Fix Kotlin facet autodetection so that it actually works and stores the correct language/API level based on project dependencies

compiler/util/src/org/jetbrains/kotlin/utils/PathUtil.java

@@ -23,6 +23,7 @@ import org.jetbrains.jps.model.java.impl.JavaSdkUtil;
 
 import java.io.File;
 import java.util.List;
+import java.util.regex.Pattern;
 
 public class PathUtil {
 
@@ -41,6 +42,8 @@ public class PathUtil {
     public static final String KOTLIN_JAVA_RUNTIME_SRC_JAR = "kotlin-runtime-sources.jar";
     public static final String KOTLIN_COMPILER_JAR = "kotlin-compiler.jar";
 
+    public static final Pattern KOTLIN_RUNTIME_JAR_PATTERN = Pattern.compile("kotlin-(stdlib|runtime)(-\\d[\\d.]+(-.+)?)?\\.jar");
+
     public static final String HOME_FOLDER_NAME = "kotlinc";
     private static final File NO_PATH = new File("<no_path>");
 

idea/idea-analysis/src/org/jetbrains/kotlin/idea/framework/JavaRuntimeDetectionUtil.java

@@ -21,7 +21,6 @@ import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.utils.LibraryUtils;
 import org.jetbrains.kotlin.utils.PathUtil;
 
 import java.util.List;
@@ -39,6 +38,11 @@ public class JavaRuntimeDetectionUtil {
 
     @Nullable
     public static VirtualFile getRuntimeJar(@NotNull List<VirtualFile> classesRoots) {
-        return LibraryUtils.getJarFile(classesRoots, PathUtil.KOTLIN_JAVA_RUNTIME_JAR);
+        for (VirtualFile root : classesRoots) {
+            if (PathUtil.KOTLIN_RUNTIME_JAR_PATTERN.matcher(root.getName()).matches()) {
+                return root;
+            }
+        }
+        return null;
     }
 }

idea/idea-analysis/src/org/jetbrains/kotlin/idea/project/Platform.kt

@@ -43,7 +43,7 @@ private val multiPlatformProjectsArg: String by lazy {
     "-" + CommonCompilerArguments::multiPlatform.annotations.filterIsInstance<Argument>().single().value
 }
 
-private fun Module.getAndCacheLanguageLevelByDependencies(): LanguageVersion {
+fun Module.getAndCacheLanguageLevelByDependencies(): LanguageVersion {
     val languageLevel = getLibraryLanguageLevel(
             this,
             null,

idea/src/org/jetbrains/kotlin/idea/facet/FacetConfigurator.kt

@@ -38,6 +38,7 @@ import com.intellij.psi.search.GlobalSearchScope
 import com.intellij.util.indexing.FileBasedIndex
 import com.intellij.util.ui.update.MergingUpdateQueue
 import com.intellij.util.ui.update.Update
+import org.jetbrains.kotlin.utils.ifEmpty
 import java.util.*
 
 // Based on com.intellij.framework.detection.impl.FrameworkDetectionManager
@@ -137,9 +138,11 @@ class FacetConfigurator(
 
         if (FrameworkDetectionUtil.removeDisabled(newDescriptions, oldDescriptions).isEmpty()) return
 
-        val framework = getValidDetectedFramework() ?: return
-        FrameworkDetectionUtil.setupFrameworks(listOf(framework), PlatformModifiableModelsProvider(), DefaultModulesProvider(myProject))
-        myDetectedFrameworksData!!.putExistentFrameworkFiles(id, framework.relatedFiles)
+        val validFrameworks = getValidDetectedFrameworks().ifEmpty { return }
+        FrameworkDetectionUtil.setupFrameworks(frameworks, PlatformModifiableModelsProvider(), DefaultModulesProvider(myProject))
+        for (framework in validFrameworks) {
+            myDetectedFrameworksData!!.putExistentFrameworkFiles(id, framework.relatedFiles)
+        }
     }
 
     private fun runDetector(detectorId: Int?,
@@ -167,12 +170,12 @@ class FacetConfigurator(
         return frameworks
     }
 
-    private fun getValidDetectedFramework(): DetectedFrameworkDescription? {
-        val id = myDetectedFrameworksData!!.detectorsForDetectedFrameworks.singleOrNull() ?: return null
+    private fun getValidDetectedFrameworks(): List<DetectedFrameworkDescription> {
+        val id = myDetectedFrameworksData!!.detectorsForDetectedFrameworks.singleOrNull() ?: return emptyList()
         val index = FileBasedIndex.getInstance()
         val excludesConfiguration = DetectionExcludesConfiguration.getInstance(myProject)
         val frameworks = runDetector(id, index, excludesConfiguration, false)
-        return FrameworkDetectionUtil.removeDisabled(frameworks).singleOrNull()
+        return FrameworkDetectionUtil.removeDisabled(frameworks)
     }
 
     private fun ensureIndexIsUpToDate(detectors: Collection<Int>) {

idea/src/org/jetbrains/kotlin/idea/facet/KotlinFrameworkDetector.kt

@@ -21,8 +21,10 @@ import com.intellij.framework.detection.FacetBasedFrameworkDetector
 import com.intellij.framework.detection.FileContentPattern
 import com.intellij.framework.detection.FrameworkDetectionContext
 import com.intellij.framework.detection.impl.FrameworkDetectorRegistry
+import com.intellij.openapi.roots.ModifiableRootModel
 import com.intellij.openapi.vfs.VirtualFile
 import org.jetbrains.kotlin.idea.KotlinFileType
+import org.jetbrains.kotlin.idea.project.getAndCacheLanguageLevelByDependencies
 
 class KotlinFrameworkDetector : FacetBasedFrameworkDetector<KotlinFacet, KotlinFacetConfiguration>(DETECTOR_ID) {
     companion object {
@@ -47,4 +49,11 @@ class KotlinFrameworkDetector : FacetBasedFrameworkDetector<KotlinFacet, KotlinF
             newFiles: Collection<VirtualFile>,
             context: FrameworkDetectionContext
     ) = super.detect(newFiles, context)
-}
+
+    override fun setupFacet(facet: KotlinFacet, model: ModifiableRootModel?) {
+        model?.module?.let { module ->
+            facet.configuration.settings.initializeIfNeeded(module, model)
+            module.getAndCacheLanguageLevelByDependencies()
+        }
+    }
+}