Patcher/.idea/.idea.Patcher/.idea/.gitignore

@@ -0,0 +1,13 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Rider ignored files
+/.idea.Patcher.iml
+/modules.xml
+/projectSettingsUpdater.xml
+/contentModel.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

Patcher/.idea/.idea.Patcher/.idea/encodings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding" addBOMForNewFiles="with BOM under Windows, with no BOM otherwise" />
+</project>

Patcher/.idea/.idea.Patcher/.idea/indexLayout.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="UserContentModel">
+    <attachedFolders />
+    <explicitIncludes />
+    <explicitExcludes />
+  </component>
+</project>

Patcher/.idea/.idea.Patcher/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>

Patcher/PatchClient/App.axaml.cs

@@ -6,6 +6,7 @@ using PatchClient.Views;
 using ReactiveUI;
 using System.Reactive;
 using System;
+using System.Linq;
 using PatcherUtils.Model;
 
 namespace PatchClient
@@ -27,13 +28,27 @@ namespace PatchClient
             if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
             {
                 bool autoClose = false;
+                bool debugOutput = false;
 
-                if(desktop.Args != null && desktop.Args.Length >= 1 && desktop.Args[0]?.ToLower() == "autoclose")
-                    autoClose = true;
+                if (desktop.Args != null && desktop.Args.Length >= 1)
+                {
+                    autoClose = desktop.Args.Any(x => x.ToLower() == "autoclose");
+                    debugOutput = desktop.Args.Any(x => x.ToLower() == "debug");
+                }
+
+                if (debugOutput)
+                {
+                    PatchLogger.LogInfo("Running in debug mode");
+                }
+
+                if (autoClose)
+                {
+                    PatchLogger.LogInfo("Running with autoclose");
+                }
 
                 desktop.MainWindow = new MainWindow
                 {
-                    DataContext = new MainWindowViewModel(autoClose),
+                    DataContext = new MainWindowViewModel(autoClose, debugOutput),
                 };
             }
 

Patcher/PatchClient/ViewModels/MainWindowViewModel.cs

@@ -18,11 +18,11 @@ namespace PatchClient.ViewModels
             }
         });
 
-        public MainWindowViewModel(bool autoClose)
+        public MainWindowViewModel(bool autoClose, bool debugOutput)
         {
             this.WhenActivated((CompositeDisposable disposable) =>
             {
-                Router.Navigate.Execute(new PatcherViewModel(this, autoClose));
+                Router.Navigate.Execute(new PatcherViewModel(this, autoClose, debugOutput));
             });
         }
     }

Patcher/PatchClient/ViewModels/PatcherViewModel.cs

@@ -18,6 +18,7 @@ namespace PatchClient.ViewModels
     {
         private bool _initLineItemProgress = true;
         private bool _autoClose = false;
+        private bool _debugOutput = false;
         private Stopwatch _patchStopwatch;
         private Timer _udpatePatchElapsedTimer = new Timer(1000);
 
@@ -52,9 +53,10 @@ namespace PatchClient.ViewModels
         }
 
 
-        public PatcherViewModel(IScreen Host, bool autoClose) : base(Host)
+        public PatcherViewModel(IScreen Host, bool autoClose, bool debugOutput) : base(Host)
         {
             _autoClose = autoClose;
+            _debugOutput = debugOutput;
             ElapsedPatchTimeDetails = "Starting ...";
             _udpatePatchElapsedTimer.Elapsed += _udpatePatchElapsedTimer_Elapsed;
 
@@ -104,7 +106,7 @@ namespace PatchClient.ViewModels
             {
                 LazyOperations.ExtractResourcesToTempDir(Assembly.GetExecutingAssembly());
 
-                PatchHelper patcher = new PatchHelper(Environment.CurrentDirectory, null, LazyOperations.PatchFolder);
+                PatchHelper patcher = new PatchHelper(Environment.CurrentDirectory, null, LazyOperations.PatchFolder, _debugOutput);
 
                 patcher.ProgressChanged += patcher_ProgressChanged;
 

Patcher/PatcherUtils/Model/PatchLogger.cs

@@ -42,6 +42,7 @@ namespace PatcherUtils.Model
             LogToFile($"{GetTimestamp()}[OS]: {RuntimeInformation.OSDescription}");
         }
 
