941 Handle offline installation

stevencohn#941
handle offline installation

OneMore/Commands/File/ImportWebCommand.cs

@@ -4,6 +4,7 @@
 
 namespace River.OneMoreAddIn.Commands
 {
+	using Microsoft.Win32;
 	using River.OneMoreAddIn.Models;
 	using River.OneMoreAddIn.UI;
 	using System;
@@ -37,6 +38,9 @@ namespace River.OneMoreAddIn.Commands
 	/// </summary>
 	internal class ImportWebCommand : Command
 	{
+		private const string ClientKey = @"SOFTWARE\WOW6432Node\Microsoft\EdgeUpdate\Clients";
+		private const string RuntimeId = "{F3017226-FE2A-4295-8BDF-00C3A9A7E4C5}";
+
 		private sealed class WebPageInfo
 		{
 			public string Content;
@@ -62,6 +66,13 @@ public override async Task Execute(params object[] args)
 				return;
 			}
 
+			var key = Registry.LocalMachine.OpenSubKey($"{ClientKey}\\{RuntimeId}");
+			if (key == null)
+			{
+				UIHelper.ShowError("Unable to use this command; Edge WebView2 is not installed");
+				return;
+			}
+
 			using (var dialog = new ImportWebDialog())
 			{
 				if (dialog.ShowDialog(owner) != DialogResult.OK)

OneMoreSetupActions/Actions/EdgeWebViewAction.cs

@@ -12,6 +12,7 @@ namespace OneMoreSetupActions
 	using System.IO;
 	using System.Linq;
 	using System.Net.Http;
+	using System.Net.NetworkInformation;
 	using System.Text.RegularExpressions;
 	using System.Threading;
 
@@ -55,8 +56,15 @@ public override int Install()
 			Path.GetTempPath(),
 			Path.GetFileNameWithoutExtension(Path.GetRandomFileName()) + ".exe");
 
+			if (!IsNetworkAvailable())
+			{
+				logger.WriteLine("no internet connection; skipping WebView2 installation");
+				return SUCCESS;
+			}
+
 			if (!DownloadBootstrap(bootstrap))
 			{
+				logger.WriteLine("unable to download WebView2 bootstrap installer");
 				return FAILURE;
 			}
 
@@ -91,6 +99,40 @@ public override int Install()
 		}
 
 
+		private static bool IsNetworkAvailable()
+		{
+			// only recognizes changes related to Internet adapters
+			if (NetworkInterface.GetIsNetworkAvailable())
+			{
+				// however, this will include all adapters
+				var interfaces = NetworkInterface.GetAllNetworkInterfaces();
+				foreach (var face in interfaces)
+				{
+					// filter so we see only Internet adapters
+					if (face.OperationalStatus == OperationalStatus.Up)
+					{
+						if ((face.NetworkInterfaceType != NetworkInterfaceType.Tunnel) &&
+							(face.NetworkInterfaceType != NetworkInterfaceType.Loopback))
+						{
+							var statistics = face.GetIPv4Statistics();
+
+							// all testing seems to prove that once an interface comes online
+							// it has already accrued statistics for both received and sent...
+
+							if ((statistics.BytesReceived > 0) &&
+								(statistics.BytesSent > 0))
+							{
+								return true;
+							}
+						}
+					}
+				}
+			}
+
+			return false;
+		}
+
+
 		private bool DownloadBootstrap(string bootstrap)
 		{
 			using (var client = new HttpClient())