/// <summary>
/// Calculates total price incl discount
/// </summary>
/// <param name="sCart"></param>
/// <returns></returns>
public static double CalcTotalPrice(ShoppingCart sCart)
{
double totPrice = 0;
sCart.Items.ToList().ForEach(x => totPrice += x.Price);
return (totPrice - CalcDiscount(sCart, totPrice));
}
public void AddRemoveBooks()
{
ShoppingCart SCart = new ShoppingCart();
//Creation of 100 books
for (int i = 0; i < 100; i++)
{
Book tmpBook = new Book(
(100 * i), "TestBook", Guid.NewGuid().ToString(), "Harry", Book.SeriesEnum.HarryPotter);
SCart.Items.Add(tmpBook);
}
Assert.AreEqual<int>(100, SCart.Count());
//Add 20 copies
SCart.AddToShoppingCart(Utils.GetSecondBook(), 20);
Assert.AreEqual<int>(120, SCart.Count());
}
public static double CalcDiscount(ShoppingCart sCart, double totPrice)
{
//Calc Harry Potter series discount
Dictionary<IList<int>, double> combinations = new Dictionary<IList<int>, double>();
//Search for all combination between 2-5 (the one's you got discount for)
for (int i = 5; i >= 2; i--)
{
double discount = 0;
var uniqueTitles = sCart.Items.Select(x => x.Title).Distinct();
HashSet<Guid> handled = new HashSet<Guid>(); //To know calculated
IList<int> uniqueSets = new List<int>();
while (sCart.Items.Any(x => !handled.Contains(x.Id)))
{
HashSet<string> tmpTitles = new HashSet<string>();
var uniques = sCart.Items.Where(x => !handled.Contains(x.Id));
foreach (var sItem in uniques)
{
if (tmpTitles.Count <= i && !tmpTitles.Contains(sItem.Title))
{
tmpTitles.Add(sItem.Title);
handled.Add(sItem.Id);
}
}
uniqueSets.Add(tmpTitles.Count);
}
//Calculate discount for each set
foreach (int uni in uniqueSets)
{
double price = sCart.Items.First().Price;
discount += CalcSetDiscount(uni, price);
}
//Save the total discount for this combination
combinations.Add(uniqueSets, discount);
}
//Pick the comination with highest possible discount
return combinations.Max(x => x.Value);
}
public void CalcTotPrice()
{
ShoppingCart SCart = new ShoppingCart();
/*
////1 copy, 1 book
SCart.AddToShoppingCart(Utils.GetFirstBook(), 1);
Assert.AreEqual<double>(8, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
////2 copies, 1book
SCart.AddToShoppingCart(Utils.GetFirstBook(), 2);
Assert.AreEqual<double>(16, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
////5 copies, 1book
SCart.AddToShoppingCart(Utils.GetFirstBook(), 5);
Assert.AreEqual<double>(40, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
*/
////2 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 1);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 1);
Assert.AreEqual<double>(15.2, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//3 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 1);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 1);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 1);
Assert.AreEqual<double>(21.6, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//4 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 1);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 1);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 1);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 1);
Assert.AreEqual<double>(25.6, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//5 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 1);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 1);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 1);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 1);
SCart.AddToShoppingCart(Utils.GetFifthBook(), 1);
Assert.AreEqual<double>(30, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//5 different books with 2 copies
SCart.AddToShoppingCart(Utils.GetFirstBook(), 2);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 2);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 2);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 2);
SCart.AddToShoppingCart(Utils.GetFifthBook(), 2);
Assert.AreEqual<double>(60, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//6 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 2);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 1);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 1);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 1);
SCart.AddToShoppingCart(Utils.GetFifthBook(), 1);
Assert.AreEqual<double>(38, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//7 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 2);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 2);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 1);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 1);
SCart.AddToShoppingCart(Utils.GetFifthBook(), 1);
Assert.AreEqual<double>(45.2, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//8 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 2);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 2);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 2);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 1);
SCart.AddToShoppingCart(Utils.GetFifthBook(), 1);
Assert.AreEqual<double>(51.2, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
//80 different books
SCart.AddToShoppingCart(Utils.GetFirstBook(), 20);
SCart.AddToShoppingCart(Utils.GetSecondBook(), 20);
SCart.AddToShoppingCart(Utils.GetThirdBook(), 20);
SCart.AddToShoppingCart(Utils.GetFourthBook(), 10);
SCart.AddToShoppingCart(Utils.GetFifthBook(), 10);
Assert.AreEqual<double>(512, Calculator.CalcTotalPrice(SCart));
SCart.Items.Clear();
}
