Removed database status in favor of much cleaner code

Implemented (but deactivated) anti corruption mechanism
WIP detect changes and save them if opening another database

ModernKeePass/App.xaml.cs

@@ -46,9 +46,16 @@ namespace ModernKeePass
                     ? exception.InnerException
                     : exception;
 
-            if (!(realException is SaveException)) return;
-            unhandledExceptionEventArgs.Handled = true;
-            MessageDialogHelper.SaveErrorDialog(realException as SaveException, Database);
+            if (realException is SaveException)
+            {
+                unhandledExceptionEventArgs.Handled = true;
+                MessageDialogHelper.SaveErrorDialog(realException as SaveException, Database);
+            }
+            else if (realException is DatabaseOpenedException)
+            {
+                unhandledExceptionEventArgs.Handled = true;
+                MessageDialogHelper.SaveUnchangedDialog(realException as DatabaseOpenedException, Database);
+            }
         }
 
         /// <summary>

ModernKeePass/Common/MessageDialogHelper.cs

@@ -2,7 +2,6 @@
 using System.Collections.Generic;
 using Windows.Storage.Pickers;
 using Windows.UI.Popups;
-using Windows.UI.Xaml.Media.Animation;
 using ModernKeePass.Exceptions;
 using ModernKeePass.Interfaces;
 
@@ -10,13 +9,16 @@ namespace ModernKeePass.Common
 {
     public static class MessageDialogHelper
     {
-        public static async void ShowActionDialog(string title, string contentText, string actionButtonText, string cancelButtonText, UICommandInvokedHandler action)
+        // TODO: include resources
+        public static async void ShowActionDialog(string title, string contentText, string actionButtonText, string cancelButtonText, UICommandInvokedHandler actionCommand, UICommandInvokedHandler cancelCommand)
         {
             // Create the message dialog and set its content
             var messageDialog = CreateBasicDialog(title, contentText, cancelButtonText);
 
             // Add commands and set their callbacks; both buttons use the same callback function instead of inline event handlers
-            messageDialog.Commands.Add(new UICommand(actionButtonText, action));
+            messageDialog.Commands.Add(new UICommand(actionButtonText, actionCommand));
+            // TODO: correct this
+            //messageDialog.Commands.Add(new UICommand(cancelButtonText, cancelCommand));
             
             // Show the message dialog
             await messageDialog.ShowAsync();
@@ -35,6 +37,19 @@ namespace ModernKeePass.Common
 
                 var file = await savePicker.PickSaveFileAsync();
                 if (file != null) database.Save(file);
+            }, null);
+        }
+
+        public static void SaveUnchangedDialog(DatabaseOpenedException exception, IDatabase database)
+        {
+            ShowActionDialog("Opened database", $"Database {database.Name} is currently opened. What to you wish to do?", "Save changes", "Discard", command => 
+            {
+                database.Save();
+                database.Close();
+            },
+            command =>
+            {
+                database.Close();
             });
         }
 

ModernKeePass/Exceptions/DatabaseOpenedException.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace ModernKeePass.Exceptions
+{
+    public class DatabaseOpenedException: Exception
+    {
+
+    }
+}

ModernKeePass/Interfaces/IDatabase.cs

@@ -1,4 +1,5 @@
-using Windows.Storage;
+using System.Threading.Tasks;
+using Windows.Storage;
 using ModernKeePass.ViewModels;
 using ModernKeePassLib;
 using ModernKeePassLib.Cryptography.KeyDerivation;
@@ -10,20 +11,23 @@ namespace ModernKeePass.Interfaces
     {
         string Name { get; }
         bool RecycleBinEnabled { get; set; }
-        int Status { get; set; }
+        //int Status { get; set; }
         GroupVm RootGroup { get; set; }
         GroupVm RecycleBin { get; set; }
         StorageFile DatabaseFile { get; set; }
         PwUuid DataCipher { get; set; }
         PwCompressionAlgorithm CompressionAlgorithm { get; set; }
         KdfParameters KeyDerivation { get; set; }
+        bool IsOpen { get; }
+        bool IsFileOpen { get; }
+        bool IsClosed { get; }
 
