Simplify StackResolver

Emby.Naming/Video/FileStackRule.cs

@@ -0,0 +1,48 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Text.RegularExpressions;
+
+namespace Emby.Naming.Video;
+
+/// <summary>
+/// Regex based rule for file stacking (eg. disc1, disc2).
+/// </summary>
+public class FileStackRule
+{
+    private readonly Regex _tokenRegex;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="FileStackRule"/> class.
+    /// </summary>
+    /// <param name="token">Token.</param>
+    /// <param name="isNumerical">Whether the file stack rule uses numerical or alphabetical numbering.</param>
+    public FileStackRule(string token, bool isNumerical)
+    {
+        _tokenRegex = new Regex(token, RegexOptions.IgnoreCase);
+        IsNumerical = isNumerical;
+    }
+
+    /// <summary>
+    /// Gets a value indicating whether the rule uses numerical or alphabetical numbering.
+    /// </summary>
+    public bool IsNumerical { get; }
+
+    /// <summary>
+    /// Match the input against the rule regex.
+    /// </summary>
+    /// <param name="input">The input.</param>
+    /// <param name="result">The part type and number or <c>null</c>.</param>
+    /// <returns>A value indicating whether the input matched the rule.</returns>
+    public bool Match(string input, [NotNullWhen(true)] out (string StackName, string PartType, string PartNumber)? result)
+    {
+        result = null;
+        var match = _tokenRegex.Match(input);
+        if (!match.Success)
+        {
+            return false;
+        }
+
+        var partType = match.Groups["parttype"].Success ? match.Groups["parttype"].Value : "vol";
+        result = (match.Groups["filename"].Value, partType, match.Groups["number"].Value);
+        return true;
+    }
+}