Files
orion/app/services/cart_service.py
Samir Boulahtit 3520bcb069 refactor: move transaction management from services to API endpoints
- Services now use db.flush() instead of db.commit() for database operations
- API endpoints handle transaction commit after service calls
- Remove db.rollback() from services (let exception handlers manage this)
- Ensures consistent transaction boundaries at API layer

This pattern gives API endpoints full control over when to commit,
allowing for better error handling and potential multi-operation transactions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2025-12-06 18:34:41 +01:00

442 lines
12 KiB
Python

# app/services/cart_service.py
"""
Shopping cart service.
This module provides:
- Session-based cart management
- Cart item operations (add, update, remove)
- Cart total calculations
"""
import logging
from sqlalchemy import and_
from sqlalchemy.orm import Session
from app.exceptions import (
CartItemNotFoundException,
InsufficientInventoryForCartException,
InvalidCartQuantityException,
ProductNotFoundException,
)
from models.database.cart import CartItem
from models.database.product import Product
logger = logging.getLogger(__name__)
class CartService:
"""Service for managing shopping carts."""
def get_cart(self, db: Session, vendor_id: int, session_id: str) -> dict:
"""
Get cart contents for a session.
Args:
db: Database session
vendor_id: Vendor ID
session_id: Session ID
Returns:
Cart data with items and totals
"""
logger.info(
"[CART_SERVICE] get_cart called",
extra={
"vendor_id": vendor_id,
"session_id": session_id,
},
)
# Fetch cart items from database
cart_items = (
db.query(CartItem)
.filter(
and_(CartItem.vendor_id == vendor_id, CartItem.session_id == session_id)
)
.all()
)
logger.info(
f"[CART_SERVICE] Found {len(cart_items)} items in database",
extra={"item_count": len(cart_items)},
)
# Build response
items = []
subtotal = 0.0
for cart_item in cart_items:
product = cart_item.product
line_total = cart_item.line_total
items.append(
{
"product_id": product.id,
"product_name": product.marketplace_product.title,
"quantity": cart_item.quantity,
"price": cart_item.price_at_add,
"line_total": line_total,
"image_url": (
product.marketplace_product.image_link
if product.marketplace_product
else None
),
}
)
subtotal += line_total
cart_data = {
"vendor_id": vendor_id,
"session_id": session_id,
"items": items,
"subtotal": subtotal,
"total": subtotal, # Could add tax/shipping later
}
logger.info(
f"[CART_SERVICE] get_cart returning: {len(cart_data['items'])} items, total: {cart_data['total']}",
extra={"cart": cart_data},
)
return cart_data
def add_to_cart(
self,
db: Session,
vendor_id: int,
session_id: str,
product_id: int,
quantity: int = 1,
) -> dict:
"""
Add product to cart.
Args:
db: Database session
vendor_id: Vendor ID
session_id: Session ID
product_id: Product ID
quantity: Quantity to add
Returns:
Updated cart
Raises:
ProductNotFoundException: If product not found
InsufficientInventoryException: If not enough inventory
"""
logger.info(
"[CART_SERVICE] add_to_cart called",
extra={
"vendor_id": vendor_id,
"session_id": session_id,
"product_id": product_id,
"quantity": quantity,
},
)
# Verify product exists and belongs to vendor
product = (
db.query(Product)
.filter(
and_(
Product.id == product_id,
Product.vendor_id == vendor_id,
Product.is_active == True,
)
)
.first()
)
if not product:
logger.error(
"[CART_SERVICE] Product not found",
extra={"product_id": product_id, "vendor_id": vendor_id},
)
raise ProductNotFoundException(product_id=product_id, vendor_id=vendor_id)
logger.info(
f"[CART_SERVICE] Product found: {product.marketplace_product.title}",
extra={
"product_id": product_id,
"product_name": product.marketplace_product.title,
"available_inventory": product.available_inventory,
},
)
# Get current price (use sale_price if available, otherwise regular price)
current_price = product.sale_price if product.sale_price else product.price
# Check if item already exists in cart
existing_item = (
db.query(CartItem)
.filter(
and_(
CartItem.vendor_id == vendor_id,
CartItem.session_id == session_id,
CartItem.product_id == product_id,
)
)
.first()
)
if existing_item:
# Update quantity
new_quantity = existing_item.quantity + quantity
# Check inventory for new total quantity
if product.available_inventory < new_quantity:
logger.warning(
"[CART_SERVICE] Insufficient inventory for update",
extra={
"product_id": product_id,
"current_in_cart": existing_item.quantity,
"adding": quantity,
"requested_total": new_quantity,
