+ Better Exception handling

+ Obfuscate file name and dates

RudeFox.FrontEnd/Models/FileSystemType.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace RudeFox.Models
+{
+    public enum FileSystemType
+    {
+        /// <summary>
+        /// New Technology File System.
+        /// </summary>
+        NTFS,
+        /// <summary>
+        /// File Allocation Table.
+        /// </summary>
+        FAT32,
+        /// <summary>
+        /// Unknown File System.
+        /// </summary>
+        Unknown,
+        /// <summary>
+        /// Used with ExpanDrive.
+        /// </summary>
+        EXFS
+    }
+}

RudeFox.FrontEnd/RudeFox.FrontEnd.csproj

@@ -68,6 +68,7 @@
       <SubType>Code</SubType>
     </Compile>
     <Compile Include="Helpers\Constants.cs" />
+    <Compile Include="Models\FileSystemType.cs" />
     <Compile Include="Models\ItemType.cs" />
     <Compile Include="Services\DialogService.cs" />
     <Compile Include="Services\ShredderService.cs" />

RudeFox.FrontEnd/Services/ShredderService.cs

@@ -1,4 +1,5 @@
 using RudeFox.Helpers;
+using RudeFox.Models;
 using System;
 using System.Collections.Generic;
 using System.IO;
@@ -19,7 +20,8 @@ private ShredderService()
         #endregion
 
         #region Fields
-        private const int MAX_BUFFER_SIZE = 1 * Constants.MEGABYTE;
+        private const int MAX_BUFFER_SIZE = Constants.MEGABYTE;
+        private const int OBFUSCATE_ROUNDS = 5;
 
         Random _random = new Random();
         #endregion
@@ -95,8 +97,7 @@ public async Task<bool> ShredFileAsync(FileInfo file, CancellationToken cancella
             };
 
             if (!file.Exists) return false;
-
-            if (cancellationToken != null) cancellationToken.ThrowIfCancellationRequested();
+            file.IsReadOnly = false;
 
             var result = await OverWriteFileAsync(file, cancellationToken, writeProgress).ConfigureAwait(false);
             if (!result) return result;
@@ -110,6 +111,8 @@ await Task.Run(() =>
                 file.Delete();
             }).ConfigureAwait(false);
 
+            await DestroyEntityMetaData(file);
+
             if (progress != null) progress.Report(1.0);
 
             return true;
@@ -160,15 +163,41 @@ public async Task<bool> ShredFolderAsync(DirectoryInfo folder, CancellationToken
                         if (percent == 1.0)
                             bytesComplete += length;
                     };
+
                     var result = await ShredFolderAsync(dir, cancellationToken, itemProgress).ConfigureAwait(false);
                     if (!result) return result;
                 }
             }
 
+            // BUG: Don't know why this causes issues.
+            // await DestroyEntityMetaData(folder);
             folder.Delete();
+
             return true;
         }
 
+        public bool IsFileLocked(FileInfo file)
+        {
+            FileStream stream = null;
+
+            try
+            {
+                stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None);
+            }
+            catch (IOException)
+            {
+                return true;
+            }
+            finally
+            {
+                if (stream != null) stream.Close();
+            }
+
+            return false;
+        }
+        #endregion
+
+        #region Private Methods
         private async Task<bool> OverWriteFileAsync(FileInfo file, CancellationToken cancellationToken, IProgress<double> progress)
         {
             if (!file.Exists) return false;
@@ -208,25 +237,44 @@ await Task.Run(() =>
 
             return true;
         }
-
-        public bool IsFileLocked(FileInfo file)
+        private async Task<bool> DestroyEntityMetaData(FileSystemInfo entity, FileSystemType fileSystemType = FileSystemType.Unknown)
         {
-            FileStream stream = null;
+            if (!entity.Exists)
+                return false;
 
             try
             {
-                stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None);
+                // prevent the indexing service from locking the file
+                entity.Attributes = FileAttributes.NotContentIndexed;
             }
-            catch (IOException)
+            catch (ArgumentException e)
             {
-                return true;
+                throw new UnauthorizedAccessException(e.Message, e);
             }
-            finally
+
+            await Task.Run(() =>
             {
-                if (stream != null) stream.Close();
-            }
+                // rename the file a few times to remove it from the file system table.
+                for (var round = 0; round < OBFUSCATE_ROUNDS; round++)
+                {
+                    var newPath = Path.Combine(Path.GetDirectoryName(entity.FullName), Path.GetRandomFileName());
 