-        void Open(CompositeKey key, bool createNew);
+        Task Open(CompositeKey key, bool createNew);
         void UpdateCompositeKey(CompositeKey key);
         void Save();
         void Save(StorageFile file);
         void CreateRecycleBin();
         void AddDeletedItem(PwUuid id);
-        void Close();
+        Task Close();
     }
 }

ModernKeePass/ModernKeePassApp.csproj

@@ -114,6 +114,7 @@
     <Compile Include="App.xaml.cs">
       <DependentUpon>App.xaml</DependentUpon>
     </Compile>
+    <Compile Include="Exceptions\DatabaseOpenedException.cs" />
     <Compile Include="Interfaces\ILicenseService.cs" />
     <Compile Include="Interfaces\IRecent.cs" />
     <Compile Include="Interfaces\IRecentItem.cs" />

ModernKeePass/Services/DatabaseService.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading.Tasks;
 using Windows.Storage;
 using Windows.UI.Xaml.Controls;
 using ModernKeePass.Exceptions;
@@ -16,7 +17,7 @@ namespace ModernKeePass.Services
 {
     public class DatabaseService: IDatabase
     {
-        public enum DatabaseStatus
+        /*public enum DatabaseStatus
         {
             Error = -3,
             NoCompositeKey = -2,
@@ -24,9 +25,10 @@ namespace ModernKeePass.Services
             Closed = 0,
             Opening = 1,
             Opened = 2
-        }
+        }*/
         private readonly PwDatabase _pwDatabase = new PwDatabase();
         private readonly ISettings _settings;
+        private StorageFile _realDatabaseFile;
         private StorageFile _databaseFile;
         private GroupVm _recycleBin;
 
@@ -42,7 +44,7 @@ namespace ModernKeePass.Services
             }
         }
         
-        public int Status { get; set; } = (int)DatabaseStatus.Closed;
+        //public int Status { get; set; } = (int)DatabaseStatus.Closed;
         public string Name => DatabaseFile?.Name;
         
         public bool RecycleBinEnabled
@@ -56,8 +58,28 @@ namespace ModernKeePass.Services
             get { return _databaseFile; }
             set
             {
+                // No file, database is closed
+                /*if (value == null)
+                    Status = (int) DatabaseStatus.Closed;
+                else
+                {
+                    // There already is an opened file
+                    if (Status == (int) DatabaseStatus.Opened)
+                    {
+                        if (_pwDatabase.Modified)
+                            throw new DatabaseOpenedException();
+                        Close().GetAwaiter().GetResult();
+                    }
+                    _databaseFile = value;
+                    Status = (int) DatabaseStatus.Opening;
+                }*/
+                if (IsOpen)
+                {
+                    //if (_pwDatabase.Modified)
+                        throw new DatabaseOpenedException();
+                    //Close().GetAwaiter().GetResult();
+                }
                 _databaseFile = value;
-                Status = (int)DatabaseStatus.Opening;
             }
         }
 
@@ -79,6 +101,10 @@ namespace ModernKeePass.Services
             set { _pwDatabase.KdfParameters = value; }
         }
 
+        public bool IsOpen => _pwDatabase.IsOpen;
+        public bool IsFileOpen => !_pwDatabase.IsOpen && _databaseFile != null;
+        public bool IsClosed => _databaseFile == null;
+
         public DatabaseService() : this(new SettingsService())
         { }
 
@@ -93,14 +119,16 @@ namespace ModernKeePass.Services
         /// <param name="key">The database composite key</param>
         /// <param name="createNew">True to create a new database before opening it</param>
         /// <returns>An error message, if any</returns>
-        public void Open(CompositeKey key, bool createNew = false)
+        public async Task Open(CompositeKey key, bool createNew = false)
         {
+            // TODO: Check if there is an existing backup file
             try
             {
                 if (key == null)
                 {
-                    Status = (int)DatabaseStatus.NoCompositeKey;
-                    return;
+                    //Status = (int)DatabaseStatus.NoCompositeKey;
+                    //return;
+                    throw new ArgumentNullException(nameof(key));
                 }
                 var ioConnection = IOConnectionInfo.FromFile(DatabaseFile);
                 if (createNew)
@@ -120,17 +148,51 @@ namespace ModernKeePass.Services
                 else _pwDatabase.Open(ioConnection, key, new NullStatusLogger());
 
