Introduce ViewRouter Component

plugin/META-INF/MANIFEST.MF

@@ -28,7 +28,7 @@ Require-Bundle: org.eclipse.core.runtime;bundle-version="3.31.0",
  org.apache.commons.logging;bundle-version="1.2.0",
  slf4j.api;bundle-version="2.0.13",
  org.apache.commons.lang3;bundle-version="3.14.0"
-Bundle-Classpath: target/classes/,
+Bundle-Classpath: .,
  target/dependency/annotations-2.28.26.jar,
  target/dependency/apache-client-2.28.26.jar,
  target/dependency/auth-2.28.26.jar,

plugin/plugin.xml

@@ -33,6 +33,12 @@
             icon="icons/AmazonQ.png"
             class="software.aws.toolkits.eclipse.amazonq.views.ChatAssetMissingView">
         </view>
+        <view
+            id="software.aws.toolkits.eclipse.amazonq.views.LspStartUpFailedView"
+            name="Amazon Q"
+            icon="icons/AmazonQ.png"
+            class="software.aws.toolkits.eclipse.amazonq.views.LspStartUpFailedView">
+        </view>
         <view
             id="software.aws.toolkits.eclipse.amazonq.views.ToolkitLoginWebview"
             name="Amazon Q"
@@ -142,6 +148,12 @@
                 relationship="stack"
                 visible="false">
             </view>
+            <view
+                id="software.aws.toolkits.eclipse.amazonq.views.LspStartUpFailedView"
+                relative="software.aws.toolkits.eclipse.amazonq.views.ToolkitLoginWebview"
+                relationship="stack"
+                visible="false">
+            </view>
         </perspectiveExtension>
     </extension>
     <extension

plugin/src/software/aws/toolkits/eclipse/amazonq/broker/EventBroker.java

@@ -3,16 +3,33 @@
 
 package software.aws.toolkits.eclipse.amazonq.broker;
 
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import io.reactivex.rxjava3.core.Observable;
 import io.reactivex.rxjava3.disposables.Disposable;
-import io.reactivex.rxjava3.functions.Consumer;
 import io.reactivex.rxjava3.schedulers.Schedulers;
-import io.reactivex.rxjava3.subjects.PublishSubject;
+import io.reactivex.rxjava3.subjects.BehaviorSubject;
 import io.reactivex.rxjava3.subjects.Subject;
 import software.aws.toolkits.eclipse.amazonq.broker.api.EventObserver;
 
 public final class EventBroker {
 
-    private final Subject<Object> eventBus = PublishSubject.create().toSerialized();
+    private final Subject<Object> eventBus;
+    private final Map<Class<?>, Observable<?>> cachedObservables;
+
+    public EventBroker() {
+        eventBus = BehaviorSubject.create().toSerialized(); // serialize for thread safety
+        eventBus.subscribeOn(Schedulers.computation()); // publish on dedicated thread
+
+        cachedObservables = new ConcurrentHashMap<>();
+        /*
+         * Create ConnectableObservable stream before publishing event and connect to it
+         * eagerly to ensure that events get published to it regardless of whether the
+         * stream has subscribers:
+         */
+        eventBus.doOnNext(event -> getOrCreateObservable(event.getClass())).subscribe();
+    }
 
     public <T> void post(final T event) {
         if (event == null) {
@@ -21,17 +38,20 @@ public <T> void post(final T event) {
         eventBus.onNext(event);
     }
 
+    @SuppressWarnings("unchecked")
+    private <T> Observable<T> getOrCreateObservable(final Class<T> eventType) { // maintain stateful observables
+        return (Observable<T>) cachedObservables.computeIfAbsent(eventType,
+                type -> eventBus.ofType(eventType).replay(1).autoConnect(-1)); // connect to stream immediately
+    }
+
     public <T> Disposable subscribe(final Class<T> eventType, final EventObserver<T> observer) {
-        Consumer<T> consumer = new Consumer<>() {
-            @Override
-            public void accept(final T event) {
-                observer.onEvent(event);
-            }
-        };
-
-        return eventBus.ofType(eventType)
-                .observeOn(Schedulers.computation())
-                .subscribe(consumer);
-        }
+        return getOrCreateObservable(eventType)
+                .observeOn(Schedulers.computation()) // subscribe on dedicated thread
+                .subscribe(observer::onEvent);
+    }
+
+    public <T> Observable<T> ofObservable(final Class<T> eventType) {
+        return getOrCreateObservable(eventType);
+    }
 
