Merge pull request #1172 from Mbucari/master

Thread safety and AccountSettings.json error handling

Source/AudibleUtilities/AudibleApiStorage.cs

@@ -5,19 +5,58 @@ using Newtonsoft.Json;
 
 namespace AudibleUtilities
 {
+	public class AccountSettingsLoadErrorEventArgs : ErrorEventArgs
+	{
+		/// <summary>
+		/// Create a new, empty <see cref="AccountsSettings"/> file if true, otherwise throw
+		/// </summary>
+		public bool Handled { get; set; }
+		/// <summary>
+		/// The file path of the AccountsSettings.json file
+		/// </summary>
+		public string SettingsFilePath { get; }
+
+		public AccountSettingsLoadErrorEventArgs(string path, Exception exception)
+			: base(exception)
+		{
+			SettingsFilePath = path;
+		}
+	}
+
 	public static class AudibleApiStorage
 	{
 		public static string AccountsSettingsFile => Path.Combine(Configuration.Instance.LibationFiles, "AccountsSettings.json");
 
+		public static event EventHandler<AccountSettingsLoadErrorEventArgs> LoadError;
+
 		public static void EnsureAccountsSettingsFileExists()
 		{
 			// saves. BEWARE: this will overwrite an existing file
 			if (!File.Exists(AccountsSettingsFile))
-				_ = new AccountsSettingsPersister(new AccountsSettings(), AccountsSettingsFile);
+			{
+				//Save the JSON file manually so that AccountsSettingsPersister.Saving and AccountsSettingsPersister.Saved
+				//are not fired. There's no need to fire those events on an empty AccountsSettings file.
+				var accountSerializerSettings = AudibleApi.Authorization.Identity.GetJsonSerializerSettings();
+				File.WriteAllText(AccountsSettingsFile, JsonConvert.SerializeObject(new AccountsSettings(), Formatting.Indented, accountSerializerSettings));
+			}
 		}
 
 		/// <summary>If you use this, be a good citizen and DISPOSE of it</summary>
-		public static AccountsSettingsPersister GetAccountsSettingsPersister() => new AccountsSettingsPersister(AccountsSettingsFile);
+		public static AccountsSettingsPersister GetAccountsSettingsPersister()
+		{
+			try
+			{
+				return new AccountsSettingsPersister(AccountsSettingsFile);
+			}
+			catch (Exception ex)
+			{
+				var args = new AccountSettingsLoadErrorEventArgs(AccountsSettingsFile, ex);
+				LoadError?.Invoke(null, args);
+				if (args.Handled)
+					return GetAccountsSettingsPersister();
+				throw;
+			}
+		}
 
 		public static string GetIdentityTokensJsonPath(this Account account)
 			=> GetIdentityTokensJsonPath(account.AccountId, account.Locale?.Name);

Source/FileManager/FileUtility.cs

@@ -157,7 +157,7 @@ namespace FileManager
 		/// <param name="extension">File extension override to use for <paramref name="destination"/></param>
 		/// <param name="overwrite">If <c>false</c> and <paramref name="destination"/> exists, append " (n)" to filename and try again.</param>
 		/// <returns>The actual destination filename</returns>
-		public static string SaferMoveToValidPath(
+		public static LongPath SaferMoveToValidPath(
 			LongPath source,
 			LongPath destination,
 			ReplacementCharacters replacements,

