FIR IDE: add Java synthetic properties support for completion

idea/idea-completion/testData/basic/java/JavaSyntheticProperty.kt

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+
+fun foo(a: java.lang.Thread) {
+    a.na<caret>
+}
+
+
+// EXIST: {"lookupString":"name","tailText":" (from getName()/setName())","allLookupStrings":"getName, name, setName","itemText":"name"}

idea/idea-completion/testData/handlers/basic/SyntheticExtension.kt

@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 import java.io.File
 
 fun foo(file: File) {

idea/idea-completion/testData/handlers/basic/SyntheticExtension.kt.after

@@ -1,3 +1,5 @@
+// FIR_COMPARISON
+
 import java.io.File
 
 fun foo(file: File) {

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JvmBasicCompletionTestGenerated.java

@@ -2950,6 +2950,11 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             runTest("idea/idea-completion/testData/basic/java/JavaPackage.kt");
         }
 
+        @TestMetadata("JavaSyntheticProperty.kt")
+        public void testJavaSyntheticProperty() throws Exception {
+            runTest("idea/idea-completion/testData/basic/java/JavaSyntheticProperty.kt");
+        }
+
         @TestMetadata("KProperty.kt")
         public void testKProperty() throws Exception {
             runTest("idea/idea-completion/testData/basic/java/KProperty.kt");

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/KotlinFirLookupElementFactory.kt

@@ -34,7 +34,7 @@ internal class KotlinFirLookupElementFactory {
     fun KtAnalysisSession.createLookupElement(symbol: KtNamedSymbol): LookupElement? {
         val elementBuilder = when (symbol) {
             is KtFunctionSymbol -> with(functionLookupElementFactory) { createLookup(symbol) }
-            is KtVariableLikeSymbol -> with(variableLookupElementFactory)  { createLookup(symbol) }
+            is KtVariableLikeSymbol -> with(variableLookupElementFactory) { createLookup(symbol) }
             is KtClassLikeSymbol -> classLookupElementFactory.createLookup(symbol)
             is KtTypeParameterSymbol -> typeParameterLookupElementFactory.createLookup(symbol)
             else -> throw IllegalArgumentException("Cannot create a lookup element for $symbol")
@@ -67,9 +67,23 @@ private class VariableLookupElementFactory {
     fun KtAnalysisSession.createLookup(symbol: KtVariableLikeSymbol): LookupElementBuilder {
         return LookupElementBuilder.create(UniqueLookupObject(), symbol.name.asString())
             .withTypeText(symbol.type.render())
+            .markIfSyntheticJavaProperty(symbol)
             .withInsertHandler(createInsertHandler(symbol))
     }
 
+    private fun LookupElementBuilder.markIfSyntheticJavaProperty(symbol: KtVariableLikeSymbol): LookupElementBuilder = when (symbol) {
+        is KtSyntheticJavaPropertySymbol -> {
+            val getterName = symbol.javaGetterName.asString()
+            val setterName = symbol.javaSetterName?.asString()
+            this.withTailText((" (from ${buildSyntheticPropertyTailText(getterName, setterName)})"))
+                .withLookupStrings(listOfNotNull(getterName, setterName))
+        }
+        else -> this
+    }
+
+    private fun buildSyntheticPropertyTailText(getterName: String, setterName: String?): String =
+        if (setterName != null) "$getterName()/$setterName()" else "$getterName()"
+
     private fun createInsertHandler(symbol: KtVariableLikeSymbol): InsertHandler<LookupElement> {
         return QuotedNamesAwareInsertionHandler(symbol.name)
     }

idea/idea-fir/tests/org/jetbrains/kotlin/idea/completion/HighLevelJvmBasicCompletionTestGenerated.java

@@ -2950,6 +2950,11 @@ public class HighLevelJvmBasicCompletionTestGenerated extends AbstractHighLevelJ
             runTest("idea/idea-completion/testData/basic/java/JavaPackage.kt");
         }
 
+        @TestMetadata("JavaSyntheticProperty.kt")
+        public void testJavaSyntheticProperty() throws Exception {
+            runTest("idea/idea-completion/testData/basic/java/JavaSyntheticProperty.kt");
+        }
+
         @TestMetadata("KProperty.kt")
         public void testKProperty() throws Exception {
             runTest("idea/idea-completion/testData/basic/java/KProperty.kt");

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirScopeProvider.kt

@@ -6,15 +6,14 @@
 package org.jetbrains.kotlin.idea.frontend.api.fir.components
 
 import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirAnonymousObject
 import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
+import org.jetbrains.kotlin.fir.resolve.calls.FirSyntheticPropertiesScope
 import org.jetbrains.kotlin.fir.resolve.scope
-import org.jetbrains.kotlin.fir.scopes.FakeOverrideTypeCalculator
+import org.jetbrains.kotlin.fir.scopes.*
-import org.jetbrains.kotlin.fir.scopes.FirContainingNamesAwareScope
-import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.impl.*
-import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.FirModuleResolveState
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.LowLevelFirApiFacadeForCompletion
 import org.jetbrains.kotlin.idea.fir.low.level.api.api.getFirFile
@@ -122,9 +121,17 @@ internal class KtFirScopeProvider(
             firResolveState.firTransformerProvider.getScopeSession(firSession),
             FakeOverrideTypeCalculator.Forced
         ) ?: return null
-        return convertToKtScope(firTypeScope)
+        return getCompositeScope(
+            listOf(
+                convertToKtScope(firTypeScope),
+                firTypeScope.getSyntheticPropertiesScope(firSession)
+            )
+        )
     }
 
+    private fun FirTypeScope.getSyntheticPropertiesScope(firSession: FirSession): KtScope =
+        convertToKtScope(FirSyntheticPropertiesScope(firSession, this))
+
     override fun getScopeContextForPosition(
         originalFile: KtFile,
         positionInFakeFile: KtElement