editorService.ts

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

import { IInstantiationService, ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
import { IResourceInput, ITextEditorOptions, IEditorOptions, EditorActivation } from 'vs/platform/editor/common/editor';
import { SideBySideEditor as SideBySideEditorChoice, IEditorInput, IEditor, GroupIdentifier, IFileEditorInput, IUntitledTextResourceInput, IResourceDiffInput, IResourceSideBySideInput, IEditorInputFactoryRegistry, Extensions as EditorExtensions, EditorInput, SideBySideEditorInput, IEditorInputWithOptions, isEditorInputWithOptions, EditorOptions, TextEditorOptions, IEditorIdentifier, IEditorCloseEvent, ITextEditor, ITextDiffEditor, ITextSideBySideEditor, IRevertOptions, SaveReason, EditorsOrder, isTextEditor, IWorkbenchEditorConfiguration, toResource } from 'vs/workbench/common/editor';
import { ResourceEditorInput } from 'vs/workbench/common/editor/resourceEditorInput';
import { Registry } from 'vs/platform/registry/common/platform';
import { ResourceMap } from 'vs/base/common/map';
import { IUntitledTextEditorService } from 'vs/workbench/services/untitled/common/untitledTextEditorService';
import { IFileService, FileOperationEvent, FileOperation, FileChangesEvent, FileChangeType, FileSystemProviderCapabilities } from 'vs/platform/files/common/files';
import { Schemas } from 'vs/base/common/network';
import { Event, Emitter } from 'vs/base/common/event';
import { URI } from 'vs/base/common/uri';
import { basename, isEqualOrParent, joinPath } from 'vs/base/common/resources';
import { DiffEditorInput } from 'vs/workbench/common/editor/diffEditorInput';
import { IEditorGroupsService, IEditorGroup, GroupsOrder, IEditorReplacement, GroupChangeKind, preferredSideBySideGroupDirection } from 'vs/workbench/services/editor/common/editorGroupsService';
import { IResourceEditor, SIDE_GROUP, IResourceEditorReplacement, IOpenEditorOverrideHandler, IVisibleEditor, IEditorService, SIDE_GROUP_TYPE, ACTIVE_GROUP_TYPE, ISaveEditorsOptions, ISaveAllEditorsOptions, IRevertAllEditorsOptions, IBaseSaveRevertAllEditorOptions } from 'vs/workbench/services/editor/common/editorService';
import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
import { Disposable, IDisposable, dispose, toDisposable, DisposableStore } from 'vs/base/common/lifecycle';
import { coalesce, distinct } from 'vs/base/common/arrays';
import { isCodeEditor, isDiffEditor, ICodeEditor, IDiffEditor } from 'vs/editor/browser/editorBrowser';
import { IEditorGroupView, IEditorOpeningEvent, EditorServiceImpl } from 'vs/workbench/browser/parts/editor/editor';
import { ILabelService } from 'vs/platform/label/common/label';
import { registerSingleton } from 'vs/platform/instantiation/common/extensions';
import { withNullAsUndefined } from 'vs/base/common/types';
import { EditorsObserver } from 'vs/workbench/browser/parts/editor/editorsObserver';
import { IEditorViewState } from 'vs/editor/common/editorCommon';
import { IUntitledTextEditorModel } from 'vs/workbench/services/untitled/common/untitledTextEditorModel';
import { UntitledTextEditorInput } from 'vs/workbench/services/untitled/common/untitledTextEditorInput';
import { IEnvironmentService } from 'vs/platform/environment/common/environment';
import { timeout } from 'vs/base/common/async';
import { IWorkspaceContextService } from 'vs/platform/workspace/common/workspace';
import { indexOfPath } from 'vs/base/common/extpath';

type CachedEditorInput = ResourceEditorInput | IFileEditorInput | UntitledTextEditorInput;
type OpenInEditorGroup = IEditorGroup | GroupIdentifier | SIDE_GROUP_TYPE | ACTIVE_GROUP_TYPE;

export class EditorService extends Disposable implements EditorServiceImpl {

	_serviceBrand: undefined;

	//#region events

	private readonly _onDidActiveEditorChange = this._register(new Emitter<void>());
	readonly onDidActiveEditorChange = this._onDidActiveEditorChange.event;

	private readonly _onDidVisibleEditorsChange = this._register(new Emitter<void>());
	readonly onDidVisibleEditorsChange = this._onDidVisibleEditorsChange.event;

	private readonly _onDidCloseEditor = this._register(new Emitter<IEditorCloseEvent>());
	readonly onDidCloseEditor = this._onDidCloseEditor.event;

	private readonly _onDidOpenEditorFail = this._register(new Emitter<IEditorIdentifier>());
	readonly onDidOpenEditorFail = this._onDidOpenEditorFail.event;

	private readonly _onDidMostRecentlyActiveEditorsChange = this._register(new Emitter<void>());
	readonly onDidMostRecentlyActiveEditorsChange = this._onDidMostRecentlyActiveEditorsChange.event;

