/// <summary>
/// Calculate the basket value from the given input
/// </summary>
/// <param name="items">The items in string array form</param>
/// <returns>The result of the calculation</returns>
public CalculationResult Calculate(string[] items)
{
var basket = new Basket(items);
var result = new CalculationResult();
foreach (var kvp in basket)
{
result.Add(GetTotal(kvp.Key, kvp.Value));
}
// copy basket because we're taking stuff out
// This is not strictly necessary but still a good idea for future
// extensions, i.e. in case we need to list the initial basket
var offerBasket = new Basket(basket);
foreach (var offer in _config.Offers)
{
// How many times do the required items fit?
int fitsTimes = offerBasket.FitsTimes(offer.Condition);
if (fitsTimes > 0)
{
// take items out and apply the offer
offerBasket.SubtractTimes(offer.Condition, fitsTimes);
result.AddOffer(offer, offer.PriceDelta * fitsTimes);
}
}
return(result);
}
public void AddOffer_WithValidOffer_AddsToTotal()
{
var cResult = new CalculationResult();
cResult.Add(12.34M);
cResult.AddOffer(new Offer
{
Description = "TestOffer",
PriceDelta = -1M
}, -3M);
Assert.AreEqual(12.34M, cResult.SubTotal);
Assert.AreEqual(9.34M, cResult.Total);
}
public void ToString_WithOffersInPence2Digits_FormatsOutputCorrectly()
{
var cResult = new CalculationResult();
cResult.Add(12.34M);
cResult.AddOffer(new Offer
{
Description = "TestOffer",
PriceDelta = -0.1M
}, -0.3M);
Assert.AreEqual(
"Subtotal: £12.34" + Environment.NewLine +
"TestOffer: -30p" + Environment.NewLine +
"Total: £12.04" + Environment.NewLine, cResult.ToString());
}