+        public static void LogDebug(string message) => LogToFile($"{GetTimestamp()}[DEBUG]: {message}");
         public static void LogInfo(string message) => LogToFile($"{GetTimestamp()}[INFO]: {message}");
         public static void LogError(string message) => LogToFile($"{GetTimestamp()}[ERROR]: {message}");
         public static void LogException(Exception ex) => LogToFile($"{GetTimestamp()}[EXCEPTION]: {ex.Message}\n\nStackTrace:\n{ex.StackTrace}");

Patcher/PatcherUtils/PatchHelper.cs

@@ -23,6 +23,8 @@ namespace PatcherUtils
         private int delCount;
         private int existCount;
 
+        private bool debugOutput;
+
         private List<LineItem> AdditionalInfo = new List<LineItem>();
 
         /// <summary>
@@ -45,11 +47,12 @@ namespace PatcherUtils
         /// <param name="TargetFolder">The directory to compare against during patch creation.</param>
         /// <param name="DeltaFolder">The directory where the patches are/will be located.</param>
         /// <remarks><paramref name="TargetFolder"/> can be null if you only plan to apply patches.</remarks>
-        public PatchHelper(string SourceFolder, string TargetFolder, string DeltaFolder)
+        public PatchHelper(string SourceFolder, string TargetFolder, string DeltaFolder, bool debugOutput = false)
         {
             this.SourceFolder = SourceFolder;
             this.TargetFolder = TargetFolder;
             this.DeltaFolder = DeltaFolder;
+            this.debugOutput = debugOutput;
         }
 
         /// <summary>
@@ -99,13 +102,74 @@ namespace PatcherUtils
         {
             string decodedPath = SourceFilePath + ".decoded";
 
-            Process.Start(new ProcessStartInfo
+            var xdeltaArgs = $"-d {(debugOutput ? "-v -v" : "")} -f -s";
+
+            if (debugOutput)
+            {
+                try
+                {
+                    var stream = File.Open(SourceFilePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
+                    stream.Close();
+                    stream.Dispose();
+                    PatchLogger.LogDebug($"File is openable: {SourceFilePath}");
+                }
+                catch (Exception ex)
+                {
+                    PatchLogger.LogException(ex);
+                }
+
+                try
+                {
+                    var stream = File.Open(SourceFilePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
+                    stream.Close();
+                    stream.Dispose();
+                    PatchLogger.LogDebug($"File is openable: {DeltaFilePath}");
+                }
+                catch (Exception ex)
+                {
+                    PatchLogger.LogException(ex);
+                }
+            }
+
+            var proc = Process.Start(new ProcessStartInfo
             {
                 FileName = LazyOperations.XDelta3Path,
-                Arguments = $"-d -f -s \"{SourceFilePath}\" \"{DeltaFilePath}\" \"{decodedPath}\"",
+                Arguments = $"{xdeltaArgs} \"{SourceFilePath}\" \"{DeltaFilePath}\" \"{decodedPath}\"",
+                RedirectStandardError = true,
+                RedirectStandardOutput = true,
                 CreateNoWindow = true
-            })
-            .WaitForExit();
+            });
+
+            if (proc == null)
+            {
+                PatchLogger.LogError($"xdelta3 process failed to start: {nameof(proc)} is null");
+                return (false, "xdelta3 process failed to start");
+            }
+            
+            proc.WaitForExit();
+
+            if (debugOutput)
+            {
+                try
+                {
+                    PatchLogger.LogDebug($"xdelta exit code :: {proc.ExitCode}");
+                    PatchLogger.LogDebug("___Dumping xdelta stdout___");
+                    while (!proc.StandardOutput.EndOfStream)
+                    {
+                        PatchLogger.LogDebug(proc.StandardOutput.ReadLine());
+                    }
+
+                    PatchLogger.LogDebug("___Dumping xdelta stderr___");
+                    while (!proc.StandardError.EndOfStream)
+                    {
+                        PatchLogger.LogDebug(proc.StandardError.ReadLine());
+                    }
+                }
+                catch (Exception ex)
+                {
+                    PatchLogger.LogException(ex);
+                }
+            }
 
             if (File.Exists(decodedPath))
             {