WIP: Share as service

NAPS2.Lib.Gtk/EntryPoints/GtkEntryPoint.cs

@@ -14,16 +14,14 @@ public static class GtkEntryPoint
         GLib.ExceptionManager.UnhandledException += UnhandledGtkException;
         EtoPlatform.Current = new GtkEtoPlatform();
 
-        if (args.Length > 0 && args[0] is "cli" or "console")
+        var subArgs = args.Skip(1).ToArray();
+        return args switch
         {
-            return ConsoleEntryPoint.Run(args.Skip(1).ToArray(), new GtkImagesModule());
-        }
-        if (args.Length > 0 && args[0] == "worker")
-        {
-            return WorkerEntryPoint.Run(args.Skip(1).ToArray(), new GtkImagesModule());
-        }
-
-        return GuiEntryPoint.Run(args, new GtkImagesModule(), new GtkModule());
+            ["cli" or "console", ..] => ConsoleEntryPoint.Run(subArgs, new GtkImagesModule()),
+            ["worker", ..] => WorkerEntryPoint.Run(subArgs, new GtkImagesModule()),
+            ["server", ..] => ServerEntryPoint.Run(subArgs, new GtkImagesModule()),
+            _ => GuiEntryPoint.Run(args, new GtkImagesModule(), new GtkModule())
+        };
     }
 
     private static void UnhandledGtkException(GLib.UnhandledExceptionArgs e)

NAPS2.Lib.Mac/EntryPoints/MacEntryPoint.cs

@@ -23,15 +23,13 @@ public static class MacEntryPoint
 
         EtoPlatform.Current = new MacEtoPlatform();
 
-        if (args.Length > 0 && args[0] is "cli" or "console")
+        var subArgs = args.Skip(1).ToArray();
+        return args switch
         {
-            return ConsoleEntryPoint.Run(args.Skip(1).ToArray(), new MacImagesModule());
-        }
-        if (args.Length > 0 && args[0] == "worker")
-        {
-            return MacWorkerEntryPoint.Run(args.Skip(1).ToArray());
-        }
-
-        return GuiEntryPoint.Run(args, new MacImagesModule(), new MacModule());
+            ["cli" or "console", ..] => ConsoleEntryPoint.Run(subArgs, new MacImagesModule()),
+            ["worker", ..] => MacWorkerEntryPoint.Run(subArgs),
+            ["server", ..] => ServerEntryPoint.Run(subArgs, new MacImagesModule()),
+            _ => GuiEntryPoint.Run(args, new MacImagesModule(), new MacModule())
+        };
     }
 }

NAPS2.Lib.Mac/Modules/MacModule.cs

@@ -17,6 +17,7 @@ public class MacModule : GuiModule
         builder.RegisterType<AppleMailEmailProvider>().As<IAppleMailEmailProvider>();
         builder.RegisterType<MacDarkModeProvider>().As<IDarkModeProvider>().SingleInstance();
         builder.RegisterType<MacIconProvider>().As<IIconProvider>();
+        builder.RegisterType<MacServiceManager>().As<IOsServiceManager>();
 
         builder.RegisterType<MacDesktopForm>().As<DesktopForm>();
         builder.RegisterType<MacPreviewForm>().As<PreviewForm>();

NAPS2.Lib.Mac/Platform/MacServiceManager.cs

@@ -0,0 +1,55 @@
+namespace NAPS2.Platform;
+
+/// <summary>
+/// Manages a user-level launchd (https://www.launchd.info/) service on macOS.
+/// </summary>
+// TODO: Is it feasible to run a system-level service?
+public class MacServiceManager : IOsServiceManager
+{
+    private const string SERVICE_NAME = "com.naps2.ScannerSharing";
+
+    private static string PlistPath =>
+        Path.Combine(
+            Environment.GetFolderPath(Environment.SpecialFolder.UserProfile),
+            $"Library/LaunchAgents/{SERVICE_NAME}.plist");
+
+    public bool IsRegistered => File.Exists(PlistPath);
+
+    public void Register()
+    {
+        var serviceDef = $"""
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+	<dict>
+		<key>Label</key>
+		<string>{SERVICE_NAME}</string>
+		<key>Program</key>
+		<string>{Environment.ProcessPath}</string>
+		<key>ProgramArguments</key>
+		<array>
+			<string>{Environment.ProcessPath}</string>
+			<string>server</string>
+		</array>
+		<key>RunAtLoad</key>
+		<true/>
+	</dict>
+</plist>
+""";
+        File.WriteAllText(PlistPath, serviceDef);
+        if (!ProcessHelper.TryRun("launchctl", $"load \"{PlistPath}\"", 1000))
+        {
+            Log.Error($"Could not load service {SERVICE_NAME}");
+        }
+    }
+
+    public void Unregister()
+    {
+	    // TODO: Longer timeout / run async?
+        if (!ProcessHelper.TryRun("launchctl", $"unload \"{PlistPath}\"", 1000))
+        {
+            Log.Error($"Could not unload service {SERVICE_NAME}");
+        }
+        File.Delete(PlistPath);
+    }
+}