                 if (!_pwDatabase.IsOpen) return;
-                Status = (int)DatabaseStatus.Opened;
+
+                // Copy database in temp directory and use this file for operations
+                if (_settings.GetSetting<bool>("AntiCorruption"))
+                {
+                    _realDatabaseFile = _databaseFile;
+                    var backupFile =
+                        await ApplicationData.Current.RoamingFolder.CreateFileAsync(Name,
+                            CreationCollisionOption.FailIfExists);
+                    Save(backupFile);
+                }
+
+                //Status = (int)DatabaseStatus.Opened;
                 RootGroup = new GroupVm(_pwDatabase.RootGroup, null, RecycleBinEnabled ? _pwDatabase.RecycleBinUuid : null);
             }
-            catch (InvalidCompositeKeyException)
+            catch (InvalidCompositeKeyException ex)
             {
-                Status = (int)DatabaseStatus.CompositeKeyError;
+                //Status = (int)DatabaseStatus.CompositeKeyError;
+                throw new ArgumentException(ex.Message, ex);
             }
-            catch (Exception)
+            /*catch (Exception)
             {
-                Status = (int)DatabaseStatus.Error;
+                //Status = (int)DatabaseStatus.Error;
                 throw;
+            }*/
+        }
+
+        /// <summary>
+        /// Commit the changes to the currently opened database to file
+        /// </summary>
+        public void Save()
+        {
+            if (!_pwDatabase.IsOpen) return;
+            try
+            {
+                _pwDatabase.Save(new NullStatusLogger());
+
+                // Test if save worked correctly
+                if (_settings.GetSetting<bool>("AntiCorruption"))
+                {
+                    _pwDatabase.Open(_pwDatabase.IOConnectionInfo, _pwDatabase.MasterKey, new NullStatusLogger());
+                }
+            }
+            catch (Exception e)
+            {
+                throw new SaveException(e);
             }
         }
 
@@ -151,35 +213,28 @@ namespace ModernKeePass.Services
                 DatabaseFile = oldFile;
                 throw;
             }
-            finally
+            /*finally
             {
                 Status = (int)DatabaseStatus.Opened;
-            }
-        }
-
-        /// <summary>
-        /// Commit the changes to the currently opened database to file
-        /// </summary>
-        public void Save()
-        {
-            if (_pwDatabase == null || !_pwDatabase.IsOpen) return;
-            try
-            {
-                _pwDatabase.Save(new NullStatusLogger());
-            }
-            catch (Exception e)
-            {
-                throw new SaveException(e);
-            }
+            }*/
         }
 
         /// <summary>
         /// Close the currently opened database
         /// </summary>
-        public void Close()
+        public async Task Close()
         {
             _pwDatabase?.Close();
-            Status = (int)DatabaseStatus.Closed;
+
+            // Restore the backup DB to the original one
+            if (_settings.GetSetting<bool>("AntiCorruption"))
+            {
+                if (_pwDatabase.Modified)
+                    Save(_realDatabaseFile);
+                await DatabaseFile.DeleteAsync();
+            }
+            DatabaseFile = null;
+
         }
 
         public void AddDeletedItem(PwUuid id)

