gradle.kts: remove useless gradle build root kinds

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/GradleBuildRoot.kt

@@ -25,23 +25,43 @@ import kotlin.script.experimental.jvm.jvm
 sealed class GradleBuildRoot {
     abstract val pathPrefix: String
 
-    abstract class Unlinked : GradleBuildRoot()
-
-    class UnlinkedUnknown(override val pathPrefix: String) : Unlinked()
-
-    class UnlinkedLegacy(override val pathPrefix: String) : Unlinked()
-
-    class UnlinkedSupported(override val pathPrefix: String) : Unlinked()
+    /**
+     * Add Gradle Project
+     * for other scripts too
+     *
+     * definitely not precompiled scripts (it is detected as in sources roots)
+     * may be also included scripts not returned by gradle: todo proper notification
+     */
+    class Unlinked(override val pathPrefix: String) : GradleBuildRoot()
 
     abstract class Linked : GradleBuildRoot() {
         @Volatile
         var importing = false
     }
 
+    /**
+     * Notification: please update to Gradle 6.0
+     * default loader, cases:
+     * - not loaded: todo: Notification: Load configration to get code insights
+     * - loaded, not up-to-date: Notifaction: Reload configuraiton
+     * - loaded, up-to-date: Nothing
+     */
     class Legacy(override val pathPrefix: String) : Linked()
 
+    /**
+     * not imported:
+     *  Notification: Import Gradle project to get code insights
+     * during import:
+     * - todo: disable action on importing. don't miss failed import
+     * - pause analyzing, todo: change status text to: importing gradle project
+     *
+     * todo:
+     *  detect precompiled scripts (in sources roots)
+     */
     class New(override val pathPrefix: String) : Linked()
 
+    // precompiled scripts not detected by gradle
+
     class Imported(
         val project: Project,
         val dir: VirtualFile,

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/GradleScriptingSupportProvider.kt

@@ -48,7 +48,6 @@ class GradleScriptingSupportProvider(val project: Project) : ScriptingSupport.Pr
     override fun isApplicable(file: VirtualFile): Boolean {
         val buildRoot = findScriptBuildRoot(file) ?: return false
         if (buildRoot is GradleBuildRoot.Legacy) return false
-        if (buildRoot is GradleBuildRoot.UnlinkedLegacy) return false
         return true
     }
 
@@ -130,7 +129,7 @@ class GradleScriptingSupportProvider(val project: Project) : ScriptingSupport.Pr
     }
 
     private fun detectUnlinkedGradleBuildRoot(file: String): GradleBuildRoot.Unlinked =
-        GradleBuildRoot.UnlinkedUnknown(file)
+        GradleBuildRoot.Unlinked(file)
 
     init {
         getGradleProjectSettings(project).forEach {

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/MissingGradleScriptConfigurationNotificationProvider.kt

@@ -29,7 +29,7 @@ class MissingGradleScriptConfigurationNotificationProvider(private val project:
         if (file.fileType != KotlinFileType.INSTANCE) return null
 
         return when (GradleScriptingSupportProvider.getInstance(project).findScriptBuildRoot(file)) {
-            is GradleBuildRoot.UnlinkedSupported -> EditorNotificationPanel().apply {
+            is GradleBuildRoot.Unlinked -> EditorNotificationPanel().apply {
                 text(KotlinIdeaGradleBundle.message("text.the.associated.gradle.project.isn.t.imported"))
 
                 val linkProjectText = KotlinIdeaGradleBundle.message("action.label.text.load.script.configuration")