Add debugging for issue #149

AaxDecrypter/AaxDecrypter.csproj

@@ -6,7 +6,6 @@
 
   <ItemGroup>
     <PackageReference Include="AAXClean" Version="0.1.10" />
-    <PackageReference Include="Dinah.Core" Version="2.0.2.1" />
   </ItemGroup>
 
   <ItemGroup>

AaxDecrypter/AaxcDownloadMultiConverter.cs

@@ -12,23 +12,13 @@ namespace AaxDecrypter
 	{
 		protected override StepSequence Steps { get; }
 
-        private Func<string, int, int, NewSplitCallback, string> multipartFileNameCallback { get; }
-        private static string DefaultMultipartFilename(string outputFileName, int partsPosition, int partsTotal, NewSplitCallback newSplitCallback)
-        {
-            var template = Path.ChangeExtension(outputFileName, null) + " - <ch# 0> - <title>" + Path.GetExtension(outputFileName);
-
-            var fileTemplate = new FileTemplate(template) { IllegalCharacterReplacements = " " };
-            fileTemplate.AddParameterReplacement("ch# 0", FileUtility.GetSequenceFormatted(partsPosition, partsTotal));
-            fileTemplate.AddParameterReplacement("title", newSplitCallback?.Chapter?.Title ?? "");
-
-            return fileTemplate.GetFilePath();
-        }
+        private Func<MultiConvertFileProperties, string> multipartFileNameCallback { get; }
 
         private static TimeSpan minChapterLength { get; } = TimeSpan.FromSeconds(3);
 		private List<string> multiPartFilePaths { get; } = new List<string>();
 
         public AaxcDownloadMultiConverter(string outFileName, string cacheDirectory, DownloadLicense dlLic, OutputFormat outputFormat,
-            Func<string, int, int, NewSplitCallback, string> multipartFileNameCallback = null)
+            Func<MultiConvertFileProperties, string> multipartFileNameCallback = null)
 			: base(outFileName, cacheDirectory, dlLic, outputFormat)
         {
             Steps = new StepSequence
@@ -39,7 +29,7 @@ namespace AaxDecrypter
                 ["Step 2: Download Decrypted Audiobook"] = Step_DownloadAudiobookAsMultipleFilesPerChapter,
                 ["Step 3: Cleanup"] = Step_Cleanup,
             };
-            this.multipartFileNameCallback = multipartFileNameCallback ?? DefaultMultipartFilename;
+            this.multipartFileNameCallback = multipartFileNameCallback ?? MultiConvertFileProperties.DefaultMultipartFilename;
         }
 
         /*
@@ -133,7 +123,13 @@ That naming may not be desirable for everyone, but it's an easy change to instea
 
         private void createOutputFileStream(int currentChapter, ChapterInfo splitChapters, NewSplitCallback newSplitCallback)
         {
-            var fileName = multipartFileNameCallback(OutputFileName, currentChapter, splitChapters.Count, newSplitCallback);
+            var fileName = multipartFileNameCallback(new()
+            {
+                OutputFileName = OutputFileName,
+                PartsPosition = currentChapter,
+                PartsTotal = splitChapters.Count,
+                Title = newSplitCallback?.Chapter?.Title
+            });
             fileName = FileUtility.GetValidFilename(fileName);
 
             multiPartFilePaths.Add(fileName);

AaxDecrypter/MultiConvertFileProperties.cs

@@ -0,0 +1,25 @@
+using System;
+using System.IO;
+using FileManager;
+
+namespace AaxDecrypter
+{
+    public class MultiConvertFileProperties
+    {
+        public string OutputFileName { get; set; }
+        public int PartsPosition { get; set; }
+        public int PartsTotal { get; set; }
+        public string Title { get; set; }
+
+        public static string DefaultMultipartFilename(MultiConvertFileProperties multiConvertFileProperties)
+        {
+            var template = Path.ChangeExtension(multiConvertFileProperties.OutputFileName, null) + " - <ch# 0> - <title>" + Path.GetExtension(multiConvertFileProperties.OutputFileName);
+
+            var fileNamingTemplate = new FileNamingTemplate(template) { IllegalCharacterReplacements = " " };
+            fileNamingTemplate.AddParameterReplacement("ch# 0", FileUtility.GetSequenceFormatted(multiConvertFileProperties.PartsPosition, multiConvertFileProperties.PartsTotal));
+            fileNamingTemplate.AddParameterReplacement("title", multiConvertFileProperties.Title ?? "");
+
+            return fileNamingTemplate.GetFilePath();
+        }
+    }
+}

AppScaffolding/AppScaffolding.csproj

@@ -3,7 +3,7 @@
 
   <PropertyGroup>
     <TargetFramework>net5.0</TargetFramework>
-    <Version>6.3.3.1</Version>
+    <Version>6.4.2.1</Version>
   </PropertyGroup>
 
   <ItemGroup>

AudibleUtilities/AudibleUtilities.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="AudibleApi" Version="2.3.2.1" />
+    <PackageReference Include="AudibleApi" Version="2.3.4.1" />
   </ItemGroup>
 
   <ItemGroup>

DataLayer/EfClasses/Book.cs

@@ -185,6 +185,9 @@ namespace DataLayer
         {
             get
             {
+                if (_seriesLink is null)
+                    return "";
+
                 // first: alphabetical by name
                 var withNames = _seriesLink
                     .Where(s => !string.IsNullOrWhiteSpace(s.Series.Name))

FileLiberator/AudioFileStorageExt.cs

@@ -11,72 +11,46 @@ namespace FileLiberator
 {
     public static class AudioFileStorageExt
     {
-        private static void AddParameterReplacement(this FileTemplate fileTemplate, TemplateTags templateTags, object value)
-            => fileTemplate.AddParameterReplacement(templateTags.TagName, value);
-
-        internal class MultipartRenamer
+        private class MultipartRenamer
         {
-            public LibraryBook libraryBook { get; }
+            private LibraryBook libraryBook { get; }
 
-            public MultipartRenamer(LibraryBook libraryBook) => this.libraryBook = libraryBook;
+            internal MultipartRenamer(LibraryBook libraryBook) => this.libraryBook = libraryBook;
 
-            internal string MultipartFilename(string outputFileName, int partsPosition, int partsTotal, AAXClean.NewSplitCallback newSplitCallback)
-                => MultipartFilename(Configuration.Instance.ChapterFileTemplate, AudibleFileStorage.DecryptInProgressDirectory, Path.GetExtension(outputFileName), partsPosition, partsTotal, newSplitCallback?.Chapter?.Title ?? "");
-
-            internal string MultipartFilename(string template, string fullDirPath, string extension, int partsPosition, int partsTotal, string chapterTitle)
-            {
-                var fileTemplate = GetFileTemplateSingle(template, libraryBook, fullDirPath, extension);
-
-                fileTemplate.AddParameterReplacement(TemplateTags.ChCount, partsTotal);
-                fileTemplate.AddParameterReplacement(TemplateTags.ChNumber, partsPosition);
-                fileTemplate.AddParameterReplacement(TemplateTags.ChNumber0, FileUtility.GetSequenceFormatted(partsPosition, partsTotal));
-                fileTemplate.AddParameterReplacement(TemplateTags.ChTitle, chapterTitle);
-
-                return fileTemplate.GetFilePath();
-            }
+            internal string MultipartFilename(AaxDecrypter.MultiConvertFileProperties props)
+                => Templates.ChapterFile.GetFilename(libraryBook.ToDto(), props);
         }
 
-        public static Func<string, int, int, AAXClean.NewSplitCallback, string> CreateMultipartRenamerFunc(this AudioFileStorage _, LibraryBook libraryBook)
+        public static Func<AaxDecrypter.MultiConvertFileProperties, string> CreateMultipartRenamerFunc(this AudioFileStorage _, LibraryBook libraryBook)
             => new MultipartRenamer(libraryBook).MultipartFilename;
 
-        public static string GetInProgressFilename(this AudioFileStorage _, LibraryBook libraryBook, string extension)
-            => GetCustomDirFilename(_, libraryBook, AudibleFileStorage.DecryptInProgressDirectory, extension);
-
-        public static string GetBooksDirectoryFilename(this AudioFileStorage _, LibraryBook libraryBook, string extension)
-            => GetCustomDirFilename(_, libraryBook, AudibleFileStorage.BooksDirectory, extension);
-
+        /// <summary>
+        /// DownloadDecryptBook:
+        /// File path for where to move files into.
+        /// Path: directory nested inside of Books directory
+        /// File name: n/a
+        /// </summary>
         public static string GetDestinationDirectory(this AudioFileStorage _, LibraryBook libraryBook)
-            => GetFileTemplateSingle(Configuration.Instance.FolderTemplate, libraryBook, AudibleFileStorage.BooksDirectory, null)
-            .GetFilePath();
+            => Templates.Folder.GetFilename(libraryBook.ToDto());
 