ModernKeePass/ViewModels/CompositeKeyVm.cs

@@ -124,37 +124,31 @@ namespace ModernKeePass.ViewModels
 
         public async Task<bool> OpenDatabase(bool createNew)
         {
-            var error = string.Empty;
             try
             {
                 _isOpening = true;
-                Database.Open(CreateCompositeKey(), createNew);
+                await Database.Open(CreateCompositeKey(), createNew);
+                await Task.Run(() => RootGroup = Database.RootGroup);
+                return true;
+            }
+            catch (ArgumentException)
+            {
+                var errorMessage = new StringBuilder(_resource.GetResourceValue("CompositeKeyErrorUserStart"));
+                if (HasPassword) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserPassword"));
+                if (HasPassword && HasKeyFile) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserOr"));
+                if (HasKeyFile) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserKeyFile"));
+                if (HasKeyFile) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserAccount"));
+                UpdateStatus(errorMessage.ToString(), StatusTypes.Error);
             }
             catch (Exception e)
             {
-                error = $"{_resource.GetResourceValue("CompositeKeyErrorOpen")}: {e.Message}";
+                var error = $"{_resource.GetResourceValue("CompositeKeyErrorOpen")}: {e.Message}";
+                UpdateStatus(error, StatusTypes.Error);
             }
             finally
             {
                 _isOpening = false;
             }
-            switch ((DatabaseService.DatabaseStatus)Database.Status)
-            {
-                case DatabaseService.DatabaseStatus.Opened:
-                    await Task.Run(() => RootGroup = Database.RootGroup);
-                    return true;
-                case DatabaseService.DatabaseStatus.CompositeKeyError:
-                    var errorMessage = new StringBuilder(_resource.GetResourceValue("CompositeKeyErrorUserStart"));
-                    if (HasPassword) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserPassword"));
-                    if (HasPassword && HasKeyFile) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserOr"));
-                    if (HasKeyFile) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserKeyFile"));
-                    if (HasKeyFile) errorMessage.Append(_resource.GetResourceValue("CompositeKeyErrorUserAccount"));
-                    UpdateStatus(errorMessage.ToString(), StatusTypes.Error);
-                    break;
-                case DatabaseService.DatabaseStatus.Error:
-                    UpdateStatus(error, StatusTypes.Error);
-                    break;
-            }
             return false;
         }
 

ModernKeePass/ViewModels/MainVm.cs

@@ -51,7 +51,7 @@ namespace ModernKeePass.ViewModels
 
         public MainVm(Frame referenceFrame, Frame destinationFrame, IDatabase database, IResource resource, IRecent recent)
         {
-            var isDatabaseOpen = database != null && database.Status == (int) DatabaseService.DatabaseStatus.Opened;
+            var isDatabaseOpen = database != null && database.IsOpen;
 
             var mainMenuItems = new ObservableCollection<MainMenuItemVm>
             {
@@ -62,7 +62,7 @@ namespace ModernKeePass.ViewModels
                     Destination = destinationFrame,
                     Parameter = referenceFrame,
                     SymbolIcon = Symbol.Page2,
-                    IsSelected = database != null && database.Status == (int) DatabaseService.DatabaseStatus.Opening
+                    IsSelected = database != null && database.IsFileOpen
                 },
                 new MainMenuItemVm
                 {
@@ -90,7 +90,7 @@ namespace ModernKeePass.ViewModels
                     Parameter = referenceFrame,
                     SymbolIcon = Symbol.Copy,
                     IsSelected =
-                        (database == null || database.Status == (int) DatabaseService.DatabaseStatus.Closed) &&
+                        (database == null || database.IsClosed) &&
                         recent.EntryCount > 0,
                     IsEnabled = recent.EntryCount > 0
                 },
@@ -120,7 +120,7 @@ namespace ModernKeePass.ViewModels
             SelectedItem = mainMenuItems.FirstOrDefault(m => m.IsSelected);
 
             // Add currently opened database to the menu
-            if (database != null && database.Status == (int) DatabaseService.DatabaseStatus.Opened)
+            if (database != null && database.IsOpen)
                 mainMenuItems.Add(new MainMenuItemVm
                 {
                     Title = database.Name,

ModernKeePass/ViewModels/OpenVm.cs

@@ -8,7 +8,7 @@ namespace ModernKeePass.ViewModels
 {
     public class OpenVm: NotifyPropertyChangedBase
     {
-        public bool ShowPasswordBox => _database?.Status == (int) DatabaseService.DatabaseStatus.Opening;
+        public bool ShowPasswordBox => _database.IsFileOpen;
 
         public string Name => _database?.Name;
 
@@ -19,7 +19,7 @@ namespace ModernKeePass.ViewModels
         public OpenVm(IDatabase database)
         {
             _database = database;
-            if (database == null || database.Status != (int) DatabaseService.DatabaseStatus.Opening) return;
+            if (database == null || !database.IsFileOpen) return;
             OpenFile(database.DatabaseFile);
         }
 

