Merge branch 'master' of https://github.com/rmcrackan/Libation

Improve library scan speed and Track and display book availability

Documentation/InstallOnMac.md

@@ -9,7 +9,9 @@ This walkthrough should get you up and running with Libation on your Mac.
 
 ## Install Libation
 
-- Download the `Libation.app-macOS-x64-x.x.x.tgz` file from the latest release and extract it. 
+- Download the file from the latest release and extract it.
+  - Apple Silicon (M1, M2, ...): `Libation.9.4.2-macOS-chardonnay-`**arm64**`.tgz`
+  - Intel: `Libation.x.x.x-macOS-chardonnay-`**x64**`.tgz`
 - Move the extracted Libation app bundle to your applications folder.
 - Open a terminal (Go > Utilities > Terminal)
 - Copy/paste/run the following command (you'll be prompted to enter your password)

Scripts/Bundle_MacOS.sh

@@ -65,6 +65,9 @@ if [ $? -ne 0 ]
  exit
 fi
 
+echo "Make fileicon executable..."
+chmod +x $BUNDLE_MACOS/fileicon
+
 echo "Moving icon..."
 mv $BUNDLE_MACOS/libation.icns $BUNDLE_RESOURCES/libation.icns
 

Source/AppScaffolding/AppScaffolding.csproj

@@ -2,7 +2,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>net7.0</TargetFramework>
-    <Version>9.4.2.1</Version>
+    <Version>9.4.4.1</Version>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Octokit" Version="5.0.0" />

Source/AppScaffolding/LibationScaffolding.cs

@@ -75,13 +75,15 @@ namespace AppScaffolding
 			??= new[] { ExecutingAssembly.GetName(), EntryAssembly.GetName() }
 			.Max(a => a.Version);
 
-        /// <summary>Run migrations before loading Configuration for the first time. Then load and return Configuration</summary>
-        public static Configuration RunPreConfigMigrations()
+		/// <summary>Run migrations before loading Configuration for the first time. Then load and return Configuration</summary>
+		public static Configuration RunPreConfigMigrations()
 		{
 			// must occur before access to Configuration instance
 			// // outdated. kept here as an example of what belongs in this area
 			// // Migrations.migrate_to_v5_2_0__pre_config();
 
+			Configuration.SetLibationVersion(BuildVersion);
+
 			//***********************************************//
 			//                                               //
 			//   do not use Configuration before this line   //

Source/ApplicationServices/LibraryCommands.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using System.Threading.Tasks;
 using AudibleApi;
 using AudibleUtilities;
@@ -242,18 +243,16 @@ namespace ApplicationServices
         #endregion
 
         #region remove/restore books
-        public static Task<int> RemoveBooksAsync(List<string> idsToRemove) => Task.Run(() => removeBooks(idsToRemove));
-        public static int RemoveBook(string idToRemove) => removeBooks(new() { idToRemove });
-        private static int removeBooks(List<string> idsToRemove)
+        public static Task<int> RemoveBooksAsync(this IEnumerable<LibraryBook> idsToRemove) => Task.Run(() => removeBooks(idsToRemove));
+        public static int RemoveBook(this LibraryBook idToRemove) => removeBooks(new[] { idToRemove });
+        private static int removeBooks(IEnumerable<LibraryBook> removeLibraryBooks)
         {
             try
             {
-                if (idsToRemove is null || !idsToRemove.Any())
+                if (removeLibraryBooks is null || !removeLibraryBooks.Any())
                     return 0;
 
                 using var context = DbContexts.GetContext();
-                var libBooks = context.GetLibrary_Flat_NoTracking();
-                var removeLibraryBooks = libBooks.Where(lb => idsToRemove.Contains(lb.Book.AudibleProductId)).ToList();
 
                 // Attach() NoTracking entities before SaveChanges()
                 foreach (var lb in removeLibraryBooks)
@@ -275,7 +274,7 @@ namespace ApplicationServices
             }
         }
 
-        public static int RestoreBooks(this List<LibraryBook> libraryBooks)
+        public static int RestoreBooks(this IEnumerable<LibraryBook> libraryBooks)
         {
             try
             {
@@ -303,6 +302,31 @@ namespace ApplicationServices
                 throw;
             }
         }
+
+        public static int PermanentlyDeleteBooks(this IEnumerable<LibraryBook> libraryBooks)
+        {
+            try
+            {
+                if (libraryBooks is null || !libraryBooks.Any())
+                    return 0;
+
+                using var context = DbContexts.GetContext();
+
+				context.LibraryBooks.RemoveRange(libraryBooks);
+				context.Books.RemoveRange(libraryBooks.Select(lb => lb.Book));				
+
+                var qtyChanges = context.SaveChanges();
+				if (qtyChanges > 0)
+					finalizeLibrarySizeChange();
+
+				return qtyChanges;
+            }
+            catch (Exception ex)
+            {
+                Log.Logger.Error(ex, "Error restoring books");
+                throw;
+            }
+        }
         #endregion
 
         // call this whenever books are added or removed from library
@@ -346,8 +370,10 @@ namespace ApplicationServices
 
                     if (rating is not null)
                         udi.UpdateRating(rating.OverallRating, rating.PerformanceRating, rating.StoryRating);
-                });
+				});
 
+        public static int UpdateBookStatus(this Book book, LiberatedStatus bookStatus, Version libationVersion)
+            => book.UpdateUserDefinedItem(udi => { udi.BookStatus = bookStatus; udi.SetLastDownloaded(libationVersion); });
         public static int UpdateBookStatus(this Book book, LiberatedStatus bookStatus)
             => book.UpdateUserDefinedItem(udi => udi.BookStatus = bookStatus);
         public static int UpdateBookStatus(this IEnumerable<Book> books, LiberatedStatus bookStatus)
@@ -428,40 +454,74 @@ namespace ApplicationServices
 
         // below are queries, not commands. maybe I should make a LibraryQueries. except there's already one of those...
 
-        public record LibraryStats(int booksFullyBackedUp, int booksDownloadedOnly, int booksNoProgress, int booksError, int pdfsDownloaded, int pdfsNotDownloaded)
+        public record LibraryStats(int booksFullyBackedUp, int booksDownloadedOnly, int booksNoProgress, int booksError, int booksUnavailable, int pdfsDownloaded, int pdfsNotDownloaded, int pdfsUnavailable)
         {
             public int PendingBooks => booksNoProgress + booksDownloadedOnly;
             public bool HasPendingBooks => PendingBooks > 0;
 
-            public bool HasBookResults => 0 < (booksFullyBackedUp + booksDownloadedOnly + booksNoProgress + booksError);
-            public bool HasPdfResults => 0 < (pdfsNotDownloaded + pdfsDownloaded);
-        }
-        public static LibraryStats GetCounts()
+            public bool HasBookResults => 0 < (booksFullyBackedUp + booksDownloadedOnly + booksNoProgress + booksError + booksUnavailable);
+            public bool HasPdfResults => 0 < (pdfsNotDownloaded + pdfsDownloaded + pdfsUnavailable);
+
+			public string StatusString => HasPdfResults ? $"{toBookStatusString()}  |  {toPdfStatusString()}" : toBookStatusString();
+
+			private string toBookStatusString()
+			{
+                if (!HasBookResults) return "No books. Begin by importing your library";
+
+                if (!HasPendingBooks && booksError + booksUnavailable == 0) return $"All {"book".PluralizeWithCount(booksFullyBackedUp)} backed up";
+
+				var sb = new StringBuilder($"BACKUPS: No progress: {booksNoProgress}  In process: {booksDownloadedOnly}  Fully backed up: {booksFullyBackedUp}");
+
+                if (booksError > 0)
+                    sb.Append($"  Errors: {booksError}");
+                if (booksUnavailable > 0)
+					sb.Append($"  Unavailable: {booksUnavailable}");
+
+				return sb.ToString();
+			}
+
+			private string toPdfStatusString()
+            {
+                if (pdfsNotDownloaded + pdfsUnavailable == 0) return $"All {pdfsDownloaded} PDFs downloaded";
+
+                var sb = new StringBuilder($"PDFs: NOT d/l'ed: {pdfsNotDownloaded}  Downloaded: {pdfsDownloaded}");
+
+                if (pdfsUnavailable > 0)
+					sb.Append($"  Unavailable: {pdfsUnavailable}");
+
+                return sb.ToString();
+			}
+		}
+        public static LibraryStats GetCounts(IEnumerable<LibraryBook> libraryBooks = null)
         {
-            var libraryBooks = DbContexts.GetLibrary_Flat_NoTracking();
+            libraryBooks ??= DbContexts.GetLibrary_Flat_NoTracking();
 
             var results = libraryBooks
                 .AsParallel()
-                .Select(lb => Liberated_Status(lb.Book))
+                .Select(lb => new { absent = lb.AbsentFromLastScan, status = Liberated_Status(lb.Book) })
                 .ToList();
-            var booksFullyBackedUp = results.Count(r => r == LiberatedStatus.Liberated);
-            var booksDownloadedOnly = results.Count(r => r == LiberatedStatus.PartialDownload);
-            var booksNoProgress = results.Count(r => r == LiberatedStatus.NotLiberated);
-            var booksError = results.Count(r => r == LiberatedStatus.Error);
 
-            Log.Logger.Information("Book counts. {@DebugInfo}", new { total = results.Count, booksFullyBackedUp, booksDownloadedOnly, booksNoProgress, booksError });
+            var booksFullyBackedUp = results.Count(r => r.status == LiberatedStatus.Liberated);
+            var booksDownloadedOnly = results.Count(r => !r.absent && r.status == LiberatedStatus.PartialDownload);
+            var booksNoProgress = results.Count(r => !r.absent && r.status == LiberatedStatus.NotLiberated);
+            var booksError = results.Count(r => r.status == LiberatedStatus.Error);
+            var booksUnavailable = results.Count(r => r.absent && r.status is LiberatedStatus.NotLiberated or LiberatedStatus.PartialDownload);
 
-            var boolResults = libraryBooks
+			Log.Logger.Information("Book counts. {@DebugInfo}", new { total = results.Count, booksFullyBackedUp, booksDownloadedOnly, booksNoProgress, booksError, booksUnavailable });
+
+            var pdfResults = libraryBooks
                 .AsParallel()
                 .Where(lb => lb.Book.HasPdf())
-                .Select(lb => Pdf_Status(lb.Book))
+                .Select(lb => new { absent = lb.AbsentFromLastScan, status = Pdf_Status(lb.Book) })
                 .ToList();
-            var pdfsDownloaded = boolResults.Count(r => r == LiberatedStatus.Liberated);
-            var pdfsNotDownloaded = boolResults.Count(r => r == LiberatedStatus.NotLiberated);
 
-            Log.Logger.Information("PDF counts. {@DebugInfo}", new { total = boolResults.Count, pdfsDownloaded, pdfsNotDownloaded });
+            var pdfsDownloaded = pdfResults.Count(r => r.status == LiberatedStatus.Liberated);
+            var pdfsNotDownloaded = pdfResults.Count(r => !r.absent && r.status == LiberatedStatus.NotLiberated);
+            var pdfsUnavailable = pdfResults.Count(r => r.absent && r.status == LiberatedStatus.NotLiberated);
 
-            return new(booksFullyBackedUp, booksDownloadedOnly, booksNoProgress, booksError, pdfsDownloaded, pdfsNotDownloaded);
+			Log.Logger.Information("PDF counts. {@DebugInfo}", new { total = pdfResults.Count, pdfsDownloaded, pdfsNotDownloaded, pdfsUnavailable });
+
+            return new(booksFullyBackedUp, booksDownloadedOnly, booksNoProgress, booksError, booksUnavailable, pdfsDownloaded, pdfsNotDownloaded, pdfsUnavailable);
         }
     }
 }

Source/ApplicationServices/LibraryExporter.cs

@@ -106,6 +106,12 @@ namespace ApplicationServices
 
 		[Name("Language")]
         public string Language { get; set; }
+
+		[Name("LastDownloaded")]
+		public DateTime? LastDownloaded { get; set; }
+
+		[Name("LastDownloadedVersion")]
+        public string LastDownloadedVersion { get; set; }
     }
 	public static class LibToDtos
 	{
@@ -140,7 +146,10 @@ namespace ApplicationServices
 				PdfStatus = a.Book.UserDefinedItem.PdfStatus.ToString(),
 				ContentType = a.Book.ContentType.ToString(),
 				AudioFormat = a.Book.AudioFormat.ToString(),
-				Language = a.Book.Language
+				Language = a.Book.Language,
+				LastDownloaded = a.Book.UserDefinedItem.LastDownloaded,
+				LastDownloadedVersion = a.Book.UserDefinedItem.LastDownloadedVersion?.ToString() ?? "",
+
 			}).ToList();
 	}
 	public static class LibraryExporter
@@ -212,7 +221,9 @@ namespace ApplicationServices
 				nameof(ExportDto.PdfStatus),
 				nameof(ExportDto.ContentType),
 				nameof(ExportDto.AudioFormat),
-                nameof(ExportDto.Language)
+                nameof(ExportDto.Language),
+                nameof(ExportDto.LastDownloaded),
+                nameof(ExportDto.LastDownloadedVersion),
             };
 			var col = 0;
 			foreach (var c in columns)
@@ -238,9 +249,9 @@ namespace ApplicationServices
 
 				row.CreateCell(col++).SetCellValue(dto.Account);
 
-				var dateAddedCell = row.CreateCell(col++);
-				dateAddedCell.CellStyle = dateStyle;
-				dateAddedCell.SetCellValue(dto.DateAdded);
+				var dateCell = row.CreateCell(col++);
+				dateCell.CellStyle = dateStyle;
+				dateCell.SetCellValue(dto.DateAdded);
 
 				row.CreateCell(col++).SetCellValue(dto.AudibleProductId);
 				row.CreateCell(col++).SetCellValue(dto.Locale);
@@ -281,6 +292,15 @@ namespace ApplicationServices
                 row.CreateCell(col++).SetCellValue(dto.AudioFormat);
                 row.CreateCell(col++).SetCellValue(dto.Language);
 
+				if (dto.LastDownloaded.HasValue)
+				{
+					dateCell = row.CreateCell(col);
+					dateCell.CellStyle = dateStyle;
+					dateCell.SetCellValue(dto.LastDownloaded.Value);
+				}
+
+                row.CreateCell(++col).SetCellValue(dto.LastDownloadedVersion);
+
                 rowIndex++;
 			}
 

Source/AudibleUtilities/ApiExtended.cs

@@ -2,8 +2,9 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.Linq;
-using System.Threading;
+using System.Threading.Channels;
 using System.Threading.Tasks;
+using System.Diagnostics;
 using AudibleApi;
 using AudibleApi.Common;
 using Dinah.Core;
@@ -19,6 +20,9 @@ namespace AudibleUtilities
 	{
 		public Api Api { get; private set; }
 
+		private const int MaxConcurrency = 10;
+		private const int BatchSize = 50;
+
 		private ApiExtended(Api api) => Api = api;
 
 		/// <summary>Get api from existing tokens else login with 'eager' choice. External browser url is provided. Response can be external browser login or continuing with native api callbacks.</summary>
@@ -85,35 +89,51 @@ namespace AudibleUtilities
 
 		private async Task<List<Item>> getItemsAsync(LibraryOptions libraryOptions, bool importEpisodes)
 		{
-			var items = new List<Item>();
-
 			Serilog.Log.Logger.Debug("Beginning library scan.");
 
-			List<Task<List<Item>>> getChildEpisodesTasks = new();
+			int count = 0;
+			List<Item> items = new();
+			List<Item> seriesItems = new();
 
-			int count = 0, maxConcurrentEpisodeScans = 5;
-			using SemaphoreSlim concurrencySemaphore = new(maxConcurrentEpisodeScans);
+			var sw = Stopwatch.StartNew();
 
-			await foreach (var item in Api.GetLibraryItemAsyncEnumerable(libraryOptions))
+			//Scan the library for all added books, and add any episode-type items to seriesItems to be scanned for episodes/parents
+			await foreach (var item in Api.GetLibraryItemAsyncEnumerable(libraryOptions, BatchSize, MaxConcurrency))
 			{
 				if ((item.IsEpisodes || item.IsSeriesParent) && importEpisodes)
-				{
-					//Get child episodes asynchronously and await all at the end
-					getChildEpisodesTasks.Add(getChildEpisodesAsync(concurrencySemaphore, item));
-				}
+					seriesItems.Add(item);
 				else if (!item.IsEpisodes && !item.IsSeriesParent)
 					items.Add(item);
 
 				count++;
 			}
 
-			Serilog.Log.Logger.Debug("Library scan complete. Found {count} books and series. Waiting on {getChildEpisodesTasksCount} series episode scans to complete.", count, getChildEpisodesTasks.Count);
+			Serilog.Log.Logger.Debug("Library scan complete. Found {count} books and series. Waiting on series episode scans to complete.", count);
+			Serilog.Log.Logger.Debug("Beginning episode scan.");
 
-			//await and add all episodes from all parents
-			foreach (var epList in await Task.WhenAll(getChildEpisodesTasks))
-				items.AddRange(epList);
+			count = 0;
 
-			Serilog.Log.Logger.Debug("Completed library scan.");
+			//'get' Tasks are activated when they are written to the channel. To avoid more concurrency than is desired, the
+			//channel is bounded with a capacity of 1. Channel write operations are blocked until the current item is read
+			var episodeChannel = Channel.CreateBounded<Task<List<Item>>>(new BoundedChannelOptions(1) { SingleReader = true });
+
+			//Start scanning for all episodes. Episode batch 'get' Tasks are written to the channel.
+			var scanAllSeriesTask = scanAllSeries(seriesItems, episodeChannel.Writer);
+
+			//Read all episodes from the channel and add them to the import items.
+			//This method blocks until episodeChannel.Writer is closed by scanAllSeries()
+			await foreach (var ep in getAllEpisodesAsync(episodeChannel.Reader))
+			{
+				items.AddRange(ep);
+				count += ep.Count;
+			}
+
+			//Be sure to await the scanAllSeries Task so that any exceptions are thrown
+			await scanAllSeriesTask;
+
+			sw.Stop();
+			Serilog.Log.Logger.Debug("Episode scan complete. Found {count} episodes and series.", count);
+			Serilog.Log.Logger.Debug($"Completed library scan in {sw.Elapsed.TotalMilliseconds:F0} ms.");
 
 #if DEBUG
 			//// this will not work for multi accounts
@@ -146,165 +166,178 @@ namespace AudibleUtilities
 
 		#region episodes and podcasts
 
-		private async Task<List<Item>> getChildEpisodesAsync(SemaphoreSlim concurrencySemaphore, Item parent)
+		/// <summary>
+		/// Read get tasks from the <paramref name="channel"/> and await results. This method maintains
+		/// a list of up to <see cref="MaxConcurrency"/> get tasks. When any of the get tasks completes,
+		/// the Items are yielded, that task is removed from the list, and a new get task is read from
+		/// the channel.
+		/// </summary>
+		private async IAsyncEnumerable<List<Item>> getAllEpisodesAsync(ChannelReader<Task<List<Item>>> channel)
 		{
-			await concurrencySemaphore.WaitAsync();
+			List<Task<List<Item>>> concurentGets = new();
 
+			for (int i = 0; i < MaxConcurrency && await channel.WaitToReadAsync(); i++)
+				concurentGets.Add(await channel.ReadAsync());
+
+			while (concurentGets.Count > 0)
+			{
+				var completed = await Task.WhenAny(concurentGets);
+				concurentGets.Remove(completed);
+
+				if (await channel.WaitToReadAsync())
+					concurentGets.Add(await channel.ReadAsync());
+
+				yield return completed.Result;
+			}
+		}
+
+		/// <summary>
+		/// Gets all child episodes and episode parents belonging to <paramref name="seriesItems"/> in batches and
+		/// writes the get tasks to <paramref name="channel"/>.
+		/// </summary>
+		private async Task scanAllSeries(IEnumerable<Item> seriesItems, ChannelWriter<Task<List<Item>>> channel)
+		{
 			try
 			{
-				Serilog.Log.Logger.Debug("Beginning episode scan for {parent}", parent);
+				List<Task> episodeScanTasks = new();
 
-				List<Item> children;
-
-				if (parent.IsEpisodes)
+				foreach (var item in seriesItems)
 				{
-					//The 'parent' is a single episode that was added to the library.
-					//Get the episode's parent and add it to the database.
+					if (item.IsEpisodes)
+						await channel.WriteAsync(getEpisodeParentAsync(item));
+					else if (item.IsSeriesParent)
+						episodeScanTasks.Add(getParentEpisodesAsync(item, channel));
+				}
 
-					Serilog.Log.Logger.Debug("Supplied Parent is an episode. Beginning parent scan for {parent}", parent);
+				//episodeScanTasks complete only after all episode batch 'gets' have been written to the channel
+				await Task.WhenAll(episodeScanTasks);
+			}
+			finally { channel.Complete(); }
+		}
 
-					children = new() { parent };
+		private async Task<List<Item>> getEpisodeParentAsync(Item episode)
+		{
+			//Item is a single episode that was added to the library.
+			//Get the episode's parent and add it to the database.
 
-					var parentAsins = parent.Relationships
-						.Where(r => r.RelationshipToProduct == RelationshipToProduct.Parent)
-						.Select(p => p.Asin);
+			Serilog.Log.Logger.Debug("Supplied Parent is an episode. Beginning parent scan for {parent}", episode);
 
-					var seriesParents = await Api.GetCatalogProductsAsync(parentAsins, CatalogOptions.ResponseGroupOptions.ALL_OPTIONS);
+			List<Item> children = new() { episode };
 
-					int numSeriesParents = seriesParents.Count(p => p.IsSeriesParent);
-					if (numSeriesParents != 1)
-					{
-						//There should only ever be 1 top-level parent per episode. If not, log
-						//so we can figure out what to do about those special cases, and don't
-						//import the episode.
-						JsonSerializerSettings Settings = new()
-						{
-							MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
-							DateParseHandling = DateParseHandling.None,
-							Converters =
-							{
-								new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
-							},
-						};
-						Serilog.Log.Logger.Error($"Found {numSeriesParents} parents for {parent.Asin}\r\nEpisode Product:\r\n{JsonConvert.SerializeObject(parent, Formatting.None, Settings)}");
-						return new List<Item>();
+			var parentAsins = episode.Relationships
+				.Where(r => r.RelationshipToProduct == RelationshipToProduct.Parent)
+				.Select(p => p.Asin);
+
+			var seriesParents = await Api.GetCatalogProductsAsync(parentAsins, CatalogOptions.ResponseGroupOptions.ALL_OPTIONS);
+
+			int numSeriesParents = seriesParents.Count(p => p.IsSeriesParent);
+			if (numSeriesParents != 1)
+			{
+				//There should only ever be 1 top-level parent per episode. If not, log
+				//so we can figure out what to do about those special cases, and don't
+				//import the episode.
+				JsonSerializerSettings Settings = new()
+				{
+					MetadataPropertyHandling = MetadataPropertyHandling.Ignore,
+					DateParseHandling = DateParseHandling.None,
+					Converters = {
+						new IsoDateTimeConverter { DateTimeStyles = DateTimeStyles.AssumeUniversal }
 					}
+				};
+				Serilog.Log.Logger.Error($"Found {numSeriesParents} parents for {episode.Asin}\r\nEpisode Product:\r\n{JsonConvert.SerializeObject(episode, Formatting.None, Settings)}");
+				return new();
+			}
 
-					var realParent = seriesParents.Single(p => p.IsSeriesParent);
-					realParent.PurchaseDate = parent.PurchaseDate;
+			var parent = seriesParents.Single(p => p.IsSeriesParent);
+			parent.PurchaseDate = episode.PurchaseDate;
 
-					Serilog.Log.Logger.Debug("Completed parent scan for {parent}", parent); 
-					parent = realParent;
-				}
-				else
+			setSeries(parent, children);
+			children.Add(parent);
+
+			Serilog.Log.Logger.Debug("Completed parent scan for {episode}", episode);
+
+			return children;
+		}
+
+		/// <summary>
+		/// Gets all episodes belonging to <paramref name="parent"/> in batches of <see cref="BatchSize"/> and writes the batch get tasks to <paramref name="channel"/>
+		/// This method only completes after all episode batch 'gets' have been written to the channel
+		/// </summary>
+		private async Task getParentEpisodesAsync(Item parent, ChannelWriter<Task<List<Item>>> channel)
+		{
+			Serilog.Log.Logger.Debug("Beginning episode scan for {parent}", parent);
+
+			var episodeIds = parent.Relationships
+				.Where(r => r.RelationshipToProduct == RelationshipToProduct.Child && r.RelationshipType == RelationshipType.Episode)
+				.Select(r => r.Asin);
+
+			for (int batchNum = 0; episodeIds.Any(); batchNum++)
+			{
+				var batch = episodeIds.Take(BatchSize);
+
+				await channel.WriteAsync(getEpisodeBatchAsync(batchNum, parent, batch));
+
+				episodeIds = episodeIds.Skip(BatchSize);
+			}
+		}
+
+		private async Task<List<Item>> getEpisodeBatchAsync(int batchNum, Item parent, IEnumerable<string> childrenIds)
+		{
+			try
+			{
+				List<Item> episodeBatch = await Api.GetCatalogProductsAsync(childrenIds, CatalogOptions.ResponseGroupOptions.ALL_OPTIONS);
+
+				setSeries(parent, episodeBatch);
+
+				if (batchNum == 0)
+					episodeBatch.Add(parent);
+
+				Serilog.Log.Logger.Debug($"Batch {batchNum}: {episodeBatch.Count} results\t({{parent}})", parent);
+
+				return episodeBatch;
+			}
+			catch (Exception ex)
+			{
+				Serilog.Log.Logger.Error(ex, "Error fetching batch of episodes. {@DebugInfo}", new
 				{
-					children = await getEpisodeChildrenAsync(parent);
-					if (!children.Any())
-						return new();
-				}
+					ParentId = parent.Asin,
+					ParentTitle = parent.Title,
+					BatchNumber = batchNum,
+					ChildIdBatch = childrenIds
+				});
+				throw;
+			}
+		}
 
-				//A series parent will always have exactly 1 Series
-				parent.Series = new Series[]
+		private static void setSeries(Item parent, IEnumerable<Item> children)
+		{
+			//A series parent will always have exactly 1 Series
+			parent.Series = new[]
+			{
+				new Series
+				{
+					Asin = parent.Asin,
+					Sequence = "-1",
+					Title = parent.TitleWithSubtitle
+				}
+			};
+
+			foreach (var child in children)
+			{
+				// use parent's 'DateAdded'. DateAdded is just a convenience prop for: PurchaseDate.UtcDateTime
+				child.PurchaseDate = parent.PurchaseDate;
+				// parent is essentially a series
+				child.Series = new[]
 				{
 					new Series
 					{
 						Asin = parent.Asin,
-						Sequence = "-1",
+						// This should properly be Single() not FirstOrDefault(), but FirstOrDefault is defensive for malformed data from audible
+						Sequence = parent.Relationships.FirstOrDefault(r => r.Asin == child.Asin)?.Sort?.ToString() ?? "0",
 						Title = parent.TitleWithSubtitle
 					}
 				};
-
-				foreach (var child in children)
-				{
-					// use parent's 'DateAdded'. DateAdded is just a convenience prop for: PurchaseDate.UtcDateTime
-					child.PurchaseDate = parent.PurchaseDate;
-					// parent is essentially a series
-					child.Series = new Series[]
-					{
-						new Series
-						{
-							Asin = parent.Asin,
-							// This should properly be Single() not FirstOrDefault(), but FirstOrDefault is defensive for malformed data from audible
-							Sequence = parent.Relationships.FirstOrDefault(r => r.Asin == child.Asin)?.Sort?.ToString() ?? "0",
-							Title = parent.TitleWithSubtitle
-						}
-					};
-				}
-
-				children.Add(parent);
-
-				Serilog.Log.Logger.Debug("Completed episode scan for {parent}", parent);
-
-				return children;
 			}
-			finally
-			{
-				concurrencySemaphore.Release();
-			}
-		}
-
-		private async Task<List<Item>> getEpisodeChildrenAsync(Item parent)
-		{
-			var childrenIds = parent.Relationships
-				.Where(r => r.RelationshipToProduct == RelationshipToProduct.Child && r.RelationshipType == RelationshipType.Episode)
-				.Select(r => r.Asin)
-				.ToList();
-
-			// fetch children in batches
-			const int batchSize = 20;
-
-			var results = new List<Item>();
-
-			for (var i = 1; ; i++)
-			{
-				var idBatch = childrenIds.Skip((i - 1) * batchSize).Take(batchSize).ToList();
-				if (!idBatch.Any())
-					break;
-
-				List<Item> childrenBatch;
-				try
-				{
-					childrenBatch = await Api.GetCatalogProductsAsync(idBatch, CatalogOptions.ResponseGroupOptions.ALL_OPTIONS);
-#if DEBUG
-					//var childrenBatchDebug = childrenBatch.Select(i => i.ToJson()).Aggregate((a, b) => $"{a}\r\n\r\n{b}");
-					//System.IO.File.WriteAllText($"children of {parent.Asin}.json", childrenBatchDebug);
-#endif
-				}
-				catch (Exception ex)
-				{
-					Serilog.Log.Logger.Error(ex, "Error fetching batch of episodes. {@DebugInfo}", new
-					{
-						ParentId = parent.Asin,
-						ParentTitle = parent.Title,
-						BatchNumber = i,
-						ChildIdBatch = idBatch
-					});
-					throw;
-				}
-
-				Serilog.Log.Logger.Debug($"Batch {i}: {childrenBatch.Count} results\t({{parent}})", parent);
-				// the service returned no results. probably indicates an error. stop running batches
-				if (!childrenBatch.Any())
-					break;
-
-				results.AddRange(childrenBatch);
-			}
-
-			Serilog.Log.Logger.Debug("Parent episodes/podcasts series. Children found. {@DebugInfo}", new
-			{
-				ParentId = parent.Asin,
-				ParentTitle = parent.Title,
-				ChildCount = childrenIds.Count
-			});
-
-			if (childrenIds.Count != results.Count)
-			{
-				var ex = new ApplicationException($"Mis-match: Children defined by parent={childrenIds.Count}. Children returned by batches={results.Count}");
-				Serilog.Log.Logger.Error(ex, "{parent} - Quantity of series episodes defined by parent does not match quantity returned by batch fetching.", parent);
-				throw ex;
-			}
-
-			return results;
 		}
 		#endregion
 	}

