extHostNotebook.ts

/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import * as vscode from 'vscode';
import { readonly } from 'vs/base/common/errors';
import { Emitter, Event } from 'vs/base/common/event';
import { Disposable, DisposableStore, IDisposable } from 'vs/base/common/lifecycle';
import { ISplice } from 'vs/base/common/sequence';
import { URI, UriComponents } from 'vs/base/common/uri';
import * as UUID from 'vs/base/common/uuid';
import { IExtensionDescription } from 'vs/platform/extensions/common/extensions';
import { CellKind, ExtHostNotebookShape, IMainContext, MainContext, MainThreadNotebookShape, NotebookCellOutputsSplice, MainThreadDocumentsShape, INotebookEditorPropertiesChangeData, INotebookDocumentsAndEditorsDelta } from 'vs/workbench/api/common/extHost.protocol';
import { ExtHostCommands } from 'vs/workbench/api/common/extHostCommands';
import { ExtHostDocumentsAndEditors } from 'vs/workbench/api/common/extHostDocumentsAndEditors';
import { CellEditType, diff, ICellEditOperation, ICellInsertEdit, INotebookDisplayOrder, INotebookEditData, NotebookCellsChangedEvent, NotebookCellsSplice2, ICellDeleteEdit, notebookDocumentMetadataDefaults, NotebookCellsChangeType, NotebookDataDto, IOutputRenderRequest, IOutputRenderResponse, IOutputRenderResponseOutputInfo, IOutputRenderResponseCellInfo, IRawOutput, CellOutputKind, IProcessedOutput, INotebookKernelInfoDto2, IMainCellDto } from 'vs/workbench/contrib/notebook/common/notebookCommon';
import * as extHostTypes from 'vs/workbench/api/common/extHostTypes';
import { CancellationToken } from 'vs/base/common/cancellation';
import { ExtHostDocumentData } from 'vs/workbench/api/common/extHostDocumentData';
import { NotImplementedProxy } from 'vs/base/common/types';
import * as typeConverters from 'vs/workbench/api/common/extHostTypeConverters';
import { asWebviewUri, WebviewInitData } from 'vs/workbench/api/common/shared/webview';
import { IExtensionStoragePaths } from 'vs/workbench/api/common/extHostStoragePaths';
import { joinPath } from 'vs/base/common/resources';
import { Schemas } from 'vs/base/common/network';
import { hash } from 'vs/base/common/hash';
import { Cache } from './cache';

interface IObservable<T> {
	proxy: T;
	onDidChange: Event<void>;
}

function getObservable<T extends Object>(obj: T): IObservable<T> {
	const onDidChange = new Emitter<void>();
	const proxy = new Proxy(obj, {
		set(target: T, p: PropertyKey, value: any, _receiver: any): boolean {
			target[p as keyof T] = value;
			onDidChange.fire();
			return true;
		}
	});

	return {
		proxy,
		onDidChange: onDidChange.event
	};
}

interface INotebookEventEmitter {
	emitModelChange(events: vscode.NotebookCellsChangeEvent): void;
	emitCellOutputsChange(event: vscode.NotebookCellOutputsChangeEvent): void;
	emitCellLanguageChange(event: vscode.NotebookCellLanguageChangeEvent): void;
}

const addIdToOutput = (output: IRawOutput, id = UUID.generateUuid()): IProcessedOutput => output.outputKind === CellOutputKind.Rich
	? ({ ...output, outputId: id }) : output;

class DettachedCellDocumentData extends ExtHostDocumentData {

	private static readonly _fakeProxy = new class extends NotImplementedProxy<MainThreadDocumentsShape>('document') {
		$trySaveDocument() {
			return Promise.reject('Cell-document cannot be saved');
		}
	};

	constructor(cell: IMainCellDto) {
		super(DettachedCellDocumentData._fakeProxy,
			URI.revive(cell.uri),
			cell.source,
			cell.eol,
			cell.language,
			0,
			false
		);
	}
}

export class ExtHostCell extends Disposable implements vscode.NotebookCell {

	private _onDidChangeOutputs = new Emitter<ISplice<IProcessedOutput>[]>();
	readonly onDidChangeOutputs: Event<ISplice<IProcessedOutput>[]> = this._onDidChangeOutputs.event;

	private _outputs: any[];
	private _outputMapping = new WeakMap<vscode.CellOutput, string | undefined /* output ID */>();

	private _metadata: vscode.NotebookCellMetadata;
	private _metadataChangeListener: IDisposable;

	readonly handle: number;
	readonly uri: URI;
	readonly cellKind: CellKind;

	// todo@jrieken this is a little fish because we have
	// vscode.TextDocument for which we never fired an onDidOpen
	// event and which doesn't appear in the list of documents.
	// this will change once the "real" document comes along. We
	// should come up with a better approach here...
	readonly defaultDocument: DettachedCellDocumentData;

	constructor(
		private _proxy: MainThreadNotebookShape,
		readonly notebook: ExtHostNotebookDocument,
		private _extHostDocument: ExtHostDocumentsAndEditors,
		cell: IMainCellDto,
	) {
		super();

		this.handle = cell.handle;
		this.uri = URI.revive(cell.uri);
		this.cellKind = cell.cellKind;
		this.defaultDocument = new DettachedCellDocumentData(cell);

		this._outputs = cell.outputs;
		for (const output of this._outputs) {
			this._outputMapping.set(output, output.outputId);
			delete output.outputId;
		}

		const observableMetadata = getObservable(cell.metadata ?? {});
		this._metadata = observableMetadata.proxy;
		this._metadataChangeListener = this._register(observableMetadata.onDidChange(() => {
			this._updateMetadata();
		}));
	}

	get document(): vscode.TextDocument {
		return this._extHostDocument.getDocument(this.uri)?.document ?? this.defaultDocument.document;
	}

	get language(): string {
		return this.document.languageId;
	}

	get outputs() {
		return this._outputs;
	}

	set outputs(newOutputs: vscode.CellOutput[]) {
		let rawDiffs = diff<vscode.CellOutput>(this._outputs || [], newOutputs || [], (a) => {
			return this._outputMapping.has(a);
		});

		const transformedDiffs: ISplice<IProcessedOutput>[] = rawDiffs.map(diff => {
			for (let i = diff.start; i < diff.start + diff.deleteCount; i++) {
				this._outputMapping.delete(this._outputs[i]);
			}

			return {
				deleteCount: diff.deleteCount,
				start: diff.start,
				toInsert: diff.toInsert.map((output): IProcessedOutput => {
					if (output.outputKind === CellOutputKind.Rich) {
						const uuid = UUID.generateUuid();
						this._outputMapping.set(output, uuid);
						return { ...output, outputId: uuid };
					}

					this._outputMapping.set(output, undefined);
					return output;
				})
			};
		});

		this._outputs = newOutputs;
		this._onDidChangeOutputs.fire(transformedDiffs);
	}