+        /// <summary>
+        /// DownloadDecryptBook:
+        /// Path: in progress directory.
+        /// File name: final file name.
+        /// </summary>
+        public static string GetInProgressFilename(this AudioFileStorage _, LibraryBook libraryBook, string extension)
+            => Templates.File.GetFilename(libraryBook.ToDto(), AudibleFileStorage.DecryptInProgressDirectory, extension);
+
+        /// <summary>
+        /// PDF: audio file does not exist
+        /// </summary>
+        public static string GetBooksDirectoryFilename(this AudioFileStorage _, LibraryBook libraryBook, string extension)
+            => Templates.File.GetFilename(libraryBook.ToDto(), AudibleFileStorage.BooksDirectory, extension);
+
+        /// <summary>
+        /// PDF: audio file already exists
+        /// </summary>
         public static string GetCustomDirFilename(this AudioFileStorage _, LibraryBook libraryBook, string dirFullPath, string extension)
-            => GetFileTemplateSingle(Configuration.Instance.FileTemplate, libraryBook, dirFullPath, extension)
-            .GetFilePath();
-
-        internal static FileTemplate GetFileTemplateSingle(string template, LibraryBook libraryBook, string dirFullPath, string extension)
-        {
-            ArgumentValidator.EnsureNotNullOrWhiteSpace(template, nameof(template));
-            ArgumentValidator.EnsureNotNull(libraryBook, nameof(libraryBook));
-            ArgumentValidator.EnsureNotNullOrWhiteSpace(dirFullPath, nameof(dirFullPath));
-
-            var fullfilename = Path.Combine(dirFullPath, template + FileUtility.GetStandardizedExtension(extension));
-            var fileTemplate = new FileTemplate(fullfilename) { IllegalCharacterReplacements = "_" };
-
-            var title = libraryBook.Book.Title ?? "";
-
-            fileTemplate.AddParameterReplacement(TemplateTags.Id, libraryBook.Book.AudibleProductId);
-            fileTemplate.AddParameterReplacement(TemplateTags.Title, title);
-            fileTemplate.AddParameterReplacement(TemplateTags.TitleShort, title.IndexOf(':') < 1 ? title : title.Substring(0, title.IndexOf(':')));
-            fileTemplate.AddParameterReplacement(TemplateTags.Author, libraryBook.Book.AuthorNames);
-            fileTemplate.AddParameterReplacement(TemplateTags.FirstAuthor, libraryBook.Book.Authors.FirstOrDefault()?.Name);
-            fileTemplate.AddParameterReplacement(TemplateTags.Narrator, libraryBook.Book.NarratorNames);
-            fileTemplate.AddParameterReplacement(TemplateTags.FirstNarrator, libraryBook.Book.Narrators.FirstOrDefault()?.Name);
-
-            var seriesLink = libraryBook.Book.SeriesLink.FirstOrDefault();
-            fileTemplate.AddParameterReplacement(TemplateTags.Series, seriesLink?.Series.Name);
-            fileTemplate.AddParameterReplacement(TemplateTags.SeriesNumber, seriesLink?.Order);
-
-            return fileTemplate;
-        }
+            => Templates.File.GetFilename(libraryBook.ToDto(), dirFullPath, extension);
     }
 }

FileLiberator/UtilityExtensions.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using DataLayer;
 using Dinah.Core;
+using LibationFileManager;
 
 namespace FileLiberator
 {
@@ -22,5 +23,21 @@ namespace FileLiberator
 			var apiExtended = await AudibleUtilities.ApiExtended.CreateAsync(libraryBook.Account, libraryBook.Book.Locale);
 			return apiExtended.Api;
 		}
+
+		public static LibraryBookDto ToDto(this LibraryBook libraryBook) => new()
+		{
+			Account = libraryBook.Account,
+
+			AudibleProductId = libraryBook.Book.AudibleProductId,
+			Title = libraryBook.Book.Title ?? "",
+			Locale = libraryBook.Book.Locale,
+
+			Authors = libraryBook.Book.Authors.Select(c => c.Name).ToList(),
+
+			Narrators = libraryBook.Book.Narrators.Select(c => c.Name).ToList(),
+
+			SeriesName = libraryBook.Book.SeriesLink.FirstOrDefault()?.Series.Name,
+			SeriesNumber = libraryBook.Book.SeriesLink.FirstOrDefault()?.Order
+		};
 	}
 }

FileManager/FileManager.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Dinah.Core" Version="2.0.2.1" />
+    <PackageReference Include="Dinah.Core" Version="3.0.1.1" />
     <PackageReference Include="Polly" Version="7.2.2" />
   </ItemGroup>
 

FileManager/FileNamingTemplate.cs

@@ -6,13 +6,13 @@ using Dinah.Core;
 namespace FileManager
 {
     /// <summary>Get valid filename. Advanced features incl. parameterized template</summary>
-    public class FileTemplate
+    public class FileNamingTemplate
     {
         /// <summary>Proposed full file path. May contain optional html-styled template tags. Eg: &lt;name&gt;</summary>
         public string Template { get; }
 
         /// <param name="template">Proposed file name with optional html-styled template tags.</param>
-        public FileTemplate(string template) => Template = ArgumentValidator.EnsureNotNullOrWhiteSpace(template, nameof(template));
+        public FileNamingTemplate(string template) => Template = ArgumentValidator.EnsureNotNullOrWhiteSpace(template, nameof(template));
 
         /// <summary>Optional step 1: Replace html-styled template tags with parameters. Eg {"name", "Bill Gates"} => /&lt;name&gt;/ => /Bill Gates/</summary>
         public Dictionary<string, object> ParameterReplacements { get; } = new Dictionary<string, object>();
@@ -45,8 +45,20 @@ namespace FileManager
             .Replace(">", "");
 
         private string formatValue(object value)
-            => ParameterMaxSize.HasValue && ParameterMaxSize.Value > 0
-            ? value?.ToString().Truncate(ParameterMaxSize.Value)
-            : value?.ToString();
+        {
+            if (value is null)
+                return "";
+
+            // Other illegal characters will be taken care of later. Must take care of slashes now so params can't introduce new folders.
+            // Esp important for file templates.
+            var val = value
+                .ToString()
+                .Replace($"{System.IO.Path.DirectorySeparatorChar}", IllegalCharacterReplacements)
+                .Replace($"{System.IO.Path.AltDirectorySeparatorChar}", IllegalCharacterReplacements);
+            return 
+                ParameterMaxSize.HasValue && ParameterMaxSize.Value > 0
+                ? val.Truncate(ParameterMaxSize.Value)
+                : val;
+        }
     }
 }

FileManager/PersistentDictionary.cs

@@ -205,8 +205,25 @@ namespace FileManager
 
         private JObject readFile()
         {
+            if (!File.Exists(Filepath))
+            {
+                var msg = "Unrecoverable error. Settings file cannot be found";
+                var ex = new FileNotFoundException(msg, Filepath);
+                Serilog.Log.Logger.Error(msg, ex);
+                throw ex;
+            }
+
             var settingsJsonContents = File.ReadAllText(Filepath);
             var jObject = JsonConvert.DeserializeObject<JObject>(settingsJsonContents);
+
+            if (jObject is null)
+            {
+                var msg = "Unrecoverable error. Unable to read settings from Settings file";
+                var ex = new NullReferenceException(msg);
+                Serilog.Log.Logger.Error(msg, ex);
+                throw ex;
+            }
+
             return jObject;
         }
     }

LibationFileManager/Configuration.cs

@@ -170,14 +170,10 @@ namespace LibationFileManager
             set => setTemplate(nameof(ChapterFileTemplate), Templates.ChapterFile, value);
         }
 
-        private string getTemplate(string settingName, Templates templ)
-        {
-            var value = persistentDictionary.GetString(settingName)?.Trim();
-            return templ.IsValid(value) ? value : templ.DefaultTemplate;
-        }
+        private string getTemplate(string settingName, Templates templ) => templ.GetValid(persistentDictionary.GetString(settingName));
         private void setTemplate(string settingName, Templates templ, string newValue)
         {
-            var template = newValue.Trim();
+            var template = newValue?.Trim();
             if (templ.IsValid(template))
                 persistentDictionary.SetString(settingName, template);
         }

LibationFileManager/LibationFileManager.csproj

@@ -9,6 +9,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\AaxDecrypter\AaxDecrypter.csproj" />
     <ProjectReference Include="..\FileManager\FileManager.csproj" />
   </ItemGroup>
 

LibationFileManager/LibraryBookDto.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace LibationFileManager
+{
+    public class BookDto
+    {
+        public string AudibleProductId { get; set; }
+        public string Title { get; set; }
+        public string Locale { get; set; }
+
+        public IEnumerable<string> Authors { get; set; }
+        public string AuthorNames => string.Join(", ", Authors);
+        public string FirstAuthor => Authors.FirstOrDefault();
+
+        public IEnumerable<string> Narrators { get; set; }
+        public string NarratorNames => string.Join(", ", Narrators);
+        public string FirstNarrator => Narrators.FirstOrDefault();
+
+        public string SeriesName { get; set; }
+        public string SeriesNumber { get; set; }
+    }
+
+    public class LibraryBookDto : BookDto
+    {
+        public string Account { get; set; }
+    }
+}

LibationFileManager/TemplateTags.cs

@@ -18,6 +18,12 @@ namespace LibationFileManager
             IsChapterOnly = isChapterOnly;
         }
 
