Fix double-tagging when file already has a release prefix

Fansub descriptor brackets like [Multiple Subtitle] or [Dual Audio]
were being misread as release group names because their individual
words didn't match any known metadata pattern. This caused a bogus
tag to be stacked in front of files that already carried their own
[Group] prefix (e.g. Erai-raws releases).

- Recognize common multi-word fansub descriptors (Multi(ple) Sub(s),
  Dual/Multi Audio, Hard/Soft sub, Uncensored/Batch/Complete, etc.)
  as metadata via whole-phrase matching in IsMetadataBracket.
- Never prepend a derived release tag when the file's own filename
  already starts with a different bracket prefix, preventing any
  tag from being stacked on top of an existing one.

Futonizer.csproj

@@ -9,8 +9,8 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <AssemblyName>Futonizer</AssemblyName>
     <RootNamespace>Futonizer</RootNamespace>
-    <Version>1.0.6</Version>
-    <FileVersion>1.0.6.0</FileVersion>
+    <Version>1.0.10</Version>
+    <FileVersion>1.0.10.0</FileVersion>
     <ApplicationIcon>Assets\app.ico</ApplicationIcon>
   </PropertyGroup>
 

Services/FileNameHelper.cs

@@ -14,11 +14,28 @@ public static class FileNameHelper
     private static readonly Regex FolderSuffixTagRegex =
         new(@"-([A-Z][A-Z0-9]{1,7})$", RegexOptions.Compiled);
 
+    // Folder suffix bracket release tag:  "Show Name ... x264 [i_c]"  →  tag = "i_c"
+    // A bracketed tag at the very end of the folder name (as opposed to
+    // PrefixTagRegex, which matches one at the start).
+    private static readonly Regex FolderSuffixBracketTagRegex =
+        new(@"\[([^\[\]]+)\]$", RegexOptions.Compiled);
+
     // File suffix release tag:  "…HEVC-DemiHuman"  →  tag = "DemiHuman"
     // Mixed case, 3-21 chars (no dots/spaces), at end of filename stem.
-    // Min 3 chars avoids false-positives like "-v2" or "-HD".
+    // Min 3 chars avoids false-positives like "-v2" or "-HD". The word
+    // immediately preceding the dash must itself be recognisable quality/
+    // source/codec metadata (checked by the caller via IsMetadataToken), so
+    // an ordinary hyphenated title word (e.g. "Scary-oke") is never mistaken
+    // for a "-GroupName" suffix.
     private static readonly Regex FileSuffixTagRegex =
-        new(@"-([A-Za-z][A-Za-z0-9]{2,20})$", RegexOptions.Compiled);
+        new(@"(?:^|[\s.])([A-Za-z0-9]+)-([A-Za-z][A-Za-z0-9]{2,20})$", RegexOptions.Compiled);
+
+    // Trailing parenthesised metadata block ending in the release group as its
+    // last word, e.g. "... (1080p AMZN WEB-DL x265 Celdra)" → group="Celdra".
+    // Common on Amazon/streaming rips that don't set the group off with a
+    // "-" or its own brackets.
+    private static readonly Regex TrailingParenGroupRegex =
+        new(@"\(([^()]*)\)$", RegexOptions.Compiled);
 
     // Prefix release tag:  "[KAA] Show Name"  →  tag = "KAA"
     private static readonly Regex PrefixTagRegex =
@@ -45,10 +62,24 @@ public static class FileNameHelper
         new(@"^(BD|BluRay|Blu-Ray|WEB|WEB-DL|WEBRip|HDTV|AMZN|NF|DSNP|HULU|MAX)$",RegexOptions.IgnoreCase | RegexOptions.Compiled), // sources
         new(@"^(Remux|Encode)$",                                                   RegexOptions.IgnoreCase | RegexOptions.Compiled), // processing
         new(@"^(HEVC|AVC|x264|x265|H\.?264|H\.?265|VP9)$",                        RegexOptions.IgnoreCase | RegexOptions.Compiled), // video codecs
-        new(@"^(FLAC|AAC|DTS|TrueHD|Atmos|AC3|EAC3|Opus|MP3)$",                  RegexOptions.IgnoreCase | RegexOptions.Compiled), // audio codecs
+        new(@"^(FLAC|AAC|DTS(-HD)?|TrueHD|Atmos|E?AC3|DDP?|Opus|MP3)(\d(\.\d)?)?$", RegexOptions.IgnoreCase | RegexOptions.Compiled), // audio codecs (+ optional channel suffix, e.g. DDP5.1)
+        new(@"^\d\.\d$",                                                           RegexOptions.Compiled),                           // bare channel count, e.g. 5.1
         new(@"^(HDR|SDR|10bit|8bit|HDR10|DV|DoVi)$",                              RegexOptions.IgnoreCase | RegexOptions.Compiled), // HDR / bit-depth
     ];
 
