perf: add logging for match key extraction

- Added logging to output the filename and pattern used for matching.
- Improved key extraction logic to handle unsuccessful matches.
- Added logging to output the matched key.

SubRenamer/Matcher/Diff.cs

@@ -105,10 +105,13 @@ public static string ExtractMatchKeyByDiff(DiffResult? diff, string filename)
                 : $"{Regex.Escape(diff.Prefix)}(.+?){Regex.Escape(diff.Suffix)}";
         }
 
+        Logger.Out.WriteLine("[Diff.ExtractMatchKeyByDiff]\n\n  Str=\"{0}\"\n  MatchPattern=\"{1}\"", filename, pattern);
+
+        var key = "";
         var match = Regex.Match(filename, pattern, RegexOptions.IgnoreCase);
-        if (!match.Success || match.Groups.Count == 0) return "";
+        key = (match.Success && match.Groups.Count > 0) ? match.Groups[1].Value.Trim() : "";
 
-        var key = match.Groups[1].Value.Trim();
+        Logger.Out.WriteLine("  MatchedKey=\"{0}\"\n", key);
 
         return key;
     }

SubRenamer/Matcher/Helper.cs

@@ -10,12 +10,16 @@ public static class Helper
 {
     public static string ExtractMatchKeyRegex(string pattern, string filename)
     {
-        try {
+        try
+        {
             var match = Regex.Match(filename, pattern, RegexOptions.IgnoreCase);
             if (match.Success) return match.Groups[1].Value;
-        } catch (Exception e) {
+        }
+        catch (Exception e)
+        {
             Logger.Out.WriteLine(e.Message);
         }
+
         return "";
     }