Source/LibationAvalonia/App.axaml

@@ -97,10 +97,13 @@
 				</Setter>
 			</Style>
 			<Style Selector="^[UseCustomTitleBar=true]">
+				<Style Selector="^[CanResize=false] Border#DialogWindowFormBorder">
+					<Setter Property="BorderThickness" Value="2" />
+				</Style>
 				<Setter Property="SystemDecorations" Value="BorderOnly"/>
 				<Setter Property="Template">
 					<ControlTemplate>
-						<Panel Background="{DynamicResource SystemControlBackgroundAltHighBrush}">
+						<Border Name="DialogWindowFormBorder" BorderBrush="{DynamicResource SystemBaseMediumLowColor}" Background="{DynamicResource SystemControlBackgroundAltHighBrush}">
 							<Grid RowDefinitions="30,*">
 								<Border Name="DialogWindowTitleBorder" Margin="5,0" Background="{DynamicResource SystemAltMediumColor}">
 									<Border.Styles>
@@ -134,7 +137,7 @@
 								<Path Stroke="{DynamicResource SystemBaseMediumLowColor}" StrokeThickness="1" VerticalAlignment="Bottom" Stretch="Fill" Data="M0,0 L1,0" />
 								<ContentPresenter Grid.Row="1" Content="{TemplateBinding Content}" />
 							</Grid>
-						</Panel>
+						</Border>
 					</ControlTemplate>
 				</Setter>
 			</Style>

Source/LibationAvalonia/ViewModels/ProductsDisplayViewModel.cs

@@ -4,6 +4,7 @@ using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Threading;
 using DataLayer;
+using Dinah.Core.Collections.Generic;
 using LibationAvalonia.Dialogs.Login;
 using LibationFileManager;
 using LibationUiBase.GridView;
@@ -11,7 +12,6 @@ using ReactiveUI;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Diagnostics;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
@@ -103,17 +103,18 @@ namespace LibationAvalonia.ViewModels
 
 		internal async Task BindToGridAsync(List<LibraryBook> dbBooks)
 		{
+			//Get the UI thread's synchronization context and set it on the current thread to ensure
+			//it's available for GetAllProductsAsync and GetAllSeriesEntriesAsync
 			var sc = await Dispatcher.UIThread.InvokeAsync(() => AvaloniaSynchronizationContext.Current);
 			AvaloniaSynchronizationContext.SetSynchronizationContext(sc);
 
 			var geList = await LibraryBookEntry<AvaloniaEntryStatus>.GetAllProductsAsync(dbBooks);
 			var seriesEntries = await SeriesEntry<AvaloniaEntryStatus>.GetAllSeriesEntriesAsync(dbBooks);
 
-			//Create the filtered-in list before adding entries to avoid a refresh
-			FilteredInGridEntries = geList.Union(seriesEntries.SelectMany(s => s.Children)).FilterEntries(FilterString);
-			//Adding entries to the Source list will invoke CollectionFilter
-			//Perform on UI thread for safety
-			await Dispatcher.UIThread.InvokeAsync(() => SOURCE.AddRange(geList.Concat(seriesEntries).OrderDescending(new RowComparer(null))));
+			//Add all IGridEntries to the SOURCE list. Note that SOURCE has not yet been linked to the UI via
+			//the GridEntries property, so adding items to SOURCE will not trigger any refreshes or UI action.
+			//This this can be done on any thread.
+			SOURCE.AddRange(geList.Concat(seriesEntries).OrderDescending(new RowComparer(null)));
 
 			//Add all children beneath their parent
 			foreach (var series in seriesEntries)
@@ -123,10 +124,15 @@ namespace LibationAvalonia.ViewModels
 					SOURCE.Insert(++seriesIndex, child);
 			}
 
-			// Adding SOURCE to the DataGridViewCollection after building the source
+			//Create the filtered-in list before adding entries to GridEntries to avoid a refresh or UI action
+			FilteredInGridEntries = geList.Union(seriesEntries.SelectMany(s => s.Children)).FilterEntries(FilterString);
+
+			// Adding SOURCE to the DataGridViewCollection _after_ building the SOURCE list 
 			//Saves ~500 ms on a library of ~4500 books.
-			//Perform on UI thread for safety
+			//Perform on UI thread for safety, but at this time, merely setting the DataGridCollectionView
+			//does not trigger UI actions in the way that modifying the list after it's been linked does.
 			await Dispatcher.UIThread.InvokeAsync(() => GridEntries = new(SOURCE) { Filter = CollectionFilter });
+
 			GridEntries.CollectionChanged += GridEntries_CollectionChanged;
 			GridEntries_CollectionChanged();
 		}
@@ -150,7 +156,7 @@ namespace LibationAvalonia.ViewModels
 			#region Add new or update existing grid entries
 