+        // putting these first is the incredibly lazy way to make them show up first in the EditTemplateDialog
+        public static TemplateTags ChCount { get; } = new TemplateTags("ch count", "Number of chapters", true);
+        public static TemplateTags ChTitle { get; } = new TemplateTags("ch title", "Chapter title", true);
+        public static TemplateTags ChNumber { get; } = new TemplateTags("ch#", "Chapter number", true);
+        public static TemplateTags ChNumber0 { get; } = new TemplateTags("ch# 0", "Chapter number with leading zeros", true);
+
         public static TemplateTags Id { get; } = new TemplateTags("id", "Audible ID");
         public static TemplateTags Title { get; } = new TemplateTags("title", "Full title");
         public static TemplateTags TitleShort { get; } = new TemplateTags("title short", "Title. Stop at first colon");
@@ -28,10 +34,7 @@ namespace LibationFileManager
         public static TemplateTags Series { get; } = new TemplateTags("series", "Name of series");
         // can't also have a leading zeros version. Too many weird edge cases. Eg: "1-4"
         public static TemplateTags SeriesNumber { get; } = new TemplateTags("series#", "Number order in series");
-
-        public static TemplateTags ChCount { get; } = new TemplateTags("ch count", "Number of chapters", true);
-        public static TemplateTags ChTitle { get; } = new TemplateTags("ch title", "Chapter title", true);
-        public static TemplateTags ChNumber { get; } = new TemplateTags("ch#", "Chapter number", true);
-        public static TemplateTags ChNumber0 { get; } = new TemplateTags("ch# 0", "Chapter number with leading zeros", true);
+        public static TemplateTags Account { get; } = new TemplateTags("account", "Audible account of this book");
+        public static TemplateTags Locale { get; } = new TemplateTags("locale", "Region/country");
     }
 }

LibationFileManager/Templates.cs

@@ -1,96 +1,274 @@
-using System;
+using Dinah.Core;
+using FileManager;
+using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 
 namespace LibationFileManager
 {
     public abstract class Templates
     {
-        public static Templates Folder { get; } = new FolderTemplate();
-        public static Templates File { get; } = new FileTemplate();
-        public static Templates ChapterFile { get; } = new ChapterFileTemplate();
+        protected static string[] Valid => Array.Empty<string>();
+        public const string ERROR_NULL_IS_INVALID = "Null template is invalid.";
+        public const string ERROR_FULL_PATH_IS_INVALID = @"No colons or full paths allowed. Eg: should not start with C:\";
+        public const string ERROR_INVALID_FILE_NAME_CHAR = @"Only file name friendly characters allowed. Eg: no colons or slashes";
+
+        public const string WARNING_EMPTY = "Template is empty.";
+        public const string WARNING_WHITE_SPACE = "Template is white space.";
+        public const string WARNING_NO_TAGS = "Should use tags. Eg: <title>";
+        public const string WARNING_HAS_CHAPTER_TAGS = "Chapter tags should only be used in the template used for naming files which are split by chapter. Eg: <ch title>";
+        public const string WARNING_NO_CHAPTER_NUMBER_TAG = "Should include chapter number tag in template used for naming files which are split by chapter. Ie: <ch#> or <ch# 0>";
+
+        public static FolderTemplate Folder { get; } = new FolderTemplate();
+        public static FileTemplate File { get; } = new FileTemplate();
+        public static ChapterFileTemplate ChapterFile { get; } = new ChapterFileTemplate();
 
         public abstract string Name { get; }
         public abstract string Description { get; }
         public abstract string DefaultTemplate { get; }
+        protected abstract bool IsChapterized { get; }
 
-        public abstract bool IsValid(string template);
-        public abstract bool IsRecommended(string template);
-        public abstract int TagCount(string template);
+        protected Templates() { }
 
-        public static bool ContainsChapterOnlyTags(string template)
-            => TemplateTags.GetAll()
-            .Where(t => t.IsChapterOnly)
-            .Any(t => ContainsTag(template, t.TagName));
+		#region validation
+		internal string GetValid(string configValue)
+        {
+            var value = configValue?.Trim();
+            return IsValid(value) ? value : DefaultTemplate;
+        }
 
-        public static bool ContainsTag(string template, string tag) => template.Contains($"<{tag}>");
+        public abstract IEnumerable<string> GetErrors(string template);
+        public bool IsValid(string template) => !GetErrors(template).Any();
 
-        protected static bool fileIsValid(string template)
+        public abstract IEnumerable<string> GetWarnings(string template);
+        public bool HasWarnings(string template) => GetWarnings(template).Any();
+
+        protected static string[] GetFileErrors(string template)
+        {
             // File name only; not path. all other path chars are valid enough to pass this check and will be handled on final save.
+
             // null is invalid. whitespace is valid but not recommended
-            => template is not null
-            && !template.Contains(':')
-            && !template.Contains(System.IO.Path.DirectorySeparatorChar)
-            && !template.Contains(System.IO.Path.AltDirectorySeparatorChar);
+            if (template is null)
+                return new[] { ERROR_NULL_IS_INVALID };
 
-        protected bool isRecommended(string template, bool isChapter)
-            => IsValid(template)
-            && !string.IsNullOrWhiteSpace(template)
-            && TagCount(template) > 0
-            && ContainsChapterOnlyTags(template) == isChapter;
+            if (template.Contains(':')
+                || template.Contains(Path.DirectorySeparatorChar)
+                || template.Contains(Path.AltDirectorySeparatorChar)
+                )
+                return new[] { ERROR_INVALID_FILE_NAME_CHAR };
 
-        protected static int tagCount(string template, Func<TemplateTags, bool> func)
-            => TemplateTags.GetAll()
-            .Where(func)
+            return Valid;
+        }
+
+        protected IEnumerable<string> GetStandardWarnings(string template)
+        {
+            var warnings = GetErrors(template).ToList();
+            if (template is null)
+                return warnings;
+
+            if (string.IsNullOrEmpty(template))
+                warnings.Add(WARNING_EMPTY);
+            else if (string.IsNullOrWhiteSpace(template))
+                warnings.Add(WARNING_WHITE_SPACE);
+
+            if (TagCount(template) == 0)
+                warnings.Add(WARNING_NO_TAGS);
+
+            if (!IsChapterized && ContainsChapterOnlyTags(template))
+                warnings.Add(WARNING_HAS_CHAPTER_TAGS);
+
+            return warnings;
+        }
+
+        internal int TagCount(string template)
+            => GetTemplateTags()
             // for <id><id> == 1, use:
             //   .Count(t => template.Contains($"<{t.TagName}>"))
             // .Sum() impl: <id><id> == 2
             .Sum(t => template.Split($"<{t.TagName}>").Length - 1);
 
-        private class FolderTemplate : Templates
+        internal static bool ContainsChapterOnlyTags(string template)
+            => TemplateTags.GetAll()
+            .Where(t => t.IsChapterOnly)
+            .Any(t => ContainsTag(template, t.TagName));
+
+        internal static bool ContainsTag(string template, string tag) => template.Contains($"<{tag}>");
+        #endregion
+
+        #region to file name
+        /// <summary>
+        /// EditTemplateDialog: Get template generated filename for portion of path
+        /// </summary>
+        public string GetPortionFilename(LibraryBookDto libraryBookDto, string template)
+            => string.IsNullOrWhiteSpace(template)
+            ? ""
+            : getFileNamingTemplate(libraryBookDto, template, null, null)
+            .GetFilePath();
+
+        internal static FileNamingTemplate getFileNamingTemplate(LibraryBookDto libraryBookDto, string template, string dirFullPath, string extension)
+        {
+            ArgumentValidator.EnsureNotNullOrWhiteSpace(template, nameof(template));
+            ArgumentValidator.EnsureNotNull(libraryBookDto, nameof(libraryBookDto));
+
+            dirFullPath = dirFullPath?.Trim() ?? "";
+            var t = template + FileUtility.GetStandardizedExtension(extension);
+            var fullfilename = dirFullPath == "" ? t : Path.Combine(dirFullPath, t);
+
+            var fileNamingTemplate = new FileNamingTemplate(fullfilename) { IllegalCharacterReplacements = "_" };
+
+            var title = libraryBookDto.Title ?? "";
+            var titleShort = title.IndexOf(':') < 1 ? title : title.Substring(0, title.IndexOf(':'));
+
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Id, libraryBookDto.AudibleProductId);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Title, title);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.TitleShort, titleShort);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Author, libraryBookDto.AuthorNames);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.FirstAuthor, libraryBookDto.FirstAuthor);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Narrator, libraryBookDto.NarratorNames);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.FirstNarrator, libraryBookDto.FirstNarrator);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Series, libraryBookDto.SeriesName);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.SeriesNumber, libraryBookDto.SeriesNumber);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Account, libraryBookDto.Account);
+            fileNamingTemplate.AddParameterReplacement(TemplateTags.Locale, libraryBookDto.Locale);
+
+            return fileNamingTemplate;
+        }
+        #endregion
+
+        public IEnumerable<TemplateTags> GetTemplateTags()
+            => TemplateTags.GetAll()
+            // yeah, this line is a little funky but it works when you think through it. also: trust the unit tests
+            .Where(t => IsChapterized || !t.IsChapterOnly);
+
+        public string Sanitize(string template)
+        {
+            var value = template ?? "";
+
+            // don't use alt slash
+            value = value.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
+
+            // don't allow double slashes
+            var sing = $"{Path.DirectorySeparatorChar}";
+            var dbl = $"{Path.DirectorySeparatorChar}{Path.DirectorySeparatorChar}";
+            while (value.Contains(dbl))
+                value = value.Replace(dbl, sing);
+
+            // trim. don't start or end with slash
+            while (true)
+            {
+                var start = value.Length;
+                value = value
+                    .Trim()
+                    .Trim(Path.DirectorySeparatorChar);
+                var end = value.Length;
+                if (start == end)
+                    break;
+            }
+
+            return value;
+        }
+
+        public class FolderTemplate : Templates
         {
 			public override string Name => "Folder Template";
             public override string Description => Configuration.GetDescription(nameof(Configuration.FolderTemplate));
 			public override string DefaultTemplate { get; } = "<title short> [<id>]";
+            protected override bool IsChapterized { get; } = false;
 
