Why is it so complicated to multiply some numbers

Using this method when running TaskExecutor.UpdateChapters to get a list of all chapters that have not yet been downloaded.

Tranga-CLI/Tranga_Cli.cs

@@ -78,15 +78,15 @@ public static class Tranga_Cli
                     string? query = Console.ReadLine();
                     while (query is null || query.Length < 1)
                         query = Console.ReadLine();
-                    PrintTasks(taskManager.GetAllTasks().Where(task =>
+                    PrintTasks(taskManager.GetAllTasks().Where(qTask =>
-                        ((Publication)task.publication!).sortName.ToLower()
+                        ((Publication)qTask.publication!).sortName.ToLower()
                         .Contains(query, StringComparison.OrdinalIgnoreCase)).ToArray());
                     Console.WriteLine("Press any key.");
                     Console.ReadKey();
                     menu = 0;
                     break; 
                 case 6:
-                    PrintTasks(taskManager.GetAllTasks().Where(task => task.isBeingExecuted).ToArray());
+                    PrintTasks(taskManager.GetAllTasks().Where(eTask => eTask.isBeingExecuted).ToArray());
                     Console.WriteLine("Press any key.");
                     Console.ReadKey();
                     menu = 0;
@@ -130,6 +130,7 @@ public static class Tranga_Cli
             selection = Console.ReadKey().Key;
             taskManager.Shutdown(selection == ConsoleKey.Y);
         }else
+            // ReSharper disable once RedundantArgumentDefaultValue Better readability
             taskManager.Shutdown(false);
     }
 
@@ -160,7 +161,7 @@ public static class Tranga_Cli
         int tIndex = 0;
         Console.WriteLine($"Tasks (Running/Total): {taskRunningCount}/{taskCount}");
         foreach(TrangaTask trangaTask in tasks)
-            Console.WriteLine($"{tIndex++:000}: {trangaTask.ToString()}");
+            Console.WriteLine($"{tIndex++:000}: {trangaTask}");
     }
 
     private static void ExecuteTaskNow(TaskManager taskManager)
@@ -315,7 +316,7 @@ public static class Tranga_Cli
             selected = Console.ReadLine();
 
         int start = 0;
-        int end = 0;
+        int end;
         if (selected == "a")
             end = chapters.Length - 1;
         else if (selected.Contains('-'))

Tranga/Chapter.cs

@@ -13,16 +13,21 @@ public struct Chapter
     public string? chapterNumber { get; }
     public string url { get; }
     public string fileName { get; }
+    public string sortNumber { get; }
 
     public Chapter(string? name, string? volumeNumber, string? chapterNumber, string url)
     {
         this.name = name;
-        this.volumeNumber = volumeNumber;
+        this.volumeNumber = volumeNumber is { Length: > 0 } ? volumeNumber : "1";
         this.chapterNumber = chapterNumber;
         this.url = url;
         string chapterName = string.Concat((name ?? "").Split(Path.GetInvalidFileNameChars()));
-        double multiplied = Convert.ToDouble(chapterNumber, new NumberFormatInfo() { NumberDecimalSeparator = "." }) *
+        NumberFormatInfo nfi = new NumberFormatInfo()
-                            Convert.ToInt32(volumeNumber);
+        {
-        this.fileName = $"{chapterName} - V{volumeNumber}C{chapterNumber} - {multiplied.ToString(new NumberFormatInfo() { NumberDecimalSeparator = "." })}";
+            NumberDecimalSeparator = "."
+        };
+        sortNumber = decimal.Round(Convert.ToDecimal(this.volumeNumber) * Convert.ToDecimal(this.chapterNumber, nfi), 1)
+            .ToString(nfi);
+        this.fileName = $"{chapterName} - V{volumeNumber}C{chapterNumber} - {sortNumber}";
     }
 }

Tranga/Connector.cs

@@ -68,16 +68,28 @@ public abstract class Connector
             File.WriteAllText(seriesInfoPath,publication.GetSeriesInfoJson());
     }
 
-    public static string CreateComicInfo(Publication publication, Chapter chapter)
+    protected static string CreateComicInfo(Publication publication, Chapter chapter)
     {
         XElement comicInfo = new XElement("ComicInfo",
             new XElement("Tags", string.Join(',',publication.tags)),
             new XElement("LanguageISO", publication.originalLanguage),
-            new XElement("Title", chapter.name)
+            new XElement("Title", chapter.name),
+            new XElement("Volume", chapter.volumeNumber),
+            new XElement("Number", chapter.sortNumber)
         );
         return comicInfo.ToString();
     }
 
