C#: Fix completion request with case insensitive resource path

Sometimes Visual Studio documents have the root path all in upper case.
Since Godot doesn't support loading resource files with a case insensitive path,
this makes script resource loading to fail when the Godot editor gets code
completion requests from Visual Studio.
This fix allows the resource path part of the path to be case insensitive. It
still doesn't support cases where the rest of the path is also case insensitive.
For that we would need a proper API for comparing paths. However, this fix
should be enough for our current cases.

3 files changed, 57 insertions, 2 deletions

diff --git a/modules/mono/editor/GodotTools/GodotTools.Core/StringExtensions.cs b/modules/mono/editor/GodotTools/GodotTools.Core/StringExtensions.cs
index 7ab5c5fc59..012b69032e 100644
--- a/modules/mono/editor/GodotTools/GodotTools.Core/StringExtensions.cs
+++ b/modules/mono/editor/GodotTools/GodotTools.Core/StringExtensions.cs
@@ -25,8 +25,9 @@ namespace GodotTools.Core
             bool rooted = path.IsAbsolutePath();
 
             path = path.Replace('\\', '/');
+            path = path[path.Length - 1] == '/' ? path.Substring(0, path.Length - 1) : path;
 
-            string[] parts = path.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
+            string[] parts = path.Split(new[] {'/'}, StringSplitOptions.RemoveEmptyEntries);
 
             path = string.Join(Path.DirectorySeparatorChar.ToString(), parts).Trim();
 
diff --git a/modules/mono/editor/GodotTools/GodotTools/Ides/MessagingServer.cs b/modules/mono/editor/GodotTools/GodotTools/Ides/MessagingServer.cs
index 98e8d13be0..17f3339560 100644
--- a/modules/mono/editor/GodotTools/GodotTools/Ides/MessagingServer.cs
+++ b/modules/mono/editor/GodotTools/GodotTools/Ides/MessagingServer.cs
@@ -12,6 +12,7 @@ using GodotTools.IdeMessaging;
 using GodotTools.IdeMessaging.Requests;
 using GodotTools.IdeMessaging.Utils;
 using GodotTools.Internals;
+using GodotTools.Utils;
 using Newtonsoft.Json;
 using Directory = System.IO.Directory;
 using File = System.IO.File;
@@ -362,8 +363,13 @@ namespace GodotTools.Ides
 
             private static async Task<Response> HandleCodeCompletionRequest(CodeCompletionRequest request)
             {
+                // This is needed if the "resource path" part of the path is case insensitive.
+                // However, it doesn't fix resource loading if the rest of the path is also case insensitive.
+                string scriptFileLocalized = FsPathUtils.LocalizePathWithCaseChecked(request.ScriptFile);
+
                 var response = new CodeCompletionResponse {Kind = request.Kind, ScriptFile = request.ScriptFile};
-                response.Suggestions = await Task.Run(() => Internal.CodeCompletionRequest(response.Kind, response.ScriptFile));
+                response.Suggestions = await Task.Run(() =>
+                    Internal.CodeCompletionRequest(response.Kind, scriptFileLocalized ?? request.ScriptFile));
                 return response;
             }
         }
diff --git a/modules/mono/editor/GodotTools/GodotTools/Utils/FsPathUtils.cs b/modules/mono/editor/GodotTools/GodotTools/Utils/FsPathUtils.cs
new file mode 100644
index 0000000000..c6724ccaf7
--- /dev/null
+++ b/modules/mono/editor/GodotTools/GodotTools/Utils/FsPathUtils.cs
@@ -0,0 +1,48 @@
+using System;
+using System.IO;
+using Godot;
+using GodotTools.Core;
+using JetBrains.Annotations;
+
+namespace GodotTools.Utils
+{
+    public static class FsPathUtils
+    {
+        private static readonly string ResourcePath = ProjectSettings.GlobalizePath("res://");
+
+        private static bool PathStartsWithAlreadyNorm(this string childPath, string parentPath)
+        {
+            // This won't work for Linux/macOS case insensitive file systems, but it's enough for our current problems
+            bool caseSensitive = !OS.IsWindows;
+
+            string parentPathNorm = parentPath.NormalizePath() + Path.DirectorySeparatorChar;
+            string childPathNorm = childPath.NormalizePath() + Path.DirectorySeparatorChar;
+
+            return childPathNorm.StartsWith(parentPathNorm,
+                caseSensitive ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase);
+        }
+
+        public static bool PathStartsWith(this string childPath, string parentPath)
+        {
+            string childPathNorm = childPath.NormalizePath() + Path.DirectorySeparatorChar;
+            string parentPathNorm = parentPath.NormalizePath() + Path.DirectorySeparatorChar;
+
+            return childPathNorm.PathStartsWithAlreadyNorm(parentPathNorm);
+        }
+
+        [CanBeNull]
+        public static string LocalizePathWithCaseChecked(string path)
+        {
+            string pathNorm = path.NormalizePath() + Path.DirectorySeparatorChar;
+            string resourcePathNorm = ResourcePath.NormalizePath() + Path.DirectorySeparatorChar;
+
+            if (!pathNorm.PathStartsWithAlreadyNorm(resourcePathNorm))
+                return null;
+
+            string result = "res://" + pathNorm.Substring(resourcePathNorm.Length);
+
+            // Remove the last separator we added
+            return result.Substring(0, result.Length - 1);
+        }
+    }
+}