.NET 2.0sify, use the same configuration framework as NBXplorer

BTCPayServer/Configuration/ConfigurationExtensions.cs

@@ -0,0 +1,52 @@
+using Microsoft.Extensions.Configuration;
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Net;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Primitives;
+
+namespace BTCPayServer.Configuration
+{
+	public static class ConfigurationExtensions
+	{
+		public static T GetOrDefault<T>(this IConfiguration configuration, string key, T defaultValue)
+		{
+			var str = configuration[key] ?? configuration[key.Replace(".", string.Empty)];
+			if(str == null)
+				return defaultValue;
+			if(typeof(T) == typeof(bool))
+			{
+				var trueValues = new[] { "1", "true" };
+				var falseValues = new[] { "0", "false" };
+				if(trueValues.Contains(str, StringComparer.OrdinalIgnoreCase))
+					return (T)(object)true;
+				if(falseValues.Contains(str, StringComparer.OrdinalIgnoreCase))
+					return (T)(object)false;
+				throw new FormatException();
+			}
+			else if(typeof(T) == typeof(Uri))
+				return (T)(object)new Uri(str, UriKind.Absolute);
+			else if(typeof(T) == typeof(string))
+				return (T)(object)str;
+			else if(typeof(T) == typeof(IPEndPoint))
+			{
+				var separator = str.LastIndexOf(":");
+				if(separator == -1)
+					throw new FormatException();
+				var ip = str.Substring(0, separator);
+				var port = str.Substring(separator + 1);
+				return (T)(object)new IPEndPoint(IPAddress.Parse(ip), int.Parse(port));
+			}
+			else if(typeof(T) == typeof(int))
+			{
+				return (T)(object)int.Parse(str, CultureInfo.InvariantCulture);
+			}
+			else
+			{
+				throw new NotSupportedException("Configuration value does not support time " + typeof(T).Name);
+			}
+		}
+	}
+}