Source/DataLayer/Configurations/BookConfig.cs

@@ -1,5 +1,6 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using System;
 
 namespace DataLayer.Configurations
 {
@@ -19,40 +20,45 @@ namespace DataLayer.Configurations
             entity.Ignore(nameof(Book.Authors));
             entity.Ignore(nameof(Book.Narrators));
             entity.Ignore(nameof(Book.AudioFormat));
-			//// these don't seem to matter
-			//entity.Ignore(nameof(Book.AuthorNames));
-			//entity.Ignore(nameof(Book.NarratorNames));
-			//entity.Ignore(nameof(Book.HasPdfs));
+            //// these don't seem to matter
+            //entity.Ignore(nameof(Book.AuthorNames));
+            //entity.Ignore(nameof(Book.NarratorNames));
+            //entity.Ignore(nameof(Book.HasPdfs));
 
-			// OwnsMany: "Can only ever appear on navigation properties of other entity types.
-			//  Are automatically loaded, and can only be tracked by a DbContext alongside their owner."
-			entity
-				.OwnsMany(b => b.Supplements, b_s =>
-				{
-					b_s.WithOwner(s => s.Book)
-						.HasForeignKey(s => s.BookId);
-					b_s.HasKey(s => s.SupplementId);
-				});
+            // OwnsMany: "Can only ever appear on navigation properties of other entity types.
+            //  Are automatically loaded, and can only be tracked by a DbContext alongside their owner."
+            entity
+                .OwnsMany(b => b.Supplements, b_s =>
+                {
+                    b_s.WithOwner(s => s.Book)
+                        .HasForeignKey(s => s.BookId);
+                    b_s.HasKey(s => s.SupplementId);
+                });
             // even though it's owned, we need to map its backing field
             entity
                 .Metadata
                 .FindNavigation(nameof(Book.Supplements))
                 .SetPropertyAccessMode(PropertyAccessMode.Field);
 
-			// owns it 1:1, store in separate table
-			entity
-				.OwnsOne(b => b.UserDefinedItem, b_udi =>
-				{
-					b_udi.WithOwner(udi => udi.Book)
-						.HasForeignKey(udi => udi.BookId);
-					b_udi.Property(udi => udi.BookId).ValueGeneratedNever();
-					b_udi.ToTable(nameof(Book.UserDefinedItem));
+            // owns it 1:1, store in separate table
+            entity
+                .OwnsOne(b => b.UserDefinedItem, b_udi =>
+                {
+                    b_udi.WithOwner(udi => udi.Book)
+                        .HasForeignKey(udi => udi.BookId);
+                    b_udi.Property(udi => udi.BookId).ValueGeneratedNever();
+                    b_udi.ToTable(nameof(Book.UserDefinedItem));
 
-					// owns it 1:1, store in same table
-					b_udi.OwnsOne(udi => udi.Rating);
-				});
+                    b_udi.Property(udi => udi.LastDownloaded);
+                    b_udi
+                        .Property(udi => udi.LastDownloadedVersion)
+                        .HasConversion(ver => ver.ToString(), str => Version.Parse(str));
 
-			entity
+                    // owns it 1:1, store in same table
+                    b_udi.OwnsOne(udi => udi.Rating);
+                });
+
+            entity
                 .Metadata
                 .FindNavigation(nameof(Book.ContributorsLink))
                 // PropertyAccessMode.Field : Contributions is a get-only property, not a field, so use its backing field
@@ -68,6 +74,6 @@ namespace DataLayer.Configurations
                 .HasOne(b => b.Category)
                 .WithMany()
                 .HasForeignKey(b => b.CategoryId);
-		}
+        }
     }
 }

Source/DataLayer/EfClasses/LibraryBook.cs

@@ -12,6 +12,7 @@ namespace DataLayer
         public string Account { get; private set; }
 
         public bool IsDeleted { get; set; }
+        public bool AbsentFromLastScan { get; set; }
 
         private LibraryBook() { }
         public LibraryBook(Book book, DateTime dateAdded, string account)

Source/DataLayer/EfClasses/UserDefinedItem.cs

@@ -24,8 +24,27 @@ namespace DataLayer
     {
         internal int BookId { get; private set; }
         public Book Book { get; private set; }
+        public DateTime? LastDownloaded { get; private set; }
+        public Version LastDownloadedVersion { get; private set; }
 
-        private UserDefinedItem() { }
+        public void SetLastDownloaded(Version version)
+        {
+            if (LastDownloadedVersion != version)
+            {
+                LastDownloadedVersion = version;
+				OnItemChanged(nameof(LastDownloadedVersion));
+			}
+
+            if (version is null)
+                LastDownloaded = null;
+            else
+            {
+				LastDownloaded = DateTime.Now;
+                OnItemChanged(nameof(LastDownloaded));
+			}
+		}
+
+		private UserDefinedItem() { }
         internal UserDefinedItem(Book book)
 		{
 			ArgumentValidator.EnsureNotNull(book, nameof(book));

Source/DataLayer/Migrations/20230302220539_AddLastDownloadedInfo.Designer.cs

@@ -0,0 +1,410 @@
+// <auto-generated />
+using System;
+using DataLayer;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace DataLayer.Migrations
+{
+    [DbContext(typeof(LibationContext))]
+    [Migration("20230302220539_AddLastDownloadedInfo")]
+    partial class AddLastDownloadedInfo
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "7.0.3");
+
+            modelBuilder.Entity("DataLayer.Book", b =>
+                {
+                    b.Property<int>("BookId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleProductId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("CategoryId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("ContentType")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime?>("DatePublished")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Description")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsAbridged")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Language")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("LengthInMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Locale")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PictureId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PictureLarge")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Title")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("_audioFormat")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("BookId");
+
+                    b.HasIndex("AudibleProductId");
+
+                    b.HasIndex("CategoryId");
+
+                    b.ToTable("Books");
+                });
+
+            modelBuilder.Entity("DataLayer.BookContributor", b =>
+                {
+                    b.Property<int>("BookId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("ContributorId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Role")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<byte>("Order")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("BookId", "ContributorId", "Role");
+
+                    b.HasIndex("BookId");
+
+                    b.HasIndex("ContributorId");
+
+                    b.ToTable("BookContributor");
+                });
+
+            modelBuilder.Entity("DataLayer.Category", b =>
+                {
+                    b.Property<int>("CategoryId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleCategoryId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("ParentCategoryCategoryId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("CategoryId");
+
+                    b.HasIndex("AudibleCategoryId");
+
+                    b.HasIndex("ParentCategoryCategoryId");
+
+                    b.ToTable("Categories");
+
+                    b.HasData(
+                        new
+                        {
+                            CategoryId = -1,
+                            AudibleCategoryId = "",
+                            Name = ""
+                        });
+                });
+
+            modelBuilder.Entity("DataLayer.Contributor", b =>
+                {
+                    b.Property<int>("ContributorId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleContributorId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("ContributorId");
+
+                    b.HasIndex("Name");
+
+                    b.ToTable("Contributors");
+
+                    b.HasData(
+                        new
+                        {
+                            ContributorId = -1,
+                            Name = ""
+                        });
+                });
+
+            modelBuilder.Entity("DataLayer.LibraryBook", b =>
+                {
+                    b.Property<int>("BookId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Account")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("DateAdded")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsDeleted")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("BookId");
+
+                    b.ToTable("LibraryBooks");
+                });
+
+            modelBuilder.Entity("DataLayer.Series", b =>
+                {
+                    b.Property<int>("SeriesId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleSeriesId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("SeriesId");
+
+                    b.HasIndex("AudibleSeriesId");
+
+                    b.ToTable("Series");
+                });
+
+            modelBuilder.Entity("DataLayer.SeriesBook", b =>
+                {
+                    b.Property<int>("SeriesId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("BookId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Order")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("SeriesId", "BookId");
+
+                    b.HasIndex("BookId");
+
+                    b.HasIndex("SeriesId");
+
+                    b.ToTable("SeriesBook");
+                });
+
+            modelBuilder.Entity("DataLayer.Book", b =>
+                {
+                    b.HasOne("DataLayer.Category", "Category")
+                        .WithMany()
+                        .HasForeignKey("CategoryId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.OwnsOne("DataLayer.Rating", "Rating", b1 =>
+                        {
+                            b1.Property<int>("BookId")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<float>("OverallRating")
+                                .HasColumnType("REAL");
+
+                            b1.Property<float>("PerformanceRating")
+                                .HasColumnType("REAL");
+
+                            b1.Property<float>("StoryRating")
+                                .HasColumnType("REAL");
+
+                            b1.HasKey("BookId");
+
+                            b1.ToTable("Books");
+
+                            b1.WithOwner()
+                                .HasForeignKey("BookId");
+                        });
+
+                    b.OwnsMany("DataLayer.Supplement", "Supplements", b1 =>
+                        {
+                            b1.Property<int>("SupplementId")
+                                .ValueGeneratedOnAdd()
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<int>("BookId")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<string>("Url")
+                                .HasColumnType("TEXT");
+
+                            b1.HasKey("SupplementId");
+
+                            b1.HasIndex("BookId");
+
+                            b1.ToTable("Supplement");
+
+                            b1.WithOwner("Book")
+                                .HasForeignKey("BookId");
+
+                            b1.Navigation("Book");
+                        });
+
+                    b.OwnsOne("DataLayer.UserDefinedItem", "UserDefinedItem", b1 =>
+                        {
+                            b1.Property<int>("BookId")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<int>("BookStatus")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<DateTime?>("LastDownloaded")
+                                .HasColumnType("TEXT");
+
+                            b1.Property<string>("LastDownloadedVersion")
+                                .HasColumnType("TEXT");
+
+                            b1.Property<int?>("PdfStatus")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<string>("Tags")
+                                .HasColumnType("TEXT");
+
+                            b1.HasKey("BookId");
+
+                            b1.ToTable("UserDefinedItem", (string)null);
+
+                            b1.WithOwner("Book")
+                                .HasForeignKey("BookId");
+
+                            b1.OwnsOne("DataLayer.Rating", "Rating", b2 =>
+                                {
+                                    b2.Property<int>("UserDefinedItemBookId")
+                                        .HasColumnType("INTEGER");
+
+                                    b2.Property<float>("OverallRating")
+                                        .HasColumnType("REAL");
+
+                                    b2.Property<float>("PerformanceRating")
+                                        .HasColumnType("REAL");
+
+                                    b2.Property<float>("StoryRating")
+                                        .HasColumnType("REAL");
+
+                                    b2.HasKey("UserDefinedItemBookId");
+
+                                    b2.ToTable("UserDefinedItem");
+
+                                    b2.WithOwner()
+                                        .HasForeignKey("UserDefinedItemBookId");
+                                });
+
+                            b1.Navigation("Book");
+
+                            b1.Navigation("Rating");
+                        });
+
+                    b.Navigation("Category");
+
+                    b.Navigation("Rating");
+
+                    b.Navigation("Supplements");
+
+                    b.Navigation("UserDefinedItem");
+                });
+
+            modelBuilder.Entity("DataLayer.BookContributor", b =>
+                {
+                    b.HasOne("DataLayer.Book", "Book")
+                        .WithMany("ContributorsLink")
+                        .HasForeignKey("BookId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("DataLayer.Contributor", "Contributor")
+                        .WithMany("BooksLink")
+                        .HasForeignKey("ContributorId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Book");
+
+                    b.Navigation("Contributor");
+                });
+
+            modelBuilder.Entity("DataLayer.Category", b =>
+                {
+                    b.HasOne("DataLayer.Category", "ParentCategory")
+                        .WithMany()
+                        .HasForeignKey("ParentCategoryCategoryId");
+
+                    b.Navigation("ParentCategory");
+                });
+
+            modelBuilder.Entity("DataLayer.LibraryBook", b =>
+                {
+                    b.HasOne("DataLayer.Book", "Book")
+                        .WithOne()
+                        .HasForeignKey("DataLayer.LibraryBook", "BookId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Book");
+                });
+
+            modelBuilder.Entity("DataLayer.SeriesBook", b =>
+                {
+                    b.HasOne("DataLayer.Book", "Book")
+                        .WithMany("SeriesLink")
+                        .HasForeignKey("BookId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("DataLayer.Series", "Series")
+                        .WithMany("BooksLink")
+                        .HasForeignKey("SeriesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Book");
+
+                    b.Navigation("Series");
+                });
+
+            modelBuilder.Entity("DataLayer.Book", b =>
+                {
+                    b.Navigation("ContributorsLink");
+
+                    b.Navigation("SeriesLink");
+                });
+
+            modelBuilder.Entity("DataLayer.Contributor", b =>
+                {
+                    b.Navigation("BooksLink");
+                });
+
+            modelBuilder.Entity("DataLayer.Series", b =>
+                {
+                    b.Navigation("BooksLink");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Source/DataLayer/Migrations/20230302220539_AddLastDownloadedInfo.cs

@@ -0,0 +1,39 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace DataLayer.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddLastDownloadedInfo : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<DateTime>(
+                name: "LastDownloaded",
+                table: "UserDefinedItem",
+                type: "TEXT",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "LastDownloadedVersion",
+                table: "UserDefinedItem",
+                type: "TEXT",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "LastDownloaded",
+                table: "UserDefinedItem");
+
+            migrationBuilder.DropColumn(
+                name: "LastDownloadedVersion",
+                table: "UserDefinedItem");
+        }
+    }
+}

Source/DataLayer/Migrations/20230308013410_AddAbsentFromLastScan.Designer.cs

@@ -0,0 +1,413 @@
+// <auto-generated />
+using System;
+using DataLayer;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace DataLayer.Migrations
+{
+    [DbContext(typeof(LibationContext))]
+    [Migration("20230308013410_AddAbsentFromLastScan")]
+    partial class AddAbsentFromLastScan
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "7.0.3");
+
+            modelBuilder.Entity("DataLayer.Book", b =>
+                {
+                    b.Property<int>("BookId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleProductId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("CategoryId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("ContentType")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime?>("DatePublished")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Description")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsAbridged")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Language")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("LengthInMinutes")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Locale")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PictureId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("PictureLarge")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Title")
+                        .HasColumnType("TEXT");
+
+                    b.Property<long>("_audioFormat")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("BookId");
+
+                    b.HasIndex("AudibleProductId");
+
+                    b.HasIndex("CategoryId");
+
+                    b.ToTable("Books");
+                });
+
+            modelBuilder.Entity("DataLayer.BookContributor", b =>
+                {
+                    b.Property<int>("BookId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("ContributorId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("Role")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<byte>("Order")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("BookId", "ContributorId", "Role");
+
+                    b.HasIndex("BookId");
+
+                    b.HasIndex("ContributorId");
+
+                    b.ToTable("BookContributor");
+                });
+
+            modelBuilder.Entity("DataLayer.Category", b =>
+                {
+                    b.Property<int>("CategoryId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleCategoryId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int?>("ParentCategoryCategoryId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("CategoryId");
+
+                    b.HasIndex("AudibleCategoryId");
+
+                    b.HasIndex("ParentCategoryCategoryId");
+
+                    b.ToTable("Categories");
+
+                    b.HasData(
+                        new
+                        {
+                            CategoryId = -1,
+                            AudibleCategoryId = "",
+                            Name = ""
+                        });
+                });
+
+            modelBuilder.Entity("DataLayer.Contributor", b =>
+                {
+                    b.Property<int>("ContributorId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleContributorId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("ContributorId");
+
+                    b.HasIndex("Name");
+
+                    b.ToTable("Contributors");
+
+                    b.HasData(
+                        new
+                        {
+                            ContributorId = -1,
+                            Name = ""
+                        });
+                });
+
+            modelBuilder.Entity("DataLayer.LibraryBook", b =>
+                {
+                    b.Property<int>("BookId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<bool>("AbsentFromLastScan")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Account")
+                        .HasColumnType("TEXT");
+
+                    b.Property<DateTime>("DateAdded")
+                        .HasColumnType("TEXT");
+
+                    b.Property<bool>("IsDeleted")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("BookId");
+
+                    b.ToTable("LibraryBooks");
+                });
+
+            modelBuilder.Entity("DataLayer.Series", b =>
+                {
+                    b.Property<int>("SeriesId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AudibleSeriesId")
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Name")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("SeriesId");
+
+                    b.HasIndex("AudibleSeriesId");
+
+                    b.ToTable("Series");
+                });
+
+            modelBuilder.Entity("DataLayer.SeriesBook", b =>
+                {
+                    b.Property<int>("SeriesId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("BookId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Order")
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("SeriesId", "BookId");
+
+                    b.HasIndex("BookId");
+
+                    b.HasIndex("SeriesId");
+
+                    b.ToTable("SeriesBook");
+                });
+
+            modelBuilder.Entity("DataLayer.Book", b =>
+                {
+                    b.HasOne("DataLayer.Category", "Category")
+                        .WithMany()
+                        .HasForeignKey("CategoryId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.OwnsOne("DataLayer.Rating", "Rating", b1 =>
+                        {
+                            b1.Property<int>("BookId")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<float>("OverallRating")
+                                .HasColumnType("REAL");
+
+                            b1.Property<float>("PerformanceRating")
+                                .HasColumnType("REAL");
+
+                            b1.Property<float>("StoryRating")
+                                .HasColumnType("REAL");
+
+                            b1.HasKey("BookId");
+
+                            b1.ToTable("Books");
+
+                            b1.WithOwner()
+                                .HasForeignKey("BookId");
+                        });
+
+                    b.OwnsMany("DataLayer.Supplement", "Supplements", b1 =>
+                        {
+                            b1.Property<int>("SupplementId")
+                                .ValueGeneratedOnAdd()
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<int>("BookId")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<string>("Url")
+                                .HasColumnType("TEXT");
+
+                            b1.HasKey("SupplementId");
+
+                            b1.HasIndex("BookId");
+
+                            b1.ToTable("Supplement");
+
+                            b1.WithOwner("Book")
+                                .HasForeignKey("BookId");
+
+                            b1.Navigation("Book");
+                        });
+
+                    b.OwnsOne("DataLayer.UserDefinedItem", "UserDefinedItem", b1 =>
+                        {
+                            b1.Property<int>("BookId")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<int>("BookStatus")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<DateTime?>("LastDownloaded")
+                                .HasColumnType("TEXT");
+
+                            b1.Property<string>("LastDownloadedVersion")
+                                .HasColumnType("TEXT");
+
+                            b1.Property<int?>("PdfStatus")
+                                .HasColumnType("INTEGER");
+
+                            b1.Property<string>("Tags")
+                                .HasColumnType("TEXT");
+
+                            b1.HasKey("BookId");
+
+                            b1.ToTable("UserDefinedItem", (string)null);
+
+                            b1.WithOwner("Book")
+                                .HasForeignKey("BookId");
+
+                            b1.OwnsOne("DataLayer.Rating", "Rating", b2 =>
+                                {
+                                    b2.Property<int>("UserDefinedItemBookId")
+                                        .HasColumnType("INTEGER");
+
+                                    b2.Property<float>("OverallRating")
+                                        .HasColumnType("REAL");
+
+                                    b2.Property<float>("PerformanceRating")
+                                        .HasColumnType("REAL");
+
+                                    b2.Property<float>("StoryRating")
+                                        .HasColumnType("REAL");
+
+                                    b2.HasKey("UserDefinedItemBookId");
+
+                                    b2.ToTable("UserDefinedItem");
+
+                                    b2.WithOwner()
+                                        .HasForeignKey("UserDefinedItemBookId");
+                                });
+
+                            b1.Navigation("Book");
+
+                            b1.Navigation("Rating");
+                        });
+
+                    b.Navigation("Category");
+
+                    b.Navigation("Rating");
+
+                    b.Navigation("Supplements");
+
+                    b.Navigation("UserDefinedItem");
+                });
+
+            modelBuilder.Entity("DataLayer.BookContributor", b =>
+                {
+                    b.HasOne("DataLayer.Book", "Book")
+                        .WithMany("ContributorsLink")
+                        .HasForeignKey("BookId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("DataLayer.Contributor", "Contributor")
+                        .WithMany("BooksLink")
+                        .HasForeignKey("ContributorId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Book");
+
+                    b.Navigation("Contributor");
+                });
+
+            modelBuilder.Entity("DataLayer.Category", b =>
+                {
+                    b.HasOne("DataLayer.Category", "ParentCategory")
+                        .WithMany()
+                        .HasForeignKey("ParentCategoryCategoryId");
+
+                    b.Navigation("ParentCategory");
+                });
+
+            modelBuilder.Entity("DataLayer.LibraryBook", b =>
+                {
+                    b.HasOne("DataLayer.Book", "Book")
+                        .WithOne()
+                        .HasForeignKey("DataLayer.LibraryBook", "BookId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Book");
+                });
+
+            modelBuilder.Entity("DataLayer.SeriesBook", b =>
+                {
+                    b.HasOne("DataLayer.Book", "Book")
+                        .WithMany("SeriesLink")
+                        .HasForeignKey("BookId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("DataLayer.Series", "Series")
+                        .WithMany("BooksLink")
+                        .HasForeignKey("SeriesId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Book");
+
+                    b.Navigation("Series");
+                });
+
+            modelBuilder.Entity("DataLayer.Book", b =>
+                {
+                    b.Navigation("ContributorsLink");
+
+                    b.Navigation("SeriesLink");
+                });
+
+            modelBuilder.Entity("DataLayer.Contributor", b =>
+                {
+                    b.Navigation("BooksLink");
+                });
+
+            modelBuilder.Entity("DataLayer.Series", b =>
+                {
+                    b.Navigation("BooksLink");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Source/DataLayer/Migrations/20230308013410_AddAbsentFromLastScan.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace DataLayer.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddAbsentFromLastScan : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "AbsentFromLastScan",
+                table: "LibraryBooks",
+                type: "INTEGER",
+                nullable: false,
+                defaultValue: false);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "AbsentFromLastScan",
+                table: "LibraryBooks");
+        }
+    }
+}

Source/DataLayer/Migrations/LibationContextModelSnapshot.cs

@@ -15,7 +15,7 @@ namespace DataLayer.Migrations
         protected override void BuildModel(ModelBuilder modelBuilder)
         {
 #pragma warning disable 612, 618
-            modelBuilder.HasAnnotation("ProductVersion", "7.0.2");
+            modelBuilder.HasAnnotation("ProductVersion", "7.0.3");
 
             modelBuilder.Entity("DataLayer.Book", b =>
                 {
@@ -157,6 +157,9 @@ namespace DataLayer.Migrations
                     b.Property<int>("BookId")
                         .HasColumnType("INTEGER");
 
+                    b.Property<bool>("AbsentFromLastScan")
+                        .HasColumnType("INTEGER");
+
                     b.Property<string>("Account")
                         .HasColumnType("TEXT");
 
@@ -272,6 +275,12 @@ namespace DataLayer.Migrations
                             b1.Property<int>("BookStatus")
                                 .HasColumnType("INTEGER");
 
+                            b1.Property<DateTime?>("LastDownloaded")
+                                .HasColumnType("TEXT");
+
+                            b1.Property<string>("LastDownloadedVersion")
+                                .HasColumnType("TEXT");
+
                             b1.Property<int?>("PdfStatus")
                                 .HasColumnType("INTEGER");
 

Source/DataLayer/QueryObjects/LibraryBookQueries.cs

@@ -107,8 +107,9 @@ namespace DataLayer
             => bookList
                 .Where(
                     lb =>
-                        lb.Book.UserDefinedItem.BookStatus is LiberatedStatus.NotLiberated or LiberatedStatus.PartialDownload
-                        || lb.Book.UserDefinedItem.PdfStatus is LiberatedStatus.NotLiberated or LiberatedStatus.PartialDownload
+                        !lb.AbsentFromLastScan &&
+                        (lb.Book.UserDefinedItem.BookStatus is LiberatedStatus.NotLiberated or LiberatedStatus.PartialDownload
+                        || lb.Book.UserDefinedItem.PdfStatus is LiberatedStatus.NotLiberated or LiberatedStatus.PartialDownload)
                     );
     }
 }

Source/DtoImporterService/ImportItem.cs

@@ -8,5 +8,7 @@ namespace DtoImporterService
 		public Item DtoItem { get; set; }
 		public string AccountId { get; set; }
 		public string LocaleName { get; set; }
+		public override string ToString()
+			=> DtoItem is null ? base.ToString() : $"[{DtoItem.ProductId}] {DtoItem.Title}";
 	}
 }

Source/DtoImporterService/LibraryBookImporter.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using AudibleUtilities;
 using DataLayer;
+using Dinah.Core;
 using Dinah.Core.Collections.Generic;
 
 namespace DtoImporterService
@@ -40,9 +41,8 @@ namespace DtoImporterService
 			//
 			// CURRENT SOLUTION: don't re-insert
 
-			var currentLibraryProductIds = DbContext.LibraryBooks.Select(l => l.Book.AudibleProductId).ToList();
 			var newItems = importItems
-				.Where(dto => !currentLibraryProductIds.Contains(dto.DtoItem.ProductId))
+				.ExceptBy(DbContext.LibraryBooks.Select(lb => lb.Book.AudibleProductId), imp => imp.DtoItem.ProductId)
 				.ToList();
 
 			// if 2 accounts try to import the same book in the same transaction: error since we're only tracking and pulling by asin.
@@ -55,7 +55,11 @@ namespace DtoImporterService
 				var libraryBook = new LibraryBook(
 					bookImporter.Cache[newItem.DtoItem.ProductId],
 					newItem.DtoItem.DateAdded,
-					newItem.AccountId);
+					newItem.AccountId)
+				{
+					AbsentFromLastScan = isPlusTitleUnavailable(newItem)
+				};
+
 				try
 				{
 					DbContext.LibraryBooks.Add(libraryBook);
@@ -66,8 +70,30 @@ namespace DtoImporterService
 				}
 			}
 
+			//If an existing Book wasn't found in the import, the owning LibraryBook's Book will be null. 
+			foreach (var nullBook in DbContext.LibraryBooks.AsEnumerable().Where(lb => lb.Book is null))
+				nullBook.AbsentFromLastScan = true;
+
+			//Join importItems on LibraryBooks before iterating over LibraryBooks to avoid
+			//quadratic complexity caused by searching all of importItems for each LibraryBook.
+			//Join uses hashing, so complexity should approach O(N) instead of O(N^2).
+			var items_lbs
+			   = importItems
+			   .Join(DbContext.LibraryBooks, o => (o.AccountId, o.DtoItem.ProductId), i => (i.Account, i.Book?.AudibleProductId), (o, i) => (o, i));
+
+			foreach ((ImportItem item, LibraryBook lb) in items_lbs)
+				lb.AbsentFromLastScan = isPlusTitleUnavailable(item);
+
 			var qtyNew = hash.Count;
 			return qtyNew;
 		}
+
+
+		//This SEEMS to work to detect plus titles which are no longer available.
+		//I have my doubts it won't yield false negatives, but I have more
+		//confidence that it won't yield many/any false positives.
+		private static bool isPlusTitleUnavailable(ImportItem item)
+			=> item.DtoItem.IsAyce is true
+			&& item.DtoItem.Plans?.Any(p => p.PlanName.ContainsInsensitive("Minerva") || p.PlanName.ContainsInsensitive("Free")) is not true;
 	}
 }