 			//Add absent entries to grid, or update existing entry
-			var allEntries = SOURCE.BookEntries().ToList();
+			var allEntries = SOURCE.BookEntries().ToDictionarySafe(b => b.AudibleProductId);
 			var seriesEntries = SOURCE.SeriesEntries().ToList();
 			var parentedEpisodes = dbBooks.ParentedEpisodes().ToHashSet();
 
@@ -158,7 +164,7 @@ namespace LibationAvalonia.ViewModels
 			{
 				foreach (var libraryBook in dbBooks.OrderBy(e => e.DateAdded))
 				{
-					var existingEntry = allEntries.FindByAsin(libraryBook.Book.AudibleProductId);
+					var existingEntry = allEntries.TryGetValue(libraryBook.Book.AudibleProductId, out var e) ? e : null;
 
 					if (libraryBook.Book.IsProduct())
 						UpsertBook(libraryBook, existingEntry);

Source/LibationAvalonia/Views/MainWindow.axaml.cs

@@ -1,6 +1,9 @@
+using AudibleUtilities;
 using Avalonia.Input;
 using Avalonia.ReactiveUI;
+using Avalonia.Threading;
 using DataLayer;
+using FileManager;
 using LibationAvalonia.ViewModels;
 using LibationFileManager;
 using LibationUiBase.GridView;
@@ -18,6 +21,7 @@ namespace LibationAvalonia.Views
 		{
 			DataContext = new MainVM(this);
 
+			AudibleApiStorage.LoadError += AudibleApiStorage_LoadError;
 			InitializeComponent();
 			Configure_Upgrade();
 
@@ -34,6 +38,62 @@ namespace LibationAvalonia.Views
 			}
 		}
 
+		private void AudibleApiStorage_LoadError(object sender, AccountSettingsLoadErrorEventArgs e)
+		{
+			try
+			{
+				//Backup AccountSettings.json and create a new, empty file.
+				var backupFile =
+					FileUtility.SaferMoveToValidPath(
+						e.SettingsFilePath,
+						e.SettingsFilePath,
+						ReplacementCharacters.Barebones,
+						"bak");
+				AudibleApiStorage.EnsureAccountsSettingsFileExists();
+				e.Handled = true;
+
+				showAccountSettingsRecoveredMessage(backupFile);
+			}
+			catch
+			{
+				showAccountSettingsUnrecoveredMessage();
+			}
+
+			async void showAccountSettingsRecoveredMessage(LongPath backupFile)
+			=> await MessageBox.Show(this, $"""
+				Libation could not load your account settings, so it had created a new, empty account settings file.
+
+				You will need to re-add you Audible account(s) before scanning or downloading.
+
+				The old account settings file has been archived at '{backupFile.PathWithoutPrefix}'
+
+				{e.GetException().ToString()}
+				""",
+				"Error Loading Account Settings",
+				MessageBoxButtons.OK,
+				MessageBoxIcon.Warning);
+
+			void showAccountSettingsUnrecoveredMessage()
+			{
+				var messageBoxWindow = MessageBox.Show(this, $"""
+				Libation could not load your account settings. The file may be corrupted, but Libation is unable to delete it.
+
+				Please move or delete the account settings file '{e.SettingsFilePath}'
+
+				{e.GetException().ToString()}
+				""",
+				"Error Loading Account Settings",
+				MessageBoxButtons.OK);
+
+				//Force the message box to show synchronously because we're not handling the exception
+				//and libation will crash after the event handler returns
+				var frame = new DispatcherFrame();
+				_ = messageBoxWindow.ContinueWith(static (_, s) => ((DispatcherFrame)s).Continue = false, frame);
+				Dispatcher.UIThread.PushFrame(frame);
+				messageBoxWindow.GetAwaiter().GetResult();
+			}
+		}
+
 		private async void MainWindow_Opened(object sender, EventArgs e)
 		{
 			if (Configuration.Instance.FirstLaunch)

