The fictional website www.great-fashion.com is an online store with the following products available for purchase:
| Product Code | Name | Price |
|---|---|---|
| 001 | Red Scarf | £9.25 |
| 002 | Silver cufflinks | £45.00 |
| 003 | Silk Dress | £19.95 |
The marketing team want to offer promotions as an incentive for customers to purchase these items.
When spending over £60, the customer gets 10% off their purchase When purchasing 2 or more of the Red Scarf, its price is reduced to £8.50.
The check-out system can scan items in any order, and because promotions will change, it needs to be flexible regarding promotional rules.
The interface to the checkout looks like this (shown in Ruby):
co = Checkout.new(promotional_rules)
co.scan(item)
co.scan(item)
price = co.total
Implement a simple checkout system that fulfills these requirements and the interface shown above.
Basket: 001, 002, 003
Total price expected: £66.78
Basket: 001, 003, 001
Total price expected: £36.95
Basket: 001, 002, 001, 003
Total price expected: £73.76