RhSolutions-AddIn/RhSolutions.AddIn/AddIn/CurrencyFunctions.cs

namespace RhSolutions.AddIn;

public static class CurrencyFunctions
{
    private static readonly ICurrencyClient currencyClient =
        RhSolutionsAddIn.ServiceProvider.GetRequiredService<ICurrencyClient>();

    [ExcelFunction(Name = "КУРСЕВРО")]
    public static object GetEuroCurrencyRate(double dateField)
    {
        DateTime date = dateField == 0 ? DateTime.Today : DateTime.FromOADate(dateField);
        var functionName = nameof(GetEuroCurrencyRate);
        var parameters = new object[] { date };

        var exchangeRate = ExcelAsyncUtil.RunTask(functionName, parameters, async () =>
        {
            var requestResult = await currencyClient.GetExchangeRate(date);            return requestResult ?? -1m;
        });

        if (exchangeRate is not decimal)
        {
            return "Загрузка...";
        }

        return (decimal)exchangeRate < 0 ? ExcelError.ExcelErrorNA : exchangeRate;
    }
}