Source/LibationUiBase/GridView/LibraryBookEntry[TStatus].cs

@@ -33,6 +33,10 @@ namespace LibationUiBase.GridView
 			LoadCover();
 		}
 
+		/// <summary>
+		/// Creates <see cref="LibraryBookEntry{TStatus}"/> for all non-episode books in an enumeration of <see cref="LibraryBook"/>.
+		/// </summary>
+		/// <remarks>Can be called from any thread, but requires the calling thread's <see cref="SynchronizationContext.Current"/> to be valid.</remarks>
 		public static async Task<List<IGridEntry>> GetAllProductsAsync(IEnumerable<LibraryBook> libraryBooks)
 		{
 			var products = libraryBooks.Where(lb => lb.Book.IsProduct()).ToArray();

Source/LibationUiBase/GridView/SeriesEntry[TStatus].cs

@@ -56,6 +56,10 @@ namespace LibationUiBase.GridView
 			LoadCover();
 		}
 
+		/// <summary>
+		/// Creates <see cref="SeriesEntry{TStatus}"/> for all episodic series in an enumeration of <see cref="LibraryBook"/>.
+		/// </summary>
+		/// <remarks>Can be called from any thread, but requires the calling thread's <see cref="SynchronizationContext.Current"/> to be valid.</remarks>
 		public static async Task<List<ISeriesEntry>> GetAllSeriesEntriesAsync(IEnumerable<LibraryBook> libraryBooks)
 		{
 			var seriesBooks = libraryBooks.Where(lb => lb.Book.IsEpisodeParent()).ToArray();

Source/LibationWinForms/Form1._NonUI.cs

@@ -1,10 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+using System.Windows.Forms;
 using ApplicationServices;
+using AudibleUtilities;
 using Dinah.Core.WindowsDesktop.Drawing;
+using FileManager;
 using LibationFileManager;
 using LibationUiBase;
 
@@ -14,6 +12,8 @@ namespace LibationWinForms
     {
         private void Configure_NonUI()
 		{
+			AudibleApiStorage.LoadError += AudibleApiStorage_LoadError;
+
 			// init default/placeholder cover art
 			var format = System.Drawing.Imaging.ImageFormat.Jpeg;
             PictureStorage.SetDefaultImage(PictureSize._80x80, Properties.Resources.default_cover_80x80.ToBytes(format));
@@ -36,5 +36,54 @@ namespace LibationWinForms
                     beginBookBackupsToolStripMenuItem_Click();
             };
 		}
+
+		private void AudibleApiStorage_LoadError(object sender, AccountSettingsLoadErrorEventArgs e)
+		{
+			try
+			{
+				//Backup AccountSettings.json and create a new, empty file.
+				var backupFile = 
+					FileUtility.SaferMoveToValidPath(
+						e.SettingsFilePath,
+						e.SettingsFilePath,
+						ReplacementCharacters.Barebones,
+						"bak");
+
+				AudibleApiStorage.EnsureAccountsSettingsFileExists();
+				e.Handled = true;
+
+				showAccountSettingsRecoveredMessage(backupFile);
+			}
+			catch
+			{
+				showAccountSettingsUnrecoveredMessage();
+			}
+
+			void showAccountSettingsRecoveredMessage(LongPath backupFile)
+			=> MessageBox.Show(this, $"""
+				Libation could not load your account settings, so it had created a new, empty account settings file.
+
+				You will need to re-add you Audible account(s) before scanning or downloading.
+
+				The old account settings file has been archived at '{backupFile.PathWithoutPrefix}'
+
+				{e.GetException().ToString()}
+				""",
+				"Error Loading Account Settings",
+				MessageBoxButtons.OK,
+				MessageBoxIcon.Warning);
+
+			void showAccountSettingsUnrecoveredMessage()
+			=> MessageBox.Show(this, $"""
+				Libation could not load your account settings. The file may be corrupted, but Libation is unable to delete it.
+
+				Please move or delete the account settings file '{e.SettingsFilePath}'
+
+				{e.GetException().ToString()}
+				""",
+				"Error Loading Account Settings",
+				MessageBoxButtons.OK,
+				MessageBoxIcon.Error);
+		}
 	}
 }

