/// <summary>
/// get daily exchange rate for the given currencies and date;
/// TODO: might even collect the latest exchange rate from the web
/// </summary>
/// <param name="ACurrencyFrom"></param>
/// <param name="ACurrencyTo"></param>
/// <param name="ADateEffective"></param>
/// <returns>Zero if no exchange rate found</returns>
public static decimal GetDailyExchangeRate(string ACurrencyFrom, string ACurrencyTo, DateTime ADateEffective)
{
if (ACurrencyFrom == ACurrencyTo)
{
return(1.0M);
}
bool NewTransaction;
TDBTransaction Transaction = DBAccess.GDBAccessObj.GetNewOrExistingTransaction
(IsolationLevel.ReadCommitted, TEnforceIsolationLevel.eilMinimum, out NewTransaction);
ADailyExchangeRateRow fittingRate = null;
// TODO: get the most recent exchange rate for the given date and currencies
bool oppositeRate = false;
ADailyExchangeRateTable rates = ADailyExchangeRateAccess.LoadByPrimaryKey(ACurrencyFrom, ACurrencyTo, ADateEffective, 0, Transaction);
if (rates.Count == 0)
{
// try other way round
rates = ADailyExchangeRateAccess.LoadByPrimaryKey(ACurrencyTo, ACurrencyFrom, ADateEffective, 0, Transaction);
oppositeRate = true;
}
if (rates.Count == 1)
{
fittingRate = rates[0];
}
else if (rates.Count == 0)
{
// TODO: collect exchange rate from the web; save to db
// see tracker http://sourceforge.net/apps/mantisbt/openpetraorg/view.php?id=87
// Or look for most recent exchange rate???
ADailyExchangeRateTable tempTable = new ADailyExchangeRateTable();
ADailyExchangeRateRow templateRow = tempTable.NewRowTyped(false);
templateRow.FromCurrencyCode = ACurrencyFrom;
templateRow.ToCurrencyCode = ACurrencyTo;
oppositeRate = false;
rates = ADailyExchangeRateAccess.LoadUsingTemplate(templateRow, Transaction);
if (rates.Count == 0)
{
templateRow.FromCurrencyCode = ACurrencyTo;
templateRow.ToCurrencyCode = ACurrencyFrom;
oppositeRate = true;
rates = ADailyExchangeRateAccess.LoadUsingTemplate(templateRow, Transaction);
}
if (rates.Count > 0)
{
// sort rates by date, look for rate just before the date we are looking for
rates.DefaultView.Sort = ADailyExchangeRateTable.GetDateEffectiveFromDBName();
rates.DefaultView.RowFilter = ADailyExchangeRateTable.GetDateEffectiveFromDBName() + "<= #" +
ADateEffective.ToString("yyyy-MM-dd") + "#";
if (rates.DefaultView.Count > 0)
{
fittingRate = (ADailyExchangeRateRow)rates.DefaultView[rates.DefaultView.Count - 1].Row;
}
}
}
if (NewTransaction)
{
DBAccess.GDBAccessObj.RollbackTransaction();
}
if (fittingRate != null)
{
if (oppositeRate)
{
return(1.0M / fittingRate.RateOfExchange);
}
return(fittingRate.RateOfExchange);
}
TLogging.Log("Cannot find daily exchange rate for " + ACurrencyFrom + " " + ACurrencyTo);
//return 1.0M;
//Instead, cause a validation error to force the user to select an exchange rate
return(0M);
}