Source/FileLiberator/DownloadDecryptBook.cs

@@ -41,7 +41,7 @@ namespace FileLiberator
 
             OnBegin(libraryBook);
 
-            try
+			try
             {
                 if (libraryBook.Book.Audio_Exists())
                     return new StatusHandler { "Cannot find decrypt. Final audio file already exists" };
@@ -61,31 +61,30 @@ namespace FileLiberator
                 }
 
                 // decrypt failed
-                if (!success)
+                if (!success || getFirstAudioFile(entries) == default)
                 {
-                    foreach (var tmpFile in entries.Where(f => f.FileType != FileType.AAXC))
-                        FileUtility.SaferDelete(tmpFile.Path);
+                    await Task.WhenAll(
+                        entries
+                        .Where(f => f.FileType != FileType.AAXC)
+                        .Select(f => Task.Run(() => FileUtility.SaferDelete(f.Path))));
 
-                    return abDownloader?.IsCanceled == true ?
-                        new StatusHandler { "Cancelled" } :
-                        new StatusHandler { "Decrypt failed" };
+                    return
+                        abDownloader?.IsCanceled is true
+                        ? new StatusHandler { "Cancelled" }
+                        : new StatusHandler { "Decrypt failed" };
                 }
 
-                // moves new files from temp dir to final dest.
-                // This could take a few seconds if moving hundreds of files.
-                var finalStorageDir = await Task.Run(() => moveFilesToBooksDir(libraryBook, entries));
+                var finalStorageDir = getDestinationDirectory(libraryBook);
 
-                // decrypt failed
-                if (finalStorageDir is null)
-                    return new StatusHandler { "Cannot find final audio file after decryption" };
+				Task[] finalTasks = new[]
+                {
+					Task.Run(() => downloadCoverArt(libraryBook)),
+					Task.Run(() => moveFilesToBooksDir(libraryBook, entries)),
+					Task.Run(() => libraryBook.Book.UpdateBookStatus(LiberatedStatus.Liberated, Configuration.LibationVersion)),
+					Task.Run(() => WindowsDirectory.SetCoverAsFolderIcon(libraryBook.Book.PictureId, finalStorageDir))
+				};
 
-                if (Configuration.Instance.DownloadCoverArt)
-                    downloadCoverArt(libraryBook);
-
-                // contains logic to check for config setting and OS
-                WindowsDirectory.SetCoverAsFolderIcon(pictureId: libraryBook.Book.PictureId, directory: finalStorageDir);
-
-                libraryBook.Book.UpdateBookStatus(LiberatedStatus.Liberated);
+				await Task.WhenAll(finalTasks);
 
                 return new StatusHandler();
             }
@@ -131,8 +130,8 @@ namespace FileLiberator
             abDownloader.RetrievedCoverArt += AaxcDownloader_RetrievedCoverArt;
             abDownloader.FileCreated += (_, path) => OnFileCreated(libraryBook, path);
 
-            // REAL WORK DONE HERE
-            return await abDownloader.RunAsync();
+			// REAL WORK DONE HERE
+			return await abDownloader.RunAsync();
         }
 
         private DownloadOptions BuildDownloadOptions(LibraryBook libraryBook, Configuration config, AudibleApi.Common.ContentLicense contentLic)
@@ -335,18 +334,12 @@ namespace FileLiberator
 
         /// <summary>Move new files to 'Books' directory</summary>
         /// <returns>Return directory if audiobook file(s) were successfully created and can be located on disk. Else null.</returns>
-        private static string moveFilesToBooksDir(LibraryBook libraryBook, List<FilePathCache.CacheEntry> entries)
+        private static void moveFilesToBooksDir(LibraryBook libraryBook, List<FilePathCache.CacheEntry> entries)
         {
             // create final directory. move each file into it
-            var destinationDir = AudibleFileStorage.Audio.GetDestinationDirectory(libraryBook);
-            Directory.CreateDirectory(destinationDir);
+            var destinationDir = getDestinationDirectory(libraryBook);
 
-            FilePathCache.CacheEntry getFirstAudio() => entries.FirstOrDefault(f => f.FileType == FileType.Audio);
-
-            if (getFirstAudio() == default)
-                return null;
-
-            for (var i = 0; i < entries.Count; i++)
+			for (var i = 0; i < entries.Count; i++)
             {
                 var entry = entries[i];
 
@@ -357,22 +350,33 @@ namespace FileLiberator
                 entries[i] = entry with { Path = realDest };
             }
 
-            var cue = entries.FirstOrDefault(f => f.FileType == FileType.Cue);
+			var cue = entries.FirstOrDefault(f => f.FileType == FileType.Cue);
             if (cue != default)
-                Cue.UpdateFileName(cue.Path, getFirstAudio().Path);
+                Cue.UpdateFileName(cue.Path, getFirstAudioFile(entries).Path);
 
             AudibleFileStorage.Audio.Refresh();
-
-            return destinationDir;
         }
 
-        private static void downloadCoverArt(LibraryBook libraryBook)
+        private static string getDestinationDirectory(LibraryBook libraryBook)
         {
+			var destinationDir = AudibleFileStorage.Audio.GetDestinationDirectory(libraryBook);
+            if (!Directory.Exists(destinationDir))
+                Directory.CreateDirectory(destinationDir);
+            return destinationDir;
+		}
+
+		private static FilePathCache.CacheEntry getFirstAudioFile(IEnumerable<FilePathCache.CacheEntry> entries)
+            => entries.FirstOrDefault(f => f.FileType == FileType.Audio);
+
+		private static void downloadCoverArt(LibraryBook libraryBook)
+        {
+            if (!Configuration.Instance.DownloadCoverArt) return;
+
             var coverPath = "[null]";
 
             try
             {
-                var destinationDir = AudibleFileStorage.Audio.GetDestinationDirectory(libraryBook);
+                var destinationDir = getDestinationDirectory(libraryBook);
                 coverPath = AudibleFileStorage.Audio.GetBooksDirectoryFilename(libraryBook, ".jpg");
                 coverPath = Path.Combine(destinationDir, Path.GetFileName(coverPath));
 

Source/LibationAvalonia/Assets/LibationStyles.xaml

@@ -8,6 +8,8 @@
 		<SolidColorBrush x:Key="ProcessQueueBookCancelledBrush" Color="Khaki" />
 		<SolidColorBrush x:Key="ProcessQueueBookDefaultBrush" Color="{StaticResource SystemAltHighColor}" />
 		<SolidColorBrush x:Key="ProcessQueueBookBorderBrush" Color="Gray" />
+		<SolidColorBrush x:Key="DisabledGrayBrush" Color="#60D3D3D3" />
+		
 	</Styles.Resources>
 	<Style Selector="TextBox[IsReadOnly=true]">
 		<Setter Property="Background" Value="LightGray" />

Source/LibationAvalonia/Controls/CheckedListBox.axaml

@@ -0,0 +1,30 @@
+<UserControl xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+			 mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
+             x:Class="LibationAvalonia.Controls.CheckedListBox">
+	
+	<UserControl.Resources>
+		<RecyclePool x:Key="RecyclePool" />
+		<DataTemplate x:Key="queuedBook">
+			<CheckBox HorizontalAlignment="Stretch" Margin="10,0,0,0" Content="{Binding Item}" IsChecked="{Binding IsChecked, Mode=TwoWay}" />
+		</DataTemplate>
+		<RecyclingElementFactory x:Key="elementFactory" RecyclePool="{StaticResource RecyclePool}">
+			<RecyclingElementFactory.Templates>
+				<StaticResource x:Key="queuedBook" ResourceKey="queuedBook" />
+			</RecyclingElementFactory.Templates>
+		</RecyclingElementFactory>
+	</UserControl.Resources>
+
+	<ScrollViewer
+		Name="scroller"
+		HorizontalScrollBarVisibility="Disabled"
+		VerticalScrollBarVisibility="Auto">
+		<ItemsRepeater IsVisible="True"
+			VerticalCacheLength="1.2"
+			HorizontalCacheLength="1"
+			Items="{Binding CheckboxItems}"
+			ItemTemplate="{StaticResource elementFactory}" />
+	</ScrollViewer>
+</UserControl>

Source/LibationAvalonia/Controls/CheckedListBox.axaml.cs

@@ -0,0 +1,46 @@
+using Avalonia;
+using Avalonia.Collections;
+using Avalonia.Controls;
+using LibationAvalonia.ViewModels;
+using ReactiveUI;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace LibationAvalonia.Controls
+{
+	public partial class CheckedListBox : UserControl
+	{
+		public static readonly StyledProperty<AvaloniaList<CheckBoxViewModel>> ItemsProperty =
+		AvaloniaProperty.Register<CheckedListBox, AvaloniaList<CheckBoxViewModel>>(nameof(Items));
+
+		public AvaloniaList<CheckBoxViewModel> Items { get => GetValue(ItemsProperty); set => SetValue(ItemsProperty, value); }
+		private CheckedListBoxViewModel _viewModel = new();	
+
+		public CheckedListBox()
+		{
+			InitializeComponent();
+			scroller.DataContext = _viewModel;
+		}
+		protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
+		{
+			if (change.Property.Name == nameof(Items) && Items != null)
+				_viewModel.CheckboxItems = Items;
+			base.OnPropertyChanged(change);
+		}
+
+		private class CheckedListBoxViewModel : ViewModelBase
+		{
+			private AvaloniaList<CheckBoxViewModel> _checkboxItems;
+			public AvaloniaList<CheckBoxViewModel> CheckboxItems { get => _checkboxItems; set => this.RaiseAndSetIfChanged(ref _checkboxItems, value); }
+		}
+	}
+
+	public class CheckBoxViewModel : ViewModelBase
+	{
+		private bool _isChecked;
+		public bool IsChecked { get => _isChecked; set => this.RaiseAndSetIfChanged(ref _isChecked, value); }
+		private object _bookText;
+		public object Item { get => _bookText; set => this.RaiseAndSetIfChanged(ref _bookText, value); }
+	}
+}

Source/LibationAvalonia/Dialogs/ImageDisplayDialog.axaml.cs

@@ -1,8 +1,5 @@
-using Avalonia;
-using Avalonia.Controls;
 using Avalonia.Markup.Xaml;
 using Avalonia.Media.Imaging;
-using Avalonia.Platform;
 using System;
 using System.ComponentModel;
 using System.IO;
@@ -16,23 +13,8 @@ namespace LibationAvalonia.Dialogs
 		public string PictureFileName { get; set; }
 		public string BookSaveDirectory { get; set; }
 
-		private byte[] _coverBytes;
-		public byte[] CoverBytes
-		{
-			get => _coverBytes;
-			set
-			{
-				_coverBytes = value;
-				var ms = new MemoryStream(_coverBytes);
-				ms.Position = 0;
-				_bitmapHolder.CoverImage = new Bitmap(ms);
-			}
-		}
-
-
 		private readonly BitmapHolder _bitmapHolder = new BitmapHolder();
 
-
 		public ImageDisplayDialog()
 		{
 			InitializeComponent();
@@ -45,6 +27,21 @@ namespace LibationAvalonia.Dialogs
 			AvaloniaXamlLoader.Load(this);
 		}
 
+		public void SetCoverBytes(byte[] cover)
+		{
+			try
+			{
+				var ms = new MemoryStream(cover);
+				_bitmapHolder.CoverImage = new Bitmap(ms);
+			}
+			catch (Exception ex)
+			{
+				Serilog.Log.Logger.Error(ex, "Error loading cover art for {file}", PictureFileName);
+				using var ms = App.OpenAsset("img-coverart-prod-unavailable_500x500.jpg");
+				_bitmapHolder.CoverImage = new Bitmap(ms);				
+			}
+		}
+
 		public async void SaveImage_Clicked(object sender, Avalonia.Interactivity.RoutedEventArgs e)
 		{
 			var options = new FilePickerSaveOptions
@@ -70,7 +67,7 @@ namespace LibationAvalonia.Dialogs
 
 			try
 			{
-				File.WriteAllBytes(uri.LocalPath, CoverBytes);
+				_bitmapHolder.CoverImage.Save(uri.LocalPath);
 			}
 			catch (Exception ex)
 			{

Source/LibationAvalonia/Dialogs/SettingsDialog.axaml

@@ -2,7 +2,7 @@
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
-        mc:Ignorable="d" d:DesignWidth="900" d:DesignHeight="700"
+        mc:Ignorable="d" d:DesignWidth="900" d:DesignHeight="750"
 		MinWidth="900" MinHeight="700"
         x:Class="LibationAvalonia.Dialogs.SettingsDialog"
         xmlns:controls="clr-namespace:LibationAvalonia.Controls"
@@ -376,7 +376,7 @@
 							Grid.Row="3"
 							Margin="5"
 							VerticalAlignment="Top"
-							IsVisible="{Binding IsWindows}"
+							IsVisible="{Binding !IsLinux}"
 							IsChecked="{Binding DownloadDecryptSettings.UseCoverAsFolderIcon, Mode=TwoWay}">
 
 							<TextBlock

Source/LibationAvalonia/Dialogs/SettingsDialog.axaml.cs

@@ -108,7 +108,8 @@ namespace LibationAvalonia.Dialogs
 			LoadSettings(config);
 		}
 
-		public bool IsWindows => AppScaffolding.LibationScaffolding.ReleaseIdentifier is AppScaffolding.ReleaseIdentifier.WindowsAvalonia;
+		public bool IsLinux => Configuration.IsLinux;
+		public bool IsWindows => Configuration.IsWindows;
 		public ImportantSettings ImportantSettings { get; private set; }
 		public ImportSettings ImportSettings { get; private set; }
 		public DownloadDecryptSettings DownloadDecryptSettings { get; private set; }

Source/LibationAvalonia/Dialogs/TrashBinDialog.axaml

@@ -0,0 +1,66 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        mc:Ignorable="d" d:DesignWidth="630" d:DesignHeight="480"
+        x:Class="LibationAvalonia.Dialogs.TrashBinDialog"
+		xmlns:controls="clr-namespace:LibationAvalonia.Controls"
+		MinWidth="630" MinHeight="480" 
+        Title="Trash Bin"
+		WindowStartupLocation="CenterOwner"
+		Icon="/Assets/libation.ico">
+	
+	<Grid
+		RowDefinitions="Auto,*,Auto">
+		
+		<TextBlock
+			Grid.Row="0"
+			Margin="5"
+			Text="Check books you want to permanently delete from or restore to Libation" />
+
+		<controls:CheckedListBox
+			Grid.Row="1"
+			Margin="5,0,5,0"
+			BorderThickness="1"
+			BorderBrush="Gray"
+			IsEnabled="{Binding	ControlsEnabled}"
+			Items="{Binding DeletedBooks}" />
+
+		<Grid
+			Grid.Row="2"
+			Margin="5"
+			ColumnDefinitions="Auto,Auto,*,Auto">
+
+			<CheckBox
+				IsEnabled="{Binding	ControlsEnabled}"
+				IsThreeState="True"
+				Margin="0,0,20,0"
+				IsChecked="{Binding EverythingChecked}"
+				Content="Everything" />
+			
+			<TextBlock
+				Grid.Column="1"
+				VerticalAlignment="Center"
+				Text="{Binding CheckedCountText}" />
+			
+			<Button
+				IsEnabled="{Binding	ControlsEnabled}"
+				Grid.Column="2"
+				Margin="0,0,20,0"
+				HorizontalAlignment="Right"
+				VerticalAlignment="Stretch"
+				VerticalContentAlignment="Center"
+				Content="Restore"
+				Click="Restore_Click" />
+			
+			<Button
+				IsEnabled="{Binding	ControlsEnabled}"
+				Grid.Column="3"
+				Click="EmptyTrash_Click" >
+				<TextBlock
+					TextAlignment="Center"
+					Text="Permanently Delete&#xa;from Libation" />
+			</Button>
+		</Grid>
+	</Grid>
+</Window>

Source/LibationAvalonia/Dialogs/TrashBinDialog.axaml.cs

@@ -0,0 +1,145 @@
+using ApplicationServices;
+using Avalonia.Collections;
+using Avalonia.Controls;
+using Avalonia.Threading;
+using DataLayer;
+using LibationAvalonia.Controls;
+using LibationAvalonia.ViewModels;
+using LibationFileManager;
+using ReactiveUI;
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace LibationAvalonia.Dialogs
+{
+	public partial class TrashBinDialog : Window
+	{
+		TrashBinViewModel _viewModel;
+
+		public TrashBinDialog()
+		{
+			InitializeComponent();
+			this.RestoreSizeAndLocation(Configuration.Instance);
+			DataContext = _viewModel = new();
+
+			this.Closing += (_,_) => this.SaveSizeAndLocation(Configuration.Instance);
+		}
+
+		public async void EmptyTrash_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
+			=> await _viewModel.PermanentlyDeleteCheckedAsync();
+		public async void Restore_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
+			=> await _viewModel.RestoreCheckedAsync();
+	}
+
+	public class TrashBinViewModel : ViewModelBase, IDisposable
+	{
+		public AvaloniaList<CheckBoxViewModel> DeletedBooks { get; }
+		public string CheckedCountText => $"Checked : {_checkedBooksCount} of {_totalBooksCount}";
+
+		private bool _controlsEnabled = true;
+		public bool ControlsEnabled { get => _controlsEnabled; set=> this.RaiseAndSetIfChanged(ref _controlsEnabled, value); }
+
+		private bool? everythingChecked = false;
+		public bool? EverythingChecked
+		{
+			get => everythingChecked;
+			set
+			{
+				everythingChecked = value ?? false;
+
+				if (everythingChecked is true)
+					CheckAll();
+				else if (everythingChecked is false)
+					UncheckAll();
+			}
+		}
+
+		private int _totalBooksCount = 0;
+		private int _checkedBooksCount = -1;
+		public int CheckedBooksCount
+		{
+			get => _checkedBooksCount;
+			set
+			{
+				if (_checkedBooksCount != value)
+				{
+					_checkedBooksCount = value;
+					this.RaisePropertyChanged(nameof(CheckedCountText));
+				}
+
+				everythingChecked
+					= _checkedBooksCount == 0 || _totalBooksCount == 0 ? false
+					: _checkedBooksCount == _totalBooksCount ? true
+					: null;
+
+				this.RaisePropertyChanged(nameof(EverythingChecked));
+			}
+		}
+
+		public IEnumerable<LibraryBook> CheckedBooks => DeletedBooks.Where(i => i.IsChecked).Select(i => i.Item).Cast<LibraryBook>();
+
+		public TrashBinViewModel()
+		{
+			DeletedBooks = new()
+			{
+				ResetBehavior = ResetBehavior.Remove
+			};
+
+			tracker = DeletedBooks.TrackItemPropertyChanged(CheckboxPropertyChanged);
+			Reload();
+		}
+
+		public void CheckAll()
+		{
+			foreach (var item in DeletedBooks)
+				item.IsChecked = true;
+		}		
+
+		public void UncheckAll()
+		{
+			foreach (var item in DeletedBooks)
+				item.IsChecked = false;
+		}
+
+		public async Task RestoreCheckedAsync()
+		{
+			ControlsEnabled = false;
+			var qtyChanges = await Task.Run(CheckedBooks.RestoreBooks);
+			if (qtyChanges > 0)
+				Reload();
+			ControlsEnabled = true;
+		}
+
+		public async Task PermanentlyDeleteCheckedAsync()
+		{
+			ControlsEnabled = false;
+			var qtyChanges = await Task.Run(CheckedBooks.PermanentlyDeleteBooks);
+			if (qtyChanges > 0)
+				Reload();
+			ControlsEnabled = true;
+		}
+
+		private void Reload()
+		{
+			var deletedBooks = DbContexts.GetContext().GetDeletedLibraryBooks();
+
+			DeletedBooks.Clear();
+			DeletedBooks.AddRange(deletedBooks.Select(lb => new CheckBoxViewModel { Item = lb }));
+
+			_totalBooksCount = DeletedBooks.Count;
+			CheckedBooksCount = 0;
+		}
+
+		private IDisposable tracker;
+		private void CheckboxPropertyChanged(Tuple<object, PropertyChangedEventArgs> e)
+		{
+			if (e.Item2.PropertyName == nameof(CheckBoxViewModel.IsChecked))
+				CheckedBooksCount = DeletedBooks.Count(b => b.IsChecked);
+		}
+
+		public void Dispose() => tracker?.Dispose();
+	}
+}

Source/LibationAvalonia/LibationAvalonia.csproj

@@ -31,6 +31,8 @@
 	<ItemGroup>
 		<AvaloniaResource Include="Assets\**" />
 		<None Remove=".gitignore" />
+		<None Remove="Assets\Arrows_left.png" />
+		<None Remove="Assets\Arrows_right.png" />
 		<None Remove="Assets\Asterisk.png" />
 		<None Remove="Assets\cancel.png" />
 		<None Remove="Assets\completed.png" />

Source/LibationAvalonia/ViewModels/GridEntry.cs

@@ -1,5 +1,6 @@
 using ApplicationServices;
 using Avalonia.Media;
+using Avalonia.Media.Imaging;
 using DataLayer;
 using Dinah.Core;
 using FileLiberator;
@@ -35,18 +36,31 @@ namespace LibationAvalonia.ViewModels
 		#region Model properties exposed to the view
 
 		private Avalonia.Media.Imaging.Bitmap _cover;
-		public Avalonia.Media.Imaging.Bitmap Cover { get => _cover; protected set { this.RaiseAndSetIfChanged(ref _cover, value); } }
-		public string PurchaseDate { get; protected set; }
-		public string Series { get; protected set; }
-		public string Title { get; protected set; }
-		public string Length { get; protected set; }
-		public string Authors { get; protected set; }
-		public string Narrators { get; protected set; }
-		public string Category { get; protected set; }
-		public string Misc { get; protected set; }
-		public string Description { get; protected set; }
-		public Rating ProductRating { get; protected set; }
+		private string _purchasedate;
+		private string _series;
+		private string _title;
+		private string _length;
+		private string _authors;
+		private string _narrators;
+		private string _category;
+		private string _misc;
+		private LastDownloadStatus _lastDownload;
+		private string _description;
+		private Rating _productrating;
 		protected Rating _myRating;
+
+		public Avalonia.Media.Imaging.Bitmap Cover { get => _cover; protected set => this.RaiseAndSetIfChanged(ref _cover, value); }
+		public string PurchaseDate { get => _purchasedate; protected set => this.RaiseAndSetIfChanged(ref _purchasedate, value); }
+		public string Series { get => _series; protected set => this.RaiseAndSetIfChanged(ref _series, value); }
+		public string Title { get => _title; protected set => this.RaiseAndSetIfChanged(ref _title, value); }
+		public string Length { get => _length; protected set => this.RaiseAndSetIfChanged(ref _length, value); }
+		public string Authors { get => _authors; protected set => this.RaiseAndSetIfChanged(ref _authors, value); }
+		public string Narrators { get => _narrators; protected set => this.RaiseAndSetIfChanged(ref _narrators, value); }
+		public string Category { get => _category; protected set => this.RaiseAndSetIfChanged(ref _category, value); }
+		public LastDownloadStatus LastDownload { get => _lastDownload; protected set => this.RaiseAndSetIfChanged(ref _lastDownload, value); }
+		public string Misc { get => _misc; protected set => this.RaiseAndSetIfChanged(ref _misc, value); }
+		public string Description { get => _description; protected set => this.RaiseAndSetIfChanged(ref _description, value); }
+		public Rating ProductRating { get => _productrating; protected set => this.RaiseAndSetIfChanged(ref _productrating, value); }
 		public Rating MyRating
 		{
 			get => _myRating;
@@ -65,7 +79,6 @@ namespace LibationAvalonia.ViewModels
 		public abstract bool? Remove { get; set; }
 		public abstract LiberateButtonStatus Liberate { get; }
 		public abstract BookTags BookTags { get; }
-		public abstract bool IsSeries { get; }
 		public abstract bool IsEpisode { get; }
 		public abstract bool IsBook { get; }
 		public IBrush BackgroundBrush => IsEpisode ? App.SeriesEntryGridBackgroundBrush : Brushes.Transparent;
@@ -111,6 +124,7 @@ namespace LibationAvalonia.ViewModels
 			{ typeof(bool), new ObjectComparer<bool>() },
 			{ typeof(DateTime), new ObjectComparer<DateTime>() },
 			{ typeof(LiberateButtonStatus), new ObjectComparer<LiberateButtonStatus>() },
+			{ typeof(LastDownloadStatus), new ObjectComparer<LastDownloadStatus>() },
 		};
 
 		#endregion
@@ -126,8 +140,7 @@ namespace LibationAvalonia.ViewModels
 				PictureStorage.PictureCached += PictureStorage_PictureCached;
 
 			// Mutable property. Set the field so PropertyChanged isn't fired.
-			using var ms = new System.IO.MemoryStream(picture);
-			_cover = new Avalonia.Media.Imaging.Bitmap(ms);
+			_cover = loadImage(picture);
 		}
 
 		private void PictureStorage_PictureCached(object sender, PictureCachedEventArgs e)
@@ -143,12 +156,28 @@ namespace LibationAvalonia.ViewModels
             // logic validation
             if (e.Definition.PictureId == Book.PictureId)
 			{
-				using var ms = new System.IO.MemoryStream(e.Picture);
-				Cover = new Avalonia.Media.Imaging.Bitmap(ms);
+				Cover = loadImage(e.Picture);
 				PictureStorage.PictureCached -= PictureStorage_PictureCached;
 			}
 		}
 
+		private Bitmap loadImage(byte[] picture)
+		{
+			try
+			{
+				using var ms = new System.IO.MemoryStream(picture);
+				return new Bitmap(ms);
+			}
+			catch (Exception ex)
+			{
+				Serilog.Log.Logger.Error(ex, "Error loading cover art for {Book}", Book);
+				return DefaultImage;
+			}
+		}
+
+		private static Bitmap _defaultImage;
+		private static Bitmap DefaultImage => _defaultImage ??= new Bitmap(App.OpenAsset("img-coverart-prod-unavailable_80x80.jpg"));
+
 		#endregion
 
 		#region Static library display functions		

Source/LibationAvalonia/ViewModels/LiberateButtonStatus.cs

@@ -8,9 +8,10 @@ namespace LibationAvalonia.ViewModels
 {
 	public class LiberateButtonStatus : ViewModelBase, IComparable
 	{
-		public LiberateButtonStatus(bool isSeries)
+		public LiberateButtonStatus(bool isSeries, bool isAbsent)
 		{
 			IsSeries = isSeries;
+			IsAbsent = isAbsent;
 		}
 		public LiberatedStatus BookStatus { get; set; }
 		public LiberatedStatus? PdfStatus { get; set; }
@@ -26,7 +27,10 @@ namespace LibationAvalonia.ViewModels
 				this.RaisePropertyChanged(nameof(ToolTip));
 			}
 		}
-		private bool IsSeries { get; }
+
+		private bool IsAbsent { get; }
+		public bool IsSeries { get; }
+		public bool IsUnavailable => !IsSeries & IsAbsent & (BookStatus is not LiberatedStatus.Liberated || PdfStatus is not null and not LiberatedStatus.Liberated);
 		public Bitmap Image => GetLiberateIcon();
 		public string ToolTip => GetTooltip();
 
@@ -40,6 +44,8 @@ namespace LibationAvalonia.ViewModels
 			if (IsSeries && !second.IsSeries) return -1;
 			else if (!IsSeries && second.IsSeries) return 1;
 			else if (IsSeries && second.IsSeries) return 0;
+			else if (IsUnavailable && !second.IsUnavailable) return 1;
+			else if (!IsUnavailable && second.IsUnavailable) return -1;
 			else if (BookStatus == LiberatedStatus.Liberated && second.BookStatus != LiberatedStatus.Liberated) return -1;
 			else if (BookStatus != LiberatedStatus.Liberated && second.BookStatus == LiberatedStatus.Liberated) return 1;
 			else return BookStatus.CompareTo(second.BookStatus);
@@ -72,11 +78,15 @@ namespace LibationAvalonia.ViewModels
 
 			return GetFromResources($"liberate_{image_lib}{image_pdf}");
 		}
+
 		private string GetTooltip()
 		{
 			if (IsSeries)
 				return Expanded ? "Click to Collpase" : "Click to Expand";
 
+			if (IsUnavailable)
+				return "This book cannot be downloaded\nbecause it wasn't found during\nthe most recent library scan";
+
 			if (BookStatus == LiberatedStatus.Error)
 				return "Book downloaded ERROR";
 

