1 files changed, 52 insertions, 0 deletions
diff --git a/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalFileLookup.cs b/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalFileLookup.cs
new file mode 100644
index 00000000..414b569b
--- /dev/null
+++ b/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalFileLookup.cs
@@ -0,0 +1,52 @@
+using System.Collections.Generic;
+using System.IO;
+
+namespace StardewModdingAPI.Toolkit.Utilities.PathLookups
+{
+    /// <summary>An API for file lookups within a root directory with minimal preprocessing.</summary>
+    internal class MinimalFileLookup : IFileLookup
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The file lookups by root path.</summary>
+        private static readonly Dictionary<string, MinimalFileLookup> CachedRoots = new();
+
+        /// <summary>The root directory path for relative paths.</summary>
+        private readonly string RootPath;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="rootPath">The root directory path for relative paths.</param>
+        public MinimalFileLookup(string rootPath)
+        {
+            this.RootPath = rootPath;
+        }
+
+        /// <inheritdoc />
+        public FileInfo GetFile(string relativePath)
+        {
+            return new(
+                Path.Combine(this.RootPath, PathUtilities.NormalizePath(relativePath))
+            );
+        }
+
+        /// <inheritdoc />
+        public void Add(string relativePath) { }
+
+        /// <summary>Get a cached dictionary of relative paths within a root path, for case-insensitive file lookups.</summary>
+        /// <param name="rootPath">The root path to scan.</param>
+        public static MinimalFileLookup GetCachedFor(string rootPath)
+        {
+            rootPath = PathUtilities.NormalizePath(rootPath);
+
+            if (!MinimalFileLookup.CachedRoots.TryGetValue(rootPath, out MinimalFileLookup? lookup))
+                MinimalFileLookup.CachedRoots[rootPath] = lookup = new MinimalFileLookup(rootPath);
+
+            return lookup;
+        }
+    }
+}