ModernKeePass/ViewModels/SaveVm.cs

@@ -1,4 +1,5 @@
-using Windows.Storage;
+using System.Threading.Tasks;
+using Windows.Storage;
 using Windows.UI.Xaml;
 using ModernKeePass.Interfaces;
 
@@ -14,10 +15,11 @@ namespace ModernKeePass.ViewModels
             _database = database;
         }
 
-        public void Save(bool close = true)
+        public async Task Save(bool close = true)
         {
             _database.Save();
-            if (close) _database.Close();
+            if (close)
+                await _database.Close();
         }
 
         public void Save(StorageFile file)

ModernKeePass/ViewModels/SettingsVm.cs

@@ -61,7 +61,7 @@ namespace ModernKeePass.ViewModels
                     Group = resource.GetResourceValue("SettingsMenuGroupDatabase"),
                     SymbolIcon = Symbol.Setting,
                     PageType = typeof(SettingsDatabasePage),
-                    IsEnabled = database?.Status == 2
+                    IsEnabled = database.IsOpen
                 },
                 new ListMenuItemVm
                 {
@@ -69,7 +69,7 @@ namespace ModernKeePass.ViewModels
                     Group = resource.GetResourceValue("SettingsMenuGroupDatabase"),
                     SymbolIcon = Symbol.Permissions,
                     PageType = typeof(SettingsSecurityPage),
-                    IsEnabled = database?.Status == 2
+                    IsEnabled = database.IsOpen
                 }
             };
             SelectedItem = menuItems.FirstOrDefault(m => m.IsSelected);

ModernKeePass/Views/EntryDetailPage.xaml.cs

@@ -83,7 +83,7 @@ namespace ModernKeePass.Views
                 ToastNotificationHelper.ShowMovedToast(Model, resource.GetResourceValue("EntityDeleting"), text);
                 Model.MarkForDelete();
                 if (Frame.CanGoBack) Frame.GoBack();
-            });
+            }, null);
         }
 
         private void RestoreButton_Click(object sender, RoutedEventArgs e)

ModernKeePass/Views/GroupDetailPage.xaml.cs

@@ -119,7 +119,7 @@ namespace ModernKeePass.Views
                     ToastNotificationHelper.ShowMovedToast(Model, resource.GetResourceValue("EntityDeleting"), text);
                     Model.MarkForDelete();
                     if (Frame.CanGoBack) Frame.GoBack();
-                });
+                }, null);
         }
 
         private void RestoreButton_Click(object sender, RoutedEventArgs e)

ModernKeePass/Views/MainPageFrames/SaveDatabasePage.xaml.cs

@@ -28,10 +28,10 @@ namespace ModernKeePass.Views
             _mainFrame = e.Parameter as Frame;
         }
 
-        private void SaveButton_OnClick(object sender, RoutedEventArgs e)
+        private async void SaveButton_OnClick(object sender, RoutedEventArgs e)
         {
-            Model.Save();
-            _mainFrame.Navigate(typeof(Views.MainPage));
+            await Model.Save();
+            _mainFrame.Navigate(typeof(MainPage));
         }
 
         private async void SaveAsButton_OnClick(object sender, RoutedEventArgs e)
@@ -47,7 +47,7 @@ namespace ModernKeePass.Views
             if (file == null) return;
             Model.Save(file);
 
-            _mainFrame.Navigate(typeof(Views.MainPage));
+            _mainFrame.Navigate(typeof(MainPage));
         }
     }
 }

ModernKeePass/Views/UserControls/CompositeKeyUserControl.xaml.cs

@@ -90,7 +90,12 @@ namespace ModernKeePass.Views.UserControls
 
         private void PasswordBox_KeyDown(object sender, KeyRoutedEventArgs e)
         {
-            if (e.Key == VirtualKey.Enter && Model.IsValid) OpenButton_OnClick(null, null);
+            if (e.Key == VirtualKey.Enter && Model.IsValid)
+            {
+                OpenButton_OnClick(sender, e);
+                // Stop the event from triggering twice
+                e.Handled = true;
+            }
         }
 
         private async void KeyFileButton_Click(object sender, RoutedEventArgs e)