Source/LibationAvalonia/ViewModels/LibraryBookEntry.cs

@@ -44,13 +44,12 @@ namespace LibationAvalonia.ViewModels
 					_pdfStatus = LibraryCommands.Pdf_Status(LibraryBook.Book);
 					lastStatusUpdate = DateTime.Now;
 				}
-				return new LiberateButtonStatus(IsSeries) { BookStatus = _bookStatus, PdfStatus = _pdfStatus };
+				return new LiberateButtonStatus(isSeries: false, LibraryBook.AbsentFromLastScan) { BookStatus = _bookStatus, PdfStatus = _pdfStatus };
 			}
 		}
 
 		public override BookTags BookTags => new() { Tags = string.Join("\r\n", Book.UserDefinedItem.TagsEnumerated) };
 
-		public override bool IsSeries => false;
 		public override bool IsEpisode => Parent is not null;
 		public override bool IsBook => Parent is null;
 
@@ -58,8 +57,22 @@ namespace LibationAvalonia.ViewModels
 
 		public LibraryBookEntry(LibraryBook libraryBook)
 		{
-			LibraryBook = libraryBook;
+			setLibraryBook(libraryBook);
 			LoadCover();
+		}
+
+		public void UpdateLibraryBook(LibraryBook libraryBook)
+		{
+			if (AudibleProductId != libraryBook.Book.AudibleProductId)
+				throw new Exception("Invalid grid entry update. IDs must match");
+
+			UserDefinedItem.ItemChanged -= UserDefinedItem_ItemChanged;
+			setLibraryBook(libraryBook);
+		}
+
+		private void setLibraryBook(LibraryBook libraryBook)
+		{
+			LibraryBook = libraryBook;
 
 			Title = Book.Title;
 			Series = Book.SeriesNames();
@@ -73,10 +86,13 @@ namespace LibationAvalonia.ViewModels
 			Narrators = Book.NarratorNames();
 			Category = string.Join(" > ", Book.CategoriesNames());
 			Misc = GetMiscDisplay(libraryBook);
+			LastDownload = new(Book.UserDefinedItem);
 			LongDescription = GetDescriptionDisplay(Book);
 			Description = TrimTextToWord(LongDescription, 62);
 			SeriesIndex = Book.SeriesLink.FirstOrDefault()?.Index ?? 0;
 
+			this.RaisePropertyChanged(nameof(MyRating));
+			this.RaisePropertyChanged(nameof(Liberate));
 			UserDefinedItem.ItemChanged += UserDefinedItem_ItemChanged;
 		}
 
@@ -112,6 +128,10 @@ namespace LibationAvalonia.ViewModels
 					_pdfStatus = udi.PdfStatus;
 					this.RaisePropertyChanged(nameof(Liberate));
 					break;
+				case nameof(udi.LastDownloaded):
+					LastDownload = new(udi);
+					this.RaisePropertyChanged(nameof(LastDownload));
+					break;
 			}
 		}
 
@@ -134,6 +154,7 @@ namespace LibationAvalonia.ViewModels
 			{ nameof(Description), () => Description },
 			{ nameof(Category), () => Category },
 			{ nameof(Misc), () => Misc },
+			{ nameof(LastDownload), () => LastDownload },
 			{ nameof(BookTags), () => BookTags?.Tags ?? string.Empty },
 			{ nameof(Liberate), () => Liberate },
 			{ nameof(DateAdded), () => DateAdded },

Source/LibationAvalonia/ViewModels/MainWindowViewModel.cs

@@ -1,5 +1,4 @@
 using ApplicationServices;
-using Dinah.Core;
 using LibationFileManager;
 using ReactiveUI;
 
@@ -135,15 +134,9 @@ namespace LibationAvalonia.ViewModels
 			set
 			{
 				this.RaiseAndSetIfChanged(ref _queueOpen, value);
-				QueueHideButtonText = _queueOpen? "❱❱❱" : "❰❰❰";
-				this.RaisePropertyChanged(nameof(QueueHideButtonText));
 			}
 		}
 
-		/// <summary> The Process Queue's Expand/Collapse button display text </summary>
-		public string QueueHideButtonText { get; private set; }
-
-
 
 		/// <summary> The number of books visible in the Product Display </summary>
 		public int VisibleCount
@@ -172,18 +165,6 @@ namespace LibationAvalonia.ViewModels
 			{
 				this.RaiseAndSetIfChanged(ref _libraryStats, value);
 
-				var backupsCountText
-					= !LibraryStats.HasBookResults ? "No books. Begin by importing your library"
-					: !LibraryStats.HasPendingBooks ? $"All {"book".PluralizeWithCount(LibraryStats.booksFullyBackedUp)} backed up"
-					: $"BACKUPS: No progress: {LibraryStats.booksNoProgress}  In process: {LibraryStats.booksDownloadedOnly}  Fully backed up: {LibraryStats.booksFullyBackedUp} {(LibraryStats.booksError > 0 ? $"  Errors : {LibraryStats.booksError}" : "")}";
-
-				var pdfCountText
-					= !LibraryStats.HasPdfResults ? ""
-					: LibraryStats.pdfsNotDownloaded == 0 ? $"  |  All {LibraryStats.pdfsDownloaded} PDFs downloaded"
-					: $"  |  PDFs: NOT d/l'ed: {LibraryStats.pdfsNotDownloaded} Downloaded: {LibraryStats.pdfsDownloaded}";
-
-				StatusCountText = backupsCountText + pdfCountText;
-
 				BookBackupsToolStripText
 					= LibraryStats.HasPendingBooks
 					? $"Begin _Book and PDF Backups: {LibraryStats.PendingBooks} remaining"
@@ -194,21 +175,17 @@ namespace LibationAvalonia.ViewModels
 					? $"Begin _PDF Only Backups: {LibraryStats.pdfsNotDownloaded} remaining"
 					: "All PDFs have been downloaded";
 
-				this.RaisePropertyChanged(nameof(StatusCountText));
 				this.RaisePropertyChanged(nameof(BookBackupsToolStripText));
 				this.RaisePropertyChanged(nameof(PdfBackupsToolStripText));
 			}
 		}
 
-		/// <summary> Bottom-left library statistics display text </summary>
-		public string StatusCountText { get; private set; } = "[Calculating backed up book quantities]  |  [Calculating backed up PDFs]";
 		/// <summary> The "Begin Book and PDF Backup" menu item header text </summary>
 		public string BookBackupsToolStripText { get; private set; } = "Begin _Book and PDF Backups: 0";
 		/// <summary> The "Begin PDF Only Backup" menu item header text </summary>
 		public string PdfBackupsToolStripText { get; private set; } = "Begin _PDF Only Backups: 0";
 
 
-
 		/// <summary> The number of books visible in the Products Display that have not yet been liberated </summary>
 		public int VisibleNotLiberated
 		{

Source/LibationAvalonia/ViewModels/ProcessQueueViewModel.cs

@@ -1,4 +1,5 @@
 using ApplicationServices;
+using Avalonia.Collections;
 using Avalonia.Controls;
 using Avalonia.Threading;
 using DataLayer;
@@ -16,9 +17,8 @@ namespace LibationAvalonia.ViewModels
 	public class ProcessQueueViewModel : ViewModelBase, ILogForm
 	{
 		public ObservableCollection<LogEntry> LogEntries { get; } = new();
-		public TrackedQueue<ProcessBookViewModel> Items { get; } = new();
-
-		private TrackedQueue<ProcessBookViewModel> Queue => Items;
+		public AvaloniaList<ProcessBookViewModel> Items { get; } = new();
+		public TrackedQueue<ProcessBookViewModel> Queue { get; }
 		public ProcessBookViewModel SelectedItem { get; set; }
 		public Task QueueRunner { get; private set; }
 		public bool Running => !QueueRunner?.IsCompleted ?? false;
@@ -28,6 +28,7 @@ namespace LibationAvalonia.ViewModels
 		public ProcessQueueViewModel()
 		{
 			Logger = LogMe.RegisterForm(this);
+			Queue = new(Items);
 			Queue.QueuededCountChanged += Queue_QueuededCountChanged;
 			Queue.CompletedCountChanged += Queue_CompletedCountChanged;
 
@@ -88,19 +89,19 @@ namespace LibationAvalonia.ViewModels
 
 		public decimal SpeedLimitIncrement { get; private set; }
 
-		private void Queue_CompletedCountChanged(object sender, int e)
+		private async void Queue_CompletedCountChanged(object sender, int e)
 		{
 			int errCount = Queue.Completed.Count(p => p.Result is ProcessBookResult.FailedAbort or ProcessBookResult.FailedSkip or ProcessBookResult.FailedRetry or ProcessBookResult.ValidationFail);
 			int completeCount = Queue.Completed.Count(p => p.Result is ProcessBookResult.Success);
 
 			ErrorCount = errCount;
 			CompletedCount = completeCount;
-			Dispatcher.UIThread.Post(() => this.RaisePropertyChanged(nameof(Progress)));
+			await Dispatcher.UIThread.InvokeAsync(() => this.RaisePropertyChanged(nameof(Progress)));
 		}
-		private void Queue_QueuededCountChanged(object sender, int cueCount)
+		private async void Queue_QueuededCountChanged(object sender, int cueCount)
 		{
 			QueuedCount = cueCount;
-			Dispatcher.UIThread.Post(() => this.RaisePropertyChanged(nameof(Progress)));
+			await Dispatcher.UIThread.InvokeAsync(() => this.RaisePropertyChanged(nameof(Progress)));
 		}
 
 		public void WriteLine(string text)

Source/LibationAvalonia/ViewModels/ProductsDisplayViewModel.cs

@@ -20,11 +20,11 @@ namespace LibationAvalonia.ViewModels
 		public event EventHandler<int> RemovableCountChanged;
 
 		/// <summary>Backing list of all grid entries</summary>
-		private readonly List<GridEntry> SOURCE = new();
+		private readonly AvaloniaList<GridEntry> SOURCE = new();
 		/// <summary>Grid entries included in the filter set. If null, all grid entries are shown</summary>
 		private List<GridEntry> FilteredInGridEntries;
 		public string FilterString { get; private set; }
-		public DataGridCollectionView GridEntries { get; }
+		public DataGridCollectionView GridEntries { get; private set; }
 
 		private bool _removeColumnVisivle;
 		public bool RemoveColumnVisivle { get => _removeColumnVisivle; private set => this.RaiseAndSetIfChanged(ref _removeColumnVisivle, value); }
@@ -42,59 +42,60 @@ namespace LibationAvalonia.ViewModels
 		public ProductsDisplayViewModel()
 		{
 			SearchEngineCommands.SearchEngineUpdated += SearchEngineCommands_SearchEngineUpdated;
-			GridEntries = new(SOURCE);
-			GridEntries.Filter = CollectionFilter;
+			VisibleCountChanged?.Invoke(this, 0);
+		}
 
-			GridEntries.CollectionChanged += (s, e)
-				=> VisibleCountChanged?.Invoke(this, GridEntries.OfType<LibraryBookEntry>().Count());
+		private static readonly System.Reflection.MethodInfo SetFlagsMethod;
+
+		/// <summary>
+		/// Tells the <see cref="DataGridCollectionView"/> whether it should process changes to the underlying collection
+		/// </summary>
+		/// <remarks> DataGridCollectionView.CollectionViewFlags.ShouldProcessCollectionChanged = 4</remarks>
+		private void SetShouldProcessCollectionChanged(bool flagSet)
+			=> SetFlagsMethod.Invoke(GridEntries, new object[] { 4, flagSet });
+
+		static ProductsDisplayViewModel()
+		{
+			/*
+			 * When a book is removed from the library, SearchEngineUpdated is fired before LibrarySizeChanged, so
+			 * the book is removed from the filtered set and the grid is refreshed before RemoveBooks() is ever
+			 * called.
+			 * 
+			 * To remove an item from DataGridCollectionView, it must be be in the current filtered view. If it's
+			 * not and you try to remove the book from the source list, the source will fire NotifyCollectionChanged
+			 * on an invalid item and the DataGridCollectionView will throw an exception. There are two ways to
+			 * remove an item that is filtered out of the DataGridCollectionView:
+			 * 
+			 * (1)  Re-add the item to the filtered-in list and refresh the grid so DataGridCollectionView knows
+			 *		that the item is present. This causes the whole grid to flicker to refresh twice in rapid
+			 *		succession, which is undesirable.
+			 *		
+			 * (2)  Remove it from the underlying collection and suppress NotifyCollectionChanged. This is the
+			 *		method used. Steps to complete a removal using this method:
+			 *		
+			 *		(a)	Set DataGridCollectionView.CollectionViewFlags.ShouldProcessCollectionChanged to false.
+			 *		(b) Remove the item from the source list. The source will fire NotifyCollectionChanged, but the
+			 *			DataGridCollectionView will ignore it.
+			 *		(c) Reset the flag to true.
+			 */
+
+			SetFlagsMethod =
+				typeof(DataGridCollectionView)
+				.GetMethod("SetFlag", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
 		}
 
 		#region Display Functions
 
-		/// <summary>
-		/// Call when there's been a change to the library
-		/// </summary>
-		public async Task DisplayBooksAsync(List<LibraryBook> dbBooks)
+		internal void BindToGrid(List<LibraryBook> dbBooks)
 		{
-			try
+			GridEntries = new(SOURCE)
 			{
-				var existingSeriesEntries = SOURCE.SeriesEntries().ToList();
+				Filter = CollectionFilter
+			};
 
-				FilteredInGridEntries?.Clear();
-				SOURCE.Clear();
-				SOURCE.AddRange(CreateGridEntries(dbBooks));
+			GridEntries.CollectionChanged += (_, _)
+				=> VisibleCountChanged?.Invoke(this, GridEntries.OfType<LibraryBookEntry>().Count());
 
-				//If replacing the list, preserve user's existing collapse/expand
-				//state. When resetting a list, default state is cosed.
-				foreach (var series in existingSeriesEntries)
-				{
-					var sEntry = SOURCE.FirstOrDefault(ge => ge.AudibleProductId == series.AudibleProductId);
-					if (sEntry is SeriesEntry se)
-						se.Liberate.Expanded = series.Liberate.Expanded;
-				}
-
-				//Run query on new list
-				FilteredInGridEntries = QueryResults(SOURCE, FilterString);
-
-				await refreshGrid();
-
-			}
-			catch (Exception ex)
-			{
-				Serilog.Log.Error(ex, "Error displaying library in {0}", nameof(ProductsDisplayViewModel));
-			}
-		}
-
-		private async Task refreshGrid()
-		{
-			if (GridEntries.IsEditingItem)
-				await Dispatcher.UIThread.InvokeAsync(GridEntries.CommitEdit);
-
-			await Dispatcher.UIThread.InvokeAsync(GridEntries.Refresh);
-		}
-
-		private static List<GridEntry> CreateGridEntries(IEnumerable<LibraryBook> dbBooks)
-		{
 			var geList = dbBooks
 				.Where(lb => lb.Book.IsProduct())
 				.Select(b => new LibraryBookEntry(b))
@@ -103,26 +104,159 @@ namespace LibationAvalonia.ViewModels
 
 			var episodes = dbBooks.Where(lb => lb.Book.IsEpisodeChild());
 
-			foreach (var parent in dbBooks.Where(lb => lb.Book.IsEpisodeParent()))
+			var seriesBooks = dbBooks.Where(lb => lb.Book.IsEpisodeParent()).ToList();
+
+			foreach (var parent in seriesBooks)
 			{
 				var seriesEpisodes = episodes.FindChildren(parent);
 
 				if (!seriesEpisodes.Any()) continue;
 
 				var seriesEntry = new SeriesEntry(parent, seriesEpisodes);
+				seriesEntry.Liberate.Expanded = false;
 
 				geList.Add(seriesEntry);
 				geList.AddRange(seriesEntry.Children);
 			}
 
-			var bookList =  geList.OrderByDescending(e => e.DateAdded).ToList();
+			//Create the filtered-in list before adding entries to avoid a refresh
+			FilteredInGridEntries = QueryResults(geList, FilterString);
+			SOURCE.AddRange(geList.OrderByDescending(e => e.DateAdded));
+		}
 
-			//ListIndex is used by RowComparer to make column sort stable
-			int index = 0;
-			foreach (GridEntry di in bookList)
-				di.ListIndex = index++;
+		/// <summary>
+		/// Call when there's been a change to the library
+		/// </summary>
+		internal async Task UpdateGridAsync(List<LibraryBook> dbBooks)
+		{
+			#region Add new or update existing grid entries
 
-			return bookList;
+			//Add absent entries to grid, or update existing entry
+			var allEntries = SOURCE.BookEntries();
+			var seriesEntries = SOURCE.SeriesEntries().ToList();
+			var parentedEpisodes = dbBooks.ParentedEpisodes();
+
+			await Dispatcher.UIThread.InvokeAsync(() =>
+			{
+				foreach (var libraryBook in dbBooks.OrderBy(e => e.DateAdded))
+				{
+					var existingEntry = allEntries.FindByAsin(libraryBook.Book.AudibleProductId);
+
+					if (libraryBook.Book.IsProduct())
+						UpsertBook(libraryBook, existingEntry);
+					else if (parentedEpisodes.Any(lb => lb == libraryBook))
+						//Only try to add or update is this LibraryBook is a know child of a parent
+						UpsertEpisode(libraryBook, existingEntry, seriesEntries, dbBooks);
+				}
+			});
+
+			#endregion
+
+			#region Remove entries no longer in the library
+
+			//Rapid successive book removals will cause changes to SOURCE after the update has
+			//begun but before it has completed, so perform all updates on a copy of the list.
+			var sourceSnapshot = SOURCE.ToList();
+
+			// remove deleted from grid.
+			// note: actual deletion from db must still occur via the RemoveBook feature. deleting from audible will not trigger this
+			var removedBooks =
+				sourceSnapshot
+				.BookEntries()
+				.ExceptBy(dbBooks.Select(lb => lb.Book.AudibleProductId), ge => ge.AudibleProductId);
+
+			//Remove books in series from their parents' Children list
+			foreach (var removed in removedBooks.Where(b => b.Parent is not null))
+				removed.Parent.RemoveChild(removed);
+
+			//Remove series that have no children
+			var removedSeries = sourceSnapshot.EmptySeries();
+
+			await Dispatcher.UIThread.InvokeAsync(() => RemoveBooks(removedBooks, removedSeries));
+
+			#endregion
+
+			await Filter(FilterString);
+			GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive, true, true);
+		}
+
+		private void RemoveBooks(IEnumerable<LibraryBookEntry> removedBooks, IEnumerable<SeriesEntry> removedSeries)
+		{
+			foreach (var removed in removedBooks.Cast<GridEntry>().Concat(removedSeries).Where(b => b is not null).ToList())
+			{
+				if (GridEntries.PassesFilter(removed))
+					GridEntries.Remove(removed);
+				else
+				{
+					SetShouldProcessCollectionChanged(false);
+					SOURCE.Remove(removed);
+					SetShouldProcessCollectionChanged(true);
+				}
+			}
+		}
+
+		private void UpsertBook(LibraryBook book, LibraryBookEntry existingBookEntry)
+		{
+			if (existingBookEntry is null)
+				// Add the new product to top
+				SOURCE.Insert(0, new LibraryBookEntry(book));
+			else
+				// update existing
+				existingBookEntry.UpdateLibraryBook(book);
+		}
+
+		private void UpsertEpisode(LibraryBook episodeBook, LibraryBookEntry existingEpisodeEntry, List<SeriesEntry> seriesEntries, IEnumerable<LibraryBook> dbBooks)
+		{
+			if (existingEpisodeEntry is null)
+			{
+				LibraryBookEntry episodeEntry;
+
+				var seriesEntry = seriesEntries.FindSeriesParent(episodeBook);
+
+				if (seriesEntry is null)
+				{
+					//Series doesn't exist yet, so create and add it
+					var seriesBook = dbBooks.FindSeriesParent(episodeBook);
+
+					if (seriesBook is null)
+					{
+						//This is only possible if the user's db  has some malformed
+						//entries from earlier Libation releases that could not be
+						//automatically fixed. Log, but don't throw.
+						Serilog.Log.Logger.Error("Episode={0}, Episode Series: {1}", episodeBook, episodeBook.Book.SeriesNames());
+						return;
+					}
+
+					seriesEntry = new SeriesEntry(seriesBook, new[] { episodeBook });
+					seriesEntries.Add(seriesEntry);
+
+					episodeEntry = seriesEntry.Children[0];
+					seriesEntry.Liberate.Expanded = true;
+					SOURCE.Insert(0, seriesEntry);
+				}
+				else
+				{
+					//Series exists. Create and add episode child then update the SeriesEntry
+					episodeEntry = new(episodeBook) { Parent = seriesEntry };
+					seriesEntry.Children.Add(episodeEntry);
+					var seriesBook = dbBooks.Single(lb => lb.Book.AudibleProductId == seriesEntry.LibraryBook.Book.AudibleProductId);
+					seriesEntry.UpdateLibraryBook(seriesBook);
+				}
+
+				//Add episode to the grid beneath the parent
+				int seriesIndex = SOURCE.IndexOf(seriesEntry);
+				SOURCE.Insert(seriesIndex + 1, episodeEntry);
+			}
+			else
+				existingEpisodeEntry.UpdateLibraryBook(episodeBook);
+		}
+
+		private async Task refreshGrid()
+		{
+			if (GridEntries.IsEditingItem)
+				await Dispatcher.UIThread.InvokeAsync(GridEntries.CommitEdit);
+
+			await Dispatcher.UIThread.InvokeAsync(GridEntries.Refresh);
 		}
 
 		public async Task ToggleSeriesExpanded(SeriesEntry seriesEntry)
@@ -138,9 +272,6 @@ namespace LibationAvalonia.ViewModels
 
 		public async Task Filter(string searchString)
 		{
-			if (searchString == FilterString)
-				return;
-
 			FilterString = searchString;
 
 			if (SOURCE.Count == 0)
@@ -206,10 +337,10 @@ namespace LibationAvalonia.ViewModels
 			if (selectedBooks.Count == 0)
 				return;
 
-			var libraryBooks = selectedBooks.Select(rge => rge.LibraryBook).ToList();
+			var booksToRemove = selectedBooks.Select(rge => rge.LibraryBook).ToList();
 			var result = await MessageBox.ShowConfirmationDialog(
 				null,
-				libraryBooks,
+				booksToRemove,
 				// do not use `$` string interpolation. See impl.
 				"Are you sure you want to remove {0} from Libation's library?",
 				"Remove books from Libation?");
@@ -220,8 +351,6 @@ namespace LibationAvalonia.ViewModels
 			foreach (var book in selectedBooks)
 				book.PropertyChanged -= GridEntry_PropertyChanged;
 
-			var idsToRemove = libraryBooks.Select(lb => lb.Book.AudibleProductId).ToList();
-
 			void BindingList_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
 			{
 				if (e.Action != System.Collections.Specialized.NotifyCollectionChangedAction.Reset)
@@ -240,7 +369,7 @@ namespace LibationAvalonia.ViewModels
 
 			//The RemoveBooksAsync will fire LibrarySizeChanged, which calls ProductsDisplay2.Display(),
 			//so there's no need to remove books from the grid display here.
-			var removeLibraryBooks = await LibraryCommands.RemoveBooksAsync(idsToRemove);
+			await booksToRemove.RemoveBooksAsync();
 
 			RemovableCountChanged?.Invoke(this, 0);
 		}

Source/LibationAvalonia/ViewModels/QueryExtensions.cs

@@ -14,6 +14,12 @@ namespace LibationAvalonia.ViewModels
 		public static IEnumerable<SeriesEntry> SeriesEntries(this IEnumerable<GridEntry> gridEntries)
 			=> gridEntries.OfType<SeriesEntry>();
 
+		public static T? FindByAsin<T>(this IEnumerable<T> gridEntries, string audibleProductID) where T : GridEntry
+			=> gridEntries.FirstOrDefault(i => i.AudibleProductId == audibleProductID);
+
+		public static IEnumerable<SeriesEntry> EmptySeries(this IEnumerable<GridEntry> gridEntries)
+			=> gridEntries.SeriesEntries().Where(i => i.Children.Count == 0);
+
 		public static SeriesEntry? FindSeriesParent(this IEnumerable<GridEntry> gridEntries, LibraryBook seriesEpisode)
 		{
 			if (seriesEpisode.Book.SeriesLink is null) return null;

Source/LibationAvalonia/ViewModels/SeriesEntry.cs

@@ -46,7 +46,6 @@ namespace LibationAvalonia.ViewModels
 		public override LiberateButtonStatus Liberate { get; }
 		public override BookTags BookTags { get; } = new();
 
-		public override bool IsSeries => true;
 		public override bool IsEpisode => false;
 		public override bool IsBook => false;
 
@@ -54,17 +53,38 @@ namespace LibationAvalonia.ViewModels
 
 		public SeriesEntry(LibraryBook parent, IEnumerable<LibraryBook> children)
 		{
-			Liberate = new LiberateButtonStatus(IsSeries);
+			Liberate = new LiberateButtonStatus(isSeries: true, isAbsent: false);
 			SeriesIndex = -1;
-			LibraryBook = parent;
-
-			LoadCover();
 
 			Children = children
 				.Select(c => new LibraryBookEntry(c) { Parent = this })
 				.OrderBy(c => c.SeriesIndex)
 				.ToList();
 
+			setLibraryBook(parent);
+			LoadCover();
+		}
+
+		public void RemoveChild(LibraryBookEntry lbe)
+		{
+			Children.Remove(lbe);
+			PurchaseDate = Children.Min(c => c.LibraryBook.DateAdded).ToString("d");
+			int bookLenMins = Children.Sum(c => c.LibraryBook.Book.LengthInMinutes);
+			Length = bookLenMins == 0 ? "" : $"{bookLenMins / 60} hr {bookLenMins % 60} min";
+		}
+
+		public void UpdateLibraryBook(LibraryBook libraryBook)
+		{
+			if (AudibleProductId != libraryBook.Book.AudibleProductId)
+				throw new Exception("Invalid grid entry update. IDs must match");
+
+			setLibraryBook(libraryBook);
+		}
+
+		private void setLibraryBook(LibraryBook libraryBook)
+		{
+			LibraryBook = libraryBook;
+
 			Title = Book.Title;
 			Series = Book.SeriesNames();
 			//Ratings are changed using Update(), which is a problem for Avalonia data bindings because
@@ -75,12 +95,15 @@ namespace LibationAvalonia.ViewModels
 			Narrators = Book.NarratorNames();
 			Category = string.Join(" > ", Book.CategoriesNames());
 			Misc = GetMiscDisplay(LibraryBook);
+			LastDownload = new();
 			LongDescription = GetDescriptionDisplay(Book);
 			Description = TrimTextToWord(LongDescription, 62);
 
 			PurchaseDate = Children.Min(c => c.LibraryBook.DateAdded).ToString("d");
 			int bookLenMins = Children.Sum(c => c.LibraryBook.Book.LengthInMinutes);
 			Length = bookLenMins == 0 ? "" : $"{bookLenMins / 60} hr {bookLenMins % 60} min";
+
+			this.RaisePropertyChanged(nameof(MyRating));
 		}
 
 
@@ -101,6 +124,7 @@ namespace LibationAvalonia.ViewModels
 			{ nameof(Description), () => Description },
 			{ nameof(Category), () => Category },
 			{ nameof(Misc), () => Misc },
+			{ nameof(LastDownload), () => LastDownload },
 			{ nameof(BookTags), () => BookTags?.Tags ?? string.Empty },
 			{ nameof(Liberate), () => Liberate },
 			{ nameof(DateAdded), () => DateAdded },

Source/LibationAvalonia/Views/MainWindow.RemoveBooks.cs

@@ -1,4 +1,5 @@
 using AudibleUtilities;
+using LibationAvalonia.Dialogs;
 using System;
 using System.Linq;
 
@@ -15,6 +16,12 @@ namespace LibationAvalonia.Views
 			_viewModel.RemoveButtonsVisible = false;
 		}
 
+		public async void openTrashBinToolStripMenuItem_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
+		{
+			var trash = new TrashBinDialog();
+			await trash.ShowDialog(this);
+		}
+
 		public void removeLibraryBooksToolStripMenuItem_Click(object sender, Avalonia.Interactivity.RoutedEventArgs e)
 		{
 			// if 0 accounts, this will not be visible

Source/LibationAvalonia/Views/MainWindow.VisibleBooks.cs

@@ -144,11 +144,8 @@ namespace LibationAvalonia.Views
 				"Remove books from Libation?",
 				MessageBoxDefaultButton.Button2);
 
