[Kotlin] Notify about unsupported features in K1 mode

KTIJ-31679


(cherry picked from commit 14791f372930eaf3f5256bf05a0ab37f6f5254b0)

IJ-CR-147299

GitOrigin-RevId: b3d6cc9104e1b1cc9010442580bb67a0c5cac6ce

plugins/kotlin/plugin/k1/resources/META-INF/kotlin-core-fe10.xml

@@ -340,4 +340,9 @@
     <psi.classFileDecompiler implementation="org.jetbrains.kotlin.analysis.decompiler.js.KotlinJavaScriptMetaFileDecompiler"/>
   </extensions>
 
+  <!-- notification about unsupported K2 features in K1 mode -->
+  <extensions defaultExtensionNs="com.intellij">
+    <editorNotificationProvider implementation="org.jetbrains.kotlin.idea.configuration.KotlinK2FeaturesInK1ModeNotifier"/>
+  </extensions>
+
 </idea-plugin>

plugins/kotlin/project-configuration/resources/messages/KotlinProjectConfigurationBundle.properties

@@ -94,4 +94,8 @@ configurator.kotlin.jvm.target.bump.manually.learn.more=<br>If you add Kotlin to
 
 configure.kotlin.changes.title=Configure Kotlin: Changes
 configure.kotlin.original.content=Original content
-configure.kotlin.modified.content=Modified content
+configure.kotlin.modified.content=Modified content
+
+k1.mode.does.not.support.features.0=K1 mode does not support the features: {0}
+enable.k2.mode=Enable K2 mode\u2026
+k1.does.not.support.features.ignore=Ignore

plugins/kotlin/project-configuration/src/org/jetbrains/kotlin/idea/configuration/KotlinK2FeaturesInK1ModeNotifier.kt

@@ -0,0 +1,75 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+
+package org.jetbrains.kotlin.idea.configuration
+
+import com.intellij.diagnostic.VMOptions
+import com.intellij.ide.util.PropertiesComponent
+import com.intellij.openapi.fileEditor.FileEditor
+import com.intellij.openapi.options.ConfigurableWithId
+import com.intellij.openapi.options.ShowSettingsUtil
+import com.intellij.openapi.project.Project
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.psi.PsiManager
+import com.intellij.ui.EditorNotificationPanel
+import com.intellij.ui.EditorNotificationProvider
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.idea.KotlinFileType
+import org.jetbrains.kotlin.idea.base.projectStructure.languageVersionSettings
+import org.jetbrains.kotlin.idea.projectConfiguration.KotlinProjectConfigurationBundle
+import org.jetbrains.kotlin.psi.KtFile
+import java.util.*
+import java.util.function.Function
+import javax.swing.JComponent
+
+private val ExperimentalFeaturesWithK2OnlySupport = EnumSet.of<LanguageFeature>(
+    LanguageFeature.BreakContinueInInlineLambdas,
+    LanguageFeature.MultiDollarInterpolation,
+    LanguageFeature.WhenGuards,
+)
+
+private const val KOTLIN_K2_FEATURES_IN_K1_MODE_NOTIFICATION_DISABLED = "kotlin.k2.features.in.k1.mode.notification.disabled"
+
+class KotlinK2FeaturesInK1ModeNotifier : EditorNotificationProvider {
+    override fun collectNotificationData(
+        project: Project,
+        file: VirtualFile
+    ): Function<in FileEditor, out JComponent?>? {
+        if (PropertiesComponent.getInstance().getBoolean(KOTLIN_K2_FEATURES_IN_K1_MODE_NOTIFICATION_DISABLED)) return null
+        val unsupportedFeatures = collectUnsupportedFeatures(project, file)
+        if (unsupportedFeatures.isEmpty()) return null
+        return Function { fileEditor: FileEditor -> createNotificationPanel(project, fileEditor, unsupportedFeatures) }
+    }
+
+    private fun collectUnsupportedFeatures(project: Project, file: VirtualFile): List<LanguageFeature> {
+        if (!file.nameSequence.endsWith(KotlinFileType.DOT_DEFAULT_EXTENSION)) return emptyList()
+        val ktFile = PsiManager.getInstance(project).findFile(file) as? KtFile ?: return emptyList()
+
+        return ExperimentalFeaturesWithK2OnlySupport.filter { feature ->
+            ktFile.languageVersionSettings.supportsFeature(feature)
+        }
+    }
+
+    private fun createNotificationPanel(
+        project: Project,
+        fileEditor: FileEditor,
+        unsupportedFeatures: List<LanguageFeature>,
+    ): JComponent {
+        val featureNames = unsupportedFeatures.joinToString { "'${it.presentableName}'" }
+
+        return EditorNotificationPanel(fileEditor, EditorNotificationPanel.Status.Warning).apply {
+            text = KotlinProjectConfigurationBundle.message("k1.mode.does.not.support.features.0", featureNames)
+            if (VMOptions.canWriteOptions()) {
+                createActionLabel(KotlinProjectConfigurationBundle.message("enable.k2.mode")) {
+                    ShowSettingsUtil.getInstance().showSettingsDialog(project, { configurable ->
+                        // KotlinLanguageConfiguration#ID, hardcoded because of a circular dependency
+                        (configurable as? ConfigurableWithId)?.id == "preferences.language.Kotlin"
+                    }, null)
+                }
+            }
+            createActionLabel(KotlinProjectConfigurationBundle.message("k1.does.not.support.features.ignore")) {
+                PropertiesComponent.getInstance().setValue(KOTLIN_K2_FEATURES_IN_K1_MODE_NOTIFICATION_DISABLED, true)
+                isVisible = false
+            }
+        }
+    }
+}