-            return false;
+                    var file = entity as FileInfo;
+                    var folder = entity as DirectoryInfo;
+
+                    if (file != null)
+                        file.MoveTo(newPath);
+                    else
+                        folder.MoveTo(newPath);
+                }
+
+                var newTime = new DateTime(1981, 1, 1, 0, 0, 1);
+                entity.LastAccessTime = newTime;
+                entity.LastWriteTime = newTime;
+                entity.CreationTime = newTime;
+            });
+
+            return true;
         }
         #endregion
     }

RudeFox.FrontEnd/ViewModels/MainWindowVM.cs

@@ -47,7 +47,6 @@ public ObservableCollection<WorkItemVM> WorkItems
         #endregion
 
         #region Drag and drop
-
         void IDropTarget.DragOver(IDropInfo dropInfo)
         {
             var data = dropInfo.Data as IDataObject;
@@ -90,6 +89,7 @@ private async void DeleteItems(List<string> paths)
                              join p in paths
                              on i.Path equals p
                              select p;
+
             paths.RemoveAll(p => duplicates.Contains(p));
 
             foreach (var path in paths)
@@ -126,8 +126,9 @@ on i.Path equals p
 
             var tasks = newItems.Select(item =>
             {
-                return ShredderService.Instance.ShredItemAsync(item.Path, item.CancellationTokenSource.Token, item.TaskProgress);
-            });
+                item.Task = ShredderService.Instance.ShredItemAsync(item.Path, item.CancellationTokenSource.Token, item.TaskProgress);
+                return item.Task;
+            }).ToList();
 
             try
             {
@@ -139,18 +140,40 @@ on i.Path equals p
             }
             catch (AggregateException exc)
             {
-                var msg = $"{exc.InnerExceptions.Count()} error(s) occured: ";
-                foreach(var ex in exc.InnerExceptions)
+                var failedTasks = tasks.Where(t => t.IsFaulted);
+                tasks.RemoveAll(t => failedTasks.Contains(t));
+
+                var failedItems = WorkItems.Where(item => item.Task.IsFaulted || item.Task.IsCanceled);
+
+                for (int i = 0; i < WorkItems.Count; i++)
                 {
-                    msg += "\n---------------------------";
-                    msg += Environment.NewLine;
-                    msg += ex.ToString();
+                    if (failedItems.Contains(WorkItems[i]))
+                    {
+                        WorkItems.RemoveAt(i);
+                        i--;
+                    }
                 }
-                MessageBox.Show(msg);
+
+                var exception = exc.Flatten();
+                MessageBox.Show(exception.ToString());
+
             }
             catch( Exception exc)
             {
-                var failed = tasks.Where(t => t.IsFaulted);
+                var failedTasks = tasks.Where(t => t.IsFaulted);
+                tasks.RemoveAll(t => failedTasks.Contains(t));
+
+                var failedItems = WorkItems.Where(item => item.Task.IsFaulted || item.Task.IsCanceled);
+
+                for (int i = 0; i < WorkItems.Count; i++)
+                {
+                    if (failedItems.Contains(WorkItems[i]))
+                    {
+                        WorkItems.RemoveAt(i);
+                        i--;
+                    }      
+                }
+
                 MessageBox.Show(exc.ToString());
             }
         }

RudeFox.FrontEnd/ViewModels/WorkItemVM.cs

@@ -63,13 +63,13 @@ public double Progress
             }
         }
 
-        private long _length = -1;
+        private long _bytes = -1;
         public long Bytes
         {
-            get { return _length; }
+            get { return _bytes; }
             set
             {
-                if (SetProperty(ref _length, value))
+                if (SetProperty(ref _bytes, value))
                     RaisePropertyChanged(nameof(Size));
             }
         }
@@ -116,6 +116,13 @@ public string Size
             }
         }
 
+        private Task _task;
+        public Task Task
+        {
+            get { return _task; }
+            set { SetProperty(ref _task, value); }
+        }
+
         public CancellationTokenSource CancellationTokenSource { get; set; }
         public Progress<double> TaskProgress { get; set; }
 
@@ -134,8 +141,10 @@ private async void CalculateBytes()
         {
             if (File.Exists(Path))
                 Bytes = new FileInfo(Path).Length;
-            else
+            else if (Directory.Exists(Path))
                 Bytes = await ShredderService.Instance.GetFolderSize(new DirectoryInfo(Path));
+            else
+                Bytes = -1;
         }
         private void OnDeleteRequested(bool canceled = false)
         {