-			if (confirmationResult != DialogResult.Yes)
-				return;
-
-			var visibleIds = visibleLibraryBooks.Select(lb => lb.Book.AudibleProductId).ToList();
-			await LibraryCommands.RemoveBooksAsync(visibleIds);
+			if (confirmationResult is DialogResult.Yes)
+				await visibleLibraryBooks.RemoveBooksAsync();
 		}
 		public async void ProductsDisplay_VisibleCountChanged(object sender, int qty)
 		{
@@ -157,9 +154,9 @@ namespace LibationAvalonia.Views
 			await Dispatcher.UIThread.InvokeAsync(setLiberatedVisibleMenuItem);
 		}
 		void setLiberatedVisibleMenuItem()
-			=> _viewModel.VisibleNotLiberated
-				= _viewModel.ProductsDisplay
-				.GetVisibleBookEntries()
-				.Count(lb => lb.Book.UserDefinedItem.BookStatus == LiberatedStatus.NotLiberated);
+		{
+			var libraryStats = LibraryCommands.GetCounts(_viewModel.ProductsDisplay.GetVisibleBookEntries());
+			_viewModel.VisibleNotLiberated = libraryStats.PendingBooks;
+		}
 	}
 }

Source/LibationAvalonia/Views/MainWindow.axaml

@@ -131,6 +131,7 @@
 						<MenuItem Click="accountsToolStripMenuItem_Click" Header="_Accounts..." />
 						<MenuItem Click="basicSettingsToolStripMenuItem_Click" Header="_Settings..." />
 						<Separator />
+						<MenuItem Click="openTrashBinToolStripMenuItem_Click" Header="Trash Bin" />
 						<MenuItem Click="launchHangoverToolStripMenuItem_Click" Header="Launch _Hangover" />
 						<Separator />
 						<MenuItem Click="aboutToolStripMenuItem_Click" Header="A_bout..." />
@@ -172,7 +173,12 @@
 
 				<StackPanel Grid.Column="2" Height="30" Orientation="Horizontal">
 					<Button Click="filterBtn_Click" Height="30" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" Content="Filter"/>
-					<Button Padding="5,0,5,0" Click="ToggleQueueHideBtn_Click" Content="{Binding QueueHideButtonText}"/>
+					<Button Padding="5,0,5,0" Click="ToggleQueueHideBtn_Click">
+						<Panel>
+							<Image Stretch="None" IsVisible="{Binding !QueueOpen}" Source="/Assets/Arrows_left.png" />
+							<Image Stretch="None" IsVisible="{Binding QueueOpen}" Source="/Assets/Arrows_right.png" />
+						</Panel>
+					</Button>
 				</StackPanel>
 
 			</Grid>
@@ -203,7 +209,7 @@
 				<TextBlock FontSize="14" Grid.Column="0" Text="Upgrading:" VerticalAlignment="Center" IsVisible="{Binding DownloadProgress, Converter={x:Static ObjectConverters.IsNotNull}}" />
 				<ProgressBar Grid.Column="1" Margin="5,0,10,0" VerticalAlignment="Stretch" Width="100" Value="{Binding DownloadProgress}" IsVisible="{Binding DownloadProgress, Converter={x:Static ObjectConverters.IsNotNull}}"/>
 				<TextBlock FontSize="14" Grid.Column="2" Text="{Binding VisibleCountText}" VerticalAlignment="Center" />
-				<TextBlock FontSize="14" Grid.Column="3" Text="{Binding StatusCountText}" VerticalAlignment="Center" />		
+				<TextBlock FontSize="14" Grid.Column="3" Text="{Binding LibraryStats.StatusString}" VerticalAlignment="Center" />		
 			</Grid>
 		</Grid>
 	</Border>

Source/LibationAvalonia/Views/MainWindow.axaml.cs

@@ -51,7 +51,7 @@ namespace LibationAvalonia.Views
 			{
 				this.LibraryLoaded += MainWindow_LibraryLoaded;
 
-				LibraryCommands.LibrarySizeChanged += async (_, _) => await _viewModel.ProductsDisplay.DisplayBooksAsync(DbContexts.GetLibrary_Flat_NoTracking(includeParents: true));
+				LibraryCommands.LibrarySizeChanged += async (_, _) => await _viewModel.ProductsDisplay.UpdateGridAsync(DbContexts.GetLibrary_Flat_NoTracking(includeParents: true));
 				Closing += (_, _) => this.SaveSizeAndLocation(Configuration.Instance);
 			}
 			Closing += MainWindow_Closing;
@@ -67,7 +67,7 @@ namespace LibationAvalonia.Views
 			if (QuickFilters.UseDefault)
 				await performFilter(QuickFilters.Filters.FirstOrDefault());
 
-			await _viewModel.ProductsDisplay.DisplayBooksAsync(dbBooks);
+			_viewModel.ProductsDisplay.BindToGrid(dbBooks);
 		}
 
 		private void InitializeComponent()

Source/LibationAvalonia/Views/ProcessQueueControl.axaml.cs

@@ -15,7 +15,7 @@ namespace LibationAvalonia.Views
 {
 	public partial class ProcessQueueControl : UserControl
     {
-		private TrackedQueue<ProcessBookViewModel> Queue => _viewModel.Items;
+		private TrackedQueue<ProcessBookViewModel> Queue => _viewModel.Queue;
 		private ProcessQueueViewModel _viewModel => DataContext as ProcessQueueViewModel;
 
 		public ProcessQueueControl()
@@ -76,14 +76,14 @@ namespace LibationAvalonia.Views
 					},
 				};
 
-				vm.Items.Enqueue(testList);
-				vm.Items.MoveNext();
-				vm.Items.MoveNext();
-				vm.Items.MoveNext();
-				vm.Items.MoveNext();
-				vm.Items.MoveNext();
-				vm.Items.MoveNext();
-				vm.Items.MoveNext();
+				vm.Queue.Enqueue(testList);
+				vm.Queue.MoveNext();
+				vm.Queue.MoveNext();
+				vm.Queue.MoveNext();
+				vm.Queue.MoveNext();
+				vm.Queue.MoveNext();
+				vm.Queue.MoveNext();
+				vm.Queue.MoveNext();
 				return;
 			}
 			#endregion

Source/LibationAvalonia/Views/ProductsDisplay.axaml

@@ -61,9 +61,13 @@
 				<controls:DataGridTemplateColumnExt CanUserSort="True" Width="75" Header="Liberate" SortMemberPath="Liberate" ClipboardContentBinding="{Binding Liberate.ToolTip}">
 					<DataGridTemplateColumn.CellTemplate>
 						<DataTemplate>
-							<Button Opacity="{Binding Opacity}" Padding="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Click="LiberateButton_Click" ToolTip.Tip="{Binding Liberate.ToolTip}">
-								<Image Source="{Binding Liberate.Image}" Stretch="None" />
-							</Button>
+							<Panel ToolTip.Tip="{Binding Liberate.ToolTip}">
+								<Button Opacity="{Binding Opacity}" Padding="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Click="LiberateButton_Click" IsVisible="{Binding !Liberate.IsUnavailable}">
+									<Image Source="{Binding Liberate.Image}" Stretch="None" />
+								</Button>
+								<Image Source="{Binding Liberate.Image}" Stretch="None" IsVisible="{Binding Liberate.IsUnavailable}"/>
+								<Panel Background="{StaticResource DisabledGrayBrush}" IsVisible="{Binding Liberate.IsUnavailable}" />
+							</Panel>
 						</DataTemplate>
 					</DataGridTemplateColumn.CellTemplate>
 				</controls:DataGridTemplateColumnExt>
@@ -183,6 +187,16 @@
 						</DataTemplate>
 					</DataGridTemplateColumn.CellTemplate>
 				</controls:DataGridTemplateColumnExt>
+				
+				<controls:DataGridTemplateColumnExt Width="102" Header="Last&#xA;Download" CanUserSort="True" SortMemberPath="LastDownload" ClipboardContentBinding="{Binding LastDownload}">
+					<DataGridTemplateColumn.CellTemplate>
+						<DataTemplate>
+							<Panel Background="{Binding BackgroundBrush}" ToolTip.Tip="{Binding LastDownload.ToolTipText}" DoubleTapped="Version_DoubleClick">
+								<TextBlock Text="{Binding LastDownload}" TextWrapping="WrapWithOverflow" FontSize="10" />
+							</Panel>
+						</DataTemplate>
+					</DataGridTemplateColumn.CellTemplate>
+				</controls:DataGridTemplateColumnExt>
 
 				<controls:DataGridTemplateColumnExt CanUserSort="True" Width="100" Header="Tags" SortMemberPath="BookTags" ClipboardContentBinding="{Binding BookTags.Tags}">
 					<DataGridTemplateColumn.CellTemplate>

Source/LibationAvalonia/Views/ProductsDisplay.axaml.cs

@@ -31,20 +31,25 @@ namespace LibationAvalonia.Views
 			if (Design.IsDesignMode)
 			{
 				using var context = DbContexts.GetContext();
-				List<LibraryBook> sampleEntries = new()
+				List<LibraryBook> sampleEntries;
+				try
 				{
-					//context.GetLibraryBook_Flat_NoTracking("B00DCD0OXU"),
-					context.GetLibraryBook_Flat_NoTracking("B017V4IM1G"),
-					context.GetLibraryBook_Flat_NoTracking("B017V4IWVG"),
-					context.GetLibraryBook_Flat_NoTracking("B017V4JA2Q"),
-					context.GetLibraryBook_Flat_NoTracking("B017V4NUPO"),
-					context.GetLibraryBook_Flat_NoTracking("B017V4NMX4"),
-					context.GetLibraryBook_Flat_NoTracking("B017V4NOZ0"),
-					context.GetLibraryBook_Flat_NoTracking("B017WJ5ZK6")
-				};
+					sampleEntries = new()
+					{
+						//context.GetLibraryBook_Flat_NoTracking("B00DCD0OXU"),try{
+						context.GetLibraryBook_Flat_NoTracking("B017WJ5ZK6"),
+						context.GetLibraryBook_Flat_NoTracking("B017V4IWVG"),
+						context.GetLibraryBook_Flat_NoTracking("B017V4JA2Q"),
+						context.GetLibraryBook_Flat_NoTracking("B017V4NUPO"),
+						context.GetLibraryBook_Flat_NoTracking("B017V4NMX4"),
+						context.GetLibraryBook_Flat_NoTracking("B017V4NOZ0"),
+						context.GetLibraryBook_Flat_NoTracking("B017WJ5ZK6")
+					};
+				}
+				catch { sampleEntries = new(); }
 
 				var pdvm = new ProductsDisplayViewModel();
-				_ = pdvm.DisplayBooksAsync(sampleEntries);
+				pdvm.BindToGrid(sampleEntries);
 				DataContext = pdvm;
 
 				return;
@@ -84,7 +89,7 @@ namespace LibationAvalonia.Views
 			{
 				var entry = args.GridEntry;
 
-                if (entry.IsSeries)
+                if (entry.Liberate.IsSeries)
 					return;
 
                 var setDownloadMenuItem = new MenuItem()
@@ -102,7 +107,7 @@ namespace LibationAvalonia.Views
                 setNotDownloadMenuItem.Click += (_, __) => entry.Book.UpdateBookStatus(LiberatedStatus.NotLiberated);
 
                 var removeMenuItem = new MenuItem() { Header = "_Remove from library" };
-				removeMenuItem.Click += async (_, __) => await Task.Run(() => LibraryCommands.RemoveBook(entry.AudibleProductId));
+				removeMenuItem.Click += async (_, __) => await Task.Run(entry.LibraryBook.RemoveBook);
 
 				var locateFileMenuItem = new MenuItem() { Header = "_Locate file..." };
                 locateFileMenuItem.Click += async (_, __) =>
@@ -135,7 +140,7 @@ namespace LibationAvalonia.Views
 				var convertToMp3MenuItem = new MenuItem
 				{
 					Header = "_Convert to Mp3",
-					IsEnabled = entry.Book.UserDefinedItem.BookStatus != LiberatedStatus.NotLiberated
+					IsEnabled = entry.Book.UserDefinedItem.BookStatus is LiberatedStatus.Liberated 
 				};
 				convertToMp3MenuItem.Click += (_, _) => ConvertToMp3Clicked?.Invoke(this, entry.LibraryBook);
 
@@ -306,6 +311,12 @@ namespace LibationAvalonia.Views
 				imageDisplayDialog.Close();
 		}
 
+		public void Version_DoubleClick(object sender, Avalonia.Input.TappedEventArgs args)
+		{
+			if (sender is Control panel && panel.DataContext is LibraryBookEntry lbe && lbe.LastDownload.IsValid)
+				lbe.LastDownload.OpenReleaseUrl();
+		}
+
 		public void Cover_Click(object sender, Avalonia.Input.TappedEventArgs args)
 		{
 			if (sender is not Image tblock || tblock.DataContext is not GridEntry gEntry)
@@ -321,7 +332,7 @@ namespace LibationAvalonia.Views
 			void PictureCached(object sender, PictureCachedEventArgs e)
 			{
 				if (e.Definition.PictureId == picDef.PictureId)
-					imageDisplayDialog.CoverBytes = e.Picture;
+					imageDisplayDialog.SetCoverBytes(e.Picture);
 
 				PictureStorage.PictureCached -= PictureCached;
 			}
@@ -336,7 +347,7 @@ namespace LibationAvalonia.Views
 			imageDisplayDialog.BookSaveDirectory = AudibleFileStorage.Audio.GetDestinationDirectory(gEntry.LibraryBook);
 			imageDisplayDialog.PictureFileName = System.IO.Path.GetFileName(AudibleFileStorage.Audio.GetBooksDirectoryFilename(gEntry.LibraryBook, ".jpg"));
 			imageDisplayDialog.Title = windowTitle;
-			imageDisplayDialog.CoverBytes = initialImageBts;
+			imageDisplayDialog.SetCoverBytes(initialImageBts);
 
 			if (!isDefault)
 				PictureStorage.PictureCached -= PictureCached;

Source/LibationFileManager/Configuration.Environment.cs

@@ -20,6 +20,8 @@ namespace LibationFileManager
 		public static bool IsWindows { get; } = OperatingSystem.IsWindows();
         public static bool IsLinux { get; } = OperatingSystem.IsLinux();
         public static bool IsMacOs { get; } = OperatingSystem.IsMacOS();
+		public static Version LibationVersion { get; private set; }
+		public static void SetLibationVersion(Version version) => LibationVersion = version;
 
 		public static OS OS { get; }
 			= IsLinux ? OS.Linux

Source/LibationFileManager/Configuration.PersistentSettings.cs

@@ -73,7 +73,7 @@ namespace LibationFileManager
 
 		public bool Exists(string propertyName) => persistentDictionary.Exists(propertyName);
 
-		[Description("Set cover art as the folder's icon. (Windows only)")]
+		[Description("Set cover art as the folder's icon. (Windows and macOS only)")]
 		public bool UseCoverAsFolderIcon { get => GetNonString(defaultValue: false); set => SetNonString(value); }
 
 		[Description("Use the beta version of Libation\r\nNew and experimental features, but probably buggy.\r\n(requires restart to take effect)")]

Source/LibationFileManager/WindowsDirectory.cs

@@ -9,11 +9,13 @@ namespace LibationFileManager
 {
     public static class WindowsDirectory
     {
+
         public static void SetCoverAsFolderIcon(string pictureId, string directory)
         {
             try
             {
-                if (!Configuration.Instance.UseCoverAsFolderIcon || !Configuration.IsWindows)
+                //Currently only works for Windows and macOS
+                if (!Configuration.Instance.UseCoverAsFolderIcon || Configuration.IsLinux)
                     return;
 
                 // get path of cover art in Images dir. Download first if not exists

Source/LibationUiBase/IcoEncoder.cs

@@ -0,0 +1,52 @@
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp;
+using System;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using SixLabors.ImageSharp.Formats;
+
+namespace LibationUiBase
+{
+	public class IcoEncoder : IImageEncoder
+	{
+		public bool SkipMetadata { get; init; } = true;
+
+		public void Encode<TPixel>(Image<TPixel> image, Stream stream) where TPixel : unmanaged, IPixel<TPixel>
+		{
+			// https://stackoverflow.com/a/21389253
+
+			using var ms = new MemoryStream();
+			//Knowing the image size ahead of time removes the
+			//requirement of the output stream to support seeking.
+			image.SaveAsPng(ms);
+
+			//Disposing of the BinaryWriter disposes the soutput stream. Let the caller clean up.
+			var bw = new BinaryWriter(stream);
+
+			// Header
+			bw.Write((short)0);   // 0-1 : reserved
+			bw.Write((short)1);   // 2-3 : 1=ico, 2=cur
+			bw.Write((short)1);   // 4-5 : number of images
+
+			// Image directory
+			var w = image.Width;
+			if (w >= 256) w = 0;
+			bw.Write((byte)w);                      // 0 : width of image
+			var h = image.Height;
+			if (h >= 256) h = 0;
+			bw.Write((byte)h);                      // 1 : height of image
+			bw.Write((byte)0);                      // 2 : number of colors in palette
+			bw.Write((byte)0);                      // 3 : reserved
+			bw.Write((short)0);                     // 4 : number of color planes
+			bw.Write((short)0);                     // 6 : bits per pixel
+			bw.Write((int)ms.Position);             // 8 : image size
+			bw.Write((int)stream.Position + 4);     // 12: offset of image data
+			ms.Position = 0;
+			ms.CopyTo(stream);                      // Image data
+		}
+
+		public Task EncodeAsync<TPixel>(Image<TPixel> image, Stream stream, CancellationToken cancellationToken) where TPixel : unmanaged, IPixel<TPixel>
+			=> throw new NotImplementedException();
+	}
+}

Source/LibationUiBase/LastDownloadStatus.cs

@@ -0,0 +1,41 @@
+using DataLayer;
+using System;
+
+namespace LibationUiBase
+{
+	public class LastDownloadStatus : IComparable
+	{
+		public bool IsValid => LastDownloadedVersion is not null && LastDownloaded.HasValue;
+		public Version LastDownloadedVersion { get; }
+		public DateTime? LastDownloaded { get; }
+		public string ToolTipText => IsValid ? $"Double click to open v{LastDownloadedVersion.ToString(3)} release notes" : "";
+
+		public LastDownloadStatus() { }
+		public LastDownloadStatus(UserDefinedItem udi)
+		{
+			LastDownloadedVersion = udi.LastDownloadedVersion;
+			LastDownloaded = udi.LastDownloaded;
+		}
+
+		public void OpenReleaseUrl()
+		{
+			if (IsValid)
+				Dinah.Core.Go.To.Url($"{AppScaffolding.LibationScaffolding.RepositoryUrl}/releases/tag/v{LastDownloadedVersion.ToString(3)}");
+		}
+
+		public override string ToString()
+			=> IsValid ? $"{dateString()}\n\nLibation v{LastDownloadedVersion.ToString(3)}" : "";
+
+		//Call ToShortDateString to use current culture's date format.
+		private string dateString() => $"{LastDownloaded.Value.ToShortDateString()} {LastDownloaded.Value:HH:mm}";
+
+		public int CompareTo(object obj)
+		{
+			if (obj is not LastDownloadStatus second) return -1;
+			else if (IsValid && !second.IsValid) return -1;
+			else if (!IsValid && second.IsValid) return 1;
+			else if (!IsValid && !second.IsValid) return 0;
+			else return LastDownloaded.Value.CompareTo(second.LastDownloaded.Value);
+		}
+	}
+}

Source/LibationUiBase/LibationUiBase.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-	<PackageReference Include="SixLabors.ImageSharp" Version="2.1.3" />
+	<PackageReference Include="SixLabors.ImageSharp" Version="3.0.0" />
   </ItemGroup>
 
   <ItemGroup>

Source/LibationUiBase/TrackedQueue[T].cs

@@ -1,9 +1,8 @@
 using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
 using System.Linq;
 
-namespace LibationAvalonia.ViewModels
+namespace LibationUiBase
 {
 	public enum QueuePosition
 	{
@@ -33,7 +32,7 @@ namespace LibationAvalonia.ViewModels
 	 * and is stored in ObservableCollection.Items.  When the primary list changes, the
 	 * secondary list is cleared and reset to match the primary. 
 	 */
-	public class TrackedQueue<T> : ObservableCollection<T> where T : class
+	public class TrackedQueue<T> where T : class
 	{
 		public event EventHandler<int> CompletedCountChanged;
 		public event EventHandler<int> QueuededCountChanged;
@@ -47,6 +46,60 @@ namespace LibationAvalonia.ViewModels
 		private readonly List<T> _completed = new();
 		private readonly object lockObject = new();
 
+		private readonly ICollection<T> _underlyingList;
+
+		public TrackedQueue(ICollection<T> underlyingList = null)
+		{
+			_underlyingList = underlyingList;
+		}
+
+		public T this[int index]
+		{
+			get
+			{
+				lock (lockObject)
+				{
+					if (index < _completed.Count)
+						return _completed[index];
+					index -= _completed.Count;
+
+					if (index == 0 && Current != null) return Current;
+
+					if (Current != null) index--;
+
+					if (index < _queued.Count) return _queued.ElementAt(index);
+
+					throw new IndexOutOfRangeException();
+				}
+			}
+		}
+
+		public int Count
+		{
+			get
+			{
+				lock (lockObject)
+				{
+					return _queued.Count + _completed.Count + (Current == null ? 0 : 1);
+				}
+			}
+		}
+
+		public int IndexOf(T item)
+		{
+			lock (lockObject)
+			{
+				if (_completed.Contains(item))
+					return _completed.IndexOf(item);
+
+				if (Current == item) return _completed.Count;
+
+				if (_queued.Contains(item))
+					return _queued.IndexOf(item) + (Current is null ? 0 : 1);
+				return -1;
+			}
+		}
+
 		public bool RemoveQueued(T item)
 		{
 			bool itemsRemoved;
@@ -188,29 +241,6 @@ namespace LibationAvalonia.ViewModels
 			}
 		}
 
-		public bool TryPeek(out T item)
-		{
-			lock (lockObject)
-			{
-				if (_queued.Count == 0)
-				{
-					item = null;
-					return false;
-				}
-				item = _queued[0];
-				return true;
-			}
-		}
-
-		public T Peek()
-		{
-			lock (lockObject)
-			{
-				if (_queued.Count == 0) throw new InvalidOperationException("Queue empty");
-				return _queued.Count > 0 ? _queued[0] : default;
-			}
-		}
-
 		public void Enqueue(IEnumerable<T> item)
 		{
 			int queueCount;
@@ -220,15 +250,15 @@ namespace LibationAvalonia.ViewModels
 				queueCount = _queued.Count;
 			}
 			foreach (var i in item)
-				base.Add(i);
+				_underlyingList?.Add(i);
 			QueuededCountChanged?.Invoke(this, queueCount);
 		}
 
 		private void RebuildSecondary()
 		{
-			base.ClearItems();
+			_underlyingList?.Clear();
 			foreach (var item in GetAllItems())
-				base.Add(item);
+				_underlyingList?.Add(item);
 		}
 
 		public IEnumerable<T> GetAllItems()

Source/LibationWinForms/Dialogs/TrashBinDialog.Designer.cs

@@ -0,0 +1,129 @@
+namespace LibationWinForms.Dialogs
+{
+	partial class TrashBinDialog
+	{
+		/// <summary>
+		/// Required designer variable.
+		/// </summary>
+		private System.ComponentModel.IContainer components = null;
+
+		/// <summary>
+		/// Clean up any resources being used.
+		/// </summary>
+		/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing && (components != null))
+			{
+				components.Dispose();
+			}
+			base.Dispose(disposing);
+		}
+
+		#region Windows Form Designer generated code
+
+		/// <summary>
+		/// Required method for Designer support - do not modify
+		/// the contents of this method with the code editor.
+		/// </summary>
+		private void InitializeComponent()
+		{
+			deletedCbl = new System.Windows.Forms.CheckedListBox();
+			label1 = new System.Windows.Forms.Label();
+			restoreBtn = new System.Windows.Forms.Button();
+			permanentlyDeleteBtn = new System.Windows.Forms.Button();
+			everythingCb = new System.Windows.Forms.CheckBox();
+			deletedCheckedLbl = new System.Windows.Forms.Label();
+			SuspendLayout();
+			// 
+			// deletedCbl
+			// 
+			deletedCbl.Anchor = System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right;
+			deletedCbl.FormattingEnabled = true;
+			deletedCbl.Location = new System.Drawing.Point(12, 27);
+			deletedCbl.Name = "deletedCbl";
+			deletedCbl.Size = new System.Drawing.Size(776, 364);
+			deletedCbl.TabIndex = 3;
+			deletedCbl.ItemCheck += deletedCbl_ItemCheck;
+			// 
+			// label1
+			// 
+			label1.AutoSize = true;
+			label1.Location = new System.Drawing.Point(12, 9);
+			label1.Name = "label1";
+			label1.Size = new System.Drawing.Size(388, 15);
+			label1.TabIndex = 4;
+			label1.Text = "Check books you want to permanently delete from or restore to Libation";
+			// 
+			// restoreBtn
+			// 
+			restoreBtn.Anchor = System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right;
+			restoreBtn.Location = new System.Drawing.Point(572, 398);
+			restoreBtn.Name = "restoreBtn";
+			restoreBtn.Size = new System.Drawing.Size(75, 40);
+			restoreBtn.TabIndex = 5;
+			restoreBtn.Text = "Restore";
+			restoreBtn.UseVisualStyleBackColor = true;
+			restoreBtn.Click += restoreBtn_Click;
+			// 
+			// permanentlyDeleteBtn
+			// 
+			permanentlyDeleteBtn.Anchor = System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right;
+			permanentlyDeleteBtn.Location = new System.Drawing.Point(653, 398);
+			permanentlyDeleteBtn.Name = "permanentlyDeleteBtn";
+			permanentlyDeleteBtn.Size = new System.Drawing.Size(135, 40);
+			permanentlyDeleteBtn.TabIndex = 5;
+			permanentlyDeleteBtn.Text = "Permanently Remove\r\nfrom Libation";
+			permanentlyDeleteBtn.UseVisualStyleBackColor = true;
+			permanentlyDeleteBtn.Click += permanentlyDeleteBtn_Click;
+			// 
+			// everythingCb
+			// 
+			everythingCb.Anchor = System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left;
+			everythingCb.AutoSize = true;
+			everythingCb.Location = new System.Drawing.Point(12, 410);
+			everythingCb.Name = "everythingCb";
+			everythingCb.Size = new System.Drawing.Size(82, 19);
+			everythingCb.TabIndex = 6;
+			everythingCb.Text = "Everything";
+			everythingCb.ThreeState = true;
+			everythingCb.UseVisualStyleBackColor = true;
+			everythingCb.CheckStateChanged += everythingCb_CheckStateChanged;
+			// 
+			// deletedCheckedLbl
+			// 
+			deletedCheckedLbl.Anchor = System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left;
+			deletedCheckedLbl.AutoSize = true;
+			deletedCheckedLbl.Location = new System.Drawing.Point(126, 411);
+			deletedCheckedLbl.Name = "deletedCheckedLbl";
+			deletedCheckedLbl.Size = new System.Drawing.Size(104, 15);
+			deletedCheckedLbl.TabIndex = 7;
+			deletedCheckedLbl.Text = "Checked: {0} of {1}";
+			// 
+			// TrashBinDialog
+			// 
+			AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+			AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+			ClientSize = new System.Drawing.Size(800, 450);
+			Controls.Add(deletedCheckedLbl);
+			Controls.Add(everythingCb);
+			Controls.Add(permanentlyDeleteBtn);
+			Controls.Add(restoreBtn);
+			Controls.Add(label1);
+			Controls.Add(deletedCbl);
+			Name = "TrashBinDialog";
+			Text = "Trash Bin";
+			ResumeLayout(false);
+			PerformLayout();
+		}
+
+		#endregion
+
+		private System.Windows.Forms.CheckedListBox deletedCbl;
+		private System.Windows.Forms.Label label1;
+		private System.Windows.Forms.Button restoreBtn;
+		private System.Windows.Forms.Button permanentlyDeleteBtn;
+		private System.Windows.Forms.CheckBox everythingCb;
+		private System.Windows.Forms.Label deletedCheckedLbl;
+	}
+}

