Initial work on Arc tree view (#11008)

* Initial work on Arc tree view

* finish my thoughts

extensions/arc/src/ui/tree/controllerTreeNode.ts

@@ -0,0 +1,56 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import { TreeNode } from './treeNode';
+import { MiaaTreeNode } from './miaaTreeNode';
+import { ResourceType } from '../../constants';
+import { PostgresTreeNode } from './postgresTreeNode';
+import { ControllerModel, Registration } from '../../models/controllerModel';
+import { ControllerDashboard } from '../dashboards/controller/controllerDashboard';
+import { PostgresModel } from '../../models/postgresModel';
+import { parseInstanceName } from '../../common/utils';
+import { MiaaModel } from '../../models/miaaModel';
+
+/**
+ * The TreeNode for displaying an Azure Arc Controller
+ */
+export class ControllerTreeNode extends TreeNode {
+
+	private _children: TreeNode[] = [];
+
+	constructor(private _model: ControllerModel, private _context: vscode.ExtensionContext) {
+		super(_model.controllerUrl, vscode.TreeItemCollapsibleState.Collapsed, ResourceType.dataControllers);
+		_model.onRegistrationsUpdated(registrations => this.refreshChildren(registrations));
+		_model.refresh().catch(err => console.log(`Error refreshing Arc Controller model for tree node : ${err}`));
+	}
+
+	public async getChildren(): Promise<TreeNode[]> {
+		return this._children;
+	}
+
+	public async openDashboard(): Promise<void> {
+		const controllerDashboard = new ControllerDashboard(this._model);
+		await controllerDashboard.showDashboard();
+	}
+
+	private refreshChildren(registrations: Registration[]): void {
+		this._children = <TreeNode[]>registrations.map(registration => {
+			if (!registration.instanceNamespace || !registration.instanceName) {
+				console.warn('Registration is missing required namespace and name values, skipping');
+				return undefined;
+			}
+			switch (registration.instanceType) {
+				case ResourceType.postgresInstances:
+					const postgresModel = new PostgresModel(this._model.controllerUrl, this._model.auth, registration.instanceNamespace, parseInstanceName(registration.instanceName));
+					return new PostgresTreeNode(postgresModel, this._model, this._context);
+				case ResourceType.sqlManagedInstances:
+					const miaaModel = new MiaaModel(this._model.controllerUrl, this._model.auth, registration.instanceNamespace, parseInstanceName(registration.instanceName));
+					return new MiaaTreeNode(miaaModel, this._model);
+			}
+			return undefined;
+		}).filter(item => item); // filter out invalid nodes (controllers or ones without required properties)
+	}
+}