=1, add-to-cart=3, purchase=5
• Three sliding windows (1h/6h/24h) via ZINCRBY trending:global:{window} + EXPIRE
• Category-level trending in parallel (trending:category:{id}:{window})
• Frontend: TrendingOne rewritten — live data, time-window tabs, category tabs, scores shown on cards

Challenge 5: Ads

• Ad creatives stored via JSON.SET ad:{uuidv7}
• Bid-ranked indexes: ZADD ads:global {bid} {adId} + ZADD ads:category:{catId} {bid} {adId}
• Daily budget enforcement via INCRBY ad_spend:{adId}:{date} (stops serving when exhausted)
• Impression/click tracking per ad per day (INCR, EXPIRE 86400)
• Frequency capping: server-side per-user/day (INCR ad_freq:{userId}:{adId}:{date}), client-side per-session
  (sessionStorage, cap=3)
• 5 sample ads seeded (POST /api/seed/ads)
• Frontend: AdBanner component — fires impression on mount, click on interaction, "Sponsored" label; placed
  on home page (global) and shop page (category-targeted)

Challenge 6: Full-Text Search

Implemented product search with full-text capabilities using the Valkey Search module, supporting autocomplete, typo tolerance, and faceted filtering.

• Index Creation — Search index built on product JSON documents covering name, description, brand, tags, category, and price fields
• Query Support — Full-text queries with stemming, prefix matching, and fuzzy matching for typo tolerance
• Faceted Search — Aggregated counts returned by category, brand, and price range alongside search results
• Autocomplete — Prefix-based search suggestions as the user types
• Sorting — Results sortable by relevance, price (asc/desc), rating, and newest