[lsp] implement inlay hints

^LSP-205 fixed

GitOrigin-RevId: 300d4294c0044f1faeee840aa5cbb74730871411

Author: darthorimar

api.features/src/com/jetbrains/ls/api/features/LSConfiguration.kt

@@ -8,7 +8,6 @@ import com.jetbrains.ls.api.features.configuration.LSUniqueConfigurationEntry
 import com.jetbrains.ls.api.features.language.LSLanguage
 import com.jetbrains.ls.api.features.language.LSLanguageConfiguration
 import com.jetbrains.ls.api.features.language.matches
-import com.jetbrains.ls.api.features.semanticTokens.LSSemanticTokensProvider
 import com.jetbrains.lsp.protocol.TextDocumentIdentifier
 
 class LSConfiguration(
@@ -60,6 +59,13 @@ class LSConfiguration(
         return entriesByLanguage[language]?.filterIsInstance<E>() ?: emptyList()
     }
 
+    inline fun <reified E : LSUniqueConfigurationEntry> entryById(
+        id: LSUniqueConfigurationEntry.UniqueId,
+    ): E? {
+        val entries = entries<E>()
+        return entries.firstOrNull { it.uniqueId == id }
+    }
+
     fun languageFor(document: TextDocumentIdentifier): LSLanguage? {
         return languages.firstOrNull { it.matches(document) }
     }
@@ -77,6 +83,10 @@ context(configuration: LSConfiguration)
 inline fun <reified E : LSLanguageSpecificConfigurationEntry> entriesFor(language: LSLanguage): List<E> =
     configuration.entriesFor(language)
 
+context(configuration: LSConfiguration)
+inline fun <reified E : LSUniqueConfigurationEntry> entryById(id: LSUniqueConfigurationEntry.UniqueId): E? =
+    configuration.entryById<E>(id)
+
 context(configuration: LSConfiguration)
 fun commandDescriptorByCommandName(commandName: String): LSCommandDescriptor? =
     configuration.commandDescriptorByCommandName(commandName)

api.features/src/com/jetbrains/ls/api/features/inlayHints/LSInlayHints.kt

@@ -0,0 +1,29 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.jetbrains.ls.api.features.inlayHints
+
+import com.jetbrains.ls.api.core.LSServer
+import com.jetbrains.ls.api.features.LSConfiguration
+import com.jetbrains.ls.api.features.configuration.LSUniqueConfigurationEntry
+import com.jetbrains.ls.api.features.entriesFor
+import com.jetbrains.ls.api.features.partialResults.LSConcurrentResponseHandler
+import com.jetbrains.ls.api.features.resolve.getConfigurationEntryId
+import com.jetbrains.ls.api.features.entryById
+import com.jetbrains.lsp.protocol.InlayHint
+import com.jetbrains.lsp.protocol.InlayHintParams
+
+object LSInlayHints {
+    context(_: LSServer, _: LSConfiguration)
+    suspend fun inlayHints(params: InlayHintParams): List<InlayHint> {
+        return LSConcurrentResponseHandler.respondDirectlyWithResultsCollectedConcurrently(
+            entriesFor<LSInlayHintsProvider>(params.textDocument),
+        ) {
+            it.getInlayHints(params)
+        }
+    }
+    context(_: LSServer, _: LSConfiguration)
+    suspend fun resolveInlayHint(hint: InlayHint): InlayHint {
+        val uniqueId = getConfigurationEntryId(hint.data) ?: return hint
+        val entry = entryById<LSInlayHintsProvider>(uniqueId) ?: return hint
+        return entry.resolveInlayHint(hint) ?: hint
+    }
+}

api.features/src/com/jetbrains/ls/api/features/inlayHints/LSInlayHintsProvider.kt

@@ -0,0 +1,17 @@
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.jetbrains.ls.api.features.inlayHints
+
+import com.jetbrains.ls.api.core.LSServer
+import com.jetbrains.ls.api.features.LSLanguageSpecificConfigurationEntry
+import com.jetbrains.ls.api.features.configuration.LSUniqueConfigurationEntry
+import com.jetbrains.lsp.protocol.InlayHint
+import com.jetbrains.lsp.protocol.InlayHintParams
+import kotlinx.coroutines.flow.Flow
+
+interface LSInlayHintsProvider : LSLanguageSpecificConfigurationEntry, LSUniqueConfigurationEntry {
+    context(_: LSServer)
+    fun getInlayHints(params: InlayHintParams): Flow<InlayHint>
+
+    context(_: LSServer)
+    suspend fun resolveInlayHint(hint: InlayHint): InlayHint?
+}

api.features/src/com/jetbrains/ls/api/features/utils/PsiSerializablePointer.kt

@@ -1,15 +1,15 @@
 // Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.jetbrains.ls.api.features.utils
 
+import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
-import com.intellij.psi.PsiElement
-import com.intellij.psi.PsiFile
-import com.intellij.psi.PsiFileSystemItem
+import com.intellij.openapi.vfs.VirtualFileManager
+import com.intellij.openapi.vfs.findPsiFile
+import com.intellij.psi.*
 import com.intellij.psi.util.endOffset
 import com.intellij.psi.util.startOffset
+import com.jetbrains.ls.api.core.util.lspUriToIntellijUri
 import com.jetbrains.ls.api.core.util.uri
-import com.jetbrains.ls.api.core.LSAnalysisContext
-import com.jetbrains.ls.api.core.LSServer
 import com.jetbrains.lsp.protocol.URI
 import kotlinx.serialization.Serializable
 
@@ -20,7 +20,14 @@ sealed class PsiSerializablePointer {
 
     abstract fun restore(psiFile: PsiFile): PsiElement?
 
-    abstract fun matches(element: PsiElement): Boolean
+    open fun restore(project: Project): PsiElement? {
+        val intellijUri = uri.lspUriToIntellijUri() ?: return null
+        val virtualFile = VirtualFileManager.getInstance().refreshAndFindFileByUrl(intellijUri) ?: return null
+        val psiFile = virtualFile.findPsiFile(project) ?: return null
+        return restore(psiFile)
+    }
+
+     abstract fun matches(element: PsiElement): Boolean
 
     @Serializable
     internal data class PsiFileSerializablePointer(
@@ -63,6 +70,12 @@ sealed class PsiSerializablePointer {
     }
 
     companion object {
+        fun fromPsiPointer(pointer: SmartPsiElementPointer<*>): PsiSerializablePointer {
+            val file = pointer.containingFile ?: error("File for pointer is null")
+            val element = pointer.element ?: error("Element for pointer is null")
+            return create(element, file.virtualFile)
+        }
+
         fun create(psi: PsiElement, file: VirtualFile): PsiSerializablePointer {
             return when (psi) {
                 is PsiFile -> {
@@ -78,4 +91,9 @@ sealed class PsiSerializablePointer {
             }
         }
     }
+}
+
+fun PsiSerializablePointer.toPsiPointer(project: Project): SmartPsiElementPointer<PsiElement> {
+    val element = restore(project) ?: error("Cannot restore ${this} for pointer")
+    return element.createSmartPointer()
 }