1 files changed, 36 insertions, 0 deletions
diff --git a/ExcelFunctions.cs b/ExcelFunctions.cs
new file mode 100644
index 0000000..adc2323
--- /dev/null
+++ b/ExcelFunctions.cs
@@ -0,0 +1,36 @@
+using ExcelAddIn.Services;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace ExcelAddIn;
+
+public static class ExcelFunctions
+{
+	[ExcelFunction]
+	public static object ExchangeRate(double dateField)
+	{
+		ICurrencyClient currencyClient = MyAddIn.ServiceProvider.GetService<ICurrencyClient>();
+		DateTime date = dateField == 0 ? DateTime.Today : DateTime.FromOADate(dateField);
+
+		if (ExcelAsyncUtil.Run(nameof(ExchangeRate), dateField, delegate
+		{
+
+			return currencyClient.GetCurrencyCourse(date)
+				.GetAwaiter()
+				.GetResult() ?? -1m;
+		}) is not decimal requestResult)
+		{
+			return "Загрузка...";
+		}
+
+		else if (requestResult < 0)
+		{
+			return ExcelError.ExcelErrorNA;
+		}
+		
+		else
+		{
+			return Math.Round(requestResult, 2);
+		}
+	}
+}
+