public async Task <IEnumerable <Rate> > GetRateByFilterAsync(RateFilterModel filterModel)
{
if (filterModel.DateTo < filterModel.DateFrom || filterModel.DateFrom.AddMonths(2) < filterModel.DateTo)
{
throw new ArgumentException("Invalid filter model. Date range is invalid.");
}
var baseIsAvailable = await _ratesRepository.CheckAvailableBaseCurrencyAsync(filterModel.BaseCurrency.Id);
var resultsIsAvailable =
await _ratesRepository.CheckAvailableResultCurrenciesAsync(
filterModel.ResultCurrencyList.Select(x => x.Id));
if (!baseIsAvailable || !resultsIsAvailable)
{
throw new ArgumentException("Invalid filter model. Check your currency accessing.");
}
var cachingRates = await _ratesRepository.GetRatesInfoAsync(filterModel);
if (cachingRates.Count() == filterModel.ResultCurrencyList.Count() *
filterModel.DateFrom.GetBusinessDaysCount(filterModel.DateTo))
{
return(cachingRates);
}
else
{
var newRates = await GetMissingRates(filterModel, cachingRates);
await _ratesRepository.AddRangeRatesInfoAsync(newRates);
var result = cachingRates.ToList();
result.AddRange(newRates);
return(result.GroupBy(x => new { x.ResultCurrencyId, x.RateDate }).Select(x => x.First()));
}
}
public async Task <IEnumerable <Rate> > GetRatesInfoAsync(RateFilterModel filterModel)
{
var resultCurrencyIds = filterModel.ResultCurrencyList.Select(x => x.Id);
return(await _appContext.Rates
.Include(x => x.BaseCurrency)
.Include(x => x.ResultCurrency)
.Where(x => x.BaseCurrencyId == filterModel.BaseCurrency.Id &&
resultCurrencyIds.Contains(x.ResultCurrencyId) &&
x.RateDate >= filterModel.DateFrom &&
x.RateDate <= filterModel.DateTo).ToListAsync());
}
private async Task <IEnumerable <Rate> > GetMissingRates(RateFilterModel filterModel,
IEnumerable <Rate> cachingRates)
{
var response = new RatesResponse();
if (!cachingRates.Any())
{
response = await _externalRatesService.GetRatesAsync(filterModel.DateFrom,
filterModel.DateTo,
filterModel.BaseCurrency.Code,
filterModel.ResultCurrencyList.Select(x => x.Code));
}
else
{
var groupingCachingRates = cachingRates.GroupBy(x => x.ResultCurrencyId);
var fullMissingResultCurrency =
GetFullMissingResultCurrencyCodes(groupingCachingRates.Select(x => x.First().ResultCurrency.Code),
filterModel.ResultCurrencyList.Select(x => x.Code));
var partiallyMissingResultCurrency =
GetPartiallyMissingResultCurrencyCodes(groupingCachingRates, filterModel.DateFrom, filterModel.DateTo);
var minMaxUpdatingInterval = new Tuple <DateTime?, DateTime?>(null, null);
if (!partiallyMissingResultCurrency.Any() && !fullMissingResultCurrency.Any())
{
return(new List <Rate>());
}
if (fullMissingResultCurrency.Any())
{
minMaxUpdatingInterval = new Tuple <DateTime?, DateTime?>(filterModel.DateFrom, filterModel.DateTo);
}
else
{
if (partiallyMissingResultCurrency.Any())
{
minMaxUpdatingInterval = GetMinMaxMissingIntervalByCachingItems(cachingRates, filterModel.DateFrom, filterModel.DateTo);
}
}
if (!minMaxUpdatingInterval.Item1.HasValue || !minMaxUpdatingInterval.Item2.HasValue)
{
throw new ArgumentException("Nothing to search. Min/Max interval not found");
}
var missingCurrencyCodes = new List <string>(fullMissingResultCurrency);
missingCurrencyCodes.AddRange(partiallyMissingResultCurrency);
response = await _externalRatesService.GetRatesAsync(minMaxUpdatingInterval.Item1.Value, minMaxUpdatingInterval.Item2.Value,
filterModel.BaseCurrency.Code,
missingCurrencyCodes);
}
return(await ConvertResponseToList(response));
}
public async Task <IActionResult> GetRates([FromBody] RateFilterModel filterModel)
{
var result = await _ratesService.GetCalculatedRatesByFilterAsync(filterModel);
return(Ok(result));
}
public async Task <IEnumerable <CalculatedRatesModel> > GetCalculatedRatesByFilterAsync(RateFilterModel filterModel)
{
var rates = await GetRateByFilterAsync(filterModel);
var grouping = rates.GroupBy(x => x.ResultCurrencyId);
var result = new List <CalculatedRatesModel>();
var badBrokerPrice = _configuration.GetValue <decimal>("BadBrokerPrice");
foreach (var item in grouping)
{
var orderedRates = item.OrderBy(x => x.RateDate).ToList();
decimal bestValue = 0;
DateTime?bestStartDate = null;
DateTime?bestEndDate = null;
//Find optimal start/stop date for buy
for (var i = 0; i < orderedRates.Count() - 1; i++)
{
for (var j = i; j < orderedRates.Count(); j++)
{
var value =
(orderedRates[i].RateValue * filterModel.InputValueMoney / orderedRates[j].RateValue)
- (orderedRates[j].RateDate.Subtract(orderedRates[i].RateDate).Days) * badBrokerPrice;
if (value > bestValue)
{
bestValue = value;
bestStartDate = orderedRates[i].RateDate;
bestEndDate = orderedRates[j].RateDate;
}
}
}
result.Add(new CalculatedRatesModel
{
ResultCurrency = orderedRates.First().ResultCurrency,
BaseCurrency = orderedRates.First().BaseCurrency,
RatesInfoList = orderedRates.Select(x => new CalculatedRatesInfoModel
{
Date = x.RateDate,
Value = x.RateValue
}),
BestStartDate = bestStartDate,
BestEndingDate = bestEndDate,
MaxMoneyValue = bestValue
});
}
return(result);
}