+    // Whole-phrase fansub/release descriptor patterns, checked against an
+    // entire bracket's contents rather than word-by-word. Catches common
+    // multi-word descriptors (e.g. "Multiple Subtitle", "Dual Audio") whose
+    // individual words wouldn't otherwise match any MetadataPatterns entry,
+    // so they'd be mistaken for a release group name.
+    private static readonly Regex[] DescriptorPhrasePatterns =
+    [
+        new(@"^Multi(ple)?[\s-]?Sub(s|title|titles)?$", RegexOptions.IgnoreCase | RegexOptions.Compiled),
+        new(@"^(Dual|Multi)[\s-]?Audio$",                RegexOptions.IgnoreCase | RegexOptions.Compiled),
+        new(@"^(Hard|Soft)[\s-]?sub(s)?$",               RegexOptions.IgnoreCase | RegexOptions.Compiled),
+        new(@"^(Uncensored|Censored|Batch|Complete)$",   RegexOptions.IgnoreCase | RegexOptions.Compiled),
+    ];
+
     // -------------------------------------------------------------------------
 
     /// <summary>
@@ -56,8 +87,10 @@ public static class FileNameHelper
     /// (in order):
     /// <list type="number">
     ///   <item>Filename suffix tag extraction — a trailing <c>-GroupName</c> on
-    ///         the filename stem is stripped and promoted to a bracket prefix.
-    ///         Takes priority over any folder-derived tag.</item>
+    ///         the filename stem, or a release group tucked in as the last word
+    ///         of a trailing <c>(...)</c> metadata block (e.g. Amazon rips like
+    ///         <c>(1080p AMZN WEB-DL x265 Celdra)</c>), is stripped and promoted
+    ///         to a bracket prefix. Takes priority over any folder-derived tag.</item>
     ///   <item>Show-name injection — if the (now tag-free) filename starts with
     ///         an episode code (e.g. S01E01) the show name is derived from the
     ///         parent folder and prepended.</item>
@@ -75,16 +108,52 @@ public static class FileNameHelper
         string? folder     = Path.GetDirectoryName(sourceFilePath);
         string folderName  = string.IsNullOrEmpty(folder) ? "" : (Path.GetFileName(folder) ?? "");
 
+        // Capture the file's own pre-existing bracket prefix (if any) before any
+        // transformation below, so we never stack a second/different tag on top
+        // of a file that already carries its own release-group prefix.
+        var originalPrefixMatch = PrefixTagRegex.Match(stemNoExt);
+        string? originalPrefixTag = originalPrefixMatch.Success ? originalPrefixMatch.Groups[1].Value : null;
+
         // 1. Extract in-filename suffix tag and remove it from the stem.
-        //    e.g. "...HEVC-DemiHuman" → tag="DemiHuman", stem="...HEVC"
+        //    e.g. "...x264-DemiHuman" → tag="DemiHuman", stem="...x264"
+        //    Only fires when the word right before the dash is itself a
+        //    recognised metadata token (codec/source/etc.), so ordinary
+        //    hyphenated title words are left alone.
         string? fileTag = null;
         var fileSuffixMatch = FileSuffixTagRegex.Match(stemNoExt);
-        if (fileSuffixMatch.Success)
+        if (fileSuffixMatch.Success
+            && IsMetadataToken(fileSuffixMatch.Groups[1].Value)
+            && !IsMetadataToken(fileSuffixMatch.Groups[2].Value))
         {
-            fileTag  = fileSuffixMatch.Groups[1].Value;
-            stemNoExt = stemNoExt[..fileSuffixMatch.Index];
+            fileTag  = fileSuffixMatch.Groups[2].Value;
+            stemNoExt = stemNoExt[..(fileSuffixMatch.Groups[2].Index - 1)];
             fileName  = stemNoExt + ext;
         }
+        else
+        {
+            // 1b. Extract a release group tucked in as the last word of a
+            //     trailing "(...)" metadata block, e.g.
+            //     "... (1080p AMZN WEB-DL x265 Celdra)" → tag="Celdra",
+            //     stem="... (1080p AMZN WEB-DL x265)".
+            var parenMatch = TrailingParenGroupRegex.Match(stemNoExt);
+            if (parenMatch.Success)
+            {
+                string parenContent = parenMatch.Groups[1].Value;
+                var words = parenContent.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+                // Only treat the last word as a release group if the rest of the
+                // block is recognisable quality/source/codec metadata — this
+                // avoids misfiring on unrelated parentheticals like "(2020)" or
+                // "(Dual Audio)" that don't carry a group name.
+                if (words.Length >= 2 && !IsMetadataToken(words[^1]) && words[..^1].Any(IsMetadataToken))
+                {
+                    fileTag = words[^1];
+                    string remaining = string.Join(" ", words[..^1]);
+                    string beforeParen = stemNoExt[..parenMatch.Index].TrimEnd();
+                    stemNoExt = string.IsNullOrEmpty(remaining) ? beforeParen : $"{beforeParen} ({remaining})";
+                    fileName = stemNoExt + ext;
+                }
+            }
+        }
 
         // 2. Determine the release tag: filename suffix > folder tag.
         string? tag = fileTag;
@@ -122,29 +191,44 @@ public static class FileNameHelper
             }
         }
 