Source/LibationWinForms/Dialogs/TrashBinDialog.cs

@@ -0,0 +1,116 @@
+using ApplicationServices;
+using System;
+using System.Data;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using DataLayer;
+using LibationFileManager;
+using System.Collections;
+
+namespace LibationWinForms.Dialogs
+{
+	public partial class TrashBinDialog : Form
+	{
+		private readonly string deletedCheckedTemplate;
+		public TrashBinDialog()
+		{
+			InitializeComponent();
+
+			this.SetLibationIcon();
+			this.RestoreSizeAndLocation(Configuration.Instance);
+			this.Closing += (_, _) => this.SaveSizeAndLocation(Configuration.Instance);
+
+			deletedCheckedTemplate = deletedCheckedLbl.Text;
+
+			var deletedBooks = DbContexts.GetContext().GetDeletedLibraryBooks();
+			foreach (var lb in deletedBooks)
+				deletedCbl.Items.Add(lb);
+
+			setLabel();
+		}
+
+		private void deletedCbl_ItemCheck(object sender, ItemCheckEventArgs e)
+		{
+			// CheckedItems.Count is not updated until after the event fires
+			setLabel(e.NewValue);
+		}
+
+		private async void permanentlyDeleteBtn_Click(object sender, EventArgs e)
+		{
+			setControlsEnabled(false);
+
+			var removed = deletedCbl.CheckedItems.Cast<LibraryBook>().ToList();
+
+			removeFromCheckList(removed);
+			await Task.Run(removed.PermanentlyDeleteBooks);
+
+			setControlsEnabled(true);
+		}
+
+		private async void restoreBtn_Click(object sender, EventArgs e)
+		{
+			setControlsEnabled(false);
+
+			var removed = deletedCbl.CheckedItems.Cast<LibraryBook>().ToList();
+
+			removeFromCheckList(removed);
+			await Task.Run(removed.RestoreBooks);
+
+			setControlsEnabled(true);
+		}
+
+		private void removeFromCheckList(IEnumerable objects)
+		{
+			foreach (var o in objects)
+				deletedCbl.Items.Remove(o);
+
+			deletedCbl.Refresh();
+			setLabel();
+		}
+
+		private void setControlsEnabled(bool enabled)
+			=> restoreBtn.Enabled = permanentlyDeleteBtn.Enabled = deletedCbl.Enabled = everythingCb.Enabled = enabled;
+
+		private void everythingCb_CheckStateChanged(object sender, EventArgs e)
+		{
+			if (everythingCb.CheckState is CheckState.Indeterminate)
+			{
+				everythingCb.CheckState = CheckState.Unchecked;
+				return;
+			}
+
+			deletedCbl.ItemCheck -= deletedCbl_ItemCheck;
+
+			for (var i = 0; i < deletedCbl.Items.Count; i++)
+				deletedCbl.SetItemChecked(i, everythingCb.CheckState is CheckState.Checked);
+
+			setLabel();
+
+			deletedCbl.ItemCheck += deletedCbl_ItemCheck;
+		}
+
+
+		private void setLabel(CheckState? checkedState = null)
+		{
+			var pre = deletedCbl.CheckedItems.Count;
+			int count = checkedState switch
+			{
+				CheckState.Checked => pre + 1,
+				CheckState.Unchecked => pre - 1,
+				_ => pre,
+			};
+
+			everythingCb.CheckStateChanged -= everythingCb_CheckStateChanged;
+
+			everythingCb.CheckState
+				= count > 0 && count == deletedCbl.Items.Count ? CheckState.Checked
+				: count == 0 ? CheckState.Unchecked
+				: CheckState.Indeterminate;
+
+			everythingCb.CheckStateChanged += everythingCb_CheckStateChanged;
+
+			deletedCheckedLbl.Text = string.Format(deletedCheckedTemplate, count, deletedCbl.Items.Count);
+		}
+	}
+}

Source/LibationWinForms/Dialogs/TrashBinDialog.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

Source/LibationWinForms/Form1.BackupCounts.cs

@@ -13,7 +13,6 @@ namespace LibationWinForms
 			// init formattable
 			beginBookBackupsToolStripMenuItem.Format(0);
 			beginPdfBackupsToolStripMenuItem.Format(0);
-			pdfsCountsLbl.Text = "|  [Calculating backed up PDFs]";
 
 			Load += setBackupCounts;
             LibraryCommands.LibrarySizeChanged += setBackupCounts;
@@ -21,9 +20,8 @@ namespace LibationWinForms
 
 			updateCountsBw.DoWork += UpdateCountsBw_DoWork;
 			updateCountsBw.RunWorkerCompleted += exportMenuEnable;
-			updateCountsBw.RunWorkerCompleted += updateBottomBookNumbers;
+			updateCountsBw.RunWorkerCompleted += updateBottomStats;
 			updateCountsBw.RunWorkerCompleted += update_BeginBookBackups_menuItem;
-			updateCountsBw.RunWorkerCompleted += updateBottomPdfNumbers;
 			updateCountsBw.RunWorkerCompleted += udpate_BeginPdfOnlyBackups_menuItem;
 		}
 
@@ -52,27 +50,13 @@ namespace LibationWinForms
 			Invoke(() => exportLibraryToolStripMenuItem.Enabled = libraryStats.HasBookResults);
 		}
 
-		// this cannot be cleanly be FormattableToolStripMenuItem because of the optional "Errors" text
-		private const string backupsCountsLbl_Format = "BACKUPS: No progress: {0}  In process: {1}  Fully backed up: {2}";
-
-		private void updateBottomBookNumbers(object _, System.ComponentModel.RunWorkerCompletedEventArgs e)
+		private void updateBottomStats(object _, System.ComponentModel.RunWorkerCompletedEventArgs e)
 		{
 			var libraryStats = e.Result as LibraryCommands.LibraryStats;
-
-			var formatString
-				= !libraryStats.HasBookResults ? "No books. Begin by importing your library"
-				: libraryStats.booksError > 0 ? backupsCountsLbl_Format + "  Errors: {3}"
-				: libraryStats.HasPendingBooks ? backupsCountsLbl_Format
-				: $"All {"book".PluralizeWithCount(libraryStats.booksFullyBackedUp)} backed up";
-			var statusStripText = string.Format(formatString,
-				libraryStats.booksNoProgress,
-				libraryStats.booksDownloadedOnly,
-				libraryStats.booksFullyBackedUp,
-				libraryStats.booksError);
-			statusStrip1.UIThreadAsync(() => backupsCountsLbl.Text = statusStripText);
+			statusStrip1.UIThreadAsync(() => backupsCountsLbl.Text = libraryStats.StatusString);
 		}
 
-		// update 'begin book backups' menu item
+		// update 'begin book and pdf backups' menu item
 		private void update_BeginBookBackups_menuItem(object _, System.ComponentModel.RunWorkerCompletedEventArgs e)
 		{
 			var libraryStats = e.Result as LibraryCommands.LibraryStats;
@@ -88,18 +72,6 @@ namespace LibationWinForms
 			});
 		}
 
-		private void updateBottomPdfNumbers(object _, System.ComponentModel.RunWorkerCompletedEventArgs e)
-		{
-			var libraryStats = e.Result as LibraryCommands.LibraryStats;
-
-			// don't need to assign the output of Format(). It just makes this logic cleaner
-			var statusStripText
-				= !libraryStats.HasPdfResults ? ""
-				: libraryStats.pdfsNotDownloaded > 0 ? pdfsCountsLbl.Format(libraryStats.pdfsNotDownloaded, libraryStats.pdfsDownloaded)
-				: $"|  All {libraryStats.pdfsDownloaded} PDFs downloaded";
-			statusStrip1.UIThreadAsync(() => pdfsCountsLbl.Text = statusStripText);
-		}
-
 		// update 'begin pdf only backups' menu item
 		private void udpate_BeginPdfOnlyBackups_menuItem(object _, System.ComponentModel.RunWorkerCompletedEventArgs e)
 		{

Source/LibationWinForms/Form1.Designer.cs

@@ -63,6 +63,7 @@
 			this.toolStripSeparator3 = new System.Windows.Forms.ToolStripSeparator();
 			this.removeToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
 			this.toolStripSeparator4 = new System.Windows.Forms.ToolStripSeparator();
+			this.openTrashBinToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
 			this.launchHangoverToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
             this.locateAudiobooksToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
 			this.settingsToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
@@ -76,7 +77,6 @@
 			this.visibleCountLbl = new LibationWinForms.FormattableToolStripStatusLabel();
             this.springLbl = new System.Windows.Forms.ToolStripStatusLabel();
             this.backupsCountsLbl = new System.Windows.Forms.ToolStripStatusLabel();
-            this.pdfsCountsLbl = new LibationWinForms.FormattableToolStripStatusLabel();
             this.addQuickFilterBtn = new System.Windows.Forms.Button();
             this.splitContainer1 = new System.Windows.Forms.SplitContainer();
             this.panel1 = new System.Windows.Forms.Panel();
@@ -383,8 +383,9 @@
             this.accountsToolStripMenuItem,
             this.basicSettingsToolStripMenuItem,
 			this.toolStripSeparator4,
+			this.openTrashBinToolStripMenuItem,
 			this.launchHangoverToolStripMenuItem,
-            this.toolStripSeparator2,
+			this.toolStripSeparator2,
             this.aboutToolStripMenuItem});
             this.settingsToolStripMenuItem.Name = "settingsToolStripMenuItem";
             this.settingsToolStripMenuItem.Size = new System.Drawing.Size(61, 20);
@@ -424,8 +425,7 @@
             this.upgradePb,
 			this.visibleCountLbl,
             this.springLbl,
-            this.backupsCountsLbl,
-            this.pdfsCountsLbl});
+            this.backupsCountsLbl});
             this.statusStrip1.Location = new System.Drawing.Point(0, 618);
             this.statusStrip1.Name = "statusStrip1";
             this.statusStrip1.Padding = new System.Windows.Forms.Padding(1, 0, 16, 0);
@@ -464,13 +464,6 @@
             this.backupsCountsLbl.Size = new System.Drawing.Size(218, 17);
             this.backupsCountsLbl.Text = "[Calculating backed up book quantities]";
             // 
-            // pdfsCountsLbl
-            // 
-            this.pdfsCountsLbl.FormatText = "|  PDFs: NOT d/l\'ed: {0}  Downloaded: {1}";
-            this.pdfsCountsLbl.Name = "pdfsCountsLbl";
-            this.pdfsCountsLbl.Size = new System.Drawing.Size(218, 17);
-            this.pdfsCountsLbl.Text = "|  PDFs: NOT d/l\'ed: {0}  Downloaded: {1}";
-            // 
             // addQuickFilterBtn
             // 
             this.addQuickFilterBtn.Location = new System.Drawing.Point(50, 3);
@@ -592,6 +585,13 @@
 			this.locateAudiobooksToolStripMenuItem.Text = "L&ocate Audiobooks";
 			this.locateAudiobooksToolStripMenuItem.Click += new System.EventHandler(this.locateAudiobooksToolStripMenuItem_Click);
 			// 
+			// openTrashBinToolStripMenuItem
+			// 
+			this.openTrashBinToolStripMenuItem.Name = "openTrashBinToolStripMenuItem";
+			this.openTrashBinToolStripMenuItem.Size = new System.Drawing.Size(247, 22);
+			this.openTrashBinToolStripMenuItem.Text = "Trash Bin";
+			this.openTrashBinToolStripMenuItem.Click += new System.EventHandler(this.openTrashBinToolStripMenuItem_Click);
+			// 
 			// launchHangoverToolStripMenuItem
 			// 
 			this.launchHangoverToolStripMenuItem.Name = "launchHangoverToolStripMenuItem";
@@ -640,7 +640,6 @@
 		private System.Windows.Forms.ToolStripMenuItem liberateToolStripMenuItem;
 		private System.Windows.Forms.ToolStripStatusLabel backupsCountsLbl;
 		private LibationWinForms.FormattableToolStripMenuItem beginBookBackupsToolStripMenuItem;
-		private LibationWinForms.FormattableToolStripStatusLabel pdfsCountsLbl;
 		private LibationWinForms.FormattableToolStripMenuItem beginPdfBackupsToolStripMenuItem;
 		private System.Windows.Forms.TextBox filterSearchTb;
 		private System.Windows.Forms.Button filterBtn;
@@ -676,6 +675,7 @@
 		private System.Windows.Forms.ToolStripSeparator toolStripSeparator3;
 		private System.Windows.Forms.ToolStripMenuItem locateAudiobooksToolStripMenuItem;
 		private System.Windows.Forms.ToolStripSeparator toolStripSeparator4;
+		private System.Windows.Forms.ToolStripMenuItem openTrashBinToolStripMenuItem;
 		private System.Windows.Forms.ToolStripMenuItem launchHangoverToolStripMenuItem;
         private LibationWinForms.FormattableToolStripMenuItem liberateVisibleToolStripMenuItem_LiberateMenu;
 		private System.Windows.Forms.SplitContainer splitContainer1;

Source/LibationWinForms/Form1.RemoveBooks.cs

@@ -16,6 +16,9 @@ namespace LibationWinForms
 		private async void removeBooksBtn_Click(object sender, EventArgs e)
 			=> await productsDisplay.RemoveCheckedBooksAsync();
 
+		private void openTrashBinToolStripMenuItem_Click(object sender, EventArgs e)
+			=> new TrashBinDialog().ShowDialog(this);
+
 		private void doneRemovingBtn_Click(object sender, EventArgs e)
 		{
 			removeBooksBtn.Visible = false;

Source/LibationWinForms/Form1.VisibleBooks.cs

@@ -27,25 +27,22 @@ namespace LibationWinForms
 			=> await Task.Run(setLiberatedVisibleMenuItem);
 		void setLiberatedVisibleMenuItem()
 		{
-			var notLiberated = productsDisplay.GetVisible().Count(lb => lb.Book.UserDefinedItem.BookStatus == DataLayer.LiberatedStatus.NotLiberated);
+			var libraryStats = LibraryCommands.GetCounts(productsDisplay.GetVisible());
 			this.UIThreadSync(() =>
 			{
-				if (notLiberated > 0)
+				if (libraryStats.HasPendingBooks)
 				{
-					liberateVisibleToolStripMenuItem_VisibleBooksMenu.Format(notLiberated);
-					liberateVisibleToolStripMenuItem_VisibleBooksMenu.Enabled = true;
-
-					liberateVisibleToolStripMenuItem_LiberateMenu.Format(notLiberated);
-					liberateVisibleToolStripMenuItem_LiberateMenu.Enabled = true;
+					liberateVisibleToolStripMenuItem_VisibleBooksMenu.Format(libraryStats.PendingBooks);
+					liberateVisibleToolStripMenuItem_LiberateMenu.Format(libraryStats.PendingBooks);
 				}
 				else
 				{
 					liberateVisibleToolStripMenuItem_VisibleBooksMenu.Text = "All visible books are liberated";
-					liberateVisibleToolStripMenuItem_VisibleBooksMenu.Enabled = false;
-
 					liberateVisibleToolStripMenuItem_LiberateMenu.Text = "All visible books are liberated";
-					liberateVisibleToolStripMenuItem_LiberateMenu.Enabled = false;
 				}
+
+				liberateVisibleToolStripMenuItem_VisibleBooksMenu.Enabled = libraryStats.HasPendingBooks;
+				liberateVisibleToolStripMenuItem_LiberateMenu.Enabled = libraryStats.HasPendingBooks;
 			});
 		}
 
@@ -168,11 +165,8 @@ namespace LibationWinForms
                 "Are you sure you want to remove {0} from Libation's library?",
 				"Remove books from Libation?");
 
-			if (confirmationResult != DialogResult.Yes)
-				return;
-
-			var visibleIds = visibleLibraryBooks.Select(lb => lb.Book.AudibleProductId).ToList();
-			await LibraryCommands.RemoveBooksAsync(visibleIds);
+			if (confirmationResult is DialogResult.Yes)
+				await visibleLibraryBooks.RemoveBooksAsync();
 		}
 
 		private async void productsDisplay_VisibleCountChanged(object sender, int qty)
@@ -183,9 +177,6 @@ namespace LibationWinForms
 			// top menu strip
 			visibleBooksToolStripMenuItem.Format(qty);
 			visibleBooksToolStripMenuItem.Enabled = qty > 0;
-
-			//Not used for anything?
-			var notLiberatedCount = productsDisplay.GetVisible().Count(lb => lb.Book.UserDefinedItem.BookStatus == DataLayer.LiberatedStatus.NotLiberated);
 			
 			await Task.Run(setLiberatedVisibleMenuItem);
 		}

Source/LibationWinForms/GridView/AsyncNotifyPropertyChanged.cs

@@ -12,6 +12,6 @@ namespace LibationWinForms.GridView
 		// per standard INotifyPropertyChanged pattern:
 		// https://docs.microsoft.com/en-us/dotnet/desktop/wpf/data/how-to-implement-property-change-notification
 		public void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
-			=> this.UIThreadAsync(() => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)));
+			=> this.UIThreadSync(() => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)));
 	}
 }

Source/LibationWinForms/GridView/GridEntry.cs

@@ -59,6 +59,7 @@ namespace LibationWinForms.GridView
 		public string Narrators { get; protected set; }
 		public string Category { get; protected set; }
 		public string Misc { get; protected set; }
+		public virtual LastDownloadStatus LastDownload { get; protected set; } = new();
 		public string Description { get; protected set; }
 		public string ProductRating { get; protected set; }
 		protected Rating _myRating;
@@ -120,6 +121,7 @@ namespace LibationWinForms.GridView
 			{ typeof(bool), new ObjectComparer<bool>() },
 			{ typeof(DateTime), new ObjectComparer<DateTime>() },
 			{ typeof(LiberateButtonStatus), new ObjectComparer<LiberateButtonStatus>() },
+			{ typeof(LastDownloadStatus), new ObjectComparer<LastDownloadStatus>() },
 		};
 
 		#endregion
@@ -136,7 +138,7 @@ namespace LibationWinForms.GridView
 				PictureStorage.PictureCached += PictureStorage_PictureCached;
 
 			// Mutable property. Set the field so PropertyChanged isn't fired.
-			_cover = ImageReader.ToImage(picture);
+			_cover = loadImage(picture);
 		}
 
 		private void PictureStorage_PictureCached(object sender, PictureCachedEventArgs e)
@@ -152,11 +154,25 @@ namespace LibationWinForms.GridView
             // logic validation
             if (e.Definition.PictureId == Book.PictureId)
 			{
-				Cover = ImageReader.ToImage(e.Picture);
+				Cover = loadImage(e.Picture);
 				PictureStorage.PictureCached -= PictureStorage_PictureCached;
 			}
 		}
 
+
+		private Image loadImage(byte[] picture)
+		{
+			try
+			{
+				return ImageReader.ToImage(picture);
+			}
+			catch (Exception ex)
+			{
+				Serilog.Log.Logger.Error(ex, "Error loading cover art for {Book}", Book);
+				return Properties.Resources.default_cover_80x80;
+			}
+		}
+
 		#endregion
 
 		#region Static library display functions		

Source/LibationWinForms/GridView/ImageDisplay.cs

@@ -9,10 +9,6 @@ namespace LibationWinForms.GridView
 	{
 		public string PictureFileName { get; set; }
 		public string BookSaveDirectory { get; set; }
-		public byte[] CoverPicture { get => _coverBytes; set => pictureBox1.Image = Dinah.Core.WindowsDesktop.Drawing.ImageReader.ToImage(_coverBytes = value); }
-
-		private byte[] _coverBytes;
-
 
 		public ImageDisplay()
 		{
@@ -21,6 +17,19 @@ namespace LibationWinForms.GridView
 			lastHeight = Height;
 		}
 
+		public void SetCoverArt(byte[] cover)
+		{
+			try
+			{
+				pictureBox1.Image = Dinah.Core.WindowsDesktop.Drawing.ImageReader.ToImage(cover);
+			}
+			catch (Exception ex)
+			{
+				Serilog.Log.Logger.Error(ex, "Error loading cover art for {file}", PictureFileName);
+				pictureBox1.Image = Properties.Resources.default_cover_500x500;
+			}
+		}
+
 		#region Make the form's aspect ratio always match the picture's aspect ratio.
 
 		private bool detectedResizeDirection = false;
@@ -106,7 +115,7 @@ namespace LibationWinForms.GridView
 
 			try
 			{
-				File.WriteAllBytes(saveFileDialog.FileName, CoverPicture);
+				pictureBox1.Image.Save(saveFileDialog.FileName);
 			}
 			catch (Exception ex)
 			{

Source/LibationWinForms/GridView/LastDownloadedGridViewColumn.cs

@@ -0,0 +1,39 @@
+using LibationUiBase;
+using System;
+using System.Drawing;
+using System.Windows.Forms;
+
+namespace LibationWinForms.GridView
+{
+	public class LastDownloadedGridViewColumn : DataGridViewColumn
+	{
+		public LastDownloadedGridViewColumn() : base(new LastDownloadedGridViewCell()) { }
+		public override DataGridViewCell CellTemplate
+		{
+			get => base.CellTemplate;
+			set
+			{
+				if (value is not LastDownloadedGridViewCell)
+					throw new InvalidCastException($"Must be a {nameof(LastDownloadedGridViewCell)}");
+
+				base.CellTemplate = value;
+			}
+		}
+	}
+
+	internal class LastDownloadedGridViewCell : DataGridViewTextBoxCell
+	{
+		private LastDownloadStatus LastDownload => (LastDownloadStatus)Value;
+		protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates cellState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts)
+		{
+			ToolTipText = ((LastDownloadStatus)value).ToolTipText;
+			base.Paint(graphics, clipBounds, cellBounds, rowIndex, cellState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, paintParts);
+		}
+
+		protected override void OnDoubleClick(DataGridViewCellEventArgs e)
+		{
+			LastDownload.OpenReleaseUrl();
+			base.OnDoubleClick(e);
+		}
+	}
+}

Source/LibationWinForms/GridView/LiberateButtonStatus.cs

@@ -8,7 +8,15 @@ namespace LibationWinForms.GridView
 		public LiberatedStatus BookStatus { get; set; }
 		public LiberatedStatus? PdfStatus { get; set; }
 		public bool Expanded { get; set; }
-		public bool IsSeries { get; init; }
+		public bool IsSeries { get; }
+		private bool IsAbsent { get; }
+		public bool IsUnavailable => !IsSeries & IsAbsent & (BookStatus is not LiberatedStatus.Liberated || PdfStatus is not null and not LiberatedStatus.Liberated);
+
+		public LiberateButtonStatus(bool isSeries, bool isAbsent)
+		{
+			IsSeries = isSeries;
+			IsAbsent = isAbsent;
+		}
 
 		/// <summary>
 		/// Defines the Liberate column's sorting behavior
@@ -20,6 +28,8 @@ namespace LibationWinForms.GridView
 			if (IsSeries && !second.IsSeries) return -1;
 			else if (!IsSeries && second.IsSeries) return 1;
 			else if (IsSeries && second.IsSeries) return 0;
+			else if (IsUnavailable && !second.IsUnavailable) return 1;
+			else if (!IsUnavailable && second.IsUnavailable) return -1;
 			else if (BookStatus == LiberatedStatus.Liberated && second.BookStatus != LiberatedStatus.Liberated) return -1;
 			else if (BookStatus != LiberatedStatus.Liberated && second.BookStatus == LiberatedStatus.Liberated) return 1;
 			else return BookStatus.CompareTo(second.BookStatus);

Source/LibationWinForms/GridView/LiberateDataGridViewImageButtonColumn.cs

@@ -17,11 +17,14 @@ namespace LibationWinForms.GridView
 	internal class LiberateDataGridViewImageButtonCell : DataGridViewImageButtonCell
 	{
 		private static readonly Color SERIES_BG_COLOR = Color.FromArgb(230, 255, 230);
+		private static readonly Brush DISABLED_GRAY = new SolidBrush(Color.FromArgb(0x60, Color.LightGray));
 		protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates elementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts)
 		{
 			if (value is LiberateButtonStatus status)
 			{
-				if (status.BookStatus is LiberatedStatus.Error)
+
+				if (status.BookStatus is LiberatedStatus.Error || status.IsUnavailable)
+					//Don't paint the button graphic
 					paintParts ^= DataGridViewPaintParts.ContentBackground | DataGridViewPaintParts.ContentForeground | DataGridViewPaintParts.SelectionBackground;
 
 				if (rowIndex >= 0 && DataGridView.GetBoundItem<GridEntry>(rowIndex) is LibraryBookEntry lbEntry && lbEntry.Parent is not null)
@@ -41,7 +44,14 @@ namespace LibationWinForms.GridView
 
 					DrawButtonImage(graphics, buttonImage, cellBounds);
 
-					ToolTipText = mouseoverText;
+					if (status.IsUnavailable)
+					{
+						//Create the "disabled" look by painting a transparent gray box over the buttom image.
+						graphics.FillRectangle(DISABLED_GRAY, cellBounds);
+						ToolTipText = "This book cannot be downloaded\r\nbecause it wasn't found during\r\nthe most recent library scan";
+					}
+					else
+						ToolTipText = mouseoverText;
 				}
 			}
 		}

Source/LibationWinForms/GridView/LibraryBookEntry.cs

@@ -1,6 +1,7 @@
 using ApplicationServices;
 using DataLayer;
 using Dinah.Core;
+using LibationUiBase;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
@@ -24,6 +25,8 @@ namespace LibationWinForms.GridView
 		private LiberatedStatus _bookStatus;
 		private LiberatedStatus? _pdfStatus;
 
+		public override LastDownloadStatus LastDownload { get; protected set; }
+
 		public override RemoveStatus Remove
 		{
 			get
@@ -49,7 +52,7 @@ namespace LibationWinForms.GridView
 					_pdfStatus = LibraryCommands.Pdf_Status(LibraryBook.Book);
 					lastStatusUpdate = DateTime.Now;
 				}
-				return new LiberateButtonStatus { BookStatus = _bookStatus, PdfStatus = _pdfStatus, IsSeries = false };
+				return new LiberateButtonStatus(isSeries: false, LibraryBook.AbsentFromLastScan) { BookStatus = _bookStatus, PdfStatus = _pdfStatus };
 			}
 		}
 		public override string DisplayTags => string.Join("\r\n", Book.UserDefinedItem.TagsEnumerated);
@@ -87,6 +90,7 @@ namespace LibationWinForms.GridView
 			Narrators = Book.NarratorNames();
 			Category = string.Join(" > ", Book.CategoriesNames());
 			Misc = GetMiscDisplay(libraryBook);
+			LastDownload = new(Book.UserDefinedItem);
 			LongDescription = GetDescriptionDisplay(Book);
 			Description = TrimTextToWord(LongDescription, 62);
 			SeriesIndex = Book.SeriesLink.FirstOrDefault()?.Index ?? 0;
@@ -126,6 +130,10 @@ namespace LibationWinForms.GridView
 					_pdfStatus = udi.PdfStatus;
 					NotifyPropertyChanged(nameof(Liberate));
 					break;
+				case nameof(udi.LastDownloaded):
+					LastDownload = new(udi);
+					NotifyPropertyChanged(nameof(LastDownload));
+					break;
 			}
 		}
 
@@ -153,6 +161,7 @@ namespace LibationWinForms.GridView
 			{ nameof(Description), () => Description },
 			{ nameof(Category), () => Category },
 			{ nameof(Misc), () => Misc },
+			{ nameof(LastDownload), () => LastDownload },
 			{ nameof(DisplayTags), () => DisplayTags },
 			{ nameof(Liberate), () => Liberate },
 			{ nameof(DateAdded), () => DateAdded },

Source/LibationWinForms/GridView/ProductsDisplay.cs

@@ -39,7 +39,7 @@ namespace LibationWinForms.GridView
 			void PictureCached(object sender, PictureCachedEventArgs e)
 			{
 				if (e.Definition.PictureId == picDef.PictureId)
-					imageDisplay.CoverPicture = e.Picture;
+					imageDisplay.SetCoverArt(e.Picture);
 
 				PictureStorage.PictureCached -= PictureCached;
 			}
@@ -51,7 +51,7 @@ namespace LibationWinForms.GridView
 
 			if (imageDisplay is null || imageDisplay.IsDisposed || !imageDisplay.Visible)
 			{
-				imageDisplay = new GridView.ImageDisplay();
+				imageDisplay = new ImageDisplay();
 				imageDisplay.RestoreSizeAndLocation(Configuration.Instance);
 				imageDisplay.FormClosed += (_, _) => imageDisplay.SaveSizeAndLocation(Configuration.Instance);
 			}
@@ -59,7 +59,7 @@ namespace LibationWinForms.GridView
 			imageDisplay.BookSaveDirectory = AudibleFileStorage.Audio.GetDestinationDirectory(liveGridEntry.LibraryBook);
 			imageDisplay.PictureFileName = System.IO.Path.GetFileName(AudibleFileStorage.Audio.GetBooksDirectoryFilename(liveGridEntry.LibraryBook, ".jpg"));
 			imageDisplay.Text = windowTitle;
-			imageDisplay.CoverPicture = initialImageBts;
+			imageDisplay.SetCoverArt(initialImageBts);
 			if (!isDefault)
 				PictureStorage.PictureCached -= PictureCached;
 
@@ -107,9 +107,9 @@ namespace LibationWinForms.GridView
 			if (selectedBooks.Count == 0)
 				return;
 