NAPS2.Lib.WinForms/EntryPoints/WinFormsEntryPoint.cs

@@ -13,11 +13,12 @@ public static class WinFormsEntryPoint
     {
         EtoPlatform.Current = new WinFormsEtoPlatform();
 
-        if (args.Length > 0 && args[0] == "worker")
+        var subArgs = args.Skip(1).ToArray();
+        return args switch
         {
-            return WindowsWorkerEntryPoint.Run(args.Skip(1).ToArray());
-        }
-
-        return GuiEntryPoint.Run(args, new GdiModule(), new WinFormsModule());
+            ["worker", ..] => WindowsWorkerEntryPoint.Run(subArgs),
+            ["server", ..] => ServerEntryPoint.Run(subArgs, new GdiModule()),
+            _ => GuiEntryPoint.Run(args, new GdiModule(), new WinFormsModule())
+        };
     }
 }

NAPS2.Lib/EntryPoints/ServerEntryPoint.cs

@@ -0,0 +1,49 @@
+using System.Threading;
+using Autofac;
+using NAPS2.Modules;
+using NAPS2.Remoting.Server;
+using NAPS2.Remoting.Worker;
+using NAPS2.Scan;
+
+namespace NAPS2.EntryPoints;
+
+/// <summary>
+/// The entry point for NAPS2 running as a server for scanner sharing.
+/// </summary>
+public static class ServerEntryPoint
+{
+    public static int Run(string[] args, Module imageModule, Action<IContainer>? run = null)
+    {
+        // Initialize Autofac (the DI framework)
+        var container = AutoFacHelper.FromModules(
+            new CommonModule(), imageModule, new WorkerModule(), new ContextModule());
+
+        TaskScheduler.UnobservedTaskException += UnhandledTaskException;
+
+        // Start a pending worker process
+        container.Resolve<IWorkerFactory>().Init(container.Resolve<ScanningContext>());
+
+        run ??= _ =>
+        {
+            var sharedDeviceManager = container.Resolve<ISharedDeviceManager>();
+            sharedDeviceManager.StartSharing();
+            AppDomain.CurrentDomain.ProcessExit += (_, _) =>
+            {
+                // TODO: Actually wait for sharing to stop
+                sharedDeviceManager.StopSharing();
+            };
+            var reset = new ManualResetEvent(false);
+            Console.CancelKeyPress += (_, _) => reset.Set();
+            reset.WaitOne();
+        };
+        run(container);
+
+        return 0;
+    }
+
+    private static void UnhandledTaskException(object? sender, UnobservedTaskExceptionEventArgs e)
+    {
+        Log.FatalException("An error occurred that caused the server task to terminate.", e.Exception);
+        e.SetObserved();
+    }
+}

NAPS2.Lib/EtoForms/Ui/ScannerSharingForm.cs

@@ -9,17 +9,25 @@ namespace NAPS2.EtoForms.Ui;
 public class ScannerSharingForm : EtoDialogBase
 {
     private readonly ISharedDeviceManager _sharedDeviceManager;
+    private readonly IOsServiceManager _osServiceManager;
+    private readonly ErrorOutput _errorOutput;
 
+    private readonly CheckBox _shareAsService = C.CheckBox(UiStrings.ShareAsService);
     private readonly IListView<SharedDevice> _listView;
 
     private readonly Command _addCommand;
     private readonly Command _editCommand;
     private readonly Command _deleteCommand;
 
-    public ScannerSharingForm(Naps2Config config, SharedDevicesListViewBehavior listViewBehavior, ISharedDeviceManager sharedDeviceManager)
+    private bool _suppressChangeEvent;
+
+    public ScannerSharingForm(Naps2Config config, SharedDevicesListViewBehavior listViewBehavior,
+        ISharedDeviceManager sharedDeviceManager, IOsServiceManager osServiceManager, ErrorOutput errorOutput)
         : base(config)
     {
         _sharedDeviceManager = sharedDeviceManager;
+        _osServiceManager = osServiceManager;
+        _errorOutput = errorOutput;
 