-			public override bool IsValid(string template)
-                // must be relative. no colons. all other path chars are valid enough to pass this check and will be handled on final save.
+            internal FolderTemplate() : base() { }
+
+            #region validation
+            public override IEnumerable<string> GetErrors(string template)
+            {
                 // null is invalid. whitespace is valid but not recommended
-                => template is not null
-                && !template.Contains(':');
+                if (template is null)
+                    return new[] { ERROR_NULL_IS_INVALID };
 
-            public override bool IsRecommended(string template) => isRecommended(template, false);
+                // must be relative. no colons. all other path chars are valid enough to pass this check and will be handled on final save.
+                if (template.Contains(':'))
+                    return new[] { ERROR_FULL_PATH_IS_INVALID };
 
-            public override int TagCount(string template) => tagCount(template, t => !t.IsChapterOnly);
+                return Valid;
+            }
+            
+            public override IEnumerable<string> GetWarnings(string template) => GetStandardWarnings(template);
+            #endregion
+
+            #region to file name
+            /// <summary>USES LIVE CONFIGURATION VALUES</summary>
+            public string GetFilename(LibraryBookDto libraryBookDto)
+                => getFileNamingTemplate(libraryBookDto, Configuration.Instance.FolderTemplate, AudibleFileStorage.BooksDirectory, null)
+                .GetFilePath();
+            #endregion
         }
 
-        private class FileTemplate : Templates
+        public class FileTemplate : Templates
         {
             public override string Name => "File Template";
             public override string Description => Configuration.GetDescription(nameof(Configuration.FileTemplate));
             public override string DefaultTemplate { get; } = "<title> [<id>]";
+            protected override bool IsChapterized { get; } = false;
 
-            public override bool IsValid(string template) => fileIsValid(template);
+            internal FileTemplate() : base() { }
 
-            public override bool IsRecommended(string template) => isRecommended(template, false);
+            #region validation
+            public override IEnumerable<string> GetErrors(string template) => GetFileErrors(template);
 
-            public override int TagCount(string template) => tagCount(template, t => !t.IsChapterOnly);
+            public override IEnumerable<string> GetWarnings(string template) => GetStandardWarnings(template);
+            #endregion
+
+            #region to file name
+            /// <summary>USES LIVE CONFIGURATION VALUES</summary>
+            public string GetFilename(LibraryBookDto libraryBookDto, string dirFullPath, string extension)
+                => getFileNamingTemplate(libraryBookDto, Configuration.Instance.FileTemplate, dirFullPath, extension)
+                .GetFilePath();
+            #endregion
         }
 
-        private class ChapterFileTemplate : Templates
+        public class ChapterFileTemplate : Templates
         {
             public override string Name => "Chapter File Template";
             public override string Description => Configuration.GetDescription(nameof(Configuration.ChapterFileTemplate));
             public override string DefaultTemplate { get; } = "<title> [<id>] - <ch# 0> - <ch title>";
+            protected override bool IsChapterized { get; } = true;
 
-            public override bool IsValid(string template) => fileIsValid(template);
+            internal ChapterFileTemplate() : base() { }
+
+            #region validation
+            public override IEnumerable<string> GetErrors(string template) => GetFileErrors(template);
+
+            public override IEnumerable<string> GetWarnings(string template)
+            {
+                var warnings = GetStandardWarnings(template).ToList();
+                if (template is null)
+                    return warnings;
 
-            public override bool IsRecommended(string template)
-                => isRecommended(template, true)
                 // recommended to incl. <ch#> or <ch# 0>
-                && (ContainsTag(template, TemplateTags.ChNumber.TagName) || ContainsTag(template, TemplateTags.ChNumber0.TagName));
+                if (!ContainsTag(template, TemplateTags.ChNumber.TagName) && !ContainsTag(template, TemplateTags.ChNumber0.TagName))
+                    warnings.Add(WARNING_NO_CHAPTER_NUMBER_TAG);
 
-            public override int TagCount(string template) => tagCount(template, t => true);
+                return warnings;
+            }
+            #endregion
+
+            #region to file name
+            /// <summary>USES LIVE CONFIGURATION VALUES</summary>
+            public string GetFilename(LibraryBookDto libraryBookDto, AaxDecrypter.MultiConvertFileProperties props)
+                => GetPortionFilename(libraryBookDto, Configuration.Instance.ChapterFileTemplate, props, AudibleFileStorage.DecryptInProgressDirectory);
+
+            public string GetPortionFilename(LibraryBookDto libraryBookDto, string template, AaxDecrypter.MultiConvertFileProperties props, string fullDirPath)
+            {
+                var fileNamingTemplate = getFileNamingTemplate(libraryBookDto, template, fullDirPath, Path.GetExtension(props.OutputFileName));
+
+                fileNamingTemplate.AddParameterReplacement(TemplateTags.ChCount, props.PartsTotal);
+                fileNamingTemplate.AddParameterReplacement(TemplateTags.ChNumber, props.PartsPosition);
+                fileNamingTemplate.AddParameterReplacement(TemplateTags.ChNumber0, FileUtility.GetSequenceFormatted(props.PartsPosition, props.PartsTotal));
+                fileNamingTemplate.AddParameterReplacement(TemplateTags.ChTitle, props.Title ?? "");
+
+                return fileNamingTemplate.GetFilePath();
+            }
+            #endregion
         }
     }
 }

LibationFileManager/UtilityExtensions.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using FileManager;
+
+namespace LibationFileManager
+{
+	public static class UtilityExtensions
+	{
+		public static void AddParameterReplacement(this FileNamingTemplate fileNamingTemplate, TemplateTags templateTags, object value)
+			=> fileNamingTemplate.AddParameterReplacement(templateTags.TagName, value);
+	}
+}