	get metadata() {
		return this._metadata;
	}

	set metadata(newMetadata: vscode.NotebookCellMetadata) {
		// Don't apply metadata defaults here, 'undefined' means 'inherit from document metadata'
		this._metadataChangeListener.dispose();
		const observableMetadata = getObservable(newMetadata);
		this._metadata = observableMetadata.proxy;
		this._metadataChangeListener = this._register(observableMetadata.onDidChange(() => {
			this._updateMetadata();
		}));

		this._updateMetadata();
	}

	private _updateMetadata(): Promise<void> {
		return this._proxy.$updateNotebookCellMetadata(this.notebook.viewType, this.notebook.uri, this.handle, this._metadata);
	}
}

export class ExtHostNotebookDocument extends Disposable implements vscode.NotebookDocument {
	private static _handlePool: number = 0;
	readonly handle = ExtHostNotebookDocument._handlePool++;

	private _cells: ExtHostCell[] = [];

	private _cellDisposableMapping = new Map<number, DisposableStore>();

	get cells() {
		return this._cells;
	}

	private _languages: string[] = [];

	get languages() {
		return this._languages = [];
	}

	set languages(newLanguages: string[]) {
		this._languages = newLanguages;
		this._proxy.$updateNotebookLanguages(this.viewType, this.uri, this._languages);
	}

	private _metadata: Required<vscode.NotebookDocumentMetadata> = notebookDocumentMetadataDefaults;
	private _metadataChangeListener: IDisposable;

	get metadata() {
		return this._metadata;
	}

	set metadata(newMetadata: Required<vscode.NotebookDocumentMetadata>) {
		this._metadataChangeListener.dispose();
		newMetadata = {
			...notebookDocumentMetadataDefaults,
			...newMetadata
		};
		if (this._metadataChangeListener) {
			this._metadataChangeListener.dispose();
		}

		const observableMetadata = getObservable(newMetadata);
		this._metadata = observableMetadata.proxy;
		this._metadataChangeListener = this._register(observableMetadata.onDidChange(() => {
			this.updateMetadata();
		}));

		this.updateMetadata();
	}

	private _displayOrder: string[] = [];

	get displayOrder() {
		return this._displayOrder;
	}

	set displayOrder(newOrder: string[]) {
		this._displayOrder = newOrder;
	}

	private _versionId = 0;

	get versionId() {
		return this._versionId;
	}

	private _backupCounter = 1;

	private _backup?: vscode.NotebookDocumentBackup;


	private readonly _edits = new Cache<vscode.NotebookDocumentEditEvent>('notebook documents');


	addEdit(item: vscode.NotebookDocumentEditEvent): number {
		return this._edits.add([item]);
	}

	async undo(editId: number, isDirty: boolean): Promise<void> {
		await this.getEdit(editId).undo();
		// if (!isDirty) {
		// 	this.disposeBackup();
		// }
	}

	async redo(editId: number, isDirty: boolean): Promise<void> {
		await this.getEdit(editId).redo();
		// if (!isDirty) {
		// 	this.disposeBackup();
		// }
	}

	private getEdit(editId: number): vscode.NotebookDocumentEditEvent {
		const edit = this._edits.get(editId, 0);
		if (!edit) {
			throw new Error('No edit found');
		}

		return edit;
	}

	disposeEdits(editIds: number[]): void {
		for (const id of editIds) {
			this._edits.delete(id);
		}
	}

	private _disposed = false;

	constructor(
		private readonly _proxy: MainThreadNotebookShape,
		private _documentsAndEditors: ExtHostDocumentsAndEditors,
		private _emitter: INotebookEventEmitter,
		public viewType: string,
		public uri: URI,
		public renderingHandler: ExtHostNotebookOutputRenderingHandler,
		private readonly _storagePath: URI | undefined
	) {
		super();

		const observableMetadata = getObservable(notebookDocumentMetadataDefaults);
		this._metadata = observableMetadata.proxy;
		this._metadataChangeListener = this._register(observableMetadata.onDidChange(() => {
			this.updateMetadata();
		}));
	}

	private updateMetadata() {
		this._proxy.$updateNotebookMetadata(this.viewType, this.uri, this._metadata);
	}

	getNewBackupUri(): URI {
		if (!this._storagePath) {
			throw new Error('Backup requires a valid storage path');
		}
		const fileName = hashPath(this.uri) + (this._backupCounter++);
		return joinPath(this._storagePath, fileName);
	}

	updateBackup(backup: vscode.NotebookDocumentBackup): void {
		this._backup?.delete();
		this._backup = backup;
	}

	disposeBackup(): void {
		this._backup?.delete();
		this._backup = undefined;
	}

	dispose() {
		this._disposed = true;
		super.dispose();
		this._cellDisposableMapping.forEach(cell => cell.dispose());
	}

	get fileName() { return this.uri.fsPath; }

	get isDirty() { return false; }

	accpetModelChanged(event: NotebookCellsChangedEvent): void {
		this._versionId = event.versionId;
		if (event.kind === NotebookCellsChangeType.Initialize) {
			this.$spliceNotebookCells(event.changes, true);
		} if (event.kind === NotebookCellsChangeType.ModelChange) {
			this.$spliceNotebookCells(event.changes, false);
		} else if (event.kind === NotebookCellsChangeType.Move) {
			this.$moveCell(event.index, event.newIdx);
		} else if (event.kind === NotebookCellsChangeType.CellClearOutput) {
			this.$clearCellOutputs(event.index);
		} else if (event.kind === NotebookCellsChangeType.CellsClearOutput) {
			this.$clearAllCellOutputs();
		} else if (event.kind === NotebookCellsChangeType.ChangeLanguage) {
			this.$changeCellLanguage(event.index, event.language);
		}
	}

	private $spliceNotebookCells(splices: NotebookCellsSplice2[], initialization: boolean): void {
		if (this._disposed) {
			return;
		}

		let contentChangeEvents: vscode.NotebookCellsChangeData[] = [];

		splices.reverse().forEach(splice => {
			let cellDtos = splice[2];
			let newCells = cellDtos.map(cell => {

				const extCell = new ExtHostCell(this._proxy, this, this._documentsAndEditors, cell);

				if (!this._cellDisposableMapping.has(extCell.handle)) {
					this._cellDisposableMapping.set(extCell.handle, new DisposableStore());
				}

				let store = this._cellDisposableMapping.get(extCell.handle)!;

				store.add(extCell.onDidChangeOutputs((diffs) => {
					this.eventuallyUpdateCellOutputs(extCell, diffs);
				}));

				return extCell;
			});

			for (let j = splice[0]; j < splice[0] + splice[1]; j++) {
				this._cellDisposableMapping.get(this.cells[j].handle)?.dispose();
				this._cellDisposableMapping.delete(this.cells[j].handle);