	//#endregion

	constructor(
		@IEditorGroupsService private readonly editorGroupService: IEditorGroupsService,
		@IUntitledTextEditorService private readonly untitledTextEditorService: IUntitledTextEditorService,
		@IInstantiationService private readonly instantiationService: IInstantiationService,
		@ILabelService private readonly labelService: ILabelService,
		@IFileService private readonly fileService: IFileService,
		@IConfigurationService private readonly configurationService: IConfigurationService,
		@IEnvironmentService private readonly environmentService: IEnvironmentService,
		@IWorkspaceContextService private readonly contextService: IWorkspaceContextService
	) {
		super();

		this.onConfigurationUpdated(configurationService.getValue<IWorkbenchEditorConfiguration>());

		this.registerListeners();
	}

	private registerListeners(): void {

		// Editor & group changes
		this.editorGroupService.whenRestored.then(() => this.onEditorsRestored());
		this.editorGroupService.onDidActiveGroupChange(group => this.handleActiveEditorChange(group));
		this.editorGroupService.onDidAddGroup(group => this.registerGroupListeners(group as IEditorGroupView));
		this.editorsObserver.onDidChange(() => this._onDidMostRecentlyActiveEditorsChange.fire());

		// Out of workspace file watchers
		this._register(this.onDidVisibleEditorsChange(() => this.handleVisibleEditorsChange()));

		// File changes & operations
		// Note: there is some duplication with the two file event handlers- Since we cannot always rely on the disk events
		// carrying all necessary data in all environments, we also use the file operation events to make sure operations are handled.
		// In any case there is no guarantee if the local event is fired first or the disk one. Thus, code must handle the case
		// that the event ordering is random as well as might not carry all information needed.
		this._register(this.fileService.onDidRunOperation(e => this.onDidRunFileOperation(e)));
		this._register(this.fileService.onDidFilesChange(e => this.onDidFilesChange(e)));

		// Configuration
		this._register(this.configurationService.onDidChangeConfiguration(e => this.onConfigurationUpdated(this.configurationService.getValue<IWorkbenchEditorConfiguration>())));
	}

	//#region Editor & group event handlers

	private lastActiveEditor: IEditorInput | undefined = undefined;

	private onEditorsRestored(): void {

		// Register listeners to each opened group
		this.editorGroupService.groups.forEach(group => this.registerGroupListeners(group as IEditorGroupView));

		// Fire initial set of editor events if there is an active editor
		if (this.activeEditor) {
			this.doHandleActiveEditorChangeEvent();
			this._onDidVisibleEditorsChange.fire();
		}
	}

	private handleActiveEditorChange(group: IEditorGroup): void {
		if (group !== this.editorGroupService.activeGroup) {
			return; // ignore if not the active group
		}

		if (!this.lastActiveEditor && !group.activeEditor) {
			return; // ignore if we still have no active editor
		}

		this.doHandleActiveEditorChangeEvent();
	}

	private doHandleActiveEditorChangeEvent(): void {

		// Remember as last active
		const activeGroup = this.editorGroupService.activeGroup;
		this.lastActiveEditor = withNullAsUndefined(activeGroup.activeEditor);

		// Fire event to outside parties
		this._onDidActiveEditorChange.fire();
	}

	private registerGroupListeners(group: IEditorGroupView): void {
		const groupDisposables = new DisposableStore();

		groupDisposables.add(group.onDidGroupChange(e => {
			if (e.kind === GroupChangeKind.EDITOR_ACTIVE) {
				this.handleActiveEditorChange(group);
				this._onDidVisibleEditorsChange.fire();
			}
		}));

		groupDisposables.add(group.onDidCloseEditor(event => {
			this._onDidCloseEditor.fire(event);
		}));

		groupDisposables.add(group.onWillOpenEditor(event => {
			this.onGroupWillOpenEditor(group, event);
		}));

		groupDisposables.add(group.onDidOpenEditorFail(editor => {
			this._onDidOpenEditorFail.fire({ editor, groupId: group.id });
		}));

		Event.once(group.onWillDispose)(() => {
			dispose(groupDisposables);
		});
	}

	//#endregion

	//#region Visible Editors Change: Install file watchers for out of workspace resources that became visible

	private readonly activeOutOfWorkspaceWatchers = new ResourceMap<IDisposable>();

	private handleVisibleEditorsChange(): void {
		const visibleOutOfWorkspaceResources = new ResourceMap<URI>();

		for (const editor of this.visibleEditors) {
			const resources = distinct(coalesce([
				toResource(editor, { supportSideBySide: SideBySideEditorChoice.MASTER }),
				toResource(editor, { supportSideBySide: SideBySideEditorChoice.DETAILS })
			]), resource => resource.toString());

			for (const resource of resources) {
				if (this.fileService.canHandleResource(resource) && !this.contextService.isInsideWorkspace(resource)) {
					visibleOutOfWorkspaceResources.set(resource, resource);
				}
			}
		}