LibationWinForms/Dialogs/EditTemplateDialog.Designer.cs

@@ -33,13 +33,18 @@
 			this.templateTb = new System.Windows.Forms.TextBox();
 			this.templateLbl = new System.Windows.Forms.Label();
 			this.resetToDefaultBtn = new System.Windows.Forms.Button();
-			this.outputTb = new System.Windows.Forms.TextBox();
+			this.listView1 = new System.Windows.Forms.ListView();
+			this.columnHeader1 = new System.Windows.Forms.ColumnHeader();
+			this.columnHeader2 = new System.Windows.Forms.ColumnHeader();
+			this.richTextBox1 = new System.Windows.Forms.RichTextBox();
+			this.warningsLbl = new System.Windows.Forms.Label();
+			this.exampleLbl = new System.Windows.Forms.Label();
 			this.SuspendLayout();
 			// 
 			// saveBtn
 			// 
 			this.saveBtn.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
-			this.saveBtn.Location = new System.Drawing.Point(714, 496);
+			this.saveBtn.Location = new System.Drawing.Point(714, 345);
 			this.saveBtn.Margin = new System.Windows.Forms.Padding(4, 3, 4, 3);
 			this.saveBtn.Name = "saveBtn";
 			this.saveBtn.Size = new System.Drawing.Size(88, 27);
@@ -52,7 +57,7 @@
 			// 
 			this.cancelBtn.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
 			this.cancelBtn.DialogResult = System.Windows.Forms.DialogResult.Cancel;
-			this.cancelBtn.Location = new System.Drawing.Point(832, 496);
+			this.cancelBtn.Location = new System.Drawing.Point(832, 345);
 			this.cancelBtn.Margin = new System.Windows.Forms.Padding(4, 3, 4, 3);
 			this.cancelBtn.Name = "cancelBtn";
 			this.cancelBtn.Size = new System.Drawing.Size(88, 27);
@@ -91,14 +96,64 @@
 			this.resetToDefaultBtn.UseVisualStyleBackColor = true;
 			this.resetToDefaultBtn.Click += new System.EventHandler(this.resetToDefaultBtn_Click);
 			// 
-			// outputTb
+			// listView1
 			// 
-			this.outputTb.Location = new System.Drawing.Point(12, 153);
-			this.outputTb.Multiline = true;
-			this.outputTb.Name = "outputTb";
-			this.outputTb.ReadOnly = true;
-			this.outputTb.Size = new System.Drawing.Size(759, 205);
-			this.outputTb.TabIndex = 100;
+			this.listView1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
+            | System.Windows.Forms.AnchorStyles.Left)));
+			this.listView1.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
+            this.columnHeader1,
+            this.columnHeader2});
+			this.listView1.HideSelection = false;
+			this.listView1.Location = new System.Drawing.Point(12, 56);
+			this.listView1.Name = "listView1";
+			this.listView1.Size = new System.Drawing.Size(328, 283);
+			this.listView1.TabIndex = 3;
+			this.listView1.UseCompatibleStateImageBehavior = false;
+			this.listView1.View = System.Windows.Forms.View.Details;
+			// 
+			// columnHeader1
+			// 
+			this.columnHeader1.Text = "Tag";
+			this.columnHeader1.Width = 90;
+			// 
+			// columnHeader2
+			// 
+			this.columnHeader2.Text = "Description";
+			this.columnHeader2.Width = 230;
+			// 
+			// richTextBox1
+			// 
+			this.richTextBox1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
+            | System.Windows.Forms.AnchorStyles.Left) 
+            | System.Windows.Forms.AnchorStyles.Right)));
+			this.richTextBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
+			this.richTextBox1.Location = new System.Drawing.Point(346, 74);
+			this.richTextBox1.Name = "richTextBox1";
+			this.richTextBox1.ReadOnly = true;
+			this.richTextBox1.Size = new System.Drawing.Size(574, 185);
+			this.richTextBox1.TabIndex = 5;
+			this.richTextBox1.Text = "";
+			// 
+			// warningsLbl
+			// 
+			this.warningsLbl.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
+			this.warningsLbl.AutoSize = true;
+			this.warningsLbl.Font = new System.Drawing.Font("Segoe UI", 9F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point);
+			this.warningsLbl.ForeColor = System.Drawing.Color.Firebrick;
+			this.warningsLbl.Location = new System.Drawing.Point(346, 262);
+			this.warningsLbl.Name = "warningsLbl";
+			this.warningsLbl.Size = new System.Drawing.Size(14, 15);
+			this.warningsLbl.TabIndex = 100;
+			this.warningsLbl.Text = "6";
+			// 
+			// exampleLbl
+			// 
+			this.exampleLbl.AutoSize = true;
+			this.exampleLbl.Location = new System.Drawing.Point(346, 56);
+			this.exampleLbl.Name = "exampleLbl";
+			this.exampleLbl.Size = new System.Drawing.Size(55, 15);
+			this.exampleLbl.TabIndex = 4;
+			this.exampleLbl.Text = "Example:";
 			// 
 			// EditTemplateDialog
 			// 
@@ -106,8 +161,11 @@
 			this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
 			this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
 			this.CancelButton = this.cancelBtn;
-			this.ClientSize = new System.Drawing.Size(933, 539);
-			this.Controls.Add(this.outputTb);
+			this.ClientSize = new System.Drawing.Size(933, 388);
+			this.Controls.Add(this.exampleLbl);
+			this.Controls.Add(this.warningsLbl);
+			this.Controls.Add(this.richTextBox1);
+			this.Controls.Add(this.listView1);
 			this.Controls.Add(this.resetToDefaultBtn);
 			this.Controls.Add(this.templateLbl);
 			this.Controls.Add(this.templateTb);
@@ -130,6 +188,11 @@
 		private System.Windows.Forms.TextBox templateTb;
 		private System.Windows.Forms.Label templateLbl;
 		private System.Windows.Forms.Button resetToDefaultBtn;
-		private System.Windows.Forms.TextBox outputTb;
+		private System.Windows.Forms.ListView listView1;
+		private System.Windows.Forms.ColumnHeader columnHeader1;
+		private System.Windows.Forms.ColumnHeader columnHeader2;
+		private System.Windows.Forms.RichTextBox richTextBox1;
+		private System.Windows.Forms.Label warningsLbl;
+		private System.Windows.Forms.Label exampleLbl;
 	}
 }

LibationWinForms/Dialogs/EditTemplateDialog.cs

@@ -10,8 +10,19 @@ namespace LibationWinForms.Dialogs
 {
 	public partial class EditTemplateDialog : Form
 	{
+		// final value. post-validity check
 		public string TemplateText { get; private set; }
 
+		// hold the work-in-progress value. not guaranteed to be valid
+		private string _workingTemplateText;
+		private string workingTemplateText
+		{
+			get => _workingTemplateText;
+			set => _workingTemplateText = template.Sanitize(value);
+		}
+
+		private void resetTextBox(string value) => this.templateTb.Text = workingTemplateText = value;
+
 		private Configuration config { get; } = Configuration.Instance;
 
 		private Templates template { get; }
@@ -35,49 +46,119 @@ namespace LibationWinForms.Dialogs
 				return;
 			}
 
+			warningsLbl.Text = "";
+
 			this.Text = $"Edit {template.Name}";
 
 			this.templateLbl.Text = template.Description;
-			this.templateTb.Text = inputTemplateText;
+			resetTextBox(inputTemplateText);
+
+			// populate list view
+			foreach (var tag in template.GetTemplateTags())
+				listView1.Items.Add(new ListViewItem(new[] { $"<{tag.TagName}>", tag.Description }));
 		}
 
-		private void resetToDefaultBtn_Click(object sender, EventArgs e) => templateTb.Text = template.DefaultTemplate;
+		private void resetToDefaultBtn_Click(object sender, EventArgs e) => resetTextBox(template.DefaultTemplate);
 
 		private void templateTb_TextChanged(object sender, EventArgs e)
 		{
+			workingTemplateText = templateTb.Text;
+
+			var isFolder = template == Templates.Folder;
+
+			var libraryBookDto = new LibraryBookDto
+			{
+				Account = "my account",
+				AudibleProductId = "123456789",
+				Title = "A Study in Scarlet: A Sherlock Holmes Novel",
+				Locale = "us",
+				Authors = new List<string> { "Arthur Conan Doyle", "Stephen Fry - introductions" },
+				Narrators = new List<string> { "Stephen Fry" },
+				SeriesName = "Sherlock Holmes",
+				SeriesNumber = "1"
+			};
+			var chapterName = "A Flight for Life";
+			var chapterNumber = 4;
+			var chaptersTotal = 10;
+
 			var books = config.Books;
-			var folderTemplate = template == Templates.Folder ? templateTb.Text : config.FolderTemplate;
-			folderTemplate = folderTemplate.Trim().Trim(new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar }).Trim();
-			var fileTemplate = template == Templates.Folder ? config.FileTemplate : templateTb.Text;
-			fileTemplate = fileTemplate.Trim();
+			var folder = Templates.Folder.GetPortionFilename(
+				libraryBookDto,
+				isFolder ? workingTemplateText : config.FolderTemplate);
+			var file
+				= template == Templates.ChapterFile
+				? Templates.ChapterFile.GetPortionFilename(
+					libraryBookDto,
+					workingTemplateText,
+					new() { OutputFileName = "", PartsPosition = chapterNumber, PartsTotal = chaptersTotal, Title = chapterName },
+					"")
+				: Templates.File.GetPortionFilename(
+					libraryBookDto,
+					isFolder ? config.FileTemplate : workingTemplateText);
 			var ext = config.DecryptToLossy ? "mp3" : "m4b";
 
-			var path = Path.Combine(books, folderTemplate, $"{fileTemplate}.{ext}");
+			const char ZERO_WIDTH_SPACE = '\u200B';
+			var sing = $"{Path.DirectorySeparatorChar}";
 
-			// this logic should be external
-			path = path.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
-			var dbl = $"{Path.DirectorySeparatorChar}{Path.DirectorySeparatorChar}";
-			while (path.Contains(dbl))
-				path = path.Replace(dbl, $"{Path.DirectorySeparatorChar}");
+			// result: can wrap long paths. eg:
+			// |-- LINE WRAP BOUNDARIES --|
+			// \books\author with a very     <= normal line break on space between words
+			// long name\narrator narrator   
+			// \title                        <= line break on the zero-with space we added before slashes
+			string slashWrap(string val) => val.Replace(sing, $"{ZERO_WIDTH_SPACE}{sing}");
 
-			outputTb.Text = @$"
-{books}
-{folderTemplate}
-{fileTemplate}
-{ext}
-{path}
-";
+			warningsLbl.Text
+				= !template.HasWarnings(workingTemplateText)
+				? ""
+				: "Warning:\r\n" +
+					template
+					.GetWarnings(workingTemplateText)
+					.Select(err => $"- {err}")
+					.Aggregate((a, b) => $"{a}\r\n{b}");
+
+			var bold = new System.Drawing.Font(richTextBox1.Font, System.Drawing.FontStyle.Bold);
+			var reg = new System.Drawing.Font(richTextBox1.Font, System.Drawing.FontStyle.Regular);
+
+			richTextBox1.Clear();
+			richTextBox1.SelectionFont = reg;
+
+			richTextBox1.AppendText(slashWrap(books));
+			richTextBox1.AppendText(sing);
+
+			if (isFolder)
+				richTextBox1.SelectionFont = bold;
+
+			richTextBox1.AppendText(slashWrap(folder));
+
+			if (isFolder)
+				richTextBox1.SelectionFont = reg;
+
+			richTextBox1.AppendText(sing);
+
+			if (!isFolder)
+				richTextBox1.SelectionFont = bold;
+
+			richTextBox1.AppendText(file);
+
+			if (!isFolder)
+				richTextBox1.SelectionFont = reg;
+
+			richTextBox1.AppendText($".{ext}");
 		}
 
 		private void saveBtn_Click(object sender, EventArgs e)
 		{
-			if (!template.IsValid(templateTb.Text))
+			if (!template.IsValid(workingTemplateText))
 			{
-				MessageBox.Show("This template text is not valid.", "Invalid", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				var errors = template
+					.GetErrors(workingTemplateText)
+					.Select(err => $"- {err}")
+					.Aggregate((a, b) => $"{a}\r\n{b}");
+				MessageBox.Show($"This template text is not valid. Errors:\r\n{errors}", "Invalid", MessageBoxButtons.OK, MessageBoxIcon.Error);
 				return;
 			}
 