			}

			const deletedItems = this.cells.splice(splice[0], splice[1], ...newCells);

			const event: vscode.NotebookCellsChangeData = {
				start: splice[0],
				deletedCount: splice[1],
				deletedItems,
				items: newCells
			};

			contentChangeEvents.push(event);
		});

		if (!initialization) {
			this._emitter.emitModelChange({
				document: this,
				changes: contentChangeEvents
			});
		}
	}

	private $moveCell(index: number, newIdx: number): void {
		const cells = this.cells.splice(index, 1);
		this.cells.splice(newIdx, 0, ...cells);
		const changes: vscode.NotebookCellsChangeData[] = [{
			start: index,
			deletedCount: 1,
			deletedItems: cells,
			items: []
		}, {
			start: newIdx,
			deletedCount: 0,
			deletedItems: [],
			items: cells
		}];
		this._emitter.emitModelChange({
			document: this,
			changes
		});
	}

	private $clearCellOutputs(index: number): void {
		const cell = this.cells[index];
		cell.outputs = [];
		const event: vscode.NotebookCellOutputsChangeEvent = { document: this, cells: [cell] };
		this._emitter.emitCellOutputsChange(event);
	}

	private $clearAllCellOutputs(): void {
		const modifedCells: vscode.NotebookCell[] = [];
		this.cells.forEach(cell => {
			if (cell.outputs.length !== 0) {
				cell.outputs = [];
				modifedCells.push(cell);
			}
		});
		const event: vscode.NotebookCellOutputsChangeEvent = { document: this, cells: modifedCells };
		this._emitter.emitCellOutputsChange(event);
	}

	private $changeCellLanguage(index: number, language: string): void {
		const cell = this.cells[index];
		cell.defaultDocument._acceptLanguageId(language);
		const event: vscode.NotebookCellLanguageChangeEvent = { document: this, cell, language };
		this._emitter.emitCellLanguageChange(event);
	}

	async eventuallyUpdateCellOutputs(cell: ExtHostCell, diffs: ISplice<IProcessedOutput>[]) {
		let renderers = new Set<number>();
		let outputDtos: NotebookCellOutputsSplice[] = diffs.map(diff => {
			let outputs = diff.toInsert;
			return [diff.start, diff.deleteCount, outputs];
		});

		await this._proxy.$spliceNotebookCellOutputs(this.viewType, this.uri, cell.handle, outputDtos, Array.from(renderers));
		this._emitter.emitCellOutputsChange({
			document: this,
			cells: [cell]
		});
	}

	getCell(cellHandle: number) {
		return this.cells.find(cell => cell.handle === cellHandle);
	}

	getCell2(cellUri: UriComponents) {
		return this.cells.find(cell => cell.uri.fragment === cellUri.fragment);
	}
}

export class NotebookEditorCellEditBuilder implements vscode.NotebookEditorCellEdit {
	private _finalized: boolean = false;
	private readonly _documentVersionId: number;
	private _collectedEdits: ICellEditOperation[] = [];
	private _renderers = new Set<number>();

	constructor(
		readonly editor: ExtHostNotebookEditor
	) {
		this._documentVersionId = editor.document.versionId;
	}

	finalize(): INotebookEditData {
		this._finalized = true;
		return {
			documentVersionId: this._documentVersionId,
			edits: this._collectedEdits,
			renderers: Array.from(this._renderers)
		};
	}

	private _throwIfFinalized() {
		if (this._finalized) {
			throw new Error('Edit is only valid while callback runs');
		}
	}

	insert(index: number, content: string | string[], language: string, type: CellKind, outputs: vscode.CellOutput[], metadata: vscode.NotebookCellMetadata | undefined): void {
		this._throwIfFinalized();

		const sourceArr = Array.isArray(content) ? content : content.split(/\r|\n|\r\n/g);
		let cell = {
			source: sourceArr,
			language,
			cellKind: type,
			outputs: outputs.map(o => addIdToOutput(o)),
			metadata,
		};

		this._collectedEdits.push({
			editType: CellEditType.Insert,
			index,
			cells: [cell]
		});
	}

	delete(index: number): void {
		this._throwIfFinalized();

		this._collectedEdits.push({
			editType: CellEditType.Delete,
			index,
			count: 1
		});
	}
}

class ExtHostWebviewCommWrapper extends Disposable {
	private readonly _onDidReceiveDocumentMessage = new Emitter<any>();
	private readonly _rendererIdToEmitters = new Map<string, Emitter<any>>();

	constructor(
		private _editorId: string,
		public uri: URI,
		private _proxy: MainThreadNotebookShape,
		private _webviewInitData: WebviewInitData,
		public document: ExtHostNotebookDocument,
	) {
		super();
	}

	public onDidReceiveMessage(forRendererId: string | undefined, message: any) {
		this._onDidReceiveDocumentMessage.fire(message);
		if (forRendererId !== undefined) {
			this._rendererIdToEmitters.get(forRendererId)?.fire(message);
		}
	}

	public readonly contentProviderComm: vscode.NotebookCommunication = {
		editorId: this._editorId,
		onDidReceiveMessage: this._onDidReceiveDocumentMessage.event,
		postMessage: (message: any) => this._proxy.$postMessage(this._editorId, undefined, message),
		asWebviewUri: (uri: vscode.Uri) => this._asWebviewUri(uri),
	};

	public getRendererComm(rendererId: string): vscode.NotebookCommunication {
		const emitter = new Emitter<any>();
		this._rendererIdToEmitters.set(rendererId, emitter);
		return {
			editorId: this._editorId,
			onDidReceiveMessage: emitter.event,
			postMessage: (message: any) => this._proxy.$postMessage(this._editorId, rendererId, message),
			asWebviewUri: (uri: vscode.Uri) => this._asWebviewUri(uri),
		};
	}


	private _asWebviewUri(localResource: vscode.Uri): vscode.Uri {
		return asWebviewUri(this._webviewInitData, this._editorId, localResource);
	}
}

export class ExtHostNotebookEditor extends Disposable implements vscode.NotebookEditor {
	private _viewColumn: vscode.ViewColumn | undefined;

	selection?: ExtHostCell = undefined;

	private _active: boolean = false;
	get active(): boolean {
		return this._active;
	}

	set active(_state: boolean) {
		throw readonly('active');
	}

	private _visible: boolean = false;
	get visible(): boolean {
		return this._visible;
	}

	set visible(_state: boolean) {
		throw readonly('visible');
	}

	_acceptVisibility(value: boolean) {
		this._visible = value;
	}

	_acceptActive(value: boolean) {
		this._active = value;
	}

	private _kernel?: vscode.NotebookKernel;

	get kernel() {
		return this._kernel;
	}

	set kernel(_kernel: vscode.NotebookKernel | undefined) {
		throw readonly('kernel');
	}

	private _onDidDispose = new Emitter<void>();
	readonly onDidDispose: Event<void> = this._onDidDispose.event;
	private _onDidReceiveMessage = new Emitter<any>();
	onDidReceiveMessage: vscode.Event<any> = this._onDidReceiveMessage.event;

	constructor(
		private readonly viewType: string,
		readonly id: string,
		public uri: URI,
		private _proxy: MainThreadNotebookShape,
		private _webComm: vscode.NotebookCommunication,
		public document: ExtHostNotebookDocument,
	) {
		super();
		this._register(this._webComm.onDidReceiveMessage(e => {
			this._onDidReceiveMessage.fire(e);
		}));
	}

	edit(callback: (editBuilder: NotebookEditorCellEditBuilder) => void): Thenable<boolean> {
		const edit = new NotebookEditorCellEditBuilder(this);
		callback(edit);
		return this._applyEdit(edit);
	}

	private _applyEdit(editBuilder: NotebookEditorCellEditBuilder): Promise<boolean> {
		const editData = editBuilder.finalize();