-			var libraryBooks = selectedBooks.Select(rge => rge.LibraryBook).ToList();
+			var booksToRemove = selectedBooks.Select(rge => rge.LibraryBook).ToList();
 			var result = MessageBoxLib.ShowConfirmationDialog(
-				libraryBooks,
+				booksToRemove,
                 // do not use `$` string interpolation. See impl.
                 "Are you sure you want to remove {0} from Libation's library?",
 				"Remove books from Libation?");
@@ -118,8 +118,7 @@ namespace LibationWinForms.GridView
 				return;
 
 			productsGrid.RemoveBooks(selectedBooks);
-			var idsToRemove = libraryBooks.Select(lb => lb.Book.AudibleProductId).ToList();
-			var removeLibraryBooks = await LibraryCommands.RemoveBooksAsync(idsToRemove);
+			await booksToRemove.RemoveBooksAsync();
 		}
 
 		public async Task ScanAndRemoveBooksAsync(params Account[] accounts)
@@ -201,7 +200,8 @@ namespace LibationWinForms.GridView
 
 		private void productsGrid_LiberateClicked(LibraryBookEntry liveGridEntry)
 		{
-			if (liveGridEntry.LibraryBook.Book.UserDefinedItem.BookStatus is not LiberatedStatus.Error)
+			if (liveGridEntry.LibraryBook.Book.UserDefinedItem.BookStatus is not LiberatedStatus.Error
+				&& !liveGridEntry.Liberate.IsUnavailable)
 				LiberateClicked?.Invoke(this, liveGridEntry.LibraryBook);
 		}
 

Source/LibationWinForms/GridView/ProductsGrid.Designer.cs

@@ -45,6 +45,7 @@
 			this.purchaseDateGVColumn = new System.Windows.Forms.DataGridViewTextBoxColumn();
 			this.myRatingGVColumn = new LibationWinForms.GridView.MyRatingGridViewColumn();
 			this.miscGVColumn = new System.Windows.Forms.DataGridViewTextBoxColumn();
+			this.lastDownloadedGVColumn = new LastDownloadedGridViewColumn();
 			this.tagAndDetailsGVColumn = new LibationWinForms.GridView.EditTagsDataGridViewImageButtonColumn();
 			this.showHideColumnsContextMenuStrip = new System.Windows.Forms.ContextMenuStrip(this.components);
 			this.syncBindingSource = new LibationWinForms.GridView.SyncBindingSource(this.components);
@@ -75,7 +76,8 @@
             this.purchaseDateGVColumn,
             this.myRatingGVColumn,
             this.miscGVColumn,
-            this.tagAndDetailsGVColumn});
+			this.lastDownloadedGVColumn,
+			this.tagAndDetailsGVColumn});
 			this.gridEntryDataGridView.ContextMenuStrip = this.showHideColumnsContextMenuStrip;
 			this.gridEntryDataGridView.DataSource = this.syncBindingSource;
 			dataGridViewCellStyle1.Alignment = System.Windows.Forms.DataGridViewContentAlignment.MiddleLeft;
@@ -216,6 +218,15 @@
 			this.miscGVColumn.ReadOnly = true;
 			this.miscGVColumn.Width = 135;
 			// 
+			// lastDownloadedGVColumn
+			// 
+			this.lastDownloadedGVColumn.DataPropertyName = "LastDownload";
+			this.lastDownloadedGVColumn.HeaderText = "Last Download";
+			this.lastDownloadedGVColumn.Name = "lastDownloadedGVColumn";
+			this.lastDownloadedGVColumn.ReadOnly = true;
+			this.lastDownloadedGVColumn.SortMode = System.Windows.Forms.DataGridViewColumnSortMode.Automatic;
+			this.lastDownloadedGVColumn.Width = 108;
+			// 
 			// tagAndDetailsGVColumn
 			// 
 			this.tagAndDetailsGVColumn.DataPropertyName = "DisplayTags";
@@ -268,6 +279,7 @@
 		private System.Windows.Forms.DataGridViewTextBoxColumn purchaseDateGVColumn;
 		private MyRatingGridViewColumn myRatingGVColumn;
 		private System.Windows.Forms.DataGridViewTextBoxColumn miscGVColumn;
+		private LastDownloadedGridViewColumn lastDownloadedGVColumn;
 		private EditTagsDataGridViewImageButtonColumn tagAndDetailsGVColumn;
 	}
 }

Source/LibationWinForms/GridView/ProductsGrid.cs

@@ -154,7 +154,7 @@ namespace LibationWinForms.GridView
             setNotDownloadMenuItem.Click += (_, __) => entry.Book.UpdateBookStatus(LiberatedStatus.NotLiberated);
 
             var removeMenuItem = new ToolStripMenuItem() { Text = "&Remove from library" };
-			removeMenuItem.Click += async (_, __) => await Task.Run(() => LibraryCommands.RemoveBook(entry.AudibleProductId));
+			removeMenuItem.Click += async (_, __) => await Task.Run(entry.LibraryBook.RemoveBook);
 
             var locateFileMenuItem = new ToolStripMenuItem() { Text = "&Locate file..." };
             locateFileMenuItem.Click += (_, __) =>
@@ -180,7 +180,7 @@ namespace LibationWinForms.GridView
 			var convertToMp3MenuItem = new ToolStripMenuItem
 			{
 				Text = "&Convert to Mp3",
-				Enabled = entry.Book.UserDefinedItem.BookStatus != LiberatedStatus.NotLiberated
+				Enabled = entry.Book.UserDefinedItem.BookStatus is LiberatedStatus.Liberated
 			};
 			convertToMp3MenuItem.Click += (_, e) => ConvertToMp3Clicked?.Invoke(entry as LibraryBookEntry);
 

Source/LibationWinForms/GridView/SeriesEntry.cs

@@ -62,7 +62,7 @@ namespace LibationWinForms.GridView
 
 		private SeriesEntry(LibraryBook parent)
 		{
-			Liberate = new LiberateButtonStatus { IsSeries = true };
+			Liberate = new LiberateButtonStatus(isSeries: true, isAbsent: false);
 			SeriesIndex = -1;
 			LibraryBook = parent;
 			LoadCover();
@@ -122,6 +122,7 @@ namespace LibationWinForms.GridView
 			{ nameof(Description), () => Description },
 			{ nameof(Category), () => Category },
 			{ nameof(Misc), () => Misc },
+			{ nameof(LastDownload), () => LastDownload },
 			{ nameof(DisplayTags), () => string.Empty },
 			{ nameof(Liberate), () => Liberate },
 			{ nameof(DateAdded), () => DateAdded },

Source/LibationWinForms/ProcessQueue/TrackedQueue[T].cs

@@ -1,250 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-
-namespace LibationWinForms.ProcessQueue
-{
-	public enum QueuePosition
-	{
-		Fisrt,
-		OneUp,
-		OneDown,
-		Last
-	}
-
-	/*
-	 * This data structure is like lifting a metal chain one link at a time.
-	 * Each time you grab and lift a new link (MoveNext call):
-	 * 
-	 *   1) you're holding a new link in your hand (Current)
-	 *   2) the remaining chain to be lifted shortens by 1 link (Queued)
-	 *   3) the pile of chain at your feet grows by 1 link (Completed)
-	 *   
-	 * The index is the link position from the first link you lifted to the
-	 * last one in the chain.
-	 */
-	public class TrackedQueue<T> where T : class
-	{
-		public event EventHandler<int> CompletedCountChanged;
-		public event EventHandler<int> QueuededCountChanged;
-		public T Current { get; private set; }
-
-		public IReadOnlyList<T> Queued => _queued;
-		public IReadOnlyList<T> Completed => _completed;
-
-		private readonly List<T> _queued = new();
-		private readonly List<T> _completed = new();
-		private readonly object lockObject = new();
-
-		public T this[int index]
-		{
-			get
-			{
-				lock (lockObject)
-				{
-					if (index < _completed.Count)
-						return _completed[index];
-					index -= _completed.Count;
-
-					if (index == 0 && Current != null) return Current;
-
-					if (Current != null) index--;
-
-					if (index < _queued.Count) return _queued.ElementAt(index);
-
-					throw new IndexOutOfRangeException();
-				}
-			}
-		}
-
-		public int Count
-		{
-			get
-			{
-				lock (lockObject)
-				{
-					return _queued.Count + _completed.Count + (Current == null ? 0 : 1);
-				}
-			}
-		}
-
-		public int IndexOf(T item)
-		{
-			lock (lockObject)
-			{
-				if (_completed.Contains(item))
-					return _completed.IndexOf(item);
-
-				if (Current == item) return _completed.Count;
-
-				if (_queued.Contains(item))
-					return _queued.IndexOf(item) + (Current is null ? 0 : 1);
-				return -1;
-			}
-		}
-
-		public bool RemoveQueued(T item)
-		{
-			bool itemsRemoved;
-			int queuedCount;
-
-			lock (lockObject)
-			{
-				itemsRemoved = _queued.Remove(item);
-				queuedCount = _queued.Count;
-			}
-
-			if (itemsRemoved)
-				QueuededCountChanged?.Invoke(this, queuedCount);
-			return itemsRemoved;
-		}
-
-		public void ClearCurrent()
-		{
-			lock(lockObject)
-				Current = null;
-		}
-		
-		public bool RemoveCompleted(T item)
-		{
-			bool itemsRemoved;
-			int completedCount;
-
-			lock (lockObject)
-			{
-				itemsRemoved = _completed.Remove(item);
-				completedCount = _completed.Count;
-			}
-
-			if (itemsRemoved)
-				CompletedCountChanged?.Invoke(this, completedCount);
-			return itemsRemoved;
-		}
-
-		public void ClearQueue()
-		{
-			lock (lockObject)
-				_queued.Clear();
-			QueuededCountChanged?.Invoke(this, 0);
-		}
-
-		public void ClearCompleted()
-		{
-			lock (lockObject)
-				_completed.Clear();
-			CompletedCountChanged?.Invoke(this, 0);
-		}
-
-		public bool Any(Func<T, bool> predicate)
-		{
-			lock (lockObject)
-			{
-				return (Current != null && predicate(Current)) || _completed.Any(predicate) || _queued.Any(predicate);
-			}
-		}
-
-		public void MoveQueuePosition(T item, QueuePosition requestedPosition)
-		{
-			lock (lockObject)
-			{
-				if (_queued.Count == 0 || !_queued.Contains(item)) return;
-
-				if ((requestedPosition == QueuePosition.Fisrt || requestedPosition == QueuePosition.OneUp) && _queued[0] == item)
-					return;
-				if ((requestedPosition == QueuePosition.Last || requestedPosition == QueuePosition.OneDown) && _queued[^1] == item)
-					return;
-
-				int queueIndex = _queued.IndexOf(item);
-
-				if (requestedPosition == QueuePosition.OneUp)
-				{
-					_queued.RemoveAt(queueIndex);
-					_queued.Insert(queueIndex - 1, item);
-				}
-				else if (requestedPosition == QueuePosition.OneDown)
-				{
-					_queued.RemoveAt(queueIndex);
-					_queued.Insert(queueIndex + 1, item);
-				}
-				else if (requestedPosition == QueuePosition.Fisrt)
-				{
-					_queued.RemoveAt(queueIndex);
-					_queued.Insert(0, item);
-				}
-				else
-				{
-					_queued.RemoveAt(queueIndex);
-					_queued.Insert(_queued.Count, item);
-				}
-			}
-		}
-
-		public bool MoveNext()
-		{
-			int completedCount = 0, queuedCount = 0;
-			bool completedChanged = false;
-			try
-			{
-				lock (lockObject)
-				{
-					if (Current != null)
-					{
-						_completed.Add(Current);
-						completedCount = _completed.Count;
-						completedChanged = true;
-					}
-					if (_queued.Count == 0)
-					{
-						Current = null;
-						return false;
-					}
-					Current = _queued[0];
-					_queued.RemoveAt(0);
-
-					queuedCount = _queued.Count;
-					return true;
-				}
-			}
-			finally
-			{
-				if (completedChanged)
-					CompletedCountChanged?.Invoke(this, completedCount);
-				QueuededCountChanged?.Invoke(this, queuedCount);
-			}
-		}
-
-		public bool TryPeek(out T item)
-		{
-			lock (lockObject)
-			{
-				if (_queued.Count == 0)
-				{
-					item = null;
-					return false;
-				}
-				item = _queued[0];
-				return true;
-			}
-		}
-
-		public T Peek()
-		{
-			lock (lockObject)
-			{
-				if (_queued.Count == 0) throw new InvalidOperationException("Queue empty");
-				return _queued.Count > 0 ? _queued[0] : default;
-			}
-		}
-
-		public void Enqueue(IEnumerable<T> item)
-		{
-			int queueCount;
-			lock (lockObject)
-			{
-				_queued.AddRange(item);
-				queueCount = _queued.Count;
-			}
-			QueuededCountChanged?.Invoke(this, queueCount);
-		}
-	}
-}

Source/LoadByOS/MacOSConfigApp/MacOSConfigApp.csproj

@@ -29,6 +29,9 @@
   </ItemGroup>
 
   <ItemGroup>
+    <None Update="fileicon">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
     <None Update="Info.plist">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
     </None>

Source/LoadByOS/MacOSConfigApp/MacOSInterop.cs

@@ -1,4 +1,5 @@
-using LibationFileManager;
+using Dinah.Core;
+using LibationFileManager;
 using System.Diagnostics;
 
 namespace MacOSConfigApp
@@ -9,8 +10,14 @@ namespace MacOSConfigApp
 		public MacOSInterop() { }
         public MacOSInterop(params object[] values) { }
 
-		public void SetFolderIcon(string image, string directory) => throw new PlatformNotSupportedException();
-        public void DeleteFolderIcon(string directory) => throw new PlatformNotSupportedException();
+		public void SetFolderIcon(string image, string directory)
+		{
+			Process.Start("fileicon", $"set {directory.SurroundWithQuotes()} {image.SurroundWithQuotes()}").WaitForExit();
+		}
+		public void DeleteFolderIcon(string directory)
+		{
+			Process.Start("fileicon", $"rm {directory.SurroundWithQuotes()}").WaitForExit();
+		}
 
 		//I haven't figured out how to find the app bundle's directory from within
 		//the running process, so don't upgrade unless it's "installed" in /Applications
@@ -21,7 +28,7 @@ namespace MacOSConfigApp
 			Serilog.Log.Information($"Extracting upgrade bundle to {AppPath}");
 
 			//tar wil overwrite existing without elevated privileges
-			Process.Start("tar", $"-xf \"{upgradeBundle}\" -C \"/Applications\"").WaitForExit();
+			Process.Start("tar", $"-xf {upgradeBundle.SurroundWithQuotes()} -C \"/Applications\"").WaitForExit();
 			
 			//For now, it seems like this step is unnecessary. We can overwrite and
 			//run Libation without needing to re-add the exception. This is insurance.