-			TemplateText = templateTb.Text;
+			TemplateText = workingTemplateText;
 
 			this.DialogResult = DialogResult.OK;
 			this.Close();

LibationWinForms/Dialogs/SettingsDialog.cs

@@ -108,47 +108,44 @@ namespace LibationWinForms.Dialogs
 		private void chapterFileTemplateBtn_Click(object sender, EventArgs e) => editTemplate(Templates.ChapterFile, chapterFileTemplateTb);
 		private static void editTemplate(Templates template, TextBox textBox)
 		{
-			TEMP_TEMP_TEMP();
-			return;
-
 			var form = new EditTemplateDialog(template, textBox.Text);
 			if (form.ShowDialog() == DialogResult.OK)
 				textBox.Text = form.TemplateText;
 		}
 
-		private static void TEMP_TEMP_TEMP()
-			=> MessageBox.Show("Sorry, not yet. Coming soon :)");
-
 		private void saveBtn_Click(object sender, EventArgs e)
 		{
 			var newBooks = booksSelectControl.SelectedDirectory;
 
 			#region validation
+			static void validationError(string text, string caption)
+				=> MessageBox.Show(text, caption, MessageBoxButtons.OK, MessageBoxIcon.Error);
 			if (string.IsNullOrWhiteSpace(newBooks))
 			{
-				MessageBox.Show("Cannot set Books Location to blank", "Location is blank", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				validationError("Cannot set Books Location to blank", "Location is blank");
 				return;
 			}
 
 			if (!Directory.Exists(newBooks) && booksSelectControl.SelectedDirectoryIsCustom)
 			{
-				MessageBox.Show($"Not saving change to Books location. This folder does not exist:\r\n{newBooks}", "Folder does not exist", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				validationError($"Not saving change to Books location. This folder does not exist:\r\n{newBooks}", "Folder does not exist");
 				return;
 			}
 
+			// these 3 should do nothing. Configuration will only init these with a valid value. EditTemplateDialog ensures valid before returning
 			if (!Templates.Folder.IsValid(folderTemplateTb.Text))
 			{
-				MessageBox.Show($"Not saving change to folder naming template. Invalid format.", "Invalid folder template", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				validationError($"Not saving change to folder naming template. Invalid format.", "Invalid folder template");
 				return;
 			}
 			if (!Templates.File.IsValid(fileTemplateTb.Text))
 			{
-				MessageBox.Show($"Not saving change to file naming template. Invalid format.", "Invalid file template", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				validationError($"Not saving change to file naming template. Invalid format.", "Invalid file template");
 				return;
 			}
 			if (!Templates.ChapterFile.IsValid(chapterFileTemplateTb.Text))
 			{
-				MessageBox.Show($"Not saving change to chapter file naming template. Invalid format.", "Invalid chapter file template", MessageBoxButtons.OK, MessageBoxIcon.Error);
+				validationError($"Not saving change to chapter file naming template. Invalid format.", "Invalid chapter file template");
 				return;
 			}
 			#endregion

LibationWinForms/LibationWinForms.csproj

@@ -29,7 +29,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Dinah.Core.WindowsDesktop" Version="2.0.2.2" />
+    <PackageReference Include="Dinah.Core.WindowsDesktop" Version="2.1.1.1" />
   </ItemGroup>
 
   <ItemGroup>

README.md

@@ -27,6 +27,7 @@
     - [Files and folders](#files-and-folders)
     - [Linux and Mac (unofficial)](#linux-and-mac)
     - [Settings](#settings)
+    - [Custom File Naming](#custom-file-naming)
     - [Command Line Interface](#command-line-interface)
 
 ## Audible audiobook manager
@@ -243,6 +244,12 @@ Although Libation only currently officially supports Windows, [some users](https
 
 * Allow Libation to fix up audiobook metadata. After decrypting a title, Libation attempts to fix details like chapters and cover art. Some power users and/or control freaks prefer to manage this themselves. By unchecking this setting, Libation will only decrypt the book and will leave metadata as-is, warts and all.
 
+### Custom File Naming
+
+In Settings, on the Download/Decrypt tab, you can specify the format in which you want your files to be named. As you edit these templates, a live example will be shown. Parameters are listed for folders, files, and files split by chapter including an explanation of what each naming option means. For instance: you can use template `<title short> - <ch# 0> of <ch count> - <ch title>` to create the file `A Study in Scarlet - 04 of 10 - A Flight for Life.m4b`.
+
+These templates apply to GUI and CLI.
+
 ### Command Line Interface
 
 Libationcli.exe allows limited access to Libation's functionalities as a CLI.

_Tests/FileLiberator.Tests/AudioFileStorageExtTests.cs

@@ -1,69 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using Dinah.Core;
-using FileLiberator;
-using FluentAssertions;
-using Microsoft.VisualStudio.TestTools.UnitTesting;
-
-using static AudioFileStorageExtTests.Shared;
-
-namespace AudioFileStorageExtTests
-{
-	public static class Shared
-	{
-		public static DataLayer.LibraryBook GetLibraryBook(string asin)
-		{
-			var book = new DataLayer.Book(new DataLayer.AudibleProductId(asin), "title", "desc", 1, DataLayer.ContentType.Product, new List<DataLayer.Contributor> { new DataLayer.Contributor("author") }, new List<DataLayer.Contributor> { new DataLayer.Contributor("narrator") }, new DataLayer.Category(new DataLayer.AudibleCategoryId("seriesId"), "name"), "us");
-			var libraryBook = new DataLayer.LibraryBook(book, DateTime.Now, "my us");
-			return libraryBook;
-		}
-	}
-
-	[TestClass]
-	public class MultipartRenamer_MultipartFilename
-	{
-		[TestMethod]
-		[DataRow("asin", "[<id>] <ch# 0> of <ch count> - <ch title>", @"C:\foo\", "txt", 6, 10, "chap", @"C:\foo\[asin] 06 of 10 - chap.txt")]
-		[DataRow("asin", "<ch#>", @"C:\foo\", "txt", 6, 10, "chap", @"C:\foo\6.txt")]
-		public void Tests(string asin, string template, string dir, string ext, int pos, int total, string chapter, string expected)
-			=> new AudioFileStorageExt.MultipartRenamer(GetLibraryBook(asin))
-			.MultipartFilename(template, dir, ext, pos, total, chapter)
-			.Should().Be(expected);
-	}
-
-	[TestClass]
-	public class GetFileTemplateSingle
-	{
-		[TestMethod]
-		[DataRow(null, "asin", @"C:\", "ext")]
-		[DataRow("f.txt", null, @"C:\", "ext")]
-		[DataRow("f.txt", "asin", null, "ext")]
-		[ExpectedException(typeof(ArgumentNullException))]
-		public void arg_null_exception(string template, string asin, string dirFullPath, string extension)
-			=> AudioFileStorageExt.GetFileTemplateSingle(template, GetLibraryBook(asin), dirFullPath, extension);
-
-		[TestMethod]
-		[DataRow("", "asin", @"C:\foo\bar", "ext")]
-		[DataRow("   ", "asin", @"C:\foo\bar", "ext")]
-		[DataRow("f.txt", "", @"C:\foo\bar", "ext")]
-		[DataRow("f.txt", "   ", @"C:\foo\bar", "ext")]
-		[DataRow("f.txt", "asin", "", "ext")]
-		[DataRow("f.txt", "asin", "   ", "ext")]
-		[ExpectedException(typeof(ArgumentException))]
-		public void arg_exception(string template, string asin, string dirFullPath, string extension)
-			=> AudioFileStorageExt.GetFileTemplateSingle(template, GetLibraryBook(asin), dirFullPath, extension);
-
-		[TestMethod]
-		public void null_extension() => Tests("f.txt", "asin", @"C:\foo\bar", null, @"C:\foo\bar\f.txt");
-
-		[TestMethod]
-		[DataRow("f.txt", "asin", @"C:\foo\bar", "ext", @"C:\foo\bar\f.txt.ext")]
-		[DataRow("f", "asin", @"C:\foo\bar", "ext", @"C:\foo\bar\f.ext")]
-		[DataRow("<id>", "asin", @"C:\foo\bar", "ext", @"C:\foo\bar\asin.ext")]
-		public void Tests(string template, string asin, string dirFullPath, string extension, string expected)
-			=> AudioFileStorageExt.GetFileTemplateSingle(template, GetLibraryBook(asin), dirFullPath, extension)
-			.GetFilePath()
-			.Should().Be(expected);
-	}
-}