		// return when there is nothing to do
		if (editData.edits.length === 0) {
			return Promise.resolve(true);
		}

		let compressedEdits: ICellEditOperation[] = [];
		let compressedEditsIndex = -1;

		for (let i = 0; i < editData.edits.length; i++) {
			if (compressedEditsIndex < 0) {
				compressedEdits.push(editData.edits[i]);
				compressedEditsIndex++;
				continue;
			}

			let prevIndex = compressedEditsIndex;
			let prev = compressedEdits[prevIndex];

			if (prev.editType === CellEditType.Insert && editData.edits[i].editType === CellEditType.Insert) {
				if (prev.index === editData.edits[i].index) {
					prev.cells.push(...(editData.edits[i] as ICellInsertEdit).cells);
					continue;
				}
			}

			if (prev.editType === CellEditType.Delete && editData.edits[i].editType === CellEditType.Delete) {
				if (prev.index === editData.edits[i].index) {
					prev.count += (editData.edits[i] as ICellDeleteEdit).count;
					continue;
				}
			}

			compressedEdits.push(editData.edits[i]);
			compressedEditsIndex++;
		}

		return this._proxy.$tryApplyEdits(this.viewType, this.uri, editData.documentVersionId, compressedEdits, editData.renderers);
	}

	get viewColumn(): vscode.ViewColumn | undefined {
		return this._viewColumn;
	}

	set viewColumn(value) {
		throw readonly('viewColumn');
	}

	updateActiveKernel(kernel?: vscode.NotebookKernel) {
		this._kernel = kernel;
	}
	async postMessage(message: any): Promise<boolean> {
		return this._webComm.postMessage(message);
	}

	asWebviewUri(localResource: vscode.Uri): vscode.Uri {
		return this._webComm.asWebviewUri(localResource);
	}
	dispose() {
		this._onDidDispose.fire();
		super.dispose();
	}
}

export class ExtHostNotebookOutputRenderer {
	private static _handlePool: number = 0;
	private resolvedComms = new WeakSet<ExtHostWebviewCommWrapper>();
	readonly handle = ExtHostNotebookOutputRenderer._handlePool++;

	constructor(
		public type: string,
		public filter: vscode.NotebookOutputSelector,
		public renderer: vscode.NotebookOutputRenderer
	) {

	}

	matches(mimeType: string): boolean {
		if (this.filter.mimeTypes) {
			if (this.filter.mimeTypes.indexOf(mimeType) >= 0) {
				return true;
			}
		}
		return false;
	}

	resolveNotebook(document: ExtHostNotebookDocument, comm: ExtHostWebviewCommWrapper) {
		if (!this.resolvedComms.has(comm) && this.renderer.resolveNotebook) {
			this.renderer.resolveNotebook(document, comm.getRendererComm(this.type));
			this.resolvedComms.add(comm);
		}
	}

	render(document: ExtHostNotebookDocument, output: vscode.CellDisplayOutput, outputId: string, mimeType: string): string {
		let html = this.renderer.render(document, { output, outputId, mimeType });

		return html;
	}
}
export interface ExtHostNotebookOutputRenderingHandler {
	outputDisplayOrder: INotebookDisplayOrder | undefined;
	findBestMatchedRenderer(mimeType: string): ExtHostNotebookOutputRenderer[];
}

export class ExtHostNotebookKernelProviderAdapter extends Disposable {
	private _kernelToId = new Map<vscode.NotebookKernel, string>();
	private _idToKernel = new Map<string, vscode.NotebookKernel>();
	constructor(
		private readonly _proxy: MainThreadNotebookShape,
		private readonly _handle: number,
		private readonly _extension: IExtensionDescription,
		private readonly _provider: vscode.NotebookKernelProvider
	) {
		super();

		if (this._provider.onDidChangeKernels) {
			this._register(this._provider.onDidChangeKernels(() => {
				this._proxy.$onNotebookKernelChange(this._handle);
			}));
		}
	}

	async provideKernels(document: ExtHostNotebookDocument, token: vscode.CancellationToken): Promise<INotebookKernelInfoDto2[]> {
		const data = await this._provider.provideKernels(document, token) || [];

		const newMap = new Map<vscode.NotebookKernel, string>();
		let kernel_unique_pool = 0;
		let kernelIdCache = new Set<string>();

		const transformedData: INotebookKernelInfoDto2[] = data.map(kernel => {
			let id = this._kernelToId.get(kernel);
			if (id === undefined) {
				if (kernel.id && kernelIdCache.has(kernel.id)) {
					id = `${this._extension.identifier.value}_${kernel.id}_${kernel_unique_pool++}`;
				} else {
					id = `${this._extension.identifier.value}_${kernel.id || UUID.generateUuid()}`;
				}

				this._kernelToId.set(kernel, id);
			}

			newMap.set(kernel, id);

			return {
				id,
				label: kernel.label,
				extension: this._extension.identifier,
				extensionLocation: this._extension.extensionLocation,
				description: kernel.description,
				isPreferred: kernel.isPreferred,
				preloads: kernel.preloads
			};
		});

		this._kernelToId = newMap;

		this._idToKernel.clear();
		this._kernelToId.forEach((value, key) => {
			this._idToKernel.set(value, key);
		});

		return transformedData;
	}

	getKernel(kernelId: string) {
		return this._idToKernel.get(kernelId);
	}

	async resolveNotebook(kernelId: string, document: ExtHostNotebookDocument, webview: vscode.NotebookCommunication, token: CancellationToken) {
		const kernel = this._idToKernel.get(kernelId);

		if (kernel && this._provider.resolveKernel) {
			return this._provider.resolveKernel(kernel, document, webview, token);
		}
	}

	async executeNotebook(kernelId: string, document: ExtHostNotebookDocument, cell: ExtHostCell | undefined, token: CancellationToken) {
		const kernel = this._idToKernel.get(kernelId);

		if (!kernel) {
			return;
		}

		if (cell) {
			return kernel.executeCell(document, cell, token);
		} else {
			return kernel.executeAllCells(document, token);
		}
	}
}

export class ExtHostNotebookController implements ExtHostNotebookShape, ExtHostNotebookOutputRenderingHandler {
	private static _notebookKernelProviderHandlePool: number = 0;