Source/LibationWinForms/GridView/ProductsGrid.cs

@@ -1,9 +1,9 @@
 using DataLayer;
 using Dinah.Core;
+using Dinah.Core.Collections.Generic;
 using Dinah.Core.WindowsDesktop.Forms;
 using LibationFileManager;
 using LibationUiBase.GridView;
-using NPOI.SS.Formula.Functions;
 using System;
 using System.Collections.Generic;
 using System.Data;
@@ -216,8 +216,12 @@ namespace LibationWinForms.GridView
 
 		internal async Task BindToGridAsync(List<LibraryBook> dbBooks)
 		{
-			var geList = await LibraryBookEntry<WinFormsEntryStatus>.GetAllProductsAsync(dbBooks);
+			//Get the UI thread's synchronization context and set it on the current thread to ensure
+			//it's available for GetAllProductsAsync and GetAllSeriesEntriesAsync
+			var sc = Invoke(() => System.Threading.SynchronizationContext.Current);
+			System.Threading.SynchronizationContext.SetSynchronizationContext(sc);
 
+			var geList = await LibraryBookEntry<WinFormsEntryStatus>.GetAllProductsAsync(dbBooks);
 			var seriesEntries = await SeriesEntry<WinFormsEntryStatus>.GetAllSeriesEntriesAsync(dbBooks);
 
 			geList.AddRange(seriesEntries);
@@ -232,9 +236,12 @@ namespace LibationWinForms.GridView
 				foreach (var child in series.Children)
 					geList.Insert(++seriesIndex, child);
 			}
+			System.Threading.SynchronizationContext.SetSynchronizationContext(null);
 						
 			bindingList = new GridEntryBindingList(geList);
 			bindingList.CollapseAll();
+
+			//The syncBindingSource ensures that the IGridEntry list is added on the UI thread 
 			syncBindingSource.DataSource = bindingList;
 			VisibleCountChanged?.Invoke(this, bindingList.GetFilteredInItems().Count());
 		}
@@ -252,14 +259,19 @@ namespace LibationWinForms.GridView
 
 			//Add absent entries to grid, or update existing entry
 
-			var allEntries = bindingList.AllItems().BookEntries();
+			var allEntries = bindingList.AllItems().BookEntries().ToDictionarySafe(b => b.AudibleProductId);
 			var seriesEntries = bindingList.AllItems().SeriesEntries().ToList();
 			var parentedEpisodes = dbBooks.ParentedEpisodes().ToHashSet();
 
+			//Get the UI thread's synchronization context and set it on the current thread to ensure
+			//it's available for creation of new IGridEntry items during upsert
+			var sc = Invoke(() => System.Threading.SynchronizationContext.Current);
+			System.Threading.SynchronizationContext.SetSynchronizationContext(sc);
+
 			bindingList.RaiseListChangedEvents = false;
 			foreach (var libraryBook in dbBooks.OrderBy(e => e.DateAdded))
 			{
-				var existingEntry = allEntries.FindByAsin(libraryBook.Book.AudibleProductId);
+				var existingEntry = allEntries.TryGetValue(libraryBook.Book.AudibleProductId, out var e) ? e : null;
 
 				if (libraryBook.Book.IsProduct())
 				{
@@ -289,6 +301,10 @@ namespace LibationWinForms.GridView
 				.BookEntries()
 				.ExceptBy(dbBooks.Select(lb => lb.Book.AudibleProductId), ge => ge.AudibleProductId);
 
+			removedBooks = bindingList
+				.AllItems()
+				.BookEntries().Take(10).ToList();
+
 			RemoveBooks(removedBooks);
 
 			gridEntryDataGridView.FirstDisplayedScrollingRowIndex = topRow;