Implemented a complete shopping cart system with database persistence,
replacing the previous stub implementation. The cart now properly stores
items across sessions and follows the project's architecture patterns.
Database Changes:
- Add cart_items table with vendor_id, session_id, product_id, quantity, price_at_add
- Create unique constraint to prevent duplicate items per session
- Add indexes for session lookups and old cart cleanup
- Run migration a2064e1dfcd4 to create cart_items table
New Models & Schemas:
- models/database/cart.py: CartItem SQLAlchemy model with relationships
- models/schema/cart.py: Pydantic schemas for requests/responses
* AddToCartRequest, UpdateCartItemRequest
* CartResponse, CartItemResponse, CartOperationResponse, ClearCartResponse
Exception Handling:
- app/exceptions/cart.py: Cart-specific exceptions following project patterns
* CartItemNotFoundException - item not found in cart
* InsufficientInventoryForCartException - not enough inventory for cart operation
* InvalidCartQuantityException - invalid quantity validation
* CartValidationException - general cart validation
* EmptyCartException - operations on empty cart
* ProductNotAvailableForCartException - product unavailable
- Updated app/exceptions/__init__.py to export cart exceptions
Service Layer:
- Implement cart_service.get_cart() - fetch cart from database with totals
- Implement cart_service.add_to_cart() - create or update cart items with inventory checks
- Implement cart_service.update_cart_item() - update quantity with validation
- Implement cart_service.remove_from_cart() - delete cart item
- Implement cart_service.clear_cart() - remove all items for session
- Replace generic exceptions with cart-specific ones
- Fix InsufficientInventoryException usage (was using wrong parameters)
API Layer:
- Update app/api/v1/shop/cart.py to use Pydantic schemas
- Add response_model declarations to all endpoints
- Add return type hints for type safety
- Convert service dict responses to Pydantic models
Features:
- Cart items persist in database across server restarts
- Inventory validation before adding/updating items
- Price captured at time of adding to cart
- Duplicate items update quantity instead of creating new entries
- Full CRUD operations with proper error handling
- Type-safe API with auto-generated OpenAPI documentation
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>