	private readonly _proxy: MainThreadNotebookShape;
	private readonly _notebookContentProviders = new Map<string, { readonly provider: vscode.NotebookContentProvider, readonly extension: IExtensionDescription; }>();
	private readonly _notebookKernels = new Map<string, { readonly kernel: vscode.NotebookKernel, readonly extension: IExtensionDescription; }>();
	private readonly _notebookKernelProviders = new Map<number, ExtHostNotebookKernelProviderAdapter>();
	private readonly _documents = new Map<string, ExtHostNotebookDocument>();
	private readonly _unInitializedDocuments = new Map<string, ExtHostNotebookDocument>();
	private readonly _editors = new Map<string, { editor: ExtHostNotebookEditor }>();
	private readonly _webviewComm = new Map<string, ExtHostWebviewCommWrapper>();
	private readonly _notebookOutputRenderers = new Map<string, ExtHostNotebookOutputRenderer>();
	private readonly _renderersUsedInNotebooks = new WeakMap<ExtHostNotebookDocument, Set<ExtHostNotebookOutputRenderer>>();
	private readonly _onDidChangeNotebookCells = new Emitter<vscode.NotebookCellsChangeEvent>();
	readonly onDidChangeNotebookCells = this._onDidChangeNotebookCells.event;
	private readonly _onDidChangeCellOutputs = new Emitter<vscode.NotebookCellOutputsChangeEvent>();
	readonly onDidChangeCellOutputs = this._onDidChangeCellOutputs.event;
	private readonly _onDidChangeCellLanguage = new Emitter<vscode.NotebookCellLanguageChangeEvent>();
	readonly onDidChangeCellLanguage = this._onDidChangeCellLanguage.event;
	private readonly _onDidChangeActiveNotebookEditor = new Emitter<vscode.NotebookEditor | undefined>();
	readonly onDidChangeActiveNotebookEditor = this._onDidChangeActiveNotebookEditor.event;

	private _outputDisplayOrder: INotebookDisplayOrder | undefined;

	get outputDisplayOrder(): INotebookDisplayOrder | undefined {
		return this._outputDisplayOrder;
	}

	private _activeNotebookEditor: ExtHostNotebookEditor | undefined;

	get activeNotebookEditor() {
		return this._activeNotebookEditor;
	}

	get notebookDocuments() {
		return [...this._documents.values()];
	}

	private _onDidOpenNotebookDocument = new Emitter<vscode.NotebookDocument>();
	onDidOpenNotebookDocument: Event<vscode.NotebookDocument> = this._onDidOpenNotebookDocument.event;
	private _onDidCloseNotebookDocument = new Emitter<vscode.NotebookDocument>();
	onDidCloseNotebookDocument: Event<vscode.NotebookDocument> = this._onDidCloseNotebookDocument.event;
	visibleNotebookEditors: ExtHostNotebookEditor[] = [];
	private _onDidChangeActiveNotebookKernel = new Emitter<{ document: ExtHostNotebookDocument, kernel: vscode.NotebookKernel | undefined }>();
	onDidChangeActiveNotebookKernel = this._onDidChangeActiveNotebookKernel.event;
	private _onDidChangeVisibleNotebookEditors = new Emitter<vscode.NotebookEditor[]>();
	onDidChangeVisibleNotebookEditors = this._onDidChangeVisibleNotebookEditors.event;

	constructor(
		mainContext: IMainContext,
		commands: ExtHostCommands,
		private _documentsAndEditors: ExtHostDocumentsAndEditors,
		private readonly _webviewInitData: WebviewInitData,
		private readonly _extensionStoragePaths?: IExtensionStoragePaths,
	) {
		this._proxy = mainContext.getProxy(MainContext.MainThreadNotebook);

		commands.registerArgumentProcessor({
			processArgument: arg => {
				if (arg && arg.$mid === 12) {
					const documentHandle = arg.notebookEditor?.notebookHandle;
					const cellHandle = arg.cell.handle;

					for (let value of this._editors) {
						if (value[1].editor.document.handle === documentHandle) {
							const cell = value[1].editor.document.getCell(cellHandle);
							if (cell) {
								return cell;
							}
						}
					}
				}
				return arg;
			}
		});
	}

	registerNotebookOutputRenderer(
		type: string,
		extension: IExtensionDescription,
		filter: vscode.NotebookOutputSelector,
		renderer: vscode.NotebookOutputRenderer
	): vscode.Disposable {
		if (this._notebookKernels.has(type)) {
			throw new Error(`Notebook renderer for '${type}' already registered`);
		}

		let extHostRenderer = new ExtHostNotebookOutputRenderer(type, filter, renderer);
		this._notebookOutputRenderers.set(extHostRenderer.type, extHostRenderer);
		this._proxy.$registerNotebookRenderer({ id: extension.identifier, location: extension.extensionLocation }, type, filter, renderer.preloads || []);
		return new extHostTypes.Disposable(() => {
			this._notebookOutputRenderers.delete(extHostRenderer.type);
			this._proxy.$unregisterNotebookRenderer(extHostRenderer.type);
		});
	}

	async $renderOutputs(uriComponents: UriComponents, id: string, request: IOutputRenderRequest<UriComponents>): Promise<IOutputRenderResponse<UriComponents> | undefined> {
		if (!this._notebookOutputRenderers.has(id)) {
			throw new Error(`Notebook renderer for '${id}' is not registered`);
		}

		const document = this._documents.get(URI.revive(uriComponents).toString());

		if (!document) {
			return;
		}

		const renderer = this._notebookOutputRenderers.get(id)!;
		this.provideCommToNotebookRenderers(document, renderer);

		const cellsResponse: IOutputRenderResponseCellInfo<UriComponents>[] = request.items.map(cellInfo => {
			const cell = document.getCell2(cellInfo.key)!;
			const outputResponse: IOutputRenderResponseOutputInfo[] = cellInfo.outputs.map(output => {
				return {
					index: output.index,
					outputId: output.outputId,
					mimeType: output.mimeType,
					handlerId: id,
					transformedOutput: renderer.render(document, cell.outputs[output.index] as vscode.CellDisplayOutput, output.outputId, output.mimeType)
				};
			});

			return {
				key: cellInfo.key,
				outputs: outputResponse
			};
		});

		return { items: cellsResponse };
	}

	/**
	 * The request carry the raw data for outputs so we don't look up in the existing document
	 */
	async $renderOutputs2<T>(uriComponents: UriComponents, id: string, request: IOutputRenderRequest<T>): Promise<IOutputRenderResponse<T> | undefined> {
		if (!this._notebookOutputRenderers.has(id)) {
			throw new Error(`Notebook renderer for '${id}' is not registered`);
		}

		const document = this._documents.get(URI.revive(uriComponents).toString());

		if (!document) {
			return;
		}

		const renderer = this._notebookOutputRenderers.get(id)!;
		this.provideCommToNotebookRenderers(document, renderer);

		const cellsResponse: IOutputRenderResponseCellInfo<T>[] = request.items.map(cellInfo => {
			const outputResponse: IOutputRenderResponseOutputInfo[] = cellInfo.outputs.map(output => {
				return {
					index: output.index,
					outputId: output.outputId,
					mimeType: output.mimeType,
					handlerId: id,
					transformedOutput: renderer.render(document, output.output! as vscode.CellDisplayOutput, output.outputId, output.mimeType)
				};
			});

			return {
				key: cellInfo.key,
				outputs: outputResponse
			};
		});

		return { items: cellsResponse };
	}

	findBestMatchedRenderer(mimeType: string): ExtHostNotebookOutputRenderer[] {
		let matches: ExtHostNotebookOutputRenderer[] = [];
		for (let renderer of this._notebookOutputRenderers) {
			if (renderer[1].matches(mimeType)) {
				matches.push(renderer[1]);
			}
		}

		return matches;
	}

	registerNotebookContentProvider(
		extension: IExtensionDescription,
		viewType: string,
		provider: vscode.NotebookContentProvider,
	): vscode.Disposable {

		if (this._notebookContentProviders.has(viewType)) {
			throw new Error(`Notebook provider for '${viewType}' already registered`);
		}

