Added empty kernel and hook up with Kernel drop down (#3173)

* Initial toolbar work
- This is in-progress and needs additional fixes

* Resolve PR comments

* Added empty kernel and hook up with Kernel dropdown

* Resolve PR comments

src/sql/services/notebook/sessionManager.ts

@@ -1,31 +1,141 @@
 'use strict';
 
 import { nb } from 'sqlops';
-import { Session } from 'electron';
+import { localize } from 'vs/nls';
+
+const noKernel: string = localize('noKernel', 'No Kernel');
+let noKernelSpec: nb.IKernelSpec = ({
+	name: noKernel,
+	language: 'python',
+	display_name: noKernel
+});
 
 export class SessionManager implements nb.SessionManager {
-	private _sessionManager: nb.SessionManager;
-
-	constructor() {
-		
-	}
 	public get isReady(): boolean {
-		return this._sessionManager.isReady;
+		return true;
 	}
 
 	public get ready(): Thenable<void> {
-		return this._sessionManager.ready;
+		return Promise.resolve();
 	}
+
 	public get specs(): nb.IAllKernels {
-		return this._sessionManager.specs;
+		let allKernels: nb.IAllKernels = {
+            defaultKernel: noKernel,
+			kernels: [noKernelSpec]
+        };
+		return allKernels;
 	}
 
 	startNew(options: nb.ISessionOptions): Thenable<nb.ISession> {
-		return this._sessionManager.startNew(options);
+		let session = new EmptySession(options);
+		return Promise.resolve(session);
 	}
 
 	shutdown(id: string): Thenable<void> {
-		return this.shutdown(id);
+		return Promise.resolve();
+	}
+}
+
+class EmptySession implements nb.ISession {
+	private _kernel: EmptyKernel;
+	private _defaultKernelLoaded = false;
+
+	public set defaultKernelLoaded(value) {
+		this._defaultKernelLoaded = value;
 	}
 
+	public get defaultKernelLoaded(): boolean {
+		return this._defaultKernelLoaded;
+	}
+
+	constructor(private options: nb.ISessionOptions) {
+		this._kernel = new EmptyKernel();
+	}
+
+	public get canChangeKernels(): boolean {
+		return true;
+	}
+
+	public get id(): string {
+		return this.options.kernelId || '';
+	}
+
+	public get path(): string {
+		return this.options.path;
+	}
+
+	public get name(): string {
+		return this.options.name || '';
+	}
+
+	public get type(): string {
+		return this.options.type || '';
+	}
+
+	public get status(): nb.KernelStatus {
+		return 'connected';
+	}
+
+	public get kernel(): nb.IKernel {
+		return this._kernel;
+	}
+
+	changeKernel(kernelInfo: nb.IKernelSpec): Thenable<nb.IKernel> {
+		return Promise.resolve(this.kernel);
+	}
 }
+
+class EmptyKernel implements nb.IKernel {
+	public get id(): string {
+		return '-1';
+	}
+
+	public get name(): string {
+		return noKernel;
+	}
+
+	public get supportsIntellisense(): boolean {
+		return false;
+	}
+
+	public get isReady(): boolean {
+		return true;
+	}
+
+	public get ready(): Thenable<void> {
+		return Promise.resolve();
+	}
+
+	public get info(): nb.IInfoReply {
+		let info: nb.IInfoReply = {
+			protocol_version: '',
+			implementation: '',
+			implementation_version: '',
+			language_info: {
+				name: '',
+				version: '',
+			},
+			banner: '',
+			help_links: [{
+				text: '',
+				url: ''
+			}]
+		};
+
+		return info;
+	}
+	getSpec(): Thenable<nb.IKernelSpec> {
+		return Promise.resolve(noKernelSpec);
+	}
+
+	requestExecute(content: nb.IExecuteRequest, disposeOnDone?: boolean): nb.IFuture {
+		throw new Error('Method not implemented.');
+	}
+
+	requestComplete(content: nb.ICompleteRequest): Thenable<nb.ICompleteReplyMsg> {
+		let response: Partial<nb.ICompleteReplyMsg> = { };
+		return Promise.resolve(response as nb.ICompleteReplyMsg);
+	}
+
+}