private void AddSharesAndCalculateNewAverageCostBasis(string symbol, int quantity, float price_per_share, DateTimeOffset purchased_at)
{
//Check if we already have a holding like this
EquityHolding nh = null;
foreach (EquityHolding h in EquityHoldings)
{
if (h.Symbol.ToUpper() == symbol.ToUpper())
{
nh = h;
}
}
//Create a new one if we couldn't find this holding that already exists.
if (nh == null)
{
nh = new EquityHolding();
nh.Symbol = symbol.ToUpper().Trim();
nh.Quantity = 0;
nh.AverageCostBasis = 0;
EquityHoldings.Add(nh);
}
//Calculate the new Average Per Share Cost basis
float CurrentTotalCost = nh.AverageCostBasis * nh.Quantity;
float NewTotalCost = price_per_share * quantity;
float NewAvgCostBasis = (CurrentTotalCost + NewTotalCost) / (quantity + nh.Quantity);
nh.AverageCostBasis = NewAvgCostBasis;
//add the shares we are buying to the balane
nh.Quantity = nh.Quantity + quantity;
//Log the transaction
EquityTransaction et = new EquityTransaction();
et.TransactedOn = purchased_at;
et.Quantity = quantity;
et.StockSymbol = symbol.ToUpper().Trim();
et.OrderType = TransactionType.Buy;
et.PriceExecutedAt = price_per_share;
EquityTransactionLog.Add(et);
}
public async Task TradeEquityAsync(string symbol, int quantity, TransactionType order_type)
{
Equity e = Equity.Create(symbol);
try
{
await e.DownloadSummaryAsync();
}
catch
{
throw new Exception("Critical error while fetching equity '" + symbol + "'. Does this equity exist?");
}
if (order_type == TransactionType.Buy)
{
//Be sure we have enough cash to buy
float cash_needed = e.Summary.Price * quantity;
if (Cash < cash_needed)
{
throw new Exception("You do not have enough cash to execute this buy order of " + symbol.ToUpper() + ". Cash needed: $" + cash_needed.ToString("#,##0.00") + ". Cash balance: $" + Cash.ToString("#,##0.00"));
}
AddSharesAndCalculateNewAverageCostBasis(symbol.ToUpper().Trim(), quantity, e.Summary.Price, DateTimeOffset.Now);
//Edit cash and add the shares we are buying to the balane
Cash = Cash - cash_needed;
}
else if (order_type == TransactionType.Sell)
{
//Find our holding
EquityHolding eh = null;
foreach (EquityHolding ceh in EquityHoldings)
{
if (ceh.Symbol.ToUpper() == symbol.ToUpper())
{
eh = ceh;
}
}
//Throw an error if we do not have any of those shares.
if (eh == null)
{
throw new Exception("You do not have any shares of " + symbol.ToUpper() + " to sell.");
}
//Throw an error if we do not have enough shares
if (eh.Quantity < quantity)
{
throw new Exception("You do not have " + quantity.ToString() + " shares to sell! You only have " + eh.Quantity.ToString() + " shares.");
}
//Execute the transaction
Cash = Cash + (quantity * e.Summary.Price);
eh.Quantity = eh.Quantity - quantity;
//Save the transaction log
EquityTransaction et = new EquityTransaction();
et.UpdateTransactionTime();
et.StockSymbol = symbol.ToUpper().Trim();
et.OrderType = TransactionType.Sell;
et.Quantity = quantity;
et.PriceExecutedAt = e.Summary.Price;
EquityTransactionLog.Add(et);
//Remove the holding if it now 0
if (eh.Quantity == 0)
{
EquityHoldings.Remove(eh);
}
}
//Take out the commission (if any)
if (TradeCost > 0)
{
EditCash(TradeCost * -1, CashTransactionType.TradingRelatedCharge);
}
}