private CashEntry UpdateItem(CashEntry oldCashEntry, CashEntry newCashEntry)
{
RemoveItem(oldCashEntry);
return(new CashEntry
{
Denomination = newCashEntry.Denomination,
Quantity = newCashEntry.Quantity
});
}
public void Delete(CashEntry cashEntry)
{
if (cashEntry == null)
{
throw new ArgumentNullException();
}
RemoveItem(cashEntry);
Save();
}
public void Insert(CashEntry cashEntry)
{
if (cashEntry == null)
{
throw new ArgumentNullException();
}
if (_items.Contains(cashEntry))
{
throw new ArgumentException("duplicate");
}
InsertItem(cashEntry);
Save();
}
public CashEntry Update(CashEntry cashEntry)
{
if (cashEntry == null)
{
throw new ArgumentNullException();
}
var item = _items.FirstOrOptional(i => i.Equals(cashEntry));
var itemToInsert = item.Handle(i => UpdateItem(i, cashEntry), () => cashEntry);
InsertItem(itemToInsert);
Save();
return(itemToInsert);
}
private void RemoveItem(CashEntry cashEntry) => _items.Remove(cashEntry);
private void InsertItem(CashEntry cashEntry) => _items.Add(cashEntry);