+    public bool ChapterIsDownloaded(Publication publication, Chapter chapter)
+    {
+        return File.Exists(CreateFullFilepath(publication, chapter));
+    }
+
+    protected string CreateFullFilepath(Publication publication, Chapter chapter)
+    {
+        return Path.Join(downloadLocation, publication.folderName, chapter.fileName);
+    }
+    
     /// <summary>
     /// Downloads Image from URL and saves it to the given path(incl. fileName)
     /// </summary>
@@ -98,6 +110,7 @@ public abstract class Connector
     /// <param name="imageUrls">List of URLs to download Images from</param>
     /// <param name="saveArchiveFilePath">Full path to save archive to (without file ending .cbz)</param>
     /// <param name="downloadClient">DownloadClient of the connector</param>
+    /// <param name="comicInfoPath">Path of the generate Chapter ComicInfo.xml, if it was generated</param>
     protected static void DownloadChapterImages(string[] imageUrls, string saveArchiveFilePath, DownloadClient downloadClient, string? comicInfoPath = null)
     {
         //Check if Publication Directory already exists
@@ -118,7 +131,7 @@ public abstract class Connector
         foreach (string imageUrl in imageUrls)
         {
             string[] split = imageUrl.Split('.');
-            string extension = split[split.Length - 1];
+            string extension = split[^1];
             DownloadImage(imageUrl, Path.Join(tempFolder, $"{chapter++}.{extension}"), downloadClient);
         }
         

Tranga/Connectors/MangaDex.cs

@@ -49,7 +49,7 @@ public class MangaDex : Connector
                 
                 string title = attributes["title"]!.AsObject().ContainsKey("en") && attributes["title"]!["en"] is not null
                     ? attributes["title"]!["en"]!.GetValue<string>()
-                    : "";
+                    : attributes["title"]![((IDictionary<string, JsonNode?>)attributes["title"]!.AsObject()).Keys.First()]!.GetValue<string>();
 
                 string? description = attributes["description"]!.AsObject().ContainsKey("en") && attributes["description"]!["en"] is not null
                     ? attributes["description"]!["en"]!.GetValue<string?>()
@@ -201,7 +201,7 @@ public class MangaDex : Connector
         File.WriteAllText(comicInfoPath, CreateComicInfo(publication, chapter));
         
         //Download Chapter-Images
-        DownloadChapterImages(imageUrls.ToArray(), Path.Join(downloadLocation, publication.folderName, chapter.fileName), this.downloadClient, comicInfoPath);
+        DownloadChapterImages(imageUrls.ToArray(), CreateFullFilepath(publication, chapter), downloadClient, comicInfoPath);
     }
 
     public override void DownloadCover(Publication publication)
@@ -224,13 +224,13 @@ public class MangaDex : Connector
         if (result is null)
             return;
 
-        string fileName = result!["data"]!["attributes"]!["fileName"]!.GetValue<string>();
+        string fileName = result["data"]!["attributes"]!["fileName"]!.GetValue<string>();
 
         string coverUrl = $"https://uploads.mangadex.org/covers/{publication.downloadUrl}/{fileName}";
         
         //Get file-extension (jpg, png)
         string[] split = coverUrl.Split('.');
-        string extension = split[split.Length - 1];
+        string extension = split[^1];
 
         string outFolderPath = Path.Join(downloadLocation, publication.folderName);
         Directory.CreateDirectory(outFolderPath);

Tranga/Publication.cs

@@ -5,10 +5,12 @@ namespace Tranga;
 /// <summary>
 /// Contains information on a Publication (Manga)
 /// </summary>
-public struct Publication
+public readonly struct Publication
 {
     public string sortName { get; }
+    // ReSharper disable UnusedAutoPropertyAccessor.Global we need it, trust
     [JsonIgnore]public string[,] altTitles { get; }
+    // ReSharper disable trice MemberCanBePrivate.Global, trust
     public string? description { get; }
     public string[] tags { get; }
     public string? posterUrl { get; }
@@ -31,7 +33,7 @@ public struct Publication
         this.originalLanguage = originalLanguage;
         this.status = status;
         this.downloadUrl = downloadUrl;
-        this.folderName = string.Concat(sortName.Split(Path.GetInvalidPathChars()));
+        this.folderName = string.Concat(sortName.Split(Path.GetInvalidPathChars().Concat(Path.GetInvalidFileNameChars()).ToArray()));
     }
 