		// if ((<any>provider).executeCell) {
		// 	throw new Error('NotebookContentKernel.executeCell is removed, please use vscode.notebook.registerNotebookKernel instead.');
		// }

		this._notebookContentProviders.set(viewType, { extension, provider });

		const listener = provider.onDidChangeNotebook
			? provider.onDidChangeNotebook(e => {
				const document = this._documents.get(URI.revive(e.document.uri).toString());

				if (!document) {
					throw new Error(`Notebook document ${e.document.uri.toString()} not found`);
				}

				if (isEditEvent(e)) {
					const editId = document.addEdit(e);
					this._proxy.$onDidEdit(e.document.uri, viewType, editId, e.label);
				} else {
					this._proxy.$onContentChange(e.document.uri, viewType);
				}
			})
			: Disposable.None;

		const supportBackup = !!provider.backupNotebook;

		this._proxy.$registerNotebookProvider({ id: extension.identifier, location: extension.extensionLocation }, viewType, supportBackup, provider.kernel ? { id: viewType, label: provider.kernel.label, extensionLocation: extension.extensionLocation, preloads: provider.kernel.preloads } : undefined);

		return new extHostTypes.Disposable(() => {
			listener.dispose();
			this._notebookContentProviders.delete(viewType);
			this._proxy.$unregisterNotebookProvider(viewType);
		});
	}

	registerNotebookKernelProvider(extension: IExtensionDescription, selector: vscode.NotebookDocumentFilter, provider: vscode.NotebookKernelProvider) {
		const handle = ExtHostNotebookController._notebookKernelProviderHandlePool++;
		const adapter = new ExtHostNotebookKernelProviderAdapter(this._proxy, handle, extension, provider);
		this._notebookKernelProviders.set(handle, adapter);
		this._proxy.$registerNotebookKernelProvider({ id: extension.identifier, location: extension.extensionLocation }, handle, {
			viewType: selector.viewType,
			filenamePattern: selector.filenamePattern ? typeConverters.GlobPattern.from(selector.filenamePattern) : undefined,
			excludeFileNamePattern: selector.excludeFileNamePattern ? typeConverters.GlobPattern.from(selector.excludeFileNamePattern) : undefined,
		});

		return new extHostTypes.Disposable(() => {
			adapter.dispose();
			this._notebookKernelProviders.delete(handle);
			this._proxy.$unregisterNotebookKernelProvider(handle);
		});
	}

	private _withAdapter<T>(handle: number, uri: UriComponents, callback: (adapter: ExtHostNotebookKernelProviderAdapter, document: ExtHostNotebookDocument) => Promise<T>) {
		const document = this._documents.get(URI.revive(uri).toString());

		if (!document) {
			return [];
		}

		const provider = this._notebookKernelProviders.get(handle);

		if (!provider) {
			return [];
		}

		return callback(provider, document);
	}

	async $provideNotebookKernels(handle: number, uri: UriComponents, token: CancellationToken): Promise<INotebookKernelInfoDto2[]> {
		return this._withAdapter<INotebookKernelInfoDto2[]>(handle, uri, (adapter, document) => {
			return adapter.provideKernels(document, token);
		});
	}

	async $resolveNotebookKernel(handle: number, editorId: string, uri: UriComponents, kernelId: string, token: CancellationToken): Promise<void> {
		await this._withAdapter<void>(handle, uri, async (adapter, document) => {
			let webComm = this._webviewComm.get(editorId);

			if (webComm) {
				await adapter.resolveNotebook(kernelId, document, webComm.contentProviderComm, token);
			}
		});
	}

	registerNotebookKernel(extension: IExtensionDescription, id: string, selectors: vscode.GlobPattern[], kernel: vscode.NotebookKernel): vscode.Disposable {
		if (this._notebookKernels.has(id)) {
			throw new Error(`Notebook kernel for '${id}' already registered`);
		}

		this._notebookKernels.set(id, { kernel, extension });
		const transformedSelectors = selectors.map(selector => typeConverters.GlobPattern.from(selector));

		this._proxy.$registerNotebookKernel({ id: extension.identifier, location: extension.extensionLocation }, id, kernel.label, transformedSelectors, kernel.preloads || []);
		return new extHostTypes.Disposable(() => {
			this._notebookKernels.delete(id);
			this._proxy.$unregisterNotebookKernel(id);
		});
	}

	async $resolveNotebookData(viewType: string, uri: UriComponents, backupId?: string): Promise<NotebookDataDto | undefined> {
		const provider = this._notebookContentProviders.get(viewType);
		const revivedUri = URI.revive(uri);

		if (provider) {
			let storageRoot: URI | undefined;
			if (this._extensionStoragePaths) {
				storageRoot = this._extensionStoragePaths.workspaceValue(provider.extension) ?? this._extensionStoragePaths.globalValue(provider.extension);
			}

			let document = this._documents.get(URI.revive(uri).toString());

			if (!document) {
				const that = this;
				document = this._unInitializedDocuments.get(revivedUri.toString()) ?? new ExtHostNotebookDocument(this._proxy, this._documentsAndEditors, {
					emitModelChange(event: vscode.NotebookCellsChangeEvent): void {
						that._onDidChangeNotebookCells.fire(event);
					},
					emitCellOutputsChange(event: vscode.NotebookCellOutputsChangeEvent): void {
						that._onDidChangeCellOutputs.fire(event);
					},
					emitCellLanguageChange(event: vscode.NotebookCellLanguageChangeEvent): void {
						that._onDidChangeCellLanguage.fire(event);
					}
				}, viewType, revivedUri, this, storageRoot);
				this._unInitializedDocuments.set(revivedUri.toString(), document);
			}

			const rawCells = await provider.provider.openNotebook(URI.revive(uri), { backupId });
			const dto = {
				metadata: {
					...notebookDocumentMetadataDefaults,
					...rawCells.metadata
				},
				languages: rawCells.languages,
				cells: rawCells.cells.map(cell => ({
					...cell,
					outputs: cell.outputs.map(o => addIdToOutput(o))
				})),
			};

