/// <summary>
/// Iterates the basket and calculates any discount on bread based on the beans cans in the basket
/// </summary>
/// <param name="basketItems">List of items in the basket</param>
/// <returns>The total eligible discount if any</returns>
public ValidDiscount Apply(IList <BasketItem> basketItems)
{
var discountType = _currentOffers.GetCurrentOffers().FirstOrDefault(discount => discount.DiscountCode == DiscountCode);
var numberOfBeansCan = basketItems.Where(item => item.ProductName == "Beans")
.Sum(x => x.NumberOfItems);
var numberOfBreadLoaf = basketItems.Where(item => item.ProductName == "Bread")
.Sum(x => x.NumberOfItems);
if (numberOfBeansCan >= 2 && numberOfBreadLoaf > 0)
{
var numbersOfBreadLoafEligibleForHalfPrice = numberOfBeansCan / 2;
var breadPrice = basketItems.First(item => item.ProductName == "Bread").PricePerItem;
if (numberOfBreadLoaf <= numbersOfBreadLoafEligibleForHalfPrice)
{
numbersOfBreadLoafEligibleForHalfPrice = numberOfBreadLoaf;
}
var discountAmount = numbersOfBreadLoafEligibleForHalfPrice * (breadPrice / 2);
return(new ValidDiscount
{
OfferType = discountType,
DiscountAmount = discountAmount
});
}
return(null);
}
/// <summary>
/// Builds a list of BasketItems and returns the list
/// </summary>
/// <param name="products">space separated products to be added to the basket </param>
/// <returns>List of BasketItems</returns>
public List <BasketItem> Build(string[] products)
{
//Group same products together
var groupedProducts = products.GroupBy(p => p)
.Select(grp => new { ProductName = grp.Key, ProductCount = grp.Count() }).ToList();
var baskets = new List <BasketItem>();
var invalidProducts = new List <string>(groupedProducts.Count);
bool skipFurtherProducts = false;
//Create BasketItem with product list and their current offers
foreach (var groupedProduct in groupedProducts)
{
var product = _productService.GetProduct(groupedProduct.ProductName);
if (product == null)
{
invalidProducts.Add(groupedProduct.ProductName);
skipFurtherProducts = true; //Don't get offers for any further products, as we will throw an exception once accumulating all invalid products
continue;
}
if (skipFurtherProducts)
{
continue;
}
//Get current offers for this product
var discountType = _currentOffers.GetCurrentOffers()
.FirstOrDefault(c => c.ProductId == product.ProductId);
//Fill the Basket
baskets.Add(new BasketItem
{
OfferType = discountType,
ProductId = product.ProductId,
NumberOfItems = groupedProduct.ProductCount,
PricePerItem = product.Price,
ProductName = product.ProductName
});
}
if (invalidProducts.Count > 0)
{
throw new Exception($"Invalid products found: {string.Join(',',invalidProducts)}");
}
return(baskets);
}
/// <summary>
/// Iterate the basket items and if any apples found, apply 10% discount
/// </summary>
/// <param name="basketItems">List of items in the basket</param>
/// <returns>The total eligible discount if any</returns>
public ValidDiscount Apply(IList <BasketItem> basketItems)
{
var discountType = _currentOffers.GetCurrentOffers().FirstOrDefault(discount => discount.DiscountCode == DiscountCode);
var productEligibleForDiscount = basketItems.Where(basket => basket.OfferType?.DiscountCode == DiscountCode)
.Select(basket => basket)
.FirstOrDefault();
if (productEligibleForDiscount != null)
{
return new ValidDiscount
{
OfferType = discountType,
DiscountAmount = (0.1m) * (productEligibleForDiscount.NumberOfItems *
productEligibleForDiscount.PricePerItem)
}
}
;
return(null);
}
}