Improve AS script folder detection performance

AngelScript folders are now detected using a FilenameIndex search for uprojects and uplugins, followed by a check for Script folders, rather than a recursive tree walk for the entire project.
- New ScriptFolderDetector to centralize folder detection logic
- ScriptFilesPanel and AngelScriptContentRootProvider updated to use ScriptFolderDetector

Author: scriptacus

src/rider/main/kotlin/com/scriptacus/riderunrealangelscript/project/AngelScriptContentRootProvider.kt

@@ -3,7 +3,6 @@ package com.scriptacus.riderunrealangelscript.project
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.module.ModuleManager
-import com.intellij.openapi.progress.ProgressManager
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.roots.ModuleRootManager
 import com.intellij.openapi.roots.ModuleRootModificationUtil
@@ -77,46 +76,7 @@ class AngelScriptContentRootProvider : ProjectActivity {
     }
 
     private fun detectScriptFolders(project: Project): List<VirtualFile> {
-        val basePath = project.basePath
-        if (basePath == null) {
-            LOG.warn("Project has no base path, cannot detect Script folders")
-            return emptyList()
-        }
-
-        val baseDir = VirtualFileManager.getInstance().findFileByUrl("file://$basePath")
-        if (baseDir == null) {
-            LOG.warn("Cannot find base directory at: $basePath")
-            return emptyList()
-        }
-
-        val scriptFolders = mutableSetOf<VirtualFile>()
-
-        // Visit all files recursively using VFS API
-        VfsUtil.visitChildrenRecursively(baseDir, object : VirtualFileVisitor<Unit>() {
-            override fun visitFile(file: VirtualFile): Boolean {
-                // Support cancellation of long-running operations
-                ProgressManager.checkCanceled()
-
-                // Skip common non-source directories for performance
-                if (file.isDirectory && file.name in SKIP_DIRS) {
-                    return false
-                }
-
-                // Check for .uproject or .uplugin files
-                if (!file.isDirectory && (file.extension == "uproject" || file.extension == "uplugin")) {
-                    val parentDir = file.parent
-                    if (parentDir != null) {
-                        val scriptFolder = parentDir.findChild("Script")
-                        if (scriptFolder != null && scriptFolder.isDirectory) {
-                            scriptFolders.add(scriptFolder)
-                        }
-                    }
-                }
-                return true
-            }
-        })
-
-        return scriptFolders.toList()
+        return ScriptFolderDetector.detectScriptFolders(project)
     }
 
     private fun findMainModule(project: Project) = ModuleManager.getInstance(project)
@@ -248,18 +208,4 @@ class AngelScriptContentRootProvider : ProjectActivity {
         )
     }
 
-    companion object {
-        // Directories to skip during VFS traversal for performance
-        private val SKIP_DIRS = setOf(
-            ".git",
-            "node_modules",
-            "Binaries",
-            "Intermediate",
-            "Saved",
-            ".idea",
-            "DerivedDataCache",
-            ".vs",
-            ".vscode"
-        )
-    }
 }

src/rider/main/kotlin/com/scriptacus/riderunrealangelscript/project/ScriptFolderDetector.kt

@@ -0,0 +1,45 @@
+package com.scriptacus.riderunrealangelscript.project
+
+import com.intellij.openapi.project.Project
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.psi.search.FilenameIndex
+import com.intellij.psi.search.GlobalSearchScope
+
+/**
+ * Shared utility for efficiently detecting AngelScript Script folders in a project.
+ *
+ * Uses FilenameIndex for O(1) lookup of .uproject and .uplugin files instead of
+ * recursive VFS traversal which is O(n) where n = total files in project.
+ */
+object ScriptFolderDetector {
+    /**
+     * Finds all Script folders next to .uproject or .uplugin files.
+     *
+     * @param project The project to search
+     * @return List of Script folder VirtualFiles
+     */
+    fun detectScriptFolders(project: Project): List<VirtualFile> {
+        val scriptFolders = mutableSetOf<VirtualFile>()
+        val scope = GlobalSearchScope.projectScope(project)
+
+        // Find all .uproject files and check for Script folders
+        val uprojectFiles = FilenameIndex.getAllFilesByExt(project, "uproject", scope)
+        for (uprojectFile in uprojectFiles) {
+            val scriptFolder = uprojectFile.parent?.findChild("Script")
+            if (scriptFolder?.isDirectory == true) {
+                scriptFolders.add(scriptFolder)
+            }
+        }
+
+        // Find all .uplugin files and check for Script folders
+        val upluginFiles = FilenameIndex.getAllFilesByExt(project, "uplugin", scope)
+        for (upluginFile in upluginFiles) {
+            val scriptFolder = upluginFile.parent?.findChild("Script")
+            if (scriptFolder?.isDirectory == true) {
+                scriptFolders.add(scriptFolder)
+            }
+        }
+
+        return scriptFolders.toList()
+    }
+}

src/rider/main/kotlin/com/scriptacus/riderunrealangelscript/toolwindow/ScriptFilesPanel.kt

@@ -359,22 +359,26 @@ class ScriptFilesPanel(private val project: Project) : JPanel(BorderLayout()) {
         val isBaseDirScriptFolder = (baseDir.name == "Script")
 
         if (!isBaseDirScriptFolder) {
-            // Normal case: search for .uproject/.uplugin files with Script folders
-            VfsUtil.visitChildrenRecursively(baseDir, object : VirtualFileVisitor<Unit>() {
-                override fun visitFile(file: VirtualFile): Boolean {
-                    if (!file.isDirectory && (file.extension == "uproject" || file.extension == "uplugin")) {
-                        val parentDir = file.parent
-                        if (parentDir != null) {
-                            val scriptFolder = parentDir.findChild("Script")
-                            if (scriptFolder != null && scriptFolder.isDirectory && containsAngelScriptFiles(scriptFolder)) {
-                                allProjectFiles.add(ProjectFileInfo(file, scriptFolder))
-                                scriptFolders.add(scriptFolder)
-                            }
+            // Use ScriptFolderDetector for efficient lookup
+            val detectedFolders = com.scriptacus.riderunrealangelscript.project.ScriptFolderDetector.detectScriptFolders(project)
+
+            // Build ProjectFileInfo list - need to find the .uproject/.uplugin file for each Script folder
+            for (scriptFolder in detectedFolders) {
+                // Only include if it contains .as files
+                if (containsAngelScriptFiles(scriptFolder)) {
+                    val parent = scriptFolder.parent
+                    if (parent != null) {
+                        // Find the .uproject or .uplugin file in parent
+                        val projectFile = parent.children.firstOrNull {
+                            it.extension == "uproject" || it.extension == "uplugin"
+                        }
+                        if (projectFile != null) {
+                            allProjectFiles.add(ProjectFileInfo(projectFile, scriptFolder))
+                            scriptFolders.add(scriptFolder)
                         }
                     }
-                    return true
                 }
-            })
+            }
         }
 
         // Find the .uproject file(s)