"available": product.available_inventory,
},
)
raise InsufficientInventoryForCartException(
product_id=product_id,
product_name=product.marketplace_product.title,
requested=new_quantity,
available=product.available_inventory,
)
existing_item.quantity = new_quantity
db.flush()
db.refresh(existing_item)
logger.info(
"[CART_SERVICE] Updated existing cart item",
extra={"cart_item_id": existing_item.id, "new_quantity": new_quantity},
)
return {
"message": "Product quantity updated in cart",
"product_id": product_id,
"quantity": new_quantity,
}
# Check inventory for new item
if product.available_inventory < quantity:
logger.warning(
"[CART_SERVICE] Insufficient inventory",
extra={
"product_id": product_id,
"requested": quantity,
"available": product.available_inventory,
},
)
raise InsufficientInventoryForCartException(
product_id=product_id,
product_name=product.marketplace_product.title,
requested=quantity,
available=product.available_inventory,
)
# Create new cart item
cart_item = CartItem(
vendor_id=vendor_id,
session_id=session_id,
product_id=product_id,
quantity=quantity,
price_at_add=current_price,
)
db.add(cart_item)
db.flush()
db.refresh(cart_item)
logger.info(
"[CART_SERVICE] Created new cart item",
extra={
"cart_item_id": cart_item.id,
"quantity": quantity,
"price": current_price,
},
)
return {
"message": "Product added to cart",
"product_id": product_id,
"quantity": quantity,
}
def update_cart_item(
self,
db: Session,
vendor_id: int,
session_id: str,
product_id: int,
quantity: int,
) -> dict:
"""
Update quantity of item in cart.
Args:
db: Database session
vendor_id: Vendor ID
session_id: Session ID
product_id: Product ID
quantity: New quantity (must be >= 1)
Returns:
Success message
Raises:
ValidationException: If quantity < 1
ProductNotFoundException: If product not found
InsufficientInventoryException: If not enough inventory
"""
if quantity < 1:
raise InvalidCartQuantityException(quantity=quantity, min_quantity=1)
# Find cart item
cart_item = (
db.query(CartItem)
.filter(
and_(
CartItem.vendor_id == vendor_id,
CartItem.session_id == session_id,
CartItem.product_id == product_id,
)
)
.first()
)
if not cart_item:
raise CartItemNotFoundException(
product_id=product_id, session_id=session_id
)
# Verify product still exists and is active
product = (
db.query(Product)
.filter(
and_(
Product.id == product_id,
Product.vendor_id == vendor_id,
Product.is_active == True,
)
)
.first()
)
if not product:
raise ProductNotFoundException(str(product_id))
# Check inventory
if product.available_inventory < quantity:
raise InsufficientInventoryForCartException(
product_id=product_id,
product_name=product.marketplace_product.title,
requested=quantity,
available=product.available_inventory,
)
# Update quantity
cart_item.quantity = quantity
db.flush()
db.refresh(cart_item)
logger.info(
"[CART_SERVICE] Updated cart item quantity",
extra={
"cart_item_id": cart_item.id,
"product_id": product_id,
"new_quantity": quantity,
},
)
return {
"message": "Cart updated",
"product_id": product_id,
"quantity": quantity,
}
def remove_from_cart(
self, db: Session, vendor_id: int, session_id: str, product_id: int
) -> dict:
"""
Remove item from cart.
Args:
db: Database session
vendor_id: Vendor ID
session_id: Session ID
product_id: Product ID
Returns:
Success message
Raises:
ProductNotFoundException: If product not in cart
"""
# Find and delete cart item
cart_item = (
db.query(CartItem)
.filter(
and_(
CartItem.vendor_id == vendor_id,
CartItem.session_id == session_id,
CartItem.product_id == product_id,
)
)
.first()
)
if not cart_item:
raise CartItemNotFoundException(
product_id=product_id, session_id=session_id
)
db.delete(cart_item)
logger.info(
"[CART_SERVICE] Removed item from cart",
extra={
"cart_item_id": cart_item.id,
"product_id": product_id,
"session_id": session_id,
},
)
return {"message": "Item removed from cart", "product_id": product_id}
def clear_cart(self, db: Session, vendor_id: int, session_id: str) -> dict:
"""
Clear all items from cart.
Args:
db: Database session
vendor_id: Vendor ID
session_id: Session ID
Returns:
Success message with count of items removed
"""
# Delete all cart items for this session
deleted_count = (
db.query(CartItem)
.filter(
and_(CartItem.vendor_id == vendor_id, CartItem.session_id == session_id)
)
.delete()
)
logger.info(
"[CART_SERVICE] Cleared cart",
extra={
"session_id": session_id,
"vendor_id": vendor_id,
"items_removed": deleted_count,
},
)
return {"message": "Cart cleared", "items_removed": deleted_count}
# Create service instance
cart_service = CartService()