			return dto;
		}

		return;
	}

	async $resolveNotebookEditor(viewType: string, uri: UriComponents, editorId: string): Promise<void> {
		const provider = this._notebookContentProviders.get(viewType);
		const revivedUri = URI.revive(uri);
		const document = this._documents.get(revivedUri.toString());
		if (!document || !provider) {
			return;
		}

		let webComm = this._webviewComm.get(editorId);
		if (!webComm) {
			webComm = new ExtHostWebviewCommWrapper(editorId, revivedUri, this._proxy, this._webviewInitData, document);
			this._webviewComm.set(editorId, webComm);
		}

		if (!provider.provider.resolveNotebook) {
			return;
		}

		await provider.provider.resolveNotebook(document, webComm.contentProviderComm);
	}

	private provideCommToNotebookRenderers(document: ExtHostNotebookDocument, renderer: ExtHostNotebookOutputRenderer) {
		let alreadyRegistered = this._renderersUsedInNotebooks.get(document);
		if (!alreadyRegistered) {
			alreadyRegistered = new Set();
			this._renderersUsedInNotebooks.set(document, alreadyRegistered);
		}

		if (alreadyRegistered.has(renderer)) {
			return;
		}

		alreadyRegistered.add(renderer);
		for (const editorId of this._editors.keys()) {
			const comm = this._webviewComm.get(editorId);
			if (comm) {
				renderer.resolveNotebook(document, comm);
			}
		}
	}

	async $executeNotebookByAttachedKernel(viewType: string, uri: UriComponents, cellHandle: number | undefined, token: CancellationToken): Promise<void> {
		let document = this._documents.get(URI.revive(uri).toString());

		if (!document) {
			return;
		}

		if (this._notebookContentProviders.has(viewType)) {
			const cell = cellHandle !== undefined ? document.getCell(cellHandle) : undefined;
			const provider = this._notebookContentProviders.get(viewType)!.provider;

			if (provider.kernel) {
				if (cell) {
					return provider.kernel.executeCell(document, cell, token);
				} else {
					return provider.kernel.executeAllCells(document, token);
				}
			}
		}
	}

	async $executeNotebookKernelFromProvider(handle: number, uri: UriComponents, kernelId: string, cellHandle: number | undefined, token: CancellationToken): Promise<void> {
		await this._withAdapter(handle, uri, async (adapter, document) => {
			let cell = cellHandle !== undefined ? document.getCell(cellHandle) : undefined;

			return adapter.executeNotebook(kernelId, document, cell, token);
		});
	}

	async $executeNotebook2(kernelId: string, viewType: string, uri: UriComponents, cellHandle: number | undefined, token: CancellationToken): Promise<void> {
		let document = this._documents.get(URI.revive(uri).toString());

		if (!document || document.viewType !== viewType) {
			return;
		}

		let kernelInfo = this._notebookKernels.get(kernelId);

		if (!kernelInfo) {
			return;
		}

		let cell = cellHandle !== undefined ? document.getCell(cellHandle) : undefined;

		if (cell) {
			return kernelInfo.kernel.executeCell(document, cell, token);
		} else {
			return kernelInfo.kernel.executeAllCells(document, token);
		}
	}

	async $saveNotebook(viewType: string, uri: UriComponents, token: CancellationToken): Promise<boolean> {
		let document = this._documents.get(URI.revive(uri).toString());
		if (!document) {
			return false;
		}

		if (this._notebookContentProviders.has(viewType)) {
			await this._notebookContentProviders.get(viewType)!.provider.saveNotebook(document, token);
			return true;
		}

		return false;
	}

	async $saveNotebookAs(viewType: string, uri: UriComponents, target: UriComponents, token: CancellationToken): Promise<boolean> {
		let document = this._documents.get(URI.revive(uri).toString());
		if (!document) {
			return false;
		}

		if (this._notebookContentProviders.has(viewType)) {
			await this._notebookContentProviders.get(viewType)!.provider.saveNotebookAs(URI.revive(target), document, token);
			return true;
		}

		return false;
	}

	async $undoNotebook(viewType: string, uri: UriComponents, editId: number, isDirty: boolean): Promise<void> {
		const document = this._documents.get(URI.revive(uri).toString());
		if (!document) {
			return;
		}

		document.undo(editId, isDirty);

	}

	async $redoNotebook(viewType: string, uri: UriComponents, editId: number, isDirty: boolean): Promise<void> {
		const document = this._documents.get(URI.revive(uri).toString());
		if (!document) {
			return;
		}

		document.redo(editId, isDirty);
	}


	async $backup(viewType: string, uri: UriComponents, cancellation: CancellationToken): Promise<string | undefined> {
		const document = this._documents.get(URI.revive(uri).toString());
		const provider = this._notebookContentProviders.get(viewType);

		if (document && provider && provider.provider.backupNotebook) {
			const backup = await provider.provider.backupNotebook(document, { destination: document.getNewBackupUri() }, cancellation);
			document.updateBackup(backup);
			return backup.id;
		}

		return;
	}

	$acceptDisplayOrder(displayOrder: INotebookDisplayOrder): void {
		this._outputDisplayOrder = displayOrder;
	}

	$acceptNotebookActiveKernelChange(event: { uri: UriComponents, providerHandle: number | undefined, kernelId: string | undefined }) {
		if (event.providerHandle !== undefined) {
			this._withAdapter(event.providerHandle, event.uri, async (adapter, document) => {
				const kernel = event.kernelId ? adapter.getKernel(event.kernelId) : undefined;
				this._editors.forEach(editor => {
					if (editor.editor.document === document) {
						editor.editor.updateActiveKernel(kernel);
					}
				});
				this._onDidChangeActiveNotebookKernel.fire({ document, kernel });
			});
		}
	}

	// TODO: remove document - editor one on one mapping
	private _getEditorFromURI(uriComponents: UriComponents) {
		const uriStr = URI.revive(uriComponents).toString();
		let editor: { editor: ExtHostNotebookEditor } | undefined;
		this._editors.forEach(e => {
			if (e.editor.uri.toString() === uriStr) {
				editor = e;
			}
		});

		return editor;
	}

	$onDidReceiveMessage(editorId: string, forRendererType: string | undefined, message: any): void {
		this._webviewComm.get(editorId)?.onDidReceiveMessage(forRendererType, message);
	}

