public IReadOnlyList <CapitalGain> CalculateCapialGains(IReadOnlyList <Transaction> transactions, AccountingMethodType accountingMethod, Crypto.CryptoType crypto)
{
var capitalGains = new List <CapitalGain>();
var sortedTransactions = transactions
.Where(x => x.Crypto == crypto)
.OrderBy(x => x.TransactionDate);
var assetCollection = new AssetCollection(accountingMethod);
foreach (var transaction in sortedTransactions)
{
switch (transaction.TransactionType)
{
case TransactionType.Buy:
assetCollection.Add(new Asset
{
TransactionDate = transaction.TransactionDate,
Amount = transaction.Quantity,
ExchangeRate = transaction.PriceInUsd
});
break;
case TransactionType.Sell:
var cryptoSellAmount = transaction.Quantity;
while (cryptoSellAmount > 0)
{
if (assetCollection.Count == 0)
{
return(null);
}
Asset soldAsset;
decimal sellAmount;
if (assetCollection.Peek().Amount <= cryptoSellAmount)
{
soldAsset = assetCollection.Pop();
sellAmount = soldAsset.Amount;
}
else
{
soldAsset = assetCollection.Peek();
sellAmount = cryptoSellAmount;
soldAsset.Amount -= sellAmount;
}
cryptoSellAmount -= sellAmount;
capitalGains.Add(new CapitalGain
{
YearIncurred = transaction.TransactionDate.Year,
AssetLifetime = transaction.TransactionDate - soldAsset.TransactionDate,
UsdAmount = sellAmount * (transaction.PriceInUsd - soldAsset.ExchangeRate)
});
}
break;
default:
throw new InvalidOperationException();
}
}
return(capitalGains);
}
private List <Asset> GetHeldAssets(IReadOnlyCollection <Transaction> transactions)
{
var assetCollection = new AssetCollection(AccountingMethodType.Lifo);
var sortedtransactions = transactions
.OrderBy(x => x.TransactionDate);
foreach (var transaction in sortedtransactions)
{
switch (transaction.TransactionType)
{
case TransactionType.Buy:
assetCollection.Add(new Asset
{
TransactionDate = transaction.TransactionDate,
Amount = transaction.Quantity,
ExchangeRate = transaction.PriceInUsd
});
break;
case TransactionType.Sell:
var cryptoSellAmount = transaction.Quantity;
while (cryptoSellAmount > 0)
{
if (assetCollection.Count == 0)
{
// return an empty list if the assets can't be correctly calculated
return(new List <Asset>());
}
Asset soldAsset;
decimal sellAmount;
if (assetCollection.Peek().Amount <= cryptoSellAmount)
{
soldAsset = assetCollection.Pop();
sellAmount = soldAsset.Amount;
}
else
{
soldAsset = assetCollection.Peek();
sellAmount = cryptoSellAmount;
soldAsset.Amount -= sellAmount;
}
cryptoSellAmount -= sellAmount;
}
break;
default:
throw new InvalidOperationException();
}
}
return(assetCollection.ToList());
}