feat(amazonq): implement TextDocumentService message handler

plugins/amazonq/shared/jetbrains-community/src/software/aws/toolkits/jetbrains/services/amazonq/lsp/AmazonQLspService.kt

@@ -39,6 +39,7 @@ import software.aws.toolkits.core.utils.warn
 import software.aws.toolkits.jetbrains.isDeveloperMode
 import software.aws.toolkits.jetbrains.services.amazonq.lsp.encryption.JwtEncryptionManager
 import software.aws.toolkits.jetbrains.services.amazonq.lsp.model.createExtendedClientMetadata
+import software.aws.toolkits.jetbrains.services.amazonq.lsp.textdocument.TextDocumentServiceHandler
 import software.aws.toolkits.jetbrains.services.telemetry.ClientMetadata
 import java.io.IOException
 import java.io.OutputStreamWriter
@@ -235,6 +236,12 @@ private class AmazonQServerInstance(private val project: Project, private val cs
             }
             languageServer.initialized(InitializedParams())
         }
+
+        TextDocumentServiceHandler(
+            project,
+            languageServer,
+            this
+        )
     }
 
     override fun dispose() {

plugins/amazonq/shared/jetbrains-community/src/software/aws/toolkits/jetbrains/services/amazonq/lsp/textdocument/TextDocumentServiceHandler.kt

@@ -0,0 +1,70 @@
+// Copyright 2025 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package software.aws.toolkits.jetbrains.services.amazonq.lsp.textdocument
+
+import com.intellij.openapi.Disposable
+import com.intellij.openapi.project.Project
+import com.intellij.openapi.fileEditor.FileEditorManager
+import com.intellij.openapi.fileEditor.FileEditorManagerListener
+import com.intellij.openapi.vfs.VirtualFile
+import org.eclipse.lsp4j.DidCloseTextDocumentParams
+import org.eclipse.lsp4j.DidOpenTextDocumentParams
+import org.eclipse.lsp4j.TextDocumentIdentifier
+import org.eclipse.lsp4j.TextDocumentItem
+import software.aws.toolkits.jetbrains.services.amazonq.lsp.AmazonQLanguageServer
+
+class TextDocumentServiceHandler(
+    private val project: Project,
+    private val languageServer: AmazonQLanguageServer,
+    private val serverInstance: Disposable
+) {
+
+    init {
+        subscribeToFileEditorEvents()
+    }
+
+    // for textDocument/ didOpen and didClose
+    private fun subscribeToFileEditorEvents() {
+        project.messageBus.connect(serverInstance).subscribe(
+            FileEditorManagerListener.FILE_EDITOR_MANAGER,
+            object: FileEditorManagerListener {
+                override fun fileOpened(
+                    source: FileEditorManager,
+                    file: VirtualFile
+                ) {
+                    languageServer.textDocumentService.didOpen(
+                        DidOpenTextDocumentParams().apply {
+                            textDocument = TextDocumentItem().apply {
+                                uri = file.url
+                                text = file.inputStream.readAllBytes().decodeToString()
+                            }
+                        }
+                    )
+                }
+
+                override fun fileClosed(
+                    source: FileEditorManager,
+                    file: VirtualFile
+                ) {
+                    languageServer.textDocumentService.didClose(
+                        DidCloseTextDocumentParams().apply {
+                            textDocument = TextDocumentIdentifier().apply {
+                                uri = file.url
+                            }
+                        }
+                    )
+                }
+            }
+        )
+    }
+
+     private fun didChange() {
+
+    }
+
+    private fun didSave() {
+
+    }
+
+}