Add .gitignore style ignoring (#13906)

Emby.Server.Implementations/Library/DotIgnoreIgnoreRule.cs

@@ -0,0 +1,77 @@
+using System;
+using System.IO;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Resolvers;
+using MediaBrowser.Model.IO;
+
+namespace Emby.Server.Implementations.Library;
+
+/// <summary>
+/// Resolver rule class for ignoring files via .ignore.
+/// </summary>
+public class DotIgnoreIgnoreRule : IResolverIgnoreRule
+{
+    private static FileInfo? FindIgnoreFile(DirectoryInfo directory)
+    {
+        var ignoreFile = new FileInfo(Path.Join(directory.FullName, ".ignore"));
+        if (ignoreFile.Exists)
+        {
+            return ignoreFile;
+        }
+
+        var parentDir = directory.Parent;
+        if (parentDir == null || parentDir.FullName == directory.FullName)
+        {
+            return null;
+        }
+
+        return FindIgnoreFile(parentDir);
+    }
+
+    /// <inheritdoc />
+    public bool ShouldIgnore(FileSystemMetadata fileInfo, BaseItem? parent)
+    {
+        return IsIgnored(fileInfo, parent);
+    }
+
+    /// <summary>
+    /// Checks whether or not the file is ignored.
+    /// </summary>
+    /// <param name="fileInfo">The file information.</param>
+    /// <param name="parent">The parent BaseItem.</param>
+    /// <returns>True if the file should be ignored.</returns>
+    public static bool IsIgnored(FileSystemMetadata fileInfo, BaseItem? parent)
+    {
+        var parentDirPath = Path.GetDirectoryName(fileInfo.FullName);
+        if (string.IsNullOrEmpty(parentDirPath))
+        {
+            return false;
+        }
+
+        var folder = new DirectoryInfo(parentDirPath);
+        var ignoreFile = FindIgnoreFile(folder);
+        if (ignoreFile is null)
+        {
+            return false;
+        }
+
+        string ignoreFileString;
+        using (var reader = ignoreFile.OpenText())
+        {
+            ignoreFileString = reader.ReadToEnd();
+        }
+
+        if (string.IsNullOrEmpty(ignoreFileString))
+        {
+            // Ignore directory if we just have the file
+            return true;
+        }
+
+        // If file has content, base ignoring off the content .gitignore-style rules
+        var ignoreRules = ignoreFileString.Split('\n', StringSplitOptions.RemoveEmptyEntries);
+        var ignore = new Ignore.Ignore();
+        ignore.Add(ignoreRules);
+
+        return ignore.IsIgnored(fileInfo.FullName);
+    }
+}