_Tests/FileManager.Tests/FileNamingTemplateTests.cs

@@ -7,7 +7,7 @@ using FileManager;
 using FluentAssertions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace FileTemplateTests
+namespace FileNamingTemplateTests
 {
 	[TestClass]
 	public class GetFilePath
@@ -17,7 +17,7 @@ namespace FileTemplateTests
 		{
 			var expected = @"C:\foo\bar\my_ book LONG_1234567890_1234567890_1234567890_123 [ID123456].txt";
 			var f1 = OLD_GetValidFilename(@"C:\foo\bar", "my: book LONG_1234567890_1234567890_1234567890_12345", "txt", "ID123456");
-			var f2 = NEW_GetValidFilename_FileTemplate(@"C:\foo\bar", "my: book LONG_1234567890_1234567890_1234567890_12345", "txt", "ID123456");
+			var f2 = NEW_GetValidFilename_FileNamingTemplate(@"C:\foo\bar", "my: book LONG_1234567890_1234567890_1234567890_12345", "txt", "ID123456");
 
 			f1.Should().Be(expected);
 			f1.Should().Be(f2);
@@ -49,16 +49,16 @@ namespace FileTemplateTests
 
 			return fullfilename;
 		}
-		private static string NEW_GetValidFilename_FileTemplate(string dirFullPath, string filename, string extension, string metadataSuffix)
+		private static string NEW_GetValidFilename_FileNamingTemplate(string dirFullPath, string filename, string extension, string metadataSuffix)
 		{
 			var template = $"<title> [<id>]";
 
 			var fullfilename = Path.Combine(dirFullPath, template + FileUtility.GetStandardizedExtension(extension));
 
-			var fileTemplate = new FileTemplate(fullfilename) { IllegalCharacterReplacements = "_" };
-			fileTemplate.AddParameterReplacement("title", filename);
-			fileTemplate.AddParameterReplacement("id", metadataSuffix);
-			return fileTemplate.GetFilePath();
+			var fileNamingTemplate = new FileNamingTemplate(fullfilename) { IllegalCharacterReplacements = "_" };
+			fileNamingTemplate.AddParameterReplacement("title", filename);
+			fileNamingTemplate.AddParameterReplacement("id", metadataSuffix);
+			return fileNamingTemplate.GetFilePath();
 		}
 
 		[TestMethod]
@@ -66,7 +66,7 @@ namespace FileTemplateTests
 		{
 			var expected = @"C:\foo\bar\my file - 002 - title.txt";
 			var f1 = OLD_GetMultipartFileName(@"C:\foo\bar\my file.txt", 2, 100, "title");
-			var f2 = NEW_GetMultipartFileName_FileTemplate(@"C:\foo\bar\my file.txt", 2, 100, "title");
+			var f2 = NEW_GetMultipartFileName_FileNamingTemplate(@"C:\foo\bar\my file.txt", 2, 100, "title");
 
 			f1.Should().Be(expected);
 			f1.Should().Be(f2);
@@ -89,7 +89,7 @@ namespace FileTemplateTests
 			var path = Path.Combine(Path.GetDirectoryName(originalPath), fileName + extension);
 			return path;
 		}
-		private static string NEW_GetMultipartFileName_FileTemplate(string originalPath, int partsPosition, int partsTotal, string suffix)
+		private static string NEW_GetMultipartFileName_FileNamingTemplate(string originalPath, int partsPosition, int partsTotal, string suffix)
 		{
 			// 1-9     => 1-9
 			// 10-99   => 01-99
@@ -98,11 +98,18 @@ namespace FileTemplateTests
 
 			var t = Path.ChangeExtension(originalPath, null) + " - <chapter> - <title>" + Path.GetExtension(originalPath);
 
-			var fileTemplate = new FileTemplate(t) { IllegalCharacterReplacements = " " };
-			fileTemplate.AddParameterReplacement("chapter", chapterCountLeadingZeros);
-			fileTemplate.AddParameterReplacement("title", suffix);
+			var fileNamingTemplate = new FileNamingTemplate(t) { IllegalCharacterReplacements = " " };
+			fileNamingTemplate.AddParameterReplacement("chapter", chapterCountLeadingZeros);
+			fileNamingTemplate.AddParameterReplacement("title", suffix);
+			return fileNamingTemplate.GetFilePath();
+		}
 
-			return fileTemplate.GetFilePath();
+		[TestMethod]
+		public void remove_slashes()
+		{
+			var fileNamingTemplate = new FileNamingTemplate(@"\foo\<title>.txt");
+			fileNamingTemplate.AddParameterReplacement("title", @"s\l/a\s/h\e/s");
+			fileNamingTemplate.GetFilePath().Should().Be(@"\foo\slashes.txt");
 		}
 	}
 }

_Tests/LibationFileManager.Tests/TemplatesTests.cs

@@ -7,8 +7,26 @@ using FluentAssertions;
 using LibationFileManager;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
+using static TemplatesTests.Shared;
+
 namespace TemplatesTests
 {
+	public static class Shared
+	{
+		public static LibraryBookDto GetLibraryBook(string asin)
+			=> new()
+			{
+				Account = "my account",
+				AudibleProductId = asin,
+				Title = "A Study in Scarlet: A Sherlock Holmes Novel",
+				Locale = "us",
+				Authors = new List<string> { "Arthur Conan Doyle", "Stephen Fry - introductions" },
+				Narrators = new List<string> { "Stephen Fry" },
+				SeriesName = "Sherlock Holmes",
+				SeriesNumber = "1"
+			};
+	}
+
 	[TestClass]
 	public class ContainsChapterOnlyTags
 	{
@@ -29,10 +47,71 @@ namespace TemplatesTests
 		[DataRow("<id><ch#>", "ch#", true)]
 		public void Tests(string template, string tag, bool expected) => Templates.ContainsTag(template, tag).Should().Be(expected);
 	}
+
+	[TestClass]
+	public class getFileNamingTemplate
+	{
+		[TestMethod]
+		[DataRow(null, "asin", @"C:\", "ext")]
+		[ExpectedException(typeof(ArgumentNullException))]
+		public void arg_null_exception(string template, string asin, string dirFullPath, string extension)
+			=> Templates.getFileNamingTemplate(GetLibraryBook(asin), template, dirFullPath, extension);
+
+		[TestMethod]
+		[DataRow("", "asin", @"C:\foo\bar", "ext")]
+		[DataRow("   ", "asin", @"C:\foo\bar", "ext")]
+		[ExpectedException(typeof(ArgumentException))]
+		public void arg_exception(string template, string asin, string dirFullPath, string extension)
+			=> Templates.getFileNamingTemplate(GetLibraryBook(asin), template, dirFullPath, extension);
+
+		[TestMethod]
+		public void null_extension() => Tests("f.txt", "asin", @"C:\foo\bar", null, @"C:\foo\bar\f.txt");
+
+		[TestMethod]
+		[DataRow("f.txt", "asin", @"C:\foo\bar", "ext", @"C:\foo\bar\f.txt.ext")]
+		[DataRow("f", "asin", @"C:\foo\bar", "ext", @"C:\foo\bar\f.ext")]
+		[DataRow("<id>", "asin", @"C:\foo\bar", "ext", @"C:\foo\bar\asin.ext")]
+		public void Tests(string template, string asin, string dirFullPath, string extension, string expected)
+			=> Templates.getFileNamingTemplate(GetLibraryBook(asin), template, dirFullPath, extension)
+			.GetFilePath()
+			.Should().Be(expected);
+	}
 }
 
 namespace Templates_Folder_Tests
 {
+	[TestClass]
+	public class GetErrors
+	{
+		[TestMethod]
+		public void null_is_invalid() => Tests(null, new[] { Templates.ERROR_NULL_IS_INVALID });
+
+		[TestMethod]
+		public void empty_is_valid() => valid_tests("");
+
+		[TestMethod]
+		public void whitespace_is_valid() => valid_tests("   ");
+
+		[TestMethod]
+		[DataRow(@"foo")]
+		[DataRow(@"\foo")]
+		[DataRow(@"foo\")]
+		[DataRow(@"\foo\")]
+		[DataRow(@"foo\bar")]
+		[DataRow(@"<id>")]
+		[DataRow(@"<id>\<title>")]
+		public void valid_tests(string template) => Tests(template, Array.Empty<string>());
+
+		[TestMethod]
+		[DataRow(@"C:\", Templates.ERROR_FULL_PATH_IS_INVALID)]
+		public void Tests(string template, params string[] expected)
+		{
+			var result = Templates.Folder.GetErrors(template);
+			result.Count().Should().Be(expected.Length);
+			result.Should().BeEquivalentTo(expected);
+		}
+	}
+
 	[TestClass]
 	public class IsValid
 	{
@@ -58,36 +137,64 @@ namespace Templates_Folder_Tests
 	}
 
 	[TestClass]
-	public class IsRecommended
+	public class GetWarnings
 	{
 		[TestMethod]
-		public void null_is_not_recommended() => Tests(null, false);
+		public void null_is_invalid() => Tests(null, new[] { Templates.ERROR_NULL_IS_INVALID });
 
 		[TestMethod]
-		public void empty_is_not_recommended() => Tests("", false);
+		public void empty_has_warnings() => Tests("", Templates.WARNING_EMPTY, Templates.WARNING_NO_TAGS);
 
 		[TestMethod]
-		public void whitespace_is_not_recommended() => Tests("   ", false);
+		public void whitespace_has_warnings() => Tests("   ", Templates.WARNING_WHITE_SPACE, Templates.WARNING_NO_TAGS);
 
