public Task Handle(OrderTransactionEvent evnt)
{
_state.HandledTransactions.TryPeek(out var handledTransaction);
if (handledTransaction == evnt.EntityId)
{
// If we've already handled this event through the evaluator,
// we don't want to mess with credits and inventory
_state.HandledTransactions.Dequeue();
return(Task.CompletedTask);
}
var fromOrder = _state.Orders[evnt.FromSellOrder];
var toOrder = _state.Orders[evnt.ToBuyOrder];
fromOrder.QuantityFulfilled += evnt.Quantity;
toOrder.QuantityFulfilled += evnt.Quantity;
fromOrder.Owner.Credits += evnt.Price;
toOrder.Owner.Credits -= evnt.Price;
fromOrder.Owner.Inventory[evnt.ItemId].Quantity -= evnt.Quantity;
if (toOrder.Owner.Inventory.TryGetValue(evnt.ItemId, out var inventory))
{
inventory.Quantity += evnt.Quantity;
}
else
{
toOrder.Owner.Inventory.Add(evnt.ItemId, new WarehouseInventory
{
ItemId = evnt.ItemId,
Quantity = evnt.Quantity,
});
}
return(Task.CompletedTask);
}
private IEnumerable <IEvent> EvaluateBuyOrder(
BrokerOrder buyOrder,
BrokerOrder sellOrder,
long quantityToSell,
State state)
{
// The quantity one order can buy will be the least of either:
// 1. As much as the buyer can buy (credits)
// 2. As much as the seller can sell (inventory/order size)
// 3. As much as the buyer wants to buy (order size)
if (sellOrder.Price == 0)
{
yield break;
}
var affordableQuantity = buyOrder.Owner.Credits / sellOrder.Price;
var quantityToBuy = Math.Min(affordableQuantity, quantityToSell); // Case 1 & 2
if (buyOrder.Quantity != -1) // Case 3
{
quantityToBuy = Math.Min(quantityToBuy, buyOrder.Quantity - buyOrder.QuantityFulfilled);
}
var evnt = new OrderTransactionEvent(Guid.NewGuid(), _initiator)
{
FromPlayer = sellOrder.Owner.PlayerId,
ToPlayer = buyOrder.Owner.PlayerId,
FromSellOrder = sellOrder.OrderId,
ToBuyOrder = buyOrder.OrderId,
ItemId = sellOrder.ItemId,
Quantity = quantityToBuy,
Price = quantityToBuy * sellOrder.Price,
};
buyOrder.Owner.Credits -= evnt.Price;
sellOrder.Owner.Credits += evnt.Price;
buyOrder.QuantityFulfilled += evnt.Quantity;
sellOrder.QuantityFulfilled += evnt.Quantity;
UpdatePlayerInventory(buyOrder.Owner, evnt.ItemId, evnt.Quantity);
UpdatePlayerInventory(sellOrder.Owner, evnt.ItemId, -evnt.Quantity);
state.HandledTransactions.Enqueue(evnt.EntityId);
yield return(evnt);
yield return(new OrderPartiallyFulfilledEvent(buyOrder.OrderId, _initiator)
{
TransactionId = evnt.EntityId,
Price = evnt.Price,
QuantityFulfilled = evnt.Quantity,
});
yield return(new OrderPartiallyFulfilledEvent(sellOrder.OrderId, _initiator)
{
TransactionId = evnt.EntityId,
Price = evnt.Price,
QuantityFulfilled = evnt.Quantity,
});
yield return(new PlayerBalanceChangedEvent(buyOrder.Owner.PlayerId, _initiator)
{
TransactionId = evnt.EntityId,
BalanceChange = -evnt.Price,
});
yield return(new PlayerBalanceChangedEvent(sellOrder.Owner.PlayerId, _initiator)
{
TransactionId = evnt.EntityId,
BalanceChange = evnt.Price,
});
yield return(new PlayerInventoryChangedEvent(buyOrder.Owner.PlayerId, _initiator)
{
TransactionId = evnt.EntityId,
InventoryChange = new[]
{
new LuaItemStack
{
Name = evnt.ItemId,
Count = evnt.Quantity,
},
},
});
yield return(new PlayerInventoryChangedEvent(sellOrder.Owner.PlayerId, _initiator)
{
TransactionId = evnt.EntityId,
InventoryChange = new[]
{
new LuaItemStack
{
Name = evnt.ItemId,
Count = -evnt.Quantity,
},
},
});
if (buyOrder.Quantity != -1 && buyOrder.QuantityFulfilled >= buyOrder.Quantity)
{
yield return(new OrderFulfilledEvent(buyOrder.OrderId, _initiator));
buyOrder.State = OrderState.Fulfilled;
_logger.Information($"Buy order ${buyOrder.OrderId} completely fulfilled!");
}
}
