/// <summary>
/// Finds out the oldest stored candle's timestamp (if any).
/// </summary>
/// <param name="assetPairId"></param>
/// <param name="priceType"></param>
/// <param name="interval"></param>
/// <returns>The oldest candle or null./></returns>
/// <exception cref="InvalidOperationException">If the specified asset pair is not currently supported by storage.</exception>
public async Task <ICandle> TryGetOldestCandleAsync(string assetPairId, CandlePriceType priceType,
CandleTimeInterval interval)
{
CheckupAssetPairOrFail(assetPairId);
var firstCandle = await _candlesHistoryRepository.TryGetFirstCandleAsync(assetPairId, interval, priceType);
return(firstCandle); // The risk of the null is minimal but not excluded.
}
// Calculating the earliest and the latest dates for the biggest interval candles fetching
public async Task <(DateTime dateFrom, DateTime dateTo)> GetDateTimeRangeAsync(string assetPairId, CandlePriceType priceType)
{
var firstBiggestCandle =
await _candlesHistoryRepository.TryGetFirstCandleAsync(assetPairId,
Constants.DbStoredIntervals.Last(),
priceType);
// If we have no such a candle in repository, we return fake dates for further decision making in the caller code
if (firstBiggestCandle == null)
{
return(dateFrom : DateTime.MinValue, dateTo : DateTime.MinValue);
}
var dtFrom = firstBiggestCandle.Timestamp; // The first candle's in storage timestamp
var dtTo = DateTime.UtcNow.TruncateTo(CandleTimeInterval.Month); // The begining of the current month (for further candles reading with exclusive upper date-time border).
return(dateFrom : dtFrom, dateTo : dtTo);
}
public async Task <ICandle> GetFirstCandleOfHistoryAsync(string assetPair, CandlePriceType priceType)
{
var candle = await _candlesHistoryRepository.TryGetFirstCandleAsync(assetPair, CandleTimeInterval.Sec, priceType);
return(candle);
}
