Added error when Nitrox is not able to write/read files

NitroxLauncher/LauncherLogic.cs

@@ -9,13 +9,15 @@
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Threading;
 using NitroxLauncher.Events;
 using NitroxLauncher.Pages;
 using NitroxLauncher.Patching;
 using NitroxModel;
 using NitroxModel.Discovery;
 using NitroxModel.Helper;
 using NitroxModel.Logger;
+using NitroxModel.OS;
 
 namespace NitroxLauncher
 {
@@ -128,6 +130,18 @@ public async Task<string> SetTargetedSubnauticaPath(string path)
             lastFindSubnauticaTask = Task.Factory.StartNew(() =>
             {
                 PirateDetection.TriggerOnDirectory(path);
+
+                // TODO: Move this if block to another place where Nitrox installation is verified (will be clear with new Nitrox Launcher design).
+                if (!FileSystem.Instance.SetFullAccessToCurrentUser(Directory.GetCurrentDirectory()) || !FileSystem.Instance.SetFullAccessToCurrentUser(path))
+                {
+                    Dispatcher.CurrentDispatcher.BeginInvoke(() =>
+                    {
+                        MessageBox.Show(Application.Current.MainWindow!, "Restart Nitrox Launcher as admin to allow Nitrox to change permissions as needed. This is only needed once. Nitrox will close after this message.", "Required file permission error", MessageBoxButton.OK,
+                                        MessageBoxImage.Error);
+                        Environment.Exit(1);
+                    }, DispatcherPriority.ApplicationIdle);
+                }
+
                 try
                 {
                     File.WriteAllText("path.txt", path);

NitroxLauncher/MainWindow.xaml.cs

@@ -87,7 +87,7 @@ public MainWindow()
                      {
                          LauncherLogic.Instance.NavigateTo<OptionPage>();
                      }
-
+                     
                      logic.CheckNitroxVersion();
                  }, CancellationToken.None, TaskContinuationOptions.OnlyOnRanToCompletion, TaskScheduler.FromCurrentSynchronizationContext());
         }

NitroxModel/OS/FileSystem.cs

@@ -12,7 +12,7 @@
 
 namespace NitroxModel.OS
 {
-    public class FileSystem
+    public abstract class FileSystem
     {
         private static readonly Lazy<FileSystem> instance = new(() => Environment.OSVersion.Platform switch
                                                                 {
@@ -26,10 +26,6 @@ public class FileSystem
         public static FileSystem Instance => instance.Value;
         public virtual string TextEditor => throw new NotSupportedException();
 
-        protected FileSystem()
-        {
-        }
-
         public virtual IEnumerable<string> GetDefaultPrograms(string file) => throw new NotSupportedException();
 
         /// <summary>
@@ -248,5 +244,7 @@ public bool ReplaceFile(string source, string target)
             }
             return true;
         }
+
+        public abstract bool SetFullAccessToCurrentUser(string directory);
     }
 }

NitroxModel/OS/MacOS/MacFileSystem.cs

@@ -8,5 +8,10 @@ public override IEnumerable<string> GetDefaultPrograms(string file)
         {
             yield return "open";
         }
+
+        public override bool SetFullAccessToCurrentUser(string directory)
+        {
+            throw new System.NotImplementedException();
+        }
     }
 }

NitroxModel/OS/Unix/UnixFileSystem.cs

@@ -8,5 +8,10 @@ public override IEnumerable<string> GetDefaultPrograms(string file)
         {
             yield return "xdg-open";
         }
+
+        public override bool SetFullAccessToCurrentUser(string directory)
+        {
+            throw new System.NotImplementedException();
+        }
     }
 }

NitroxModel/OS/Windows/WinFileSystem.cs

@@ -1,5 +1,8 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.IO;
+using System.Security.AccessControl;
+using System.Security.Principal;
 using Microsoft.Win32;
 
 namespace NitroxModel.OS.Windows
@@ -60,5 +63,29 @@ string SearchExecutableInSameDirectory(string path)
                 yield return fullPath;
             }
         }
+
+        /// <summary>
+        ///     Adds full access flag to the directory (and sub files/directories) for the current user.
+        /// </summary>
+        /// <param name="directory"></param>
+        /// <returns>True if set, false if program is not allowed to change permissions.</returns>
+        public override bool SetFullAccessToCurrentUser(string directory)
+        {
+            try
+            {
+                string identity = WindowsIdentity.GetCurrent().Name;
+
+                DirectorySecurity flags = Directory.GetAccessControl(directory);
+                flags.AddAccessRule(new(identity, FileSystemRights.FullControl, InheritanceFlags.None, PropagationFlags.InheritOnly, AccessControlType.Allow));
+                flags.AddAccessRule(new (identity, FileSystemRights.FullControl, InheritanceFlags.ContainerInherit, PropagationFlags.InheritOnly, AccessControlType.Allow));
+                flags.AddAccessRule(new (identity, FileSystemRights.FullControl, InheritanceFlags.ObjectInherit, PropagationFlags.InheritOnly, AccessControlType.Allow));
+                Directory.SetAccessControl(directory, flags);
+                return true;
+            }
+            catch (UnauthorizedAccessException)
+            {
+                return false;
+            }
+        }
     }
 }