	$acceptModelChanged(uriComponents: UriComponents, event: NotebookCellsChangedEvent): void {
		const document = this._documents.get(URI.revive(uriComponents).toString());

		if (document) {
			document.accpetModelChanged(event);
		}
	}

	$acceptEditorPropertiesChanged(uriComponents: UriComponents, data: INotebookEditorPropertiesChangeData): void {
		let editor = this._getEditorFromURI(uriComponents);

		if (!editor) {
			return;
		}

		if (data.selections) {
			const cells = editor.editor.document.cells;

			if (data.selections.selections.length) {
				const firstCell = data.selections.selections[0];
				editor.editor.selection = cells.find(cell => cell.handle === firstCell);
			} else {
				editor.editor.selection = undefined;
			}
		}

		if (data.metadata) {
			editor.editor.document.metadata = {
				...notebookDocumentMetadataDefaults,
				...data.metadata
			};
		}
	}

	private _createExtHostEditor(document: ExtHostNotebookDocument, editorId: string, selections: number[]) {
		const revivedUri = document.uri;
		let webComm = this._webviewComm.get(editorId);

		if (!webComm) {
			webComm = new ExtHostWebviewCommWrapper(editorId, revivedUri, this._proxy, this._webviewInitData, document);
			this._webviewComm.set(editorId, webComm);
		}

		let editor = new ExtHostNotebookEditor(
			document.viewType,
			editorId,
			revivedUri,
			this._proxy,
			webComm.contentProviderComm,
			document
		);

		const cells = editor.document.cells;

		if (selections.length) {
			const firstCell = selections[0];
			editor.selection = cells.find(cell => cell.handle === firstCell);
		} else {
			editor.selection = undefined;
		}

		this._editors.get(editorId)?.editor.dispose();

		for (const renderer of this._renderersUsedInNotebooks.get(document) ?? []) {
			renderer.resolveNotebook(document, webComm);
		}

		this._editors.set(editorId, { editor });
	}

	async $acceptDocumentAndEditorsDelta(delta: INotebookDocumentsAndEditorsDelta) {
		let editorChanged = false;

		if (delta.removedDocuments) {
			delta.removedDocuments.forEach((uri) => {
				const revivedUri = URI.revive(uri);
				const revivedUriStr = revivedUri.toString();
				let document = this._documents.get(revivedUriStr);

				if (document) {
					document.dispose();
					this._documents.delete(revivedUriStr);
					this._onDidCloseNotebookDocument.fire(document);
				}

				[...this._editors.values()].forEach((e) => {
					if (e.editor.uri.toString() === revivedUriStr) {
						e.editor.dispose();
						this._editors.delete(e.editor.id);
						editorChanged = true;
					}
				});
			});
		}

		if (delta.addedDocuments) {
			delta.addedDocuments.forEach(modelData => {
				const revivedUri = URI.revive(modelData.uri);
				const revivedUriStr = revivedUri.toString();
				const viewType = modelData.viewType;
				const entry = this._notebookContentProviders.get(viewType);
				let storageRoot: URI | undefined;
				if (entry && this._extensionStoragePaths) {
					storageRoot = this._extensionStoragePaths.workspaceValue(entry.extension) ?? this._extensionStoragePaths.globalValue(entry.extension);
				}

				if (!this._documents.has(revivedUriStr)) {
					const that = this;

					let document = this._unInitializedDocuments.get(revivedUriStr) ?? new ExtHostNotebookDocument(this._proxy, this._documentsAndEditors, {
						emitModelChange(event: vscode.NotebookCellsChangeEvent): void {
							that._onDidChangeNotebookCells.fire(event);
						},
						emitCellOutputsChange(event: vscode.NotebookCellOutputsChangeEvent): void {
							that._onDidChangeCellOutputs.fire(event);
						},
						emitCellLanguageChange(event: vscode.NotebookCellLanguageChangeEvent): void {
							that._onDidChangeCellLanguage.fire(event);
						}
					}, viewType, revivedUri, this, storageRoot);

					this._unInitializedDocuments.delete(revivedUriStr);
					if (modelData.metadata) {
						document.metadata = {
							...notebookDocumentMetadataDefaults,
							...modelData.metadata
						};
					}

					document.accpetModelChanged({
						kind: NotebookCellsChangeType.Initialize,
						versionId: modelData.versionId,
						changes: [[
							0,
							0,
							modelData.cells
						]]
					});

					this._documents.get(revivedUriStr)?.dispose();
					this._documents.set(revivedUriStr, document);

					// create editor if populated
					if (modelData.attachedEditor) {
						this._createExtHostEditor(document, modelData.attachedEditor.id, modelData.attachedEditor.selections);
						editorChanged = true;
					}
				}

				const document = this._documents.get(revivedUriStr)!;
				this._onDidOpenNotebookDocument.fire(document);
			});
		}

		if (delta.addedEditors) {
			delta.addedEditors.forEach(editorModelData => {
				if (this._editors.has(editorModelData.id)) {
					return;
				}

				const revivedUri = URI.revive(editorModelData.documentUri);
				const document = this._documents.get(revivedUri.toString());

				if (document) {
					this._createExtHostEditor(document, editorModelData.id, editorModelData.selections);
					editorChanged = true;
				}
			});
		}

		const removedEditors: { editor: ExtHostNotebookEditor }[] = [];

		if (delta.removedEditors) {
			delta.removedEditors.forEach(editorid => {
				const editor = this._editors.get(editorid);

				if (editor) {
					editorChanged = true;
					this._editors.delete(editorid);

					if (this.activeNotebookEditor?.id === editor.editor.id) {
						this._activeNotebookEditor = undefined;
					}

					removedEditors.push(editor);
				}
			});
		}

		if (editorChanged) {
			removedEditors.forEach(e => {
				e.editor.dispose();
			});
		}

		if (delta.visibleEditors) {
			this.visibleNotebookEditors = delta.visibleEditors.map(id => this._editors.get(id)!.editor).filter(editor => !!editor) as ExtHostNotebookEditor[];
			const visibleEditorsSet = new Set<string>();
			this.visibleNotebookEditors.forEach(editor => visibleEditorsSet.add(editor.id));

			[...this._editors.values()].forEach((e) => {
				const newValue = visibleEditorsSet.has(e.editor.id);
				e.editor._acceptVisibility(newValue);
			});

			this.visibleNotebookEditors = [...this._editors.values()].map(e => e.editor).filter(e => e.visible);
			this._onDidChangeVisibleNotebookEditors.fire(this.visibleNotebookEditors);
		}

		if (delta.newActiveEditor !== undefined) {
			if (delta.newActiveEditor) {
				this._activeNotebookEditor = this._editors.get(delta.newActiveEditor)?.editor;
				this._activeNotebookEditor?._acceptActive(true);
				[...this._editors.values()].forEach((e) => {
					if (e.editor !== this.activeNotebookEditor) {
						e.editor._acceptActive(false);
					}
				});
			} else {
				// clear active notebook as current active editor is non-notebook editor
				this._activeNotebookEditor = undefined;

				[...this._editors.values()].forEach((e) => {
					e.editor._acceptActive(false);
				});

			}

			this._onDidChangeActiveNotebookEditor.fire(this._activeNotebookEditor);
		}
	}
}

function hashPath(resource: URI): string {
	const str = resource.scheme === Schemas.file || resource.scheme === Schemas.untitled ? resource.fsPath : resource.toString();
	return hash(str) + '';
}

function isEditEvent(e: vscode.NotebookDocumentEditEvent | vscode.NotebookDocumentContentChangeEvent): e is vscode.NotebookDocumentEditEvent {
	return typeof (e as vscode.NotebookDocumentEditEvent).undo === 'function'
		&& typeof (e as vscode.NotebookDocumentEditEvent).redo === 'function';
}