public async Task <DalResult> BuyFromOfferAsync(int buyerid, long quantity, OfferEntity offer, bool oldestFirst)
{
if (buyerid <= 0)
{
return(new(DalErrorCode.Invalid, new("Buyer id is invalid")));
}
if (quantity == 0)
{
return(new(DalErrorCode.Invalid, new("Quantity must be greater than zero")));
}
if (offer is null)
{
return(new(DalErrorCode.Invalid, new ArgumentNullException(nameof(offer))));
}
if (offer.UserId <= 0)
{
return(new(DalErrorCode.Invalid, new Exception("Seller id in offer is invalid")));
}
var bean = await _beanRepository.ReadAsync(offer.BeanId);
if (bean is null)
{
return(new(DalErrorCode.NotFound, new Exception($"No bean with the id {offer.BeanId} was found")));
}
var buyer = await _userRepository.ReadAsync(buyerid);
if (buyer is null)
{
return(new(DalErrorCode.NotFound, new($"No user with the id {buyerid} was found")));
}
if (buyer.Balance < quantity * offer.Price)
{
return(new(DalErrorCode.NSF, new("Buyer does not have sufficient funds")));
}
var seller = await _userRepository.ReadAsync(offer.UserId);
if (seller is null)
{
return(new(DalErrorCode.NotFound, new($"No user with the id {offer.User} was found")));
}
var beansHeld = await _holdingRepository.BeansHeldByUserAndBeanAsync(offer.UserId, offer.BeanId);
if (quantity > beansHeld)
{
return(new(DalErrorCode.NSF, new("Seller has insufficient beans")));
}
var holdings = await _holdingRepository.GetHoldingsAsync(oldestFirst, offer.UserId, offer.BeanId, quantity);
if (holdings.Length == 0)
{
return(new(DalErrorCode.NotFound, new("Unable to locate holdings to satisfy sale")));
}
using var conn = new SqlConnection(ConnectionString);
await conn.OpenAsync();
using var transaction = await conn.BeginTransactionAsync();
try
{
var profit = 0M;
long satisfied = 0;
var ix = 0;
while (ix < holdings.Length - 1)
{
var holding = await _holdingRepository.ReadAsync(holdings[ix]);
if (holding is null)
{
await transaction.RollbackAsync();
return(new(DalErrorCode.NotFound, new($"No holding with the id {holdings[ix]} was found")));
}
var sale = new SaleEntity
{
Id = 0,
UserId = seller.Id,
BeanId = bean.Id,
PurchaseDate = holding.PurchaseDate,
SaleDate = DateTime.UtcNow,
CostBasis = holding.Price,
Quantity = holding.Quantity,
SalePrice = offer.Price,
Bean = null
};
var insresult = await conn.InsertAsync(sale, transaction : transaction);
profit += holding.Quantity * offer.Price;
satisfied += holding.Quantity;
await conn.DeleteAsync(holding, transaction : transaction);
ix++;
}
var lastHolding = await _holdingRepository.ReadAsync(holdings[^ 1]);
public async Task <long> BeansHeldByUserAndBeanAsync(int userid, int beanid) => await _holdingRepository.BeansHeldByUserAndBeanAsync(userid, beanid);