     /// <summary>
@@ -47,6 +49,7 @@ public struct Publication
     //Only for series.json
     private struct SeriesInfo
     {
+        // ReSharper disable once UnusedAutoPropertyAccessor.Local we need it, trust
         [JsonRequired]public Metadata metadata { get; }
         public SeriesInfo(Metadata metadata) => this.metadata = metadata;
     }
@@ -54,6 +57,7 @@ public struct Publication
     //Only for series.json what an abomination, why are all the fields not-null????
     private struct Metadata
     {
+        // ReSharper disable UnusedAutoPropertyAccessor.Local we need it, trust
         [JsonRequired] public string type { get; }
         [JsonRequired] public string publisher { get; }
         // ReSharper disable twice IdentifierTypo

Tranga/TaskExecutor.cs

@@ -93,14 +93,11 @@ public static class TaskExecutor
     private static List<Chapter> UpdateChapters(Connector connector, Publication publication, string language, Dictionary<Publication, List<Chapter>> chapterCollection)
     {
         List<Chapter> newChaptersList = new();
-        if (!chapterCollection.ContainsKey(publication))
+        chapterCollection.TryAdd(publication, newChaptersList); //To ensure publication is actually in collection
-            return newChaptersList;
         
-        List<Chapter> currentChapters = chapterCollection[publication];
         Chapter[] newChapters = connector.GetChapters(publication, language);
+        newChaptersList = newChapters.Where(nChapter => !connector.ChapterIsDownloaded(publication, nChapter)).ToList();
         
-        newChaptersList = newChapters.ToList()
-            .ExceptBy(currentChapters.Select(cChapter => cChapter.url), nChapter => nChapter.url).ToList();
         return newChaptersList;
     }
 }

Tranga/TaskManager.cs

@@ -12,8 +12,7 @@ public class TaskManager
     private readonly Dictionary<Publication, List<Chapter>> _chapterCollection;
     private readonly HashSet<TrangaTask> _allTasks;
     private bool _continueRunning = true;
-    private readonly Connector[] connectors;
+    private readonly Connector[] _connectors;
-    private readonly string folderPath;
 
     /// <summary>
     /// 
@@ -21,8 +20,7 @@ public class TaskManager
     /// <param name="folderPath">Local path to save data (Manga) to</param>
     public TaskManager(string folderPath)
     {
-        this.folderPath = folderPath;
+        this._connectors = new Connector[]{ new MangaDex(folderPath) };
-        this.connectors = new Connector[]{ new MangaDex(folderPath) };
         _chapterCollection = new();
         _allTasks = ImportTasks(Directory.GetCurrentDirectory());
         Thread taskChecker = new(TaskCheckerThread);
@@ -36,7 +34,7 @@ public class TaskManager
             foreach (TrangaTask task in _allTasks)
             {
                 if(task.ShouldExecute()) 
-                    TaskExecutor.Execute(this.connectors, task, this._chapterCollection);
+                    TaskExecutor.Execute(this._connectors, task, this._chapterCollection); //Might crash here, when adding new Task while another Task is running. Check later
             }
             Thread.Sleep(1000);
         }
@@ -53,7 +51,7 @@ public class TaskManager
         
         Task t = new Task(() =>
         {
-            TaskExecutor.Execute(this.connectors, task, this._chapterCollection);
+            TaskExecutor.Execute(this._connectors, task, this._chapterCollection);
         });
         t.Start();
     }
@@ -71,7 +69,7 @@ public class TaskManager
         string language = "")
     {
         //Get appropriate Connector from available Connectors for TrangaTask
-        Connector? connector = connectors.FirstOrDefault(c => c.name == connectorName);
+        Connector? connector = _connectors.FirstOrDefault(c => c.name == connectorName);
         if (connector is null)
             throw new ArgumentException($"Connector {connectorName} is not a known connector.");
         
@@ -108,7 +106,7 @@ public class TaskManager
     /// <returns>All available Connectors</returns>
     public Dictionary<string, Connector> GetAvailableConnectors()
     {
-        return this.connectors.ToDictionary(connector => connector.name, connector => connector);
+        return this._connectors.ToDictionary(connector => connector.name, connector => connector);
     }
 
     /// <summary>

Tranga/TrangaTask.cs

@@ -7,6 +7,8 @@ namespace Tranga;
 /// </summary>
 public class TrangaTask
 {
+    // ReSharper disable once CommentTypo ...tell me why!
+    // ReSharper disable once MemberCanBePrivate.Global I want it thaaat way
     public TimeSpan reoccurrence { get; }
     public DateTime lastExecuted { get; set; }
     public string connectorName { get; }