 }

plugin/src/software/aws/toolkits/eclipse/amazonq/handlers/AbstractQChatEditorActionsHandler.java

@@ -15,6 +15,7 @@
 import software.aws.toolkits.eclipse.amazonq.chat.models.GenericCommandParams;
 import software.aws.toolkits.eclipse.amazonq.chat.models.SendToPromptParams;
 import software.aws.toolkits.eclipse.amazonq.chat.models.TriggerType;
+import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspStatusManager;
 import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
 import software.aws.toolkits.eclipse.amazonq.telemetry.ToolkitTelemetryProvider;
 import software.aws.toolkits.eclipse.amazonq.telemetry.metadata.ExceptionMetadata;
@@ -27,7 +28,7 @@ public abstract class AbstractQChatEditorActionsHandler extends AbstractHandler
     @Override
     public final boolean isEnabled() {
         try {
-            return Activator.getLoginService().getAuthState().isLoggedIn();
+            return Activator.getLoginService().getAuthState().isLoggedIn() && !LspStatusManager.getInstance().lspFailed();
         } catch (Exception e) {
             return false;
         }

plugin/src/software/aws/toolkits/eclipse/amazonq/handlers/QOpenLoginViewHandler.java

@@ -5,17 +5,17 @@
 
 import org.eclipse.core.commands.AbstractHandler;
 import org.eclipse.core.commands.ExecutionEvent;
-import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
 
+import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspStatusManager;
 import software.aws.toolkits.eclipse.amazonq.views.ViewVisibilityManager;
 
 public class QOpenLoginViewHandler extends AbstractHandler {
     @Override
     public final Object execute(final ExecutionEvent event) {
-        if (Activator.getLoginService().getAuthState().isLoggedIn()) {
-            ViewVisibilityManager.showChatView("statusBar");
+        if (LspStatusManager.getInstance().lspFailed()) {
+            ViewVisibilityManager.showLspStartUpFailedView("statusBar");
         } else {
-            ViewVisibilityManager.showLoginView("statusBar");
+            ViewVisibilityManager.showDefaultView("statusBar");
         }
         return null;
     }

plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/connection/QLspConnectionProvider.java

@@ -14,32 +14,39 @@
 import software.amazon.awssdk.utils.StringUtils;
 import software.aws.toolkits.eclipse.amazonq.lsp.encryption.DefaultLspEncryptionManager;
 import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspManager;
+import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspStatusManager;
 import software.aws.toolkits.eclipse.amazonq.lsp.manager.fetcher.RecordLspSetupArgs;
+import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
+import software.aws.toolkits.eclipse.amazonq.preferences.AmazonQPreferencePage;
 import software.aws.toolkits.eclipse.amazonq.providers.LspManagerProvider;
 import software.aws.toolkits.eclipse.amazonq.telemetry.LanguageServerTelemetryProvider;
 import software.aws.toolkits.eclipse.amazonq.telemetry.metadata.ExceptionMetadata;
 import software.aws.toolkits.eclipse.amazonq.util.ProxyUtil;
 import software.aws.toolkits.telemetry.TelemetryDefinitions.Result;
-import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
-import software.aws.toolkits.eclipse.amazonq.preferences.AmazonQPreferencePage;
 
 public class QLspConnectionProvider extends AbstractLspConnectionProvider {
 
     public QLspConnectionProvider() throws IOException {
         super();
-        LanguageServerTelemetryProvider.setAllStartPoint(Instant.now());
-        LspManager lspManager = LspManagerProvider.getInstance();
-        var lspInstallResult = lspManager.getLspInstallation();
+        try {
+            LanguageServerTelemetryProvider.setAllStartPoint(Instant.now());
+            LspManager lspManager = LspManagerProvider.getInstance();
+            var lspInstallResult = lspManager.getLspInstallation();
+
+            setWorkingDirectory(lspInstallResult.getServerDirectory());
 
