Show welcome view when controller repo is not setup

This will add a welcome view to the database panel which is shown when
the controller repository is not setup. This welcome view will show a
button which can be used to set up the controller repository.

extensions/ql-vscode/package.json

@@ -1310,6 +1310,11 @@
       {
         "view": "codeQLEvalLogViewer",
         "contents": "Run the 'Show Evaluator Log (UI)' command on a CodeQL query run in the Query History view."
+      },
+      {
+        "view": "codeQLVariantAnalysisRepositories",
+        "contents": "Set up a controller repository to start using variant analysis.\n[Set up controller repository](command:codeQLVariantAnalysisRepositories.setupControllerRepository)",
+        "when": "!config.codeQL.variantAnalysis.controllerRepo"
       }
     ]
   },

extensions/ql-vscode/src/config.ts

@@ -539,6 +539,27 @@ export async function setRemoteControllerRepo(repo: string | undefined) {
   await REMOTE_CONTROLLER_REPO.updateValue(repo, ConfigurationTarget.Global);
 }
 
+export interface VariantAnalysisConfig {
+  controllerRepo: string | undefined;
+  onDidChangeConfiguration?: Event<void>;
+}
+
+export class VariantAnalysisConfigListener
+  extends ConfigListener
+  implements VariantAnalysisConfig
+{
+  protected handleDidChangeConfiguration(e: ConfigurationChangeEvent): void {
+    this.handleDidChangeConfigurationForRelevantSettings(
+      [VARIANT_ANALYSIS_SETTING],
+      e,
+    );
+  }
+
+  public get controllerRepo(): string | undefined {
+    return getRemoteControllerRepo();
+  }
+}
+
 /**
  * The branch of "github/codeql-variant-analysis-action" to use with the "Run Variant Analysis" command.
  * Default value is "main".

extensions/ql-vscode/src/databases/db-module.ts

@@ -24,7 +24,7 @@ export class DbModule extends DisposableObject {
       const dbModule = new DbModule(app);
       app.subscriptions.push(dbModule);
 
-      await dbModule.initialize();
+      await dbModule.initialize(app);
       return dbModule;
     }
 
@@ -39,12 +39,12 @@ export class DbModule extends DisposableObject {
     return isCanary() && isVariantAnalysisReposPanelEnabled();
   }
 
-  private async initialize(): Promise<void> {
+  private async initialize(app: App): Promise<void> {
     void extLogger.log("Initializing database module");
 
     await this.dbConfigStore.initialize();
 
-    const dbPanel = new DbPanel(this.dbManager);
+    const dbPanel = new DbPanel(this.dbManager, app.credentials);
     await dbPanel.initialize();
 
     this.push(dbPanel);

extensions/ql-vscode/src/databases/ui/db-panel.ts

@@ -29,6 +29,9 @@ import { DbManager } from "../db-manager";
 import { DbTreeDataProvider } from "./db-tree-data-provider";
 import { DbTreeViewItem } from "./db-tree-view-item";
 import { getGitHubUrl } from "./db-tree-view-item-action";
+import { getControllerRepo } from "../../remote-queries/run-remote-query";
+import { getErrorMessage } from "../../pure/helpers-pure";
+import { Credentials } from "../../common/authentication";
 
 export interface RemoteDatabaseQuickPickItem extends QuickPickItem {
   kind: string;
@@ -42,7 +45,10 @@ export class DbPanel extends DisposableObject {
   private readonly dataProvider: DbTreeDataProvider;
   private readonly treeView: TreeView<DbTreeViewItem>;
 
-  public constructor(private readonly dbManager: DbManager) {
+  public constructor(
+    private readonly dbManager: DbManager,
+    private readonly credentials: Credentials,
+  ) {
     super();
 
     this.dataProvider = new DbTreeDataProvider(dbManager);
@@ -112,6 +118,12 @@ export class DbPanel extends DisposableObject {
         (treeViewItem: DbTreeViewItem) => this.removeItem(treeViewItem),
       ),
     );
+    this.push(
+      commandRunner(
+        "codeQLVariantAnalysisRepositories.setupControllerRepository",
+        () => this.setupControllerRepository(),
+      ),
+    );
   }
 
   private async openConfigFile(): Promise<void> {
@@ -383,4 +395,21 @@ export class DbPanel extends DisposableObject {
 
     await commands.executeCommand("vscode.open", Uri.parse(githubUrl));
   }
+
+  private async setupControllerRepository(): Promise<void> {
+    try {
+      // This will also validate that the controller repository is valid
+      await getControllerRepo(this.credentials);
+    } catch (e: unknown) {
+      if (e instanceof UserCancellationException) {
+        return;
+      }
+
+      void showAndLogErrorMessage(
+        `An error occurred while setting up the controller repository: ${getErrorMessage(
+          e,
+        )}`,
+      );
+    }
+  }
 }

extensions/ql-vscode/src/databases/ui/db-tree-data-provider.ts

@@ -13,6 +13,7 @@ import {
   DbConfigValidationError,
   DbConfigValidationErrorKind,
 } from "../db-validation-errors";
+import { VariantAnalysisConfigListener } from "../../config";
 
 export class DbTreeDataProvider
   extends DisposableObject
@@ -27,8 +28,17 @@ export class DbTreeDataProvider
   );
   private dbTreeItems: DbTreeViewItem[];
 
+  private variantAnalysisConfig: VariantAnalysisConfigListener;
+
   public constructor(private readonly dbManager: DbManager) {
     super();
+
+    this.variantAnalysisConfig = this.push(new VariantAnalysisConfigListener());
+    this.variantAnalysisConfig.onDidChangeConfiguration(() => {
+      this.dbTreeItems = this.createTree();
+      this._onDidChangeTreeData.fire(undefined);
+    });
+
     this.dbTreeItems = this.createTree();
     this.onDidChangeTreeData = this._onDidChangeTreeData.event;
 
@@ -62,6 +72,11 @@ export class DbTreeDataProvider
   }
 
   private createTree(): DbTreeViewItem[] {
+    // Returning an empty tree here will show the welcome view
+    if (!this.variantAnalysisConfig.controllerRepo) {
+      return [];
+    }
+
     const dbItemsResult = this.dbManager.getDbItems();
 
     if (dbItemsResult.isFailure) {

extensions/ql-vscode/src/remote-queries/run-remote-query.ts

@@ -376,10 +376,10 @@ export async function getControllerRepo(
     );
     controllerRepoNwo = await window.showInputBox({
       title:
-        "Controller repository in which to run the GitHub Actions workflow for this variant analysis",
+        "Controller repository in which to run GitHub Actions workflows for variant analyses",
       placeHolder: "<owner>/<repo>",
       prompt:
-        "Enter the name of a GitHub repository in the format <owner>/<repo>",
+        "Enter the name of a GitHub repository in the format <owner>/<repo>. You can change this in the extension settings.",
       ignoreFocusOut: true,
     });
     if (!controllerRepoNwo) {