 		[TestMethod]
-		[DataRow(@"no tags", false)]
-		[DataRow(@"<id>\foo\bar", true)]
-		[DataRow("<ch#> <id>", false)]
-		[DataRow("<ch#> chapter tag", false)]
-		public void Tests(string template, bool expected) => Templates.Folder.IsRecommended(template).Should().Be(expected);
+		[DataRow(@"<id>\foo\bar")]
+		public void valid_tests(string template) => Tests(template, Array.Empty<string>());
+
+		[TestMethod]
+		[DataRow(@"no tags", Templates.WARNING_NO_TAGS)]
+		[DataRow("<ch#> <id>", Templates.WARNING_HAS_CHAPTER_TAGS)]
+		[DataRow("<ch#> chapter tag", Templates.WARNING_NO_TAGS, Templates.WARNING_HAS_CHAPTER_TAGS)]
+		public void Tests(string template, params string[] expected)
+		{
+			var result = Templates.Folder.GetWarnings(template);
+			result.Count().Should().Be(expected.Length);
+			result.Should().BeEquivalentTo(expected);
+		}
+	}
+
+	[TestClass]
+	public class HasWarnings
+	{
+		[TestMethod]
+		public void null_has_warnings() => Tests(null, true);
+
+		[TestMethod]
+		public void empty_has_warnings() => Tests("", true);
+
+		[TestMethod]
+		public void whitespace_has_warnings() => Tests("   ", true);
+
+		[TestMethod]
+		[DataRow(@"no tags", true)]
+		[DataRow(@"<id>\foo\bar", false)]
+		[DataRow("<ch#> <id>", true)]
+		[DataRow("<ch#> chapter tag", true)]
+		public void Tests(string template, bool expected) => Templates.Folder.HasWarnings(template).Should().Be(expected);
 	}
 
 	[TestClass]
 	public class TagCount
 	{
 		[TestMethod]
-		public void null_is_not_recommended() => Assert.ThrowsException<NullReferenceException>(() => Tests(null, -1));
+		public void null_throws() => Assert.ThrowsException<NullReferenceException>(() => Templates.Folder.TagCount(null));
 
 		[TestMethod]
-		public void empty_is_not_recommended() => Tests("", 0);
+		public void empty() => Tests("", 0);
 
 		[TestMethod]
-		public void whitespace_is_not_recommended() => Tests("   ", 0);
+		public void whitespace() => Tests("   ", 0);
 
 		[TestMethod]
 		[DataRow("no tags", 0)]
@@ -105,6 +212,37 @@ namespace Templates_Folder_Tests
 
 namespace Templates_File_Tests
 {
+	[TestClass]
+	public class GetErrors
+	{
+		[TestMethod]
+		public void null_is_invalid() => Tests(null, new[] { Templates.ERROR_NULL_IS_INVALID });
+
+		[TestMethod]
+		public void empty_is_valid() => valid_tests("");
+
+		[TestMethod]
+		public void whitespace_is_valid() => valid_tests("   ");
+
+		[TestMethod]
+		[DataRow(@"foo")]
+		[DataRow(@"<id>")]
+		public void valid_tests(string template) => Tests(template, Array.Empty<string>());
+
+
+		[TestMethod]
+		[DataRow(@"C:\", Templates.ERROR_INVALID_FILE_NAME_CHAR)]
+		[DataRow(@"\foo", Templates.ERROR_INVALID_FILE_NAME_CHAR)]
+		[DataRow(@"/foo", Templates.ERROR_INVALID_FILE_NAME_CHAR)]
+		[DataRow(@"C:\", Templates.ERROR_INVALID_FILE_NAME_CHAR)]
+		public void Tests(string template, params string[] expected)
+		{
+			var result = Templates.File.GetErrors(template);
+			result.Count().Should().Be(expected.Length);
+			result.Should().BeEquivalentTo(expected);
+		}
+	}
+
 	[TestClass]
 	public class IsValid
 	{
@@ -126,9 +264,13 @@ namespace Templates_File_Tests
 		public void Tests(string template, bool expected) => Templates.File.IsValid(template).Should().Be(expected);
 	}
 
-	// same as Templates.Folder.IsRecommended 
+	// same as Templates.Folder.GetWarnings
 	//[TestClass]
-	//public class IsRecommended { }
+	//public class GetWarnings { }
+
+	// same as Templates.Folder.HasWarnings 
+	//[TestClass]
+	//public class HasWarnings { }
 
 	// same as Templates.Folder.TagCount 
 	//[TestClass]
@@ -137,29 +279,62 @@ namespace Templates_File_Tests
 
 namespace Templates_ChapterFile_Tests
 {
+	// same as Templates.File.GetErrors
+	//[TestClass]
+	//public class GetErrors { }
+
 	// same as Templates.File.IsValid
 	//[TestClass]
 	//public class IsValid { }
 
 	[TestClass]
-	public class IsRecommended
+	public class GetWarnings
 	{
 		[TestMethod]
-		public void null_is_not_recommended() => Tests(null, false);
+		public void null_is_invalid() => Tests(null, new[] { Templates.ERROR_NULL_IS_INVALID });
 
 		[TestMethod]
-		public void empty_is_not_recommended() => Tests("", false);
+		public void empty_has_warnings() => Tests("", Templates.WARNING_EMPTY, Templates.WARNING_NO_TAGS, Templates.WARNING_NO_CHAPTER_NUMBER_TAG);
 
 		[TestMethod]
-		public void whitespace_is_not_recommended() => Tests("   ", false);
+		public void whitespace_has_warnings() => Tests("   ", Templates.WARNING_WHITE_SPACE, Templates.WARNING_NO_TAGS, Templates.WARNING_NO_CHAPTER_NUMBER_TAG);
 
 		[TestMethod]
-		[DataRow(@"no tags", false)]
-		[DataRow(@"<id>\foo\bar", false)]
-		[DataRow("<ch#> <id>", true)]
-		[DataRow("<ch#> -- chapter tag", true)]
-		[DataRow("<chapter count> -- chapter tag but not ch# or ch_#", false)]
-		public void Tests(string template, bool expected) => Templates.ChapterFile.IsRecommended(template).Should().Be(expected);
+		[DataRow("<ch#>")]
+		[DataRow("<ch#> <id>")]
+		public void valid_tests(string template) => Tests(template, Array.Empty<string>());
+
+		[TestMethod]
+		[DataRow(@"no tags", Templates.WARNING_NO_TAGS, Templates.WARNING_NO_CHAPTER_NUMBER_TAG)]
+		[DataRow(@"<id>\foo\bar", Templates.ERROR_INVALID_FILE_NAME_CHAR, Templates.WARNING_NO_CHAPTER_NUMBER_TAG)]
+		[DataRow("<chapter count> -- chapter tag but not ch# or ch_#", Templates.WARNING_NO_TAGS, Templates.WARNING_NO_CHAPTER_NUMBER_TAG)]
+		public void Tests(string template, params string[] expected)
+		{
+			var result = Templates.ChapterFile.GetWarnings(template);
+			result.Count().Should().Be(expected.Length);
+			result.Should().BeEquivalentTo(expected);
+		}
+	}
+
+	[TestClass]
+	public class HasWarnings
+	{
+		[TestMethod]
+		public void null_has_warnings() => Tests(null, true);
+
+		[TestMethod]
+		public void empty_has_warnings() => Tests("", true);
+
+		[TestMethod]
+		public void whitespace_has_warnings() => Tests("   ", true);
+
+		[TestMethod]
+		[DataRow(@"no tags", true)]
+		[DataRow(@"<id>\foo\bar", true)]
+		[DataRow("<ch#> <id>", false)]
+		[DataRow("<ch#> -- chapter tag", false)]
+		[DataRow("<chapter count> -- chapter tag but not ch# or ch_#", true)]
+		public void Tests(string template, bool expected) => Templates.ChapterFile.HasWarnings(template).Should().Be(expected);
 	}
 
 	[TestClass]
@@ -186,4 +361,15 @@ namespace Templates_ChapterFile_Tests
 		[DataRow("<ID> case specific", 0)]
 		public void Tests(string template, int expected) => Templates.ChapterFile.TagCount(template).Should().Be(expected);
 	}
+
+	[TestClass]
+	public class GetPortionFilename
+	{
+		[TestMethod]
+		[DataRow("asin", "[<id>] <ch# 0> of <ch count> - <ch title>", @"C:\foo\", "txt", 6, 10, "chap", @"C:\foo\[asin] 06 of 10 - chap.txt")]
+		[DataRow("asin", "<ch#>", @"C:\foo\", "txt", 6, 10, "chap", @"C:\foo\6.txt")]
+		public void Tests(string asin, string template, string dir, string ext, int pos, int total, string chapter, string expected)
+			=> Templates.ChapterFile.GetPortionFilename(GetLibraryBook(asin), template, new() { OutputFileName = $"xyz.{ext}", PartsPosition = pos, PartsTotal = total, Title = chapter }, dir)
+			.Should().Be(expected);
+	}
 }

__README - COLLABORATORS.txt

@@ -24,7 +24,7 @@ STRUCTURE
 * 2 Utilities (domain ignorant)
   Stand-alone libraries with no knowledge of anything having to do with Libation or other programs. In theory any of these should be able to one day be converted to a nuget pkg
 * 3 Domain Internal Utilities (db ignorant)
-  Can have knowledge of Libation concepts. Cannot access the database.
+  Cannot access the database. Can have knowledge of Libation concepts. Can even have knowledge of some db concepts, but no actual db access.
 * 4 Domain (db)
   All database access
 * 5 Domain Utilities (db aware)