/// <summary>
/// Add new exchange rates history entries to database
/// </summary>
/// <param name="rates">list of entities to add</param>
private void AddRatesToDb(List <ExchangeRatesHistory> rates)
{
try
{
using (ExchangeRatesDataModelContainer dbModel = new ExchangeRatesDataModelContainer())
{
foreach (var rate in rates)
{
rate.Currency = dbModel.Currencies.Where(c => c.ServiceCode == rate.Currency.ServiceCode).First();
dbModel.ExchangeRatesHistories.AddObject(rate);
}
dbModel.SaveChanges();
}
}
catch (Exception e)
{
throw new ApplicationException("Unable to add rates history to Database", e);
}
}
/// <summary>
/// Get list of exchange rates history entities for specific period (from model) for specific currency
/// </summary>
/// <param name="statisticsModel">Data Model</param>
/// <param name="currencyCode">Currency Code</param>
/// <returns></returns>
private List <ExchangeRatesHistory> GetExchangeRatesForCurrency(ExchangeRatesStatisticsModel statisticsModel, string currencyCode)
{
List <ExchangeRatesHistory> ratesHistory = new List <ExchangeRatesHistory>();
try
{
using (ExchangeRatesDataModelContainer dbModel = new ExchangeRatesDataModelContainer())
{
//Extract existing data from database
ratesHistory = dbModel.ExchangeRatesHistories
.Where(r =>
r.Date >= statisticsModel.StartDate &&
r.Date <= statisticsModel.EndDate &&
(r.Currency.ServiceCode == currencyCode))
.ToList();
}
}
catch (Exception e)
{
throw new ApplicationException("Unable to get rates history from Database", e);
}
for (DateTime currentDate = statisticsModel.StartDate; currentDate <= statisticsModel.EndDate; currentDate = currentDate.AddDays(1))
{
List <ExchangeRatesHistory> existingRate = ratesHistory
.Where(rh => rh.Date == currentDate).ToList();
if (existingRate.Count == 0)
{
List <ExchangeRatesHistory> ratesFromService = GetExchangeRatesFromService(currentDate)
.Where(r => r.Currency.ServiceCode == currencyCode).ToList();
AddRatesToDb(ratesFromService);
ratesHistory.AddRange(ratesFromService);
}
}
return(ratesHistory);
}
