1 files changed, 30 insertions, 9 deletions
diff --git a/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalPathLookup.cs b/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalPathLookup.cs
index 2cf14704..414b569b 100644
--- a/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalPathLookup.cs
+++ b/src/SMAPI.Toolkit/Utilities/PathLookups/MinimalPathLookup.cs
@@ -1,31 +1,52 @@
+using System.Collections.Generic;
+using System.IO;
+
 namespace StardewModdingAPI.Toolkit.Utilities.PathLookups
 {
-    /// <summary>An API for relative path lookups within a root directory with minimal preprocessing.</summary>
-    internal class MinimalPathLookup : IFilePathLookup
+    /// <summary>An API for file lookups within a root directory with minimal preprocessing.</summary>
+    internal class MinimalFileLookup : IFileLookup
     {
         /*********
         ** Accessors
         *********/
-        /// <summary>A singleton instance for reuse.</summary>
-        public static readonly MinimalPathLookup Instance = new();
+        /// <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
         *********/
-        /// <inheritdoc />
-        public string GetFilePath(string relativePath)
+        /// <summary>Construct an instance.</summary>
+        /// <param name="rootPath">The root directory path for relative paths.</param>
+        public MinimalFileLookup(string rootPath)
         {
-            return PathUtilities.NormalizePath(relativePath);
+            this.RootPath = rootPath;
         }
 
         /// <inheritdoc />
-        public string GetAssetName(string relativePath)
+        public FileInfo GetFile(string relativePath)
         {
-            return PathUtilities.NormalizeAssetName(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;
+        }
     }
 }