Add ClientContext and ProxiedScanDriver implementation

NAPS2.Core/ClientServer/ClientContext.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.ServiceModel;
+using NAPS2.Util;
+
+namespace NAPS2.ClientServer
+{
+    public class ClientContext : IDisposable
+    {
+        public IServerService Service { get; set; }
+
+        public IServerCallback Callback { get; set; }
+
+        public void Dispose()
+        {
+            try
+            {
+                ((IDisposable)Service)?.Dispose();
+            }
+            catch (CommunicationObjectFaultedException)
+            {
+            }
+            catch (Exception e)
+            {
+                Log.ErrorException("Error cleaning up client", e);
+            }
+        }
+    }
+}

NAPS2.Core/ClientServer/ClientContextFactory.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.ServiceModel;
+using NAPS2.Scan;
+
+namespace NAPS2.ClientServer
+{
+    public class ClientContextFactory
+    {
+        public ClientContext Create(ScanProxyConfig proxyConfig)
+        {
+            // TODO: Validate IP
+            var uri = new Uri($"net.tcp://{proxyConfig.Ip}:{proxyConfig.Port}/NAPS2.Server");
+            var callback = new ServerCallback();
+            var instanceContext = new InstanceContext(callback);
+            var channelFactory = new DuplexChannelFactory<IServerService>(instanceContext,
+                new NetTcpBinding
+                {
+                    MaxReceivedMessageSize = 1024 * 1024 * 1024
+                },
+                new EndpointAddress(uri));
+            var channel = channelFactory.CreateChannel();
+            return new ClientContext { Service = channel, Callback = callback };
+        }
+    }
+}

NAPS2.Core/ClientServer/ProxiedScanDriver.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using NAPS2.Recovery;
+using NAPS2.Scan;
+using NAPS2.Scan.Exceptions;
+using NAPS2.Scan.Images;
+using NAPS2.WinForms;
+
+namespace NAPS2.ClientServer
+{
+    public class ProxiedScanDriver : ScanDriverBase
+    {
+        public const string DRIVER_NAME = "proxy";
+
+        private readonly ClientContextFactory clientContextFactory;
+        private readonly IFormFactory formFactory;
+
+        public ProxiedScanDriver(ClientContextFactory clientContextFactory, IFormFactory formFactory)
+        {
+            this.clientContextFactory = clientContextFactory;
+            this.formFactory = formFactory;
+        }
+
+        public override string DriverName => DRIVER_NAME;
+
+        public override bool IsSupported => true;
+
+        protected override ScanDevice PromptForDeviceInternal()
+        {
+            var deviceList = GetDeviceList();
+
+            if (!deviceList.Any())
+            {
+                throw new NoDevicesFoundException();
+            }
+
+            var form = formFactory.Create<FSelectDevice>();
+            form.DeviceList = deviceList;
+            form.ShowDialog();
+            return form.SelectedDevice;
+        }
+
+        protected override List<ScanDevice> GetDeviceListInternal()
+        {
+            if (ScanProfile == null)
+            {
+                throw new InvalidOperationException("ScanProfile must be set before calling methods on ProxiedScanDriver.");
+            }
+            if (ScanProfile.ProxyConfig == null)
+            {
+                throw new InvalidOperationException("ScanProfile.ProxyConfig must be specified to use ProxiedScanDriver.");
+            }
+
+            using (var client = clientContextFactory.Create(ScanProfile.ProxyConfig))
+            {
+                return client.Service.GetDeviceList(ScanProfile.ProxyConfig.RemoteDriverName);
+            }
+        }
+
+        protected override Task ScanInternal(ScannedImageSource.Concrete source)
+        {
+            if (ScanProfile == null)
+            {
+                throw new InvalidOperationException("ScanProfile must be set before calling methods on ProxiedScanDriver.");
+            }
+            if (ScanProfile.ProxyConfig == null)
+            {
+                throw new InvalidOperationException("ScanProfile.ProxyConfig must be specified to use ProxiedScanDriver.");
+            }
+
+            return Task.Factory.StartNew(() =>
+            {
+                using (var client = clientContextFactory.Create(ScanProfile.ProxyConfig))
+                {
+                    client.Callback.ImageCallback += (imageBytes, indexImage) =>
+                    {
+                        indexImage.FileName = RecoveryImage.GetNextFileName() + Path.GetExtension(indexImage.FileName);
+                        var recoveryFilePath = Path.Combine(RecoveryImage.RecoveryFolder.FullName, indexImage.FileName);
+                        File.WriteAllBytes(recoveryFilePath, imageBytes);
+                        var image = new ScannedImage(indexImage);
+                        // TODO: Post-processing etc.
+                        // TODO: Also add a ScanParams flag to disable post-processing on the server
+                        source.Put(image);
+                    };
+                    client.Service.Scan(ScanProfile, ScanParams);
+                }
+            }, TaskCreationOptions.LongRunning);
+        }
+    }
+}

NAPS2.Core/NAPS2.Core.csproj

@@ -149,8 +149,11 @@
     <Compile Include="Automation\ConsoleOverwritePrompt.cs" />
     <Compile Include="Automation\ConsolePdfPasswordProvider.cs" />
     <Compile Include="Automation\ConsoleComponentInstallPrompt.cs" />
+    <Compile Include="ClientServer\ClientContext.cs" />
+    <Compile Include="ClientServer\ClientContextFactory.cs" />
     <Compile Include="ClientServer\IServerCallback.cs" />
     <Compile Include="ClientServer\IServerService.cs" />
+    <Compile Include="ClientServer\ProxiedScanDriver.cs" />
     <Compile Include="ClientServer\ServerCallback.cs" />
     <Compile Include="ClientServer\ServerService.cs" />
     <Compile Include="Dependencies\ComponentManager.cs" />

NAPS2.Core/Recovery/RecoveryImage.cs

@@ -96,7 +96,7 @@ namespace NAPS2.Recovery
             }
         }
 
-        private static string GetNextFileName()
+        public static string GetNextFileName()
         {
             lock (RecoveryFileNumberLock)
             {

NAPS2.Core/Scan/ScanProfile.cs

@@ -47,6 +47,8 @@ namespace NAPS2.Scan
         [XmlIgnore]
         public bool IsDeviceLocked { get; set; }
 
+        public ScanProxyConfig ProxyConfig { get; set; }
+
         public ScanDevice Device { get; set; }
 
         public string DriverName { get; set; }
@@ -118,6 +120,17 @@ namespace NAPS2.Scan
         public KeyValueScanOptions KeyValueOptions { get; set; }
     }
 
+    public class ScanProxyConfig
+    {
+        public string Name { get; set; }
+
+        public string RemoteDriverName { get; set; }
+
+        public string Ip { get; set; }
+
+        public int Port { get; set; }
+    }
+
     /// <summary>
     /// User configuration for the Auto Save feature, which saves to a file immediately after scanning.
     /// </summary>