-        // 4. Prepend release tag if not already present.
+        // 4. Prepend release tag if not already present. Skip when the file
+        //    already carries its own (different) bracket prefix — never stack
+        //    a second tag on top of an existing one.
         if (!string.IsNullOrEmpty(tag))
         {
-            string tagPrefix = $"[{tag}]";
-            if (!fileName.StartsWith(tagPrefix, StringComparison.OrdinalIgnoreCase))
-                fileName = tagPrefix + " " + fileName;
+            bool differsFromOriginalTag = originalPrefixTag != null
+                && !string.Equals(originalPrefixTag, tag, StringComparison.OrdinalIgnoreCase);
+
+            if (!differsFromOriginalTag)
+            {
+                string tagPrefix = $"[{tag}]";
+                if (!fileName.StartsWith(tagPrefix, StringComparison.OrdinalIgnoreCase))
+                    fileName = tagPrefix + " " + fileName;
+            }
         }
 
         return fileName;
     }
 
     /// <summary>
-    /// Extracts the release tag string (without brackets) from a folder name.
-    /// Suffix pattern (<c>-TAG</c>) takes priority over prefix pattern
-    /// (<c>[TAG]</c>).  Returns <c>null</c> when neither is present.
+    /// Extracts the release tag string (without brackets) from a folder name,
+    /// checking (in priority order): a dash suffix (<c>-TAG</c>), a bracketed
+    /// suffix (<c>[tag]</c> at the end), then a bracketed prefix (<c>[tag]</c>
+    /// at the start). Returns <c>null</c> when none are present.
     /// </summary>
     public static string? ExtractReleaseTag(string folderName)
     {
         var suffixMatch = FolderSuffixTagRegex.Match(folderName);
-        if (suffixMatch.Success) return suffixMatch.Groups[1].Value;
+        if (suffixMatch.Success && !IsMetadataToken(suffixMatch.Groups[1].Value))
+            return suffixMatch.Groups[1].Value;
+
+        var bracketSuffixMatch = FolderSuffixBracketTagRegex.Match(folderName);
+        if (bracketSuffixMatch.Success && !IsMetadataBracket(bracketSuffixMatch.Groups[1].Value))
+            return bracketSuffixMatch.Groups[1].Value;
 
         var prefixMatch = PrefixTagRegex.Match(folderName);
-        if (prefixMatch.Success) return prefixMatch.Groups[1].Value;
+        if (prefixMatch.Success && !IsMetadataBracket(prefixMatch.Groups[1].Value))
+            return prefixMatch.Groups[1].Value;
 
         return null;
     }
@@ -163,6 +247,7 @@ public static class FileNameHelper
     {
         // Strip release tags first.
         string name = FolderSuffixTagRegex.Replace(folderName, "").Trim();
+        name = FolderSuffixBracketTagRegex.Replace(name, "").Trim();
         name = PrefixTagRegex.Replace(name, "").Trim();
 
         // Nothing left, or what remains immediately starts with a bracket — no show name.
@@ -191,4 +276,19 @@ public static class FileNameHelper
             if (pattern.IsMatch(token)) return true;
         return false;
     }
+
+    /// <summary>
+    /// True when every word inside a bracketed block is recognisable quality/
+    /// source/codec metadata (e.g. "[HEVC]", "[1080p-FLAC]"), meaning it's
+    /// just another metadata tag rather than an actual release group name
+    /// (e.g. "[i_c]").
+    /// </summary>
+    private static bool IsMetadataBracket(string content)
+    {
+        string trimmed = content.Trim();
+        if (DescriptorPhrasePatterns.Any(p => p.IsMatch(trimmed))) return true;
+
+        var parts = trimmed.Split(new[] { ' ', '-' }, StringSplitOptions.RemoveEmptyEntries);
+        return parts.Length > 0 && parts.All(IsMetadataToken);
+    }
 }

Services/MkvService.cs

@@ -93,9 +93,12 @@ public class MkvService
 
     /// <summary>
     /// Builds the list of <see cref="TrackItem"/> objects for a file. Video
-    /// tracks are always pre-checked. Exactly one audio track is pre-checked:
-    /// among Japanese/Chinese/undefined-language tracks, a stereo (2-channel)
-    /// track is preferred, otherwise the first matching track in file order.
+    /// tracks are always pre-checked. Exactly one audio track is always
+    /// pre-checked: among Japanese/Chinese/undefined-language tracks, a
+    /// stereo (2-channel) track is preferred, otherwise the first matching
+    /// track in file order. If no such track exists (e.g. only English
+    /// audio), the very first audio track in the file is pre-checked instead,
+    /// so a file is never left with no audio track selected.
     /// Subtitle tracks are never pre-checked — the user picks one via the
     /// track table, and the choice propagates to other queued files.
     /// </summary>
@@ -108,7 +111,8 @@ public class MkvService
             .ToList();
 
         MkvTrack? preferredAudio = eligibleAudio.FirstOrDefault(t => t.Properties?.AudioChannels == 2)
-                                    ?? eligibleAudio.FirstOrDefault();
+                                    ?? eligibleAudio.FirstOrDefault()
+                                    ?? audioTracks.FirstOrDefault();
 
         var items = info.Tracks.Select(t =>
         {