public void sell(string symbolName, int quantity)
{
if (quantity < 1)
{
throw new System.ServiceModel.FaultException <ArgumentException>(new ArgumentException("Quantity must be greater than zero.", "quantity"));
}
TraderContext db = DbContext;
Symbol s = db.Symbols.Where(x => x.name == symbolName).FirstOrDefault();
if (s == null)
{
throw new System.ServiceModel.FaultException <ArgumentException>(new ArgumentException("Symbol not found.", "symbol"));
}
Quote lastPrice = db.FindLastQuoteFor(s);
if (lastPrice == null)
{
// if we have no prices, the operation cannot complete
return;
}
Portfolio portfolio = db.Portfolios.FirstOrDefault();
Position pos = portfolio.Positions.Where(x => x.Symbol == s && x.status == positionStatus.Open).FirstOrDefault();
if (pos == null || pos.quantity < quantity)
{
// the user does not own enough shares to complete the requested sell transaction
throw new System.ServiceModel.FaultException <InsufficientQuantityFault>(new InsufficientQuantityFault(quantity, pos.quantity));
}
// figure out which shares to sell to get the best price
List <Trade> byProfit = pos.Trades.Where(t => t.type == tradeTypes.Buy).OrderByDescending(o => (lastPrice.price - o.price)).ToList <Trade>();
List <Trade> toSell = new List <Trade>();
string transaction_id = Guid.NewGuid().ToString();
foreach (Trade t in byProfit)
{
int remaining = quantity - toSell.Sum(x => x.quantity);
Trade next = t.sell(Math.Min(t.quantity, remaining));
next.price = lastPrice.price;
next.TransactionId = transaction_id;
toSell.Add(next);
if (toSell.Sum(x => x.quantity) == quantity)
{
break;
}
}
pos.Trades.AddRange(toSell);
// update subtotals in the postition to reflect the new transaction
pos.Recalculate();
// add the proceeds of the sale to our available cash
portfolio.Cash += toSell.Sum(x => (x.price * x.quantity) - x.PaidCommission);
db.SaveChanges();
db.Dispose();
}