private IList <CoinWithQuantity> GetChange()
{
var insertedAmount = State.InsertedCoins.Sum(x => (int)x);
var change = insertedAmount - State.PricesProvider.GetPrice(State.SelectedProduct);
var insertedCoinsWithQuantity = State.InsertedCoins
.GroupBy(x => x)
.ToDictionary(grp => grp.Key, v => v.Count());
var coinsWithQuantity = new Dictionary <Coin, int>(
State.Wallet.GetAll()
);
foreach (var c in insertedCoinsWithQuantity)
{
coinsWithQuantity.TryGetValue(c.Key, out var quantity);
coinsWithQuantity[c.Key] = quantity + c.Value;
}
var coinsToReturn = _changeCalculator.CalculateMinimum(
coinsWithQuantity.Select(x => new CoinWithQuantity(x.Key, x.Value))
.OrderByDescending(x => x.Denomination).ToList(),
change
);
return(coinsToReturn);
}
public void MinimumCoins()
{
var coinsWithQuantity = new List <CoinWithQuantity>
{
new CoinWithQuantity(Coin.OneEuro, 3),
new CoinWithQuantity(Coin.HalfEuro, 5),
new CoinWithQuantity(Coin.TwentyCent, 5),
new CoinWithQuantity(Coin.TenCent, 10)
};
var changeCoins = _changeCalculator.CalculateMinimum(coinsWithQuantity, 370)
.ToDictionary(grp => grp.Denomination, v => v.Quantity);
//100 100 100 50 20
Assert.Equal(3, changeCoins.Count);
Assert.Equal(3, changeCoins[100]);
Assert.Equal(1, changeCoins[50]);
Assert.Equal(1, changeCoins[20]);
}