         _listView = EtoPlatform.Current.CreateListView(listViewBehavior);
         _addCommand = new ActionCommand(DoAdd)
@@ -39,6 +47,8 @@ public class ScannerSharingForm : EtoDialogBase
             Shortcut = Keys.Delete
         };
 
+        _shareAsService.Checked = _osServiceManager.IsRegistered;
+        _shareAsService.CheckedChanged += ShareAsServiceCheckedChanged;
         _listView.ImageSize = 48;
         _listView.SelectionChanged += SelectionChanged;
 
@@ -64,6 +74,7 @@ public class ScannerSharingForm : EtoDialogBase
 
         LayoutController.Content = L.Column(
             C.Label(UiStrings.ScannerSharingIntro).DynamicWrap(400),
+            _shareAsService,
             C.Spacer(),
             _listView.Control.Scale().NaturalHeight(80),
             L.Row(
@@ -100,6 +111,34 @@ public class ScannerSharingForm : EtoDialogBase
         _deleteCommand.Enabled = SelectedDevice != null;
     }
 
+    private void ShareAsServiceCheckedChanged(object? sender, EventArgs e)
+    {
+        if (_suppressChangeEvent) return;
+        _suppressChangeEvent = true;
+        try
+        {
+            if (_shareAsService.IsChecked())
+            {
+                _osServiceManager.Register();
+            }
+            else
+            {
+                _osServiceManager.Unregister();
+            }
+        }
+        catch (Exception ex)
+        {
+            // TODO: Maybe we display a generic string here?
+            Log.ErrorException(ex.Message, ex);
+            _errorOutput.DisplayError(ex.Message, ex);
+            _shareAsService.Checked = _osServiceManager.IsRegistered;
+        }
+        finally
+        {
+            _suppressChangeEvent = false;
+        }
+    }
+
     private void DoAdd()
     {
         var fedit = FormFactory.Create<SharedDeviceForm>();

NAPS2.Lib/ImportExport/Email/ThunderbirdEmailProvider.cs

@@ -13,7 +13,7 @@ public class ThunderbirdEmailProvider : IEmailProvider
 
     // Note we can't really support the Flatpak version of Thunderbird as it won't have access to attachment files from
     // the sandbox.
-    public bool IsAvailable => ProcessHelper.IsSuccessful("thunderbird", "-v", 1000);
+    public bool IsAvailable => ProcessHelper.TryRun("thunderbird", "-v", 1000);
 
     public Task<bool> SendEmail(EmailMessage message, ProgressHandler progress = default)
     {

NAPS2.Lib/Lang/Resources/UiStrings.Designer.cs

@@ -2191,5 +2191,14 @@ namespace NAPS2.Lang.Resources {
                 return ResourceManager.GetString("ZoomOut", resourceCulture);
             }
         }
+
+        /// <summary>
+        ///   Looks up a localized string similar to Share even when NAPS2 is closed.
+        /// </summary>
+        internal static string ShareAsService {
+            get {
+                return ResourceManager.GetString("ShareAsService", resourceCulture);
+            }
+        }
     }
 }

NAPS2.Lib/Lang/Resources/UiStrings.resx

@@ -828,4 +828,7 @@
   <data name="ConfirmDeleteSharedDevice" xml:space="preserve">
     <value>Are you sure you want to stop sharing {0}?</value>
   </data>
+  <data name="ShareAsService" xml:space="preserve">
+    <value>Share even when NAPS2 is closed</value>
+  </data>
 </root>

NAPS2.Lib/Platform/IOsServiceManager.cs

@@ -0,0 +1,13 @@
+namespace NAPS2.Platform;
+
+/// <summary>
+/// Abstraction for OS-specific "run on startup" registration logic.
+/// </summary>
+public interface IOsServiceManager
+{
+    bool IsRegistered { get; }
+
+    void Register();
+
+    void Unregister();
+}

NAPS2.Lib/Util/ProcessHelper.cs

@@ -16,7 +16,7 @@ public static class ProcessHelper
 
     public static void OpenFolder(string folder) => OpenFile(folder);
 
-    public static bool IsSuccessful(string command, string args, int timeoutMs)
+    public static bool TryRun(string command, string args, int timeoutMs)
     {
         try
         {