Django transaction handling with atomic decorator

                  from django.db import transaction
from django.shortcuts import get_object_or_404
from rest_framework import status
from rest_framework.decorators import api_view
from rest_framework.response import Response
from .models import Order, OrderItem, Product


@api_view(['POST'])
@transaction.atomic
def create_order(request):
    """Create an order with items atomically."""
    order = Order.objects.create(
        customer=request.user,
        status='pending'
    )

    items_data = request.data.get('items', [])

    for item_data in items_data:
        product = get_object_or_404(Product, id=item_data['product_id'])

        # Check inventory
        if product.stock < item_data['quantity']:
            # Transaction will rollback
            return Response(
                {'error': f'Insufficient stock for {product.name}'},
                status=status.HTTP_400_BAD_REQUEST
            )

        # Reduce stock
        product.stock -= item_data['quantity']
        product.save()

        # Create order item
        OrderItem.objects.create(
            order=order,
            product=product,
            quantity=item_data['quantity'],
            price=product.price
        )

    # Send email only after successful commit
    transaction.on_commit(
        lambda: send_order_confirmation.delay(order.id)
    )

    return Response({'order_id': order.id}, status=status.HTTP_201_CREATED)