-        setWorkingDirectory(lspInstallResult.getServerDirectory());
+            var serverCommand = Paths.get(lspInstallResult.getServerDirectory(), lspInstallResult.getServerCommand());
+            List<String> commands = new ArrayList<>();
+            commands.add(serverCommand.toString());
+            commands.add(lspInstallResult.getServerCommandArgs());
+            commands.add("--stdio");
+            commands.add("--set-credentials-encryption-key");
+            setCommands(commands);
+        } catch (Exception e) {
+            LspStatusManager.getInstance().setToFailed();
+            throw(e);
+        }
 
-        var serverCommand = Paths.get(lspInstallResult.getServerDirectory(), lspInstallResult.getServerCommand());
-        List<String> commands = new ArrayList<>();
-        commands.add(serverCommand.toString());
-        commands.add(lspInstallResult.getServerCommandArgs());
-        commands.add("--stdio");
-        commands.add("--set-credentials-encryption-key");
-        setCommands(commands);
     }
 
     @Override
@@ -70,10 +77,12 @@ public final void start() throws IOException {
 
                 lspEncryption.initializeEncryptedCommunication(serverStdIn);
             } catch (Exception e) {
+                LspStatusManager.getInstance().setToFailed();
                 emitInitFailure(ExceptionMetadata.scrubException(e));
                 Activator.getLogger().error("Error occured while initializing communication with Amazon Q Lsp Server", e);
             }
         } catch (Exception e) {
+            LspStatusManager.getInstance().setToFailed();
             emitInitFailure(ExceptionMetadata.scrubException(e));
             throw e;
         }

plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/manager/LspState.java

@@ -0,0 +1,10 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package software.aws.toolkits.eclipse.amazonq.lsp.manager;
+
+public enum LspState {
+    ACTIVE,
+    FAILED,
+    PENDING
+}

plugin/src/software/aws/toolkits/eclipse/amazonq/lsp/manager/LspStatusManager.java

@@ -0,0 +1,49 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package software.aws.toolkits.eclipse.amazonq.lsp.manager;
+
+import software.aws.toolkits.eclipse.amazonq.plugin.Activator;
+import software.aws.toolkits.eclipse.amazonq.views.ViewVisibilityManager;
+
+public final class LspStatusManager {
+
+    private static final LspStatusManager INSTANCE;
+    private LspState lspState;
+
+    static {
+        INSTANCE = new LspStatusManager();
+    }
+
+    private LspStatusManager() {
+        lspState = LspState.PENDING;
+        Activator.getEventBroker().post(lspState);
+    }
+
+    public static LspStatusManager getInstance() {
+        return INSTANCE;
+    }
+
+
+    public boolean lspFailed() {
+        return (lspState == LspState.FAILED);
+    }
+
+    public void setToActive() {
+        lspState = LspState.ACTIVE;
+        Activator.getEventBroker().post(lspState);
+        ViewVisibilityManager.showDefaultView("restart");
+    }
+
+    public void setToFailed() {
+        if (lspState != LspState.FAILED) {
+            ViewVisibilityManager.showLspStartUpFailedView("update");
+            lspState = LspState.FAILED;
+        }
+
+        Activator.getEventBroker().post(lspState);
+    }
+    public LspState getLspState() {
+        return lspState;
+    }
+}

plugin/src/software/aws/toolkits/eclipse/amazonq/plugin/Activator.java

@@ -20,6 +20,7 @@
 import software.aws.toolkits.eclipse.amazonq.util.DefaultCodeReferenceLoggingService;
 import software.aws.toolkits.eclipse.amazonq.util.LoggingService;
 import software.aws.toolkits.eclipse.amazonq.util.PluginLogger;
+import software.aws.toolkits.eclipse.amazonq.views.router.ViewRouter;
 