Source/LoadByOS/MacOSConfigApp/fileicon

@@ -0,0 +1,732 @@
+#!/usr/bin/env bash
+
+###
+# Home page: https://github.com/mklement0/fileicon
+# Author:   Michael Klement <mklement0@gmail.com> (http://same2u.net)
+# Invoke with:
+#   --version for version information
+#   --help for usage information
+###
+
+# --- STANDARD SCRIPT-GLOBAL CONSTANTS
+
+kTHIS_NAME=${BASH_SOURCE##*/}
+kTHIS_HOMEPAGE='https://github.com/mklement0/fileicon'
+kTHIS_VERSION='v0.3.3' # NOTE: This assignment is automatically updated by `make version VER=<newVer>` - DO keep the 'v' prefix.
+
+unset CDPATH  # To prevent unpredictable `cd` behavior.
+
+# --- Begin: STANDARD HELPER FUNCTIONS
+
+die() { echo "$kTHIS_NAME: ERROR: ${1:-"ABORTING due to unexpected error."}" 1>&2; exit ${2:-1}; }
+dieSyntax() { echo "$kTHIS_NAME: ARGUMENT ERROR: ${1:-"Invalid argument(s) specified."} Use -h for help." 1>&2; exit 2; }
+
+# SYNOPSIS
+#   openUrl <url>
+# DESCRIPTION
+#   Opens the specified URL in the system's default browser.
+openUrl() {
+  local url=$1 platform=$(uname) cmd=()
+  case $platform in
+    'Darwin') # OSX
+      cmd=( open "$url" )
+      ;;
+    'CYGWIN_'*) # Cygwin on Windows; must call cmd.exe with its `start` builtin
+      cmd=( cmd.exe /c start '' "$url " )  # !! Note the required trailing space.
+      ;;
+    'MINGW32_'*) # MSYS or Git Bash on Windows; they come with a Unix `start` binary
+      cmd=( start '' "$url" )
+      ;;
+    *) # Otherwise, assume a Freedesktop-compliant OS, which includes many Linux distros, PC-BSD, OpenSolaris, ...
+      cmd=( xdg-open "$url" )
+      ;;
+  esac
+  "${cmd[@]}" || { echo "Cannot locate or failed to open default browser; please go to '$url' manually." >&2; return 1; }
+}
+
+# Prints the embedded Markdown-formatted man-page source to stdout.
+printManPageSource() {
+  /usr/bin/sed -n -e $'/^: <<\'EOF_MAN_PAGE\'/,/^EOF_MAN_PAGE/ { s///; t\np;}' "$BASH_SOURCE"
+}
+
+# Opens the man page, if installed; otherwise, tries to display the embedded Markdown-formatted man-page source; if all else fails: tries to display the man page online.
+openManPage() {
+  local pager embeddedText
+  if ! man 1 "$kTHIS_NAME" 2>/dev/null; then
+    # 2nd attempt: if present, display the embedded Markdown-formatted man-page source
+    embeddedText=$(printManPageSource)
+    if [[ -n $embeddedText ]]; then
+      pager='more'
+      command -v less &>/dev/null && pager='less' # see if the non-standard `less` is available, because it's preferable to the POSIX utility `more`
+      printf '%s\n' "$embeddedText" | "$pager"
+    else # 3rd attempt: open the the man page on the utility's website
+      openUrl "${kTHIS_HOMEPAGE}/doc/${kTHIS_NAME}.md"
+    fi
+  fi
+}
+
+# Prints the contents of the synopsis chapter of the embedded Markdown-formatted man-page source for quick reference.
+printUsage() {
+  local embeddedText
+  # Extract usage information from the SYNOPSIS chapter of the embedded Markdown-formatted man-page source.
+  embeddedText=$(/usr/bin/sed -n -e $'/^: <<\'EOF_MAN_PAGE\'/,/^EOF_MAN_PAGE/!d; /^## SYNOPSIS$/,/^#/{ s///; t\np; }' "$BASH_SOURCE")
+  if [[ -n $embeddedText ]]; then
+    # Print extracted synopsis chapter - remove backticks for uncluttered display.
+    printf '%s\n\n' "$embeddedText" | tr -d '`'
+  else # No SYNOPIS chapter found; fall back to displaying the man page.
+    echo "WARNING: usage information not found; opening man page instead." >&2
+    openManPage
+  fi
+}
+
+# --- End: STANDARD HELPER FUNCTIONS
+
+# ---  PROCESS STANDARD, OUTPUT-INFO-THEN-EXIT OPTIONS.
+case $1 in
+  --version)
+    # Output version number and exit, if requested.
+    ver="v0.3.3"; echo "$kTHIS_NAME $kTHIS_VERSION"$'\nFor license information and more, visit '"$kTHIS_HOMEPAGE"; exit 0
+    ;;
+  -h|--help)
+    # Print usage information and exit.
+    printUsage; exit
+    ;;
+  --man)
+    # Display the manual page and exit.
+    openManPage; exit
+    ;;
+  --man-source) # private option, used by `make update-doc`
+    # Print raw, embedded Markdown-formatted man-page source and exit
+    printManPageSource; exit
+    ;;
+  --home)
+    # Open the home page and exit.
+    openUrl "$kTHIS_HOMEPAGE"; exit
+    ;;
+esac
+
+# --- Begin: SPECIFIC HELPER FUNCTIONS
+
+# NOTE: The functions below operate on byte strings such as the one above:
+#       A single single string of pairs of hex digits, without separators or line breaks.
+#       Thus, a given byte position is easily calculated: to get byte $byteIndex, use
+#         ${byteString:byteIndex*2:2}
+
+# Outputs the specified EXTENDED ATTRIBUTE VALUE as a byte string (a hex dump that is a single-line string of pairs of hex digits, without separators or line breaks, such as "000A2C".
+# IMPORTANT: Hex. digits > 9 use UPPPERCASE characters.
+#   getAttribByteString <file> <attrib_name>
+getAttribByteString() {
+  /usr/bin/xattr -px "$2" "$1" | tr -d ' \n'
+  return ${PIPESTATUS[0]}
+}
+
+# Outputs the specified file's RESOURCE FORK as a byte string (a hex dump that is a single-line string of pairs of hex digits, without separators or line breaks, such as "000a2c".
+# IMPORTANT: Hex. digits > 9 use *lowercase* characters.
+# Note: This function relies on `xxd -p <file>/..namedfork/rsrc | tr -d '\n'` rather than the conceptually equivalent call,
+#       `getAttribByteString <file> com.apple.ResourceFork`, for PERFORMANCE reasons: 
+#       getAttribByteString() (defined above) relies on `xattr`, which is a *Python* script [!! seemingly no longer, as of macOS 10.16] 
+#       and therefore quite slow due to Python's startup cost.
+#   getResourceByteString <file>
+getResourceByteString() {
+  xxd -p "$1"/..namedfork/rsrc | tr -d '\n'
+}
+
+# Patches a single byte in the byte string provided via stdin.
+#  patchByteInByteString ndx byteSpec
+#   ndx is the 0-based byte index
+# - If <byteSpec> has NO prefix: <byteSpec> becomes the new byte
+# - If <byteSpec> has prefix '|': "adds" the value: the result of a bitwise OR with the existing byte becomes the new byte
+# - If <byteSpec> has prefix '~': "removes" the value: the result of a applying a bitwise AND with the bitwise complement of <byteSpec> to the existing byte becomes the new byte
+patchByteInByteString() {
+  local ndx=$1 byteSpec=$2 byteVal byteStr charPos op='' charsBefore='' charsAfter='' currByte
+  byteStr=$(</dev/stdin)
+  charPos=$(( 2 * ndx ))
+  # Validat the byte spec.
+  case ${byteSpec:0:1} in
+    '|')
+      op='|'
+      byteVal=${byteSpec:1}
+      ;;
+    '~')
+      op='& ~'
+      byteVal=${byteSpec:1}
+      ;;
+    *)
+      byteVal=$byteSpec
+      ;;
+  esac
+  [[ $byteVal == [0-9A-Fa-f][0-9A-Fa-f] ]] || return 1
+  # Validat the byte index.
+  (( charPos > 0 && charPos < ${#byteStr} )) || return 1
+  # Determine the target byte, and strings before and after the byte to patch.
+  (( charPos >= 2 )) && charsBefore=${byteStr:0:charPos}
+  charsAfter=${byteStr:charPos + 2}
+  # Determine the new byte value
+  if [[ -n $op ]]; then
+      currByte=${byteStr:charPos:2}
+      printf -v patchedByte '%02X' "$(( 0x${currByte} $op 0x${byteVal} ))"
+  else
+      patchedByte=$byteSpec
+  fi
+  printf '%s%s%s' "$charsBefore" "$patchedByte" "$charsAfter"
+}
+
+#  hasAttrib <fileOrFolder> <attrib_name>
+hasAttrib() {
+  /usr/bin/xattr "$1" | /usr/bin/grep -Fqx "$2"
+}
+
+#  hasIconData <file>
+# Test if the file has a resource fork with icon data in it, or,
+# in the case of a .VolumeIcon.icns file, has icon data *as the file contents*
+hasIconData() {
+  local file=$1
+  if [[ $(basename "$file") == $kFILENAME_VOLUMECUSTOMICON ]]; then
+    # special file for any folder that is a *volume mountpoint*: has the icon data as the file's *content*
+    file "$file" | /usr/bin/grep -Fq ' Mac OS X icon'
+  else
+    # file itself or special helper file $'Icon\r' for a regular folder: has the icon data *in its resource fork*.
+    getResourceByteString "$file" | /usr/bin/grep -Fq "$kMAGICBYTES_ICNS_RESOURCE"
+  fi
+}
+
+#  isVolumeMountPoint <folder>
+isVolumeMountPoint() {
+  local folder=$1
+  # Must resolve to the physical underlying path, as that is what `mount` shows
+  folder=$(cd -P -- "$1"; pwd)
+  mount | grep -qF "on $folder (" # !! Is there a more robust way to test for mountpoints?
+}
+
+#  getFileWithIconData <fileOrFolder>
+# Returns the path of the file that contains the actual icon data, based on whether the target is
+#  * a file ... the file path itself
+#  * a folder:
+#     * regular folder: file $'Icon\r' inside that folder, with the icon data in its resource fork
+#     * volume mountpoint: file '.VolumeIcon.icns' inside that folder, with the icon data inside the file.
+getFileWithIconData() {
+  local fileOrFolder=$1
+  if [[ -f $fileOrFolder ]]; then # file
+    printf '%s' "$fileOrFolder"
+  elif isVolumeMountPoint "$fileOrFolder"; then # volume mountpoint
+    printf '%s' "$fileOrFolder/$kFILENAME_VOLUMECUSTOMICON"
+  else # regular folder
+    printf '%s' "$fileOrFolder/$kFILENAME_FOLDERCUSTOMICON"
+  fi
+}
+
+#  getTargetType <fileOrFolder>
+# Returns a descriptor for the specified target path:
+#  * a file ... 'file'
+#  * a folder:
+#     * regular folder: 'folder'
+#     * volume mountpoint: 'volume'
+getTargetType() {
+  local fileOrFolder=$1
+  if [[ -f $fileOrFolder ]]; then # file
+    printf 'file'
+  elif isVolumeMountPoint "$fileOrFolder"; then # volume mountpoint
+    printf 'volume'
+  else # regular folder
+    printf 'folder'
+  fi
+}
+
+
+#  setCustomIcon <fileOrFolder> <imgFile>
+# Tips for debugging:
+#  * To exercise this function, from the repo dir.:
+#      touch /tmp/tf; ./bin/fileicon set /tmp/tf ./test/.fixtures/img.png
+# !!??? VOLUME SUPPORT, as of macOS 13.1:
+# !!   * While targeting volume root folders is now supported *in principle*, 
+# !!     assigning the 'com.apple.FinderInfo' extended attribute to the mountpoint folder 
+# !!     typically (always??) fails, so the icon doesn't take effect.
+# !!     SetFile -a C <file> also fails - with or without `sudo` - with "ERROR: Unexpected Error. (-5000)  on file: <file>"
+# !!     (SetFile -a c <file> clears the custom-icon flag; note that SetFile isn't installed by default and is DEPRECATED: "Tools supporting Carbon development, including /usr/bin/SetFile, were deprecated with Xcode 6.")
+# !!     ?? It feels like at *some point* on 13.1 our NFS mount from our NAS seemed to support it, but inexplicably no longer.
+# !!   * SOME volumes, even if *network* volumes, support custom icons for their files and folders,
+# !!     such as a SMB mount.
+# !!     ?? Our NFS mount from our NAS seemed to support that *for a while* on 13.1, but inexplicably no longer.
+setCustomIcon() {
+
+  local fileOrFolder=$1 imgFile=$2 fileWithIconData
+
+  [[ (-f $fileOrFolder || -d $fileOrFolder) && -r $fileOrFolder && -w $fileOrFolder ]] || return 3
+  [[ -f $imgFile ]] || return 3
+
+  # !! Sadly, Apple decided to remove the `-i` / `--addicon` option from the `sips` utility.
+  # !! Therefore, use of *Cocoa* is required, which we do *via AppleScript* and its ObjC bridge,
+  # !! which has the added advantage of creating a *set* of icons from the source image, scaling as necessary
+  # !!  to create a 512 x 512 top resolution icon (whereas sips -i created a single, 128 x 128 icon).
+  # !! Thanks:
+  # !!  * https://apple.stackexchange.com/a/161984/28668 (Python original)
+  # !!  * @scriptingosx (https://github.com/mklement0/fileicon/issues/32#issuecomment-1074124748) (AppleScript-ObjC version)
+  # !! Note: We moved from Python to AppleScript when the system Python was removed in macOS 12.3
+
+  # !! Note: The setIcon method seemingly always indicates True, even with invalid image files, so
+  # !!       we attempt no error handling in the AppleScript code, and instead verify success explicitly later.
+  osascript <<EOF >/dev/null || die
+    use framework "Cocoa"
+
+    set sourcePath to "$imgFile"
+    set destPath to "$fileOrFolder"
+
+    set imageData to (current application's NSImage's alloc()'s initWithContentsOfFile:sourcePath)
+    (current application's NSWorkspace's sharedWorkspace()'s setIcon:imageData forFile:destPath options:2)
+EOF
+
+  # Fully verify that everything worked as intended.
+  # Unfortunately, several things can go wrong.
+  testForCustomIcon "$targetFileOrFolder" 2>/dev/null && return 0
+  ec=$?
+
+  if (( ec == 1 )); then
+    cat >&2 <<EOF
+Failed to assign a custom icon.
+Typically, this means that the specified image file is not supported or corrupt: $imgFile
+Supported image formats: jpeg | tiff | png | gif | jp2 | pict | bmp | qtif| psd | sgi | tga
+EOF
+  elif ((ec == 2 )); then
+    cat >&2 <<EOF
+Failed to set the custom-icon flag in the 'com.apple.FinderInfo' extended attribute of: $targetFileOrFolder
+Typically, this means that you're targeting a volume itself or a file or folder on a volume that doesn't support custom icons.
+Rerun with "rm" to clean up.
+EOF
+  elif ((ec == 3 )); then
+    cat >&2 <<EOF
+The custom-icon flag in the 'com.apple.FinderInfo' extended attribute of: $imgFile
+was successfully set, but, unexpectedly, the associated icon data was not.
+Rerun with "rm" to clean up.
+EOF
+  fi
+
+  return $ec
+
+}
+
+#  getCustomIcon <fileOrFolder> <icnsOutFile>
+getCustomIcon() {
+
+  local fileOrFolder=$1 icnsOutFile=$2 byteStr fileWithIconData byteOffset byteCount
+
+  [[ (-f $fileOrFolder || -d $fileOrFolder) && -r $fileOrFolder ]] || return 3
+
+  # Determine what file to extract the resource fork from.
+  if [[ -d $fileOrFolder ]]; then
+
+    fileWithIconData=$(getFileWithIconData "$fileOrFolder")
+    [[ -f $fileWithIconData ]] || { echo "Custom-icon file does not exist: '${fileWithIconData/$'\r'/\\r}'" >&2; return 1; }
+
+    if [[ $(basename "$fileWithIconData") == $kFILENAME_VOLUMECUSTOMICON ]]; then
+      # !! Volume mount points are an exception: their helper file contains the icon data as the file's *content*
+      # !! rather than in a *resource fork*; therefore, simply *copying* the file's content is enough.
+      # !! However, we use `cat` rather than `cp`, so as not to also copy the extended attributes.
+      cat "$fileWithIconData" > "$icnsOutFile" || die
+      return 0
+    fi
+    # Otherwise: proceed below to extract the data from the resource fork.
+
+  else
+    fileWithIconData=$fileOrFolder
+  fi
+
+  # Determine (based on format description at https://en.wikipedia.org/wiki/Apple_Icon_Image_format):
+  # - the byte offset at which the icns resource begins, via the magic literal identifying an icns resource
+  # - the length of the resource, which is encoded in the 4 bytes right after the magic literal.
+  read -r byteOffset byteCount < <(getResourceByteString "$fileWithIconData" | /usr/bin/awk -F "$kMAGICBYTES_ICNS_RESOURCE" '{ printf "%s %d", (length($1) + 2) / 2, "0x" substr($2, 0, 8) }')
+  (( byteOffset > 0 && byteCount > 0 )) || { echo "Custom-icon file contains no icons resource: '${fileWithIconData/$'\r'/\\r}'" >&2; return 1; }
+
+  # Extract the actual bytes using tail and head and save them to the output file.
+  tail -c "+${byteOffset}" "$fileWithIconData/..namedfork/rsrc" | head -c $byteCount > "$icnsOutFile" || return
+
+  return 0
+}
+
+#  removeCustomIcon <fileOrFolder>
+removeCustomIcon() {
+
+  local fileOrFolder=$1 byteStr
+
+  [[ (-f $fileOrFolder || -d $fileOrFolder) && -r $fileOrFolder && -w $fileOrFolder ]] || return 1
+
+  # Step 1: Turn off the custom-icon flag in the com.apple.FinderInfo extended attribute.
+  #         Note: Using SetFile -a c <file> is tempting, but SetFile doesn't come with macOS by default (part of XCode CLI package)
+  if hasAttrib "$fileOrFolder" com.apple.FinderInfo; then
+    byteStr=$(getAttribByteString "$fileOrFolder" com.apple.FinderInfo | patchByteInByteString $kFI_BYTEOFFSET_CUSTOMICON '~'$kFI_VAL_CUSTOMICON) || return
+    if [[ $byteStr == "$kFI_BYTES_BLANK" ]]; then # All bytes cleared? Remove the entire attribute.
+      /usr/bin/xattr -d com.apple.FinderInfo "$fileOrFolder"
+    else # Update the attribute.
+      /usr/bin/xattr -wx com.apple.FinderInfo "$byteStr" "$fileOrFolder" || return
+    fi
+  fi
+
+  # Step 2: Remove the resource fork (if target is a file) / hidden file with custom icon (if target is a folder)
+  if [[ -d $fileOrFolder ]]; then # folder or volume -> remove the special file inside it.
+    rm -f "$(getFileWithIconData "$fileOrFolder")"
+  else # file -> remove the resource fork
+    if hasIconData "$fileOrFolder"; then
+      /usr/bin/xattr -d com.apple.ResourceFork "$fileOrFolder"
+    fi
+  fi
+
+  return 0
+}
+
+#  testForCustomIcon <fileOrFolder>
+testForCustomIcon() {
+
+  local fileOrFolder=$1 byteStr byteVal fileWithIconData hasCustomIconFlag hasIconData 
+
+  [[ (-f $fileOrFolder || -d $fileOrFolder) && -r $fileOrFolder ]] || return 3
+
+  # Step 1: Check if the com.apple.FinderInfo extended attribute has the custom-icon
+  #         flag set. This applies to *all* target types.
+  byteStr=$(getAttribByteString "$fileOrFolder" com.apple.FinderInfo 2>/dev/null) #  || return 1
+  byteVal=${byteStr:2*kFI_BYTEOFFSET_CUSTOMICON:2}
+  hasCustomIconFlag=$(( byteVal & kFI_VAL_CUSTOMICON ))
+
+  fileWithIconData=$(getFileWithIconData "$fileOrFolder")
+  # Step 2: Check if there's actual icon data present,
+  #         via the resource fork of the file or the folder's helper file or the file content of a
+  #         volume mountpoint's helper file (./.VolumeIcon.icns)
+  hasIconData "$fileWithIconData" 2>/dev/null && hasIconData=1 || hasIconData=0
+
+  # Provide a specific exit code reflecting the state.
+  # !! This is used by setCustomIcon()
+  if (( hasCustomIconFlag && hasIconData )); then
+    return 0   # has custom icon
+  elif (( ! hasCustomIconFlag && ! hasIconData  )); then
+    return 1   # typical case of file/folder NOT having a custom icon
+  elif (( ! hasCustomIconFlag )); then
+    echo "WARNING: Custom-icon data is present, but the 'com.apple.FinderInfo' extended attribute isn't set for $(getTargetType "$fileOrFolder") '$fileOrFolder'"  >&2
+    return 2   # broken state: has icons, but no custom flag
+  else # (( ! hasIconData )) 
+    echo "WARNING: While the 'com.apple.FinderInfo' extended attribute is set for $(getTargetType "$fileOrFolder") '$fileOrFolder', associated icon data is missing."  >&2
+    return 3   # broken state: has custom flag, but no icons
+  fi
+
+}
+
+# --- End: SPECIFIC HELPER FUNCTIONS
+
+# --- Begin: SPECIFIC SCRIPT-GLOBAL CONSTANTS
+
+kFILENAME_FOLDERCUSTOMICON=$'Icon\r' # the helper file for regular folders, with the actual icon image data in its *resource fork*
+kFILENAME_VOLUMECUSTOMICON='.VolumeIcon.icns' # the helper file for volume mountpoints, with the actual icon image data in the file's *content*.
+
+# The blank hex dump form (single string of pairs of hex digits) of the 32-byte data structure stored in extended attribute
+# com.apple.FinderInfo
+kFI_BYTES_BLANK='0000000000000000000000000000000000000000000000000000000000000000'
+
+# [UPDATE]
+#  * THIS CONSTANT ISN'T USED ANYMORE.
+#  * Also, on macOS 13 (Ventura): seemingly, the Icon\r file's com.apple.FinderInfo extended attribute is now 
+#    SIMPLER: where the folder itself has 0x4 in its 9th byte, Icon\r now has 0x40
+# [ORIGINAL COMMENT]
+# The hex dump form of the full 32 bytes that Finder assigns to the hidden $'Icon\r'
+# file whose com.apple.ResourceFork extended attribute contains the icon image data for the enclosing folder.
+# The first 8 bytes spell out the magic literal 'iconMACS'; they are followed by the invisibility flag, '40' in the 9th byte, and '10' (?? specifying what?)
+# in the 10th byte.
+# NOTE: Since file $'Icon\r' serves no other purpose than to store the icon, it is
+#       safe to simply assign all 32 bytes blindly, without having to worry about
+#       preserving existing values.
+# kFI_BYTES_CUSTOMICONFILEFORFOLDER='69636F6E4D414353401000000000000000000000000000000000000000000000'
+
+# The hex dump form of the magic literal inside a resource fork that marks the
+# start of an icns (icons) resource.
+# NOTE: This will be used with `xxd -p .. | tr -d '\n'`, which uses *lowercase*
+#       hex digits, so we must use lowercase here.
+kMAGICBYTES_ICNS_RESOURCE='69636e73'
+
+# The byte values (as hex strings) of the flags at the relevant byte position
+# of the com.apple.FinderInfo extended attribute.
+kFI_VAL_CUSTOMICON='04'
+
+# The custom-icon-flag byte offset in the com.apple.FinderInfo extended attribute.
+kFI_BYTEOFFSET_CUSTOMICON=8
+
+# --- End: SPECIFIC SCRIPT-GLOBAL CONSTANTS
+
+# Option defaults.
+force=0 quiet=0
+
+# --- Begin: OPTIONS PARSING
+allowOptsAfterOperands=1 operands=() i=0 optName= isLong=0 prefix= optArg= haveOptArgAttached=0 haveOptArgAsNextArg=0 acceptOptArg=0 needOptArg=0
+while (( $# )); do
+  if [[ $1 =~ ^(-)[a-zA-Z0-9]+.*$ || $1 =~ ^(--)[a-zA-Z0-9]+.*$ ]]; then # an option: either a short option / multiple short options in compressed form or a long option
+    prefix=${BASH_REMATCH[1]}; [[ $prefix == '--' ]] && isLong=1 || isLong=0
+    for (( i = 1; i < (isLong ? 2 : ${#1}); i++ )); do
+        acceptOptArg=0 needOptArg=0 haveOptArgAttached=0 haveOptArgAsNextArg=0 optArgAttached= optArgOpt= optArgReq=
+        if (( isLong )); then # long option: parse into name and, if present, argument
+          optName=${1:2}
+          [[ $optName =~ ^([^=]+)=(.*)$ ]] && { optName=${BASH_REMATCH[1]}; optArgAttached=${BASH_REMATCH[2]}; haveOptArgAttached=1; }
+        else # short option: *if* it takes an argument, the rest of the string, if any, is by definition the argument.
+          optName=${1:i:1}; optArgAttached=${1:i+1}; (( ${#optArgAttached} >= 1 )) && haveOptArgAttached=1
+        fi
+        (( haveOptArgAttached )) && optArgOpt=$optArgAttached optArgReq=$optArgAttached || { (( $# > 1 )) && { optArgReq=$2; haveOptArgAsNextArg=1; }; }
+        # ---- BEGIN: CUSTOMIZE HERE
+        case $optName in
+          f|force)
+            force=1
+            ;;
+          q|quiet)
+            quiet=1
+            ;;
+          *)
+            dieSyntax "Unknown option: ${prefix}${optName}."
+            ;;
+        esac
+        # ---- END: CUSTOMIZE HERE
+        (( needOptArg )) && { (( ! haveOptArgAttached && ! haveOptArgAsNextArg )) && dieSyntax "Option ${prefix}${optName} is missing its argument." || (( haveOptArgAsNextArg )) && shift; }
+        (( acceptOptArg || needOptArg )) && break
+    done
+  else # an operand
+    if [[ $1 == '--' ]]; then
+      shift; operands+=( "$@" ); break
+    elif (( allowOptsAfterOperands )); then
+      operands+=( "$1" ) # continue
+    else
+      operands=( "$@" )
+      break
+    fi
+  fi
+  shift
+done
+(( "${#operands[@]}" > 0 )) && set -- "${operands[@]}"; unset allowOptsAfterOperands operands i optName isLong prefix optArgAttached haveOptArgAttached haveOptArgAsNextArg acceptOptArg needOptArg
+# --- End: OPTIONS PARSING: "$@" now contains all operands (non-option arguments).
+
+# Validate the command
+cmd=$(printf %s "$1" | tr '[:upper:]' '[:lower:]') # translate to all-lowercase - we don't want the command name to be case-sensitive
+[[ $cmd == 'remove' ]] && cmd='rm'  # support alias 'remove' for 'rm'
+case $cmd in
+  set|get|rm|remove|test)
+    shift
+    ;;
+  *)
+    dieSyntax "Unrecognized or missing command: '$cmd'."
+    ;;
+esac
+
+# Validate file operands
+(( $# > 0 )) || dieSyntax "Missing operand(s)."
+
+# Target file or folder.
+targetFileOrFolder=$1 imgFile= outFile=
+[[ -f $targetFileOrFolder || -d $targetFileOrFolder ]] || die "Target not found or neither file nor folder: '$targetFileOrFolder'"
+# Make sure the target file/folder is readable, and, unless only getting or testing for an icon are requested, writeable too.
+[[ -r $targetFileOrFolder ]] || die "Cannot access '$targetFileOrFolder': you do not have read permissions."
+[[ $cmd == 'test' || $cmd == 'get' || -w $targetFileOrFolder ]] || die "Cannot modify '$targetFileOrFolder': you do not have write permissions."
+
+# Other operands, if any, and their number.
+valid=0
+case $cmd in
+  'set')
+    (( $# <= 2 )) && {
+      valid=1
+      # If no image file was specified, the target file is assumed to be an image file itself whose image should be self-assigned as an icon.
+      (( $# == 2 )) && imgFile=$2 || imgFile=$1
+      # !! Apparently, a regular file is required - a process subsitution such 
+      # !! as `<(base64 -D <encoded-file.txt)` is NOT supported by NSImage.initWithContentsOfFile()
+      [[ -f $imgFile && -r $imgFile ]] || die "Image file not found or not a (readable) regular file: $imgFile"
+    }
+    ;;
+  'rm'|'test')
+    (( $# == 1 )) && valid=1
+    ;;
+  'get')
+    (( $# == 1 || $# == 2 )) && {
+      valid=1
+      outFile=$2
+      if [[ $outFile == '-' ]]; then
+        outFile=/dev/stdout
+      else
+        # By default, we extract to a file with the same filename root + '.icns'
+        # in the current folder.
+        [[ -z $outFile ]] && outFile=${targetFileOrFolder##*/}
+        # Unless already specified, we append '.icns' to the output filename.
+        mustReset=$(shopt -q nocasematch; echo $?); shopt -s nocasematch
+        [[ $outFile =~ \.icns$ ]] || outFile+='.icns'
+        (( mustReset )) && shopt -u nocasematch
+        [[ -e $outFile && $force -eq 0 ]] && die "Output file '$outFile' already exists. To force its replacement, use -f."
+      fi
+    }
+    ;;
+esac
+(( valid )) || dieSyntax "Unexpected number of operands."
+
+case $cmd in
+  'set')
+    setCustomIcon "$targetFileOrFolder" "$imgFile" || die
+    (( quiet )) || echo "Custom icon assigned to $(getTargetType "$targetFileOrFolder") '$targetFileOrFolder' based on '$imgFile'."
+    ;;
+  'rm')
+    removeCustomIcon "$targetFileOrFolder" || die
+    (( quiet )) || echo "Custom icon (if any) removed from $(getTargetType "$targetFileOrFolder") '$targetFileOrFolder'."
+    ;;
+  'get')
+    getCustomIcon "$targetFileOrFolder" "$outFile" || die
+    (( quiet )) || { [[ $outFile != '/dev/stdout' ]] && echo "Custom icon extracted to '$outFile'."; }
+    exit 0
+    ;;
+  'test')
+    if (( quiet )); then
+      testForCustomIcon "$targetFileOrFolder" 2>/dev/null
+    else
+      testForCustomIcon "$targetFileOrFolder" # This may issue warnings.
+    fi
+    ec=$?
+    if (( ! quiet )); then
+      echo "$( (( ec == 0 )) && printf 'HAS' || printf 'Has NO' ) custom icon: $(getTargetType "$targetFileOrFolder") '$targetFileOrFolder'"
+    fi
+    exit $ec
+    ;;
+  *)
+    die "DESIGN ERROR: unanticipated command: $cmd"
+    ;;
+esac
+
+exit 0
+
+####
+# MAN PAGE MARKDOWN SOURCE
+#  - Place a Markdown-formatted version of the man page for this script
+#    inside the here-document below.
+#    The document must be formatted to look good in all 3 viewing scenarios:
+#     - as a man page, after conversion to ROFF with marked-man
+#     - as plain text (raw Markdown source)
+#     - as HTML (rendered Markdown)
+#  Markdown formatting tips:
+#   - GENERAL
+#     To support plain-text rendering in the terminal, limit all lines to 80 chars.,
+#     and, for similar rendering as HTML, *end every line with 2 trailing spaces*.
+#   - HEADINGS
+#     - For better plain-text rendering, leave an empty line after a heading
+#       marked-man will remove it from the ROFF version.
+#     - The first heading must be a level-1 heading containing the utility
+#       name and very brief description; append the manual-section number
+#       directly to the CLI name; e.g.:
+#         # foo(1) - does bar
+#     - The 2nd, level-2 heading must be '## SYNOPSIS' and the chapter's body
+#       must render reasonably as plain text, because it is printed to stdout
+#       when  `-h`, `--help` is specified:
+#         Use 4-space indentation without markup for both the syntax line and the
+#         block of brief option descriptions; represent option-arguments and operands
+#         in angle brackets; e.g., '<foo>'
+#     - All other headings should be level-2 headings in ALL-CAPS.
+#   - TEXT
+#      - Use NO indentation for regular chapter text; if you do, it will
+#        be indented further than list items.
+#      - Use 4-space indentation, as usual, for code blocks.
+#      - Markup character-styling markup translates to ROFF rendering as follows:
+#         `...` and **...** render as bolded (red) text
+#         _..._ and *...* render as word-individually underlined text
+#   - LISTS
+#      - Indent list items by 2 spaces for better plain-text viewing, but note
+#        that the ROFF generated by marked-man still renders them unindented.
+#      - End every list item (bullet point) itself with 2 trailing spaces too so
+#        that it renders on its own line.
+#      - Avoid associating more than 1 paragraph with a list item, if possible,
+#        because it requires the following trick, which hampers plain-text readability:
+#        Use '&nbsp;<space><space>' in lieu of an empty line.
+####
+: <<'EOF_MAN_PAGE'
+# fileicon(1) - manage file and folder custom icons
+
+## SYNOPSIS
+
+Manage custom icons for files and folders on macOS.  
+
+SET a custom icon for a file or folder:
+
+    fileicon set      <fileOrFolder> [<imageFile>]
+
+REMOVE a custom icon from a file or folder:
+
+    fileicon rm       <fileOrFolder>
+
+GET a file or folder's custom icon:
+
+    fileicon get [-f] <fileOrFolder> [<iconOutputFile>]
+
+    -f ... force replacement of existing output file
+
+TEST if a file or folder has a custom icon:
+
+    fileicon test     <fileOrFolder>
+
+All forms: option -q silences status output.
+
+Standard options: `--help`, `--man`, `--version`, `--home`
+
+## DESCRIPTION
+
+`<fileOrFolder>` is the file or folder whose custom icon should be managed.  
+Note that symlinks are followed to their (ultimate target); that is, you  
+can only assign custom icons to regular files and folders, not to symlinks  
+to them.
+
+`<imageFile>` can be an image file of any format supported by the system.  
+It is converted to an icon and assigned to `<fileOrFolder>`.  
+If you omit `<imageFile>`, `<fileOrFolder>` must itself be an image file whose
+image should become its own icon.
+
+`<iconOutputFile>` specifies the file to extract the custom icon to:  
+Defaults to the filename of `<fileOrFolder>` with extension `.icns` appended.  
+If a value is specified, extension `.icns` is appended, unless already present.  
+Either way, extraction fails if the target file already exists; use `-f` to  
+override.  
+Specify `-` to extract to stdout.  
+
+Command `test` signals with its exit code whether a custom icon is set (0)  
+or not (1); any other exit code signals an unexpected error.
+
+**Options**:
+
+  * `-f`, `--force`  
+    When getting (extracting) a custom icon, forces replacement of the  
+    output file, if it already exists.
+
+  * `-q`, `--quiet`  
+    Suppresses output of the status information that is by default output to  
+    stdout.  
+    Note that errors and warnings are still printed to stderr.
+
+## NOTES
+
+Custom icons are stored in extended attributes of the HFS+ filesystem.  
+Thus, if you copy files or folders to a different filesystem that doesn't  
+support such attributes, custom icons are lost; for instance, custom icons  
+cannot be stored in a Git repository.
+
+To determine if a give file or folder has extended attributes, use  
+`ls -l@ <fileOrFolder>`.
+
+When setting an image as a custom icon, a set of icons with several resolutions  
+is created, with the highest resolution at 512 x 512 pixels.
+
+All icons created are square, so images with a non-square aspect ratio will  
+appear distorted; for best results, use square imges.
+
+## STANDARD OPTIONS
+
+All standard options provide information only.
+
+* `-h, --help`  
+  Prints the contents of the synopsis chapter to stdout for quick reference.
+
+* `--man`  
+  Displays this manual page, which is a helpful alternative to using `man`, 
+  if the manual page isn't installed.
+
+* `--version`  
+  Prints version information.
+  
+* `--home`  
+  Opens this utility's home page in the system's default web browser.
+
+## LICENSE
+
+For license information and more, visit the home page by running  
+`fileicon --home`
+
+EOF_MAN_PAGE

Source/LoadByOS/WindowsConfigApp/FolderIcon.cs

@@ -1,45 +1,17 @@
-using SixLabors.ImageSharp;
-using SixLabors.ImageSharp.Formats.Png;
+using LibationUiBase;
+using SixLabors.ImageSharp;
 using System;
 using System.IO;
-using System.Runtime.InteropServices;
 
 namespace WindowsConfigApp
-{
+{	
 	internal static partial class FolderIcon
 	{
-		// https://stackoverflow.com/a/21389253
+		static readonly IcoEncoder IcoEncoder = new();
 		public static byte[] ToIcon(this Image img)
 		{
-			using var ms = new MemoryStream();
-			using var bw = new BinaryWriter(ms);
-			// Header
-			bw.Write((short)0);   // 0-1 : reserved
-			bw.Write((short)1);   // 2-3 : 1=ico, 2=cur
-			bw.Write((short)1);   // 4-5 : number of images
-								  // Image directory
-			var w = img.Width;
-			if (w >= 256) w = 0;
-			bw.Write((byte)w);    // 0 : width of image
-			var h = img.Height;
-			if (h >= 256) h = 0;
-			bw.Write((byte)h);    // 1 : height of image
-			bw.Write((byte)0);    // 2 : number of colors in palette
-			bw.Write((byte)0);    // 3 : reserved
-			bw.Write((short)0);   // 4 : number of color planes
-			bw.Write((short)0);   // 6 : bits per pixel
-			var sizeHere = ms.Position;
-			bw.Write((int)0);     // 8 : image size
-			var start = (int)ms.Position + 4;
-			bw.Write(start);      // 12: offset of image data
-								  // Image data
-			img.Save(ms, new PngEncoder());
-			var imageSize = (int)ms.Position - start;
-			ms.Seek(sizeHere, SeekOrigin.Begin);
-			bw.Write(imageSize);
-			ms.Seek(0, SeekOrigin.Begin);
-
-			// And load it
+			using var ms = new MemoryStream();			
+			img.Save(ms, IcoEncoder);			
 			return ms.ToArray();
 		}
 
@@ -57,50 +29,33 @@ namespace WindowsConfigApp
 					File.Delete(text);
 				}
 			}
-
-			refresh();
 		}
 
 		// https://github.com/dimuththarindu/FIC-Folder-Icon-Changer/blob/master/project/FIC/Classes/IconCustomizer.cs
 
-		public static void SetIcon(this DirectoryInfo directoryInfo, string icoPath, string folderType)
-			=> SetIcon(directoryInfo.FullName, icoPath, folderType);
+		public static void SetIcon(this DirectoryInfo directoryInfo, byte[] icon, string folderType)
+			=> SetIcon(directoryInfo.FullName, icon, folderType);
 
-		public static void SetIcon(string dir, string icoPath, string folderType)
+		public static void SetIcon(string dir, byte[] icon, string folderType)
 		{
 			var desktop_ini = Path.Combine(dir, "desktop.ini");
 			var Icon_ico = Path.Combine(dir, "Icon.ico");
-			var hidden = Path.Combine(dir, ".hidden");
 
 			//deleting existing files
 			DeleteIcon(dir);
 
 			//copying Icon file //overwriting
-			File.Copy(icoPath, Icon_ico, true);
+			File.WriteAllBytes(Icon_ico, icon);
 
 			//writing configuration file
-			string[] desktopLines = { "[.ShellClassInfo]", "IconResource=Icon.ico,0", "[ViewState]", "Mode=", "Vid=", $"FolderType={folderType}" };
+			string[] desktopLines = { "[.ShellClassInfo]", "ConfirmFileOp=0", "IconResource=Icon.ico,0", "[ViewState]", "Mode=", "Vid=", $"FolderType={folderType}" };
 			File.WriteAllLines(desktop_ini, desktopLines);
 
-			//configure file 2            
-			string[] hiddenLines = { "desktop.ini", "Icon.ico" };
-			File.WriteAllLines(hidden, hiddenLines);
+			File.SetAttributes(desktop_ini, File.GetAttributes(desktop_ini) | FileAttributes.Hidden | FileAttributes.ReadOnly);
+			File.SetAttributes(Icon_ico, File.GetAttributes(Icon_ico) | FileAttributes.Hidden | FileAttributes.ReadOnly);
 
-			//making system files
-			File.SetAttributes(desktop_ini, File.GetAttributes(desktop_ini) | FileAttributes.Hidden | FileAttributes.System | FileAttributes.ReadOnly);
-			File.SetAttributes(Icon_ico, File.GetAttributes(Icon_ico) | FileAttributes.Hidden | FileAttributes.System | FileAttributes.ReadOnly);
-			File.SetAttributes(hidden, File.GetAttributes(hidden) | FileAttributes.Hidden | FileAttributes.System | FileAttributes.ReadOnly);
-
-			// this strangely completes the process. also hides these 3 hidden system files, even if "show hidden items" is checked
-			File.SetAttributes(dir, File.GetAttributes(dir) | FileAttributes.ReadOnly);
-
-			refresh();
+			//https://learn.microsoft.com/en-us/windows/win32/shell/how-to-customize-folders-with-desktop-ini
+			File.SetAttributes(dir, File.GetAttributes(dir) | FileAttributes.System);
 		}
-
-		private static void refresh() => SHChangeNotify(0x08000000, 0x0000, 0, 0); //SHCNE_ASSOCCHANGED SHCNF_IDLIST
-
-
-		[DllImport("shell32.dll", SetLastError = true)]
-		private static extern void SHChangeNotify(int wEventId, int uFlags, nint dwItem1, nint dwItem2);
 	}
 }

Source/LoadByOS/WindowsConfigApp/WinInterop.cs

@@ -14,22 +14,9 @@ namespace WindowsConfigApp
 
         public void SetFolderIcon(string image, string directory)
         {
-            string iconPath = null;
-
-            try
-            {
-				var icon = Image.Load(File.ReadAllBytes(image)).ToIcon();
-                iconPath = Path.Combine(directory, $"{Guid.NewGuid()}.ico");
-                File.WriteAllBytes(iconPath, icon);
-
-				new DirectoryInfo(directory)?.SetIcon(iconPath, "Music");
-            }
-            finally
-            {
-                if (File.Exists(iconPath))
-                    File.Delete(iconPath);
-            }
-        }
+			var icon = Image.Load(image).ToIcon();
+			new DirectoryInfo(directory)?.SetIcon(icon, "Music");
+		}
 
         public void DeleteFolderIcon(string directory)
             => new DirectoryInfo(directory)?.DeleteIcon();