From 9b34863a06af20512dc03944492232bad018420f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niggemann=2C=20Andr=C3=A9=20=28n7md82=29?=
 <aniggemann@phoenixcontact.com>
Date: Thu, 23 Nov 2023 08:09:23 +0100
Subject: [PATCH] Add MoryxService to handle closing the console window. Add
 extension method to KernelServiceCollectionExtensions to use the
 MoryxService. Add dependency to Microsoft.Extensions.Hosting to make
 background services available.

---
 Directory.Build.targets                       |  1 +
 .../KernelServiceCollectionExtensions.cs      |  9 +++
 .../Moryx.Runtime.Kernel.csproj               |  2 +-
 src/Moryx.Runtime.Kernel/MoryxService.cs      | 81 +++++++++++++++++++
 4 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 src/Moryx.Runtime.Kernel/MoryxService.cs

diff --git a/Directory.Build.targets b/Directory.Build.targets
index 801993952..7cabbb043 100644
--- a/Directory.Build.targets
+++ b/Directory.Build.targets
@@ -33,6 +33,7 @@
 		<PackageReference Update="Microsoft.Extensions.Logging" Version="$(dotnetVersion)" />
 		<PackageReference Update="Microsoft.Extensions.Configuration.Json" Version="$(dotnetVersion)" />
 		<PackageReference Update="Microsoft.Extensions.Configuration.FileExtensions" Version="$(dotnetVersion)" />
+        <PackageReference Update="Microsoft.Extensions.Hosting" Version="$(dotnetVersion)" />
 		<PackageReference Update="Microsoft.Data.Sqlite" Version="$(dotnetVersion)" />
 
 		<PackageReference Update="Microsoft.EntityFrameworkCore" Version="$(efCoreVersion)" />
diff --git a/src/Moryx.Runtime.Kernel/KernelServiceCollectionExtensions.cs b/src/Moryx.Runtime.Kernel/KernelServiceCollectionExtensions.cs
index 83bc5b833..4ca6b5931 100644
--- a/src/Moryx.Runtime.Kernel/KernelServiceCollectionExtensions.cs
+++ b/src/Moryx.Runtime.Kernel/KernelServiceCollectionExtensions.cs
@@ -74,6 +74,15 @@ public static void AddMoryxModules(this IServiceCollection serviceCollection)
             }
         }
 
+        /// <summary>
+        /// Register BackgroundService that controls that starts and stops the MORYX modules inside the lifetime of the host.
+        /// The MORYX Service can hook into the command line and gracefuly stop the modules when the user tries to close the window.
+        /// </summary>
+        public static void AddMoryxService(this IServiceCollection serviceCollection)
+        {
+            serviceCollection.AddHostedService<MoryxService>();
+        }
+        
         /// <summary>
         /// Use the moryx config manager
         /// </summary>
diff --git a/src/Moryx.Runtime.Kernel/Moryx.Runtime.Kernel.csproj b/src/Moryx.Runtime.Kernel/Moryx.Runtime.Kernel.csproj
index fdc0e91d4..e08ab3cbd 100644
--- a/src/Moryx.Runtime.Kernel/Moryx.Runtime.Kernel.csproj
+++ b/src/Moryx.Runtime.Kernel/Moryx.Runtime.Kernel.csproj
@@ -11,6 +11,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Json" />
+    <PackageReference Include="Microsoft.Extensions.Hosting" />
   </ItemGroup>
 
   <ItemGroup>
@@ -18,6 +19,5 @@
     <ProjectReference Include="..\Moryx.Container\Moryx.Container.csproj" />
     <ProjectReference Include="..\Moryx.Runtime\Moryx.Runtime.csproj" />
   </ItemGroup>
-
 </Project>
  
\ No newline at end of file
diff --git a/src/Moryx.Runtime.Kernel/MoryxService.cs b/src/Moryx.Runtime.Kernel/MoryxService.cs
new file mode 100644
index 000000000..b020ec1a8
--- /dev/null
+++ b/src/Moryx.Runtime.Kernel/MoryxService.cs
@@ -0,0 +1,81 @@
+using Castle.Core.Logging;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Moryx.Runtime.Modules;
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Moryx.Runtime.Kernel
+{
+    internal class MoryxService : BackgroundService
+    {
+        private readonly IModuleManager moduleManager;
+        private readonly IHost lifeTime;
+        private readonly ILogger<MoryxService> logger;
+
+        // Console shutdown handling according to https://stackoverflow.com/questions/21751545/how-to-make-a-console-app-exit-gracefully-when-it-is-closed
+        [DllImport("Kernel32")]
+        public static extern bool SetConsoleCtrlHandler(HandlerRoutine Handler, bool Add);
+
+        // A delegate type to be used as the handler routine 
+        // for SetConsoleCtrlHandler.
+        public delegate bool HandlerRoutine(CtrlTypes CtrlType);
+
+        // An enumerated type for the control messages
+        // sent to the handler routine.
+        public enum CtrlTypes
+        {
+            CTRL_C_EVENT = 0,
+            CTRL_BREAK_EVENT,
+            CTRL_CLOSE_EVENT,
+            CTRL_LOGOFF_EVENT = 5,
+            CTRL_SHUTDOWN_EVENT
+        }
+
+        /// <summary>
+        /// Callback that is called when a console event is raised.
+        /// </summary>
+        /// <param name="ctrlType"></param>
+        /// <returns></returns>
+        private bool ConsoleCtrlCheck(CtrlTypes ctrlType)
+        {
+            // Stop the host and await shutdown.
+            lifeTime.StopAsync(TimeSpan.FromSeconds(100)).ContinueWith(task =>
+            {
+                if (task.IsFaulted)
+                {
+                    logger.LogError(task.Exception, "Received failure on shutdown.");
+                }
+            }).Wait();
+            return true;
+        }
+
+        public MoryxService(IModuleManager moduleManager, IHost lifetTime, ILogger<MoryxService> logger)
+        {
+            this.moduleManager = moduleManager;
+            this.lifeTime = lifetTime;
+            this.logger = logger;
+        }
+
+        public override async Task StartAsync(CancellationToken cancellationToken)
+        {
+            SetConsoleCtrlHandler(ConsoleCtrlCheck, true);
+            moduleManager.StartModules();
+            await base.StartAsync(cancellationToken);
+        }
+        protected override Task ExecuteAsync(CancellationToken stoppingToken)
+        {
+            return Task.CompletedTask;
+        }
+
+        public override async Task StopAsync(CancellationToken cancellationToken)
+        {
+            moduleManager.StopModules();
+            await base.StopAsync(cancellationToken);
+        }
+    }
+}