Book download validation: librarybook.accountname and/or book.locale is null/blank

DtoImporterService/UNTESTED/LibraryImporter.cs

@@ -23,6 +23,17 @@ namespace DtoImporterService
 
 		private int upsertLibraryBooks(IEnumerable<Item> items)
 		{
+			// technically, we should be able to have duplicate books from separate accounts.
+			// this would violate the current pk and would be difficult to deal with elsewhere:
+			// - what to show in the grid
+			// - which to consider liberated
+			//
+			// sqlite cannot alter pk. the work around is an extensive headache. it'll be fixed in pre .net5/efcore5
+			//
+			// currently, inserting LibraryBook will throw error if the same book is in multiple accounts for the same region.
+			//
+			// CURRENT SOLUTION: don't re-insert
+			
 			var currentLibraryProductIds = DbContext.Library.Select(l => l.Book.AudibleProductId).ToList();
 			var newItems = items.Where(dto => !currentLibraryProductIds.Contains(dto.ProductId)).ToList();
 

FileLiberator/UNTESTED/DownloadBook.cs

@@ -43,6 +43,8 @@ namespace FileLiberator
 
 		private async Task<string> downloadBookAsync(LibraryBook libraryBook, string tempAaxFilename)
 		{
+			validate(libraryBook);
+
 			var api = await AudibleApiActions.GetApiAsync(libraryBook.Account, libraryBook.Book.Locale);
 
 			var actualFilePath = await PerformDownloadAsync(
@@ -77,6 +79,28 @@ namespace FileLiberator
 			throw ex;
 		}
 
+		private static void validate(LibraryBook libraryBook)
+		{
+			string errorString(string field)
+				=> $"{errorTitle()}\r\nCannot download book. {field} is not known. Try re-importing the account which owns this book.";
+
+			string errorTitle()
+			{
+				var title
+					= (libraryBook.Book.Title.Length > 53)
+					? $"{libraryBook.Book.Title.Truncate(50)}..."
+					: libraryBook.Book.Title;
+				var errorBookTitle = $"{title} [{libraryBook.Book.AudibleProductId}]";
+				return errorBookTitle;
+			};
+
+			if (string.IsNullOrWhiteSpace(libraryBook.Account))
+				throw new Exception(errorString("Account"));
+
+			if (string.IsNullOrWhiteSpace(libraryBook.Book.Locale))
+				throw new Exception(errorString("Locale"));
+		}
+
 		private void moveBook(LibraryBook libraryBook, string actualFilePath)
 		{
 			var newAaxFilename = FileUtility.GetValidFilename(

LibationLauncher/LibationLauncher.csproj

@@ -13,7 +13,7 @@
     <!-- <PublishSingleFile>true</PublishSingleFile> -->
     <RuntimeIdentifier>win-x64</RuntimeIdentifier>
 
-    <Version>3.1.12.221</Version>
+    <Version>3.1.12.222</Version>
   </PropertyGroup>
 
   <ItemGroup>