// Side effect free function
public BasketPricingBreakdown calculate_total_price_for(IEnumerable<BasketItem> items, IEnumerable<Coupon> coupons)
{
var basketPricingBreakdown = new BasketPricingBreakdown();
var basket_discount = new Money();
var coupon_issue = CouponIssues.NotApplied;
//foreach (var coupon in coupons)
//{
// // 1. Get all coupons associted with the basket
// // 2. Check if it is applicable or which one wins.
// var promotion = _promotions_repository.find_by(coupon.code);
// if (promotion.is_still_active() && promotion.can_be_applied_to(basket))
// {
// basket_discount = promotion.calculate_discount_for(items);
// coupon_issue = CouponIssues.NoIssue;
// }
// else
// {
// coupon_issue = coupon.reason_why_cannot_be_applied_to(items);
// }
//}
var total = new Money();
foreach(var item in items)
{
total = total.add(item.line_total());
}
basketPricingBreakdown.basket_total = total;
basketPricingBreakdown.discount = basket_discount;
basketPricingBreakdown.coupon_message = coupon_issue;
return basketPricingBreakdown;
}
public Money calculate_discount_for(Basket basket)
{
var discount = new Money();
if (this.meets_criteria_for_discount(basket))
{
discount = discount.add(_discount);
}
else
{
determine_why_not_applicable_for(basket); // This sets why the voucher is not applicable
}
return discount;
}