 public class Activator extends AbstractUIPlugin {
 
@@ -32,6 +33,7 @@ public class Activator extends AbstractUIPlugin {
     private static CodeReferenceLoggingService codeReferenceLoggingService;
     private static PluginStore pluginStore;
     private static EventBroker eventBroker = new EventBroker();
+    private static ViewRouter viewRouter = ViewRouter.builder().build();
 
     public Activator() {
         super();

plugin/src/software/aws/toolkits/eclipse/amazonq/providers/LspProviderImpl.java

@@ -11,6 +11,7 @@
 import org.eclipse.lsp4j.services.LanguageServer;
 
 import software.aws.toolkits.eclipse.amazonq.lsp.AmazonQLspServer;
+import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspStatusManager;
 import software.aws.toolkits.eclipse.amazonq.lsp.manager.fetcher.RecordLspSetupArgs;
 import software.aws.toolkits.eclipse.amazonq.telemetry.LanguageServerTelemetryProvider;
 import software.aws.toolkits.telemetry.TelemetryDefinitions.Result;
@@ -52,6 +53,7 @@ public void setAmazonQServer(final LanguageServer server) {
                 future.complete(server);
             }
             emitInitializeMetric();
+            LspStatusManager.getInstance().setToActive();
         }
     }
 

plugin/src/software/aws/toolkits/eclipse/amazonq/views/AmazonQChatWebview.java

@@ -21,6 +21,7 @@
 import software.aws.toolkits.eclipse.amazonq.configuration.PluginStoreKeys;
 import software.aws.toolkits.eclipse.amazonq.lsp.AwsServerCapabiltiesProvider;
 import software.aws.toolkits.eclipse.amazonq.lsp.auth.model.AuthState;
+import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspStatusManager;
 import software.aws.toolkits.eclipse.amazonq.lsp.model.ChatOptions;
 import software.aws.toolkits.eclipse.amazonq.lsp.model.QuickActions;
 import software.aws.toolkits.eclipse.amazonq.lsp.model.QuickActionsCommandGroup;
@@ -141,7 +142,7 @@ public final void onEvent(final AuthState authState) {
                 // chat view
                 if (browser != null && !browser.isDisposed() && !chatStateManager.hasPreservedState()) {
                     Optional<String> content = getContent();
-                    if (!content.isPresent()) {
+                    if (!content.isPresent() && !LspStatusManager.getInstance().lspFailed()) {
                         canDisposeState = true;
                         ViewVisibilityManager.showChatAssetMissingView("update");
                     } else {

plugin/src/software/aws/toolkits/eclipse/amazonq/views/LspStartUpFailedView.java

@@ -0,0 +1,44 @@
+// Copyright 2024 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+package software.aws.toolkits.eclipse.amazonq.views;
+import java.util.concurrent.CompletableFuture;
+
+import software.aws.toolkits.eclipse.amazonq.lsp.manager.LspStatusManager;
+
+public final class LspStartUpFailedView extends BaseView {
+    public static final String ID = "software.aws.toolkits.eclipse.amazonq.views.LspStartUpFailedView";
+
+    private static final String ICON_PATH = "icons/AmazonQ64.png";
+    private static final String HEADER_LABEL = "Language Server failed to start.";
+    private static final String DETAIL_MESSAGE = "Restart Eclipse or review error logs for troubleshooting";
+
+    /* TODO: After refactor of LSP error handling is completed,
+     * add logic to base detail_message on error code returned from exception
+     *  */
+    @Override
+    protected String getIconPath() {
+        return ICON_PATH;
+    }
+
+    @Override
+    protected String getHeaderLabel() {
+        return HEADER_LABEL;
+    }
+
+    @Override
+    protected String getDetailMessage() {
+        return DETAIL_MESSAGE;
+    }
+
+    @Override
+    protected void showAlternateView() {
+        ViewVisibilityManager.showDefaultView("restart");
+    }
+
+    @Override
+    protected CompletableFuture<Boolean> isViewDisplayable() {
+        return CompletableFuture.completedFuture(LspStatusManager.getInstance().lspFailed());
+    }
+
+}