		// Handle no longer visible out of workspace resources
		this.activeOutOfWorkspaceWatchers.keys().forEach(resource => {
			if (!visibleOutOfWorkspaceResources.get(resource)) {
				dispose(this.activeOutOfWorkspaceWatchers.get(resource));
				this.activeOutOfWorkspaceWatchers.delete(resource);
			}
		});

		// Handle newly visible out of workspace resources
		visibleOutOfWorkspaceResources.forEach(resource => {
			if (!this.activeOutOfWorkspaceWatchers.get(resource)) {
				const disposable = this.fileService.watch(resource);
				this.activeOutOfWorkspaceWatchers.set(resource, disposable);
			}
		});
	}

	//#endregion

	//#region File Changes: Move & Deletes to move or close opend editors

	private onDidRunFileOperation(e: FileOperationEvent): void {

		// Handle moves specially when file is opened
		if (e.isOperation(FileOperation.MOVE)) {
			this.handleMovedFile(e.resource, e.target.resource);
		}

		// Handle deletes
		if (e.isOperation(FileOperation.DELETE) || e.isOperation(FileOperation.MOVE)) {
			this.handleDeletedFile(e.resource, false, e.target ? e.target.resource : undefined);
		}
	}

	private onDidFilesChange(e: FileChangesEvent): void {
		if (e.gotDeleted()) {
			this.handleDeletedFile(e, true);
		}
	}

	private handleMovedFile(source: URI, target: URI): void {
		for (const group of this.editorGroupService.groups) {
			let replacements: (IResourceEditorReplacement | IEditorReplacement)[] = [];

			for (const editor of group.editors) {
				const resource = editor.resource;
				if (!resource || !isEqualOrParent(resource, source)) {
					continue; // not matching our resource
				}

				// Determine new resulting target resource
				let targetResource: URI;
				if (source.toString() === resource.toString()) {
					targetResource = target; // file got moved
				} else {
					const ignoreCase = !this.fileService.hasCapability(resource, FileSystemProviderCapabilities.PathCaseSensitive);
					const index = indexOfPath(resource.path, source.path, ignoreCase);
					targetResource = joinPath(target, resource.path.substr(index + source.path.length + 1)); // parent folder got moved
				}

				// Delegate move() to editor instance
				const moveResult = editor.move(group.id, targetResource);
				if (!moveResult) {
					return; // not target - ignore
				}

				const optionOverrides = {
					preserveFocus: true,
					pinned: group.isPinned(editor),
					index: group.getIndexOfEditor(editor),
					inactive: !group.isActive(editor)
				};

				// Construct a replacement with our extra options mixed in
				if (moveResult.editor instanceof EditorInput) {
					replacements.push({
						editor,
						replacement: moveResult.editor,
						options: {
							...moveResult.options,
							...optionOverrides
						}
					});
				} else {
					replacements.push({
						editor: { resource: editor.resource },
						replacement: {
							...moveResult.editor,
							options: {
								...moveResult.editor.options,
								...optionOverrides
							}
						}
					});
				}
			}

			// Apply replacements
			if (replacements.length) {
				this.replaceEditors(replacements, group);
			}
		}
	}

	private closeOnFileDelete: boolean = false;
	private fileInputFactory = Registry.as<IEditorInputFactoryRegistry>(EditorExtensions.EditorInputFactories).getFileInputFactory();
	private onConfigurationUpdated(configuration: IWorkbenchEditorConfiguration): void {
		if (typeof configuration.workbench?.editor?.closeOnFileDelete === 'boolean') {
			this.closeOnFileDelete = configuration.workbench.editor.closeOnFileDelete;
		} else {
			this.closeOnFileDelete = false; // default
		}
	}

	private handleDeletedFile(arg1: URI | FileChangesEvent, isExternal: boolean, movedTo?: URI): void {
		for (const editor of this.getAllNonDirtyEditors({ includeUntitled: false, supportSideBySide: true })) {
			(async () => {
				const resource = editor.resource;
				if (!resource) {
					return;
				}

				// Handle deletes in opened editors depending on:
				// - the user has not disabled the setting closeOnFileDelete
				// - the file change is local
				// - the input is  a file that is not resolved (we need to dispose because we cannot restore otherwise since we do not have the contents)
				if (this.closeOnFileDelete || !isExternal || (this.fileInputFactory.isFileInput(editor) && !editor.isResolved())) {

					// Do NOT close any opened editor that matches the resource path (either equal or being parent) of the
					// resource we move to (movedTo). Otherwise we would close a resource that has been renamed to the same
					// path but different casing.
					if (movedTo && isEqualOrParent(resource, movedTo)) {
						return;
					}

					let matches = false;
					if (arg1 instanceof FileChangesEvent) {
						matches = arg1.contains(resource, FileChangeType.DELETED);
					} else {
						matches = isEqualOrParent(resource, arg1);
					}

					if (!matches) {
						return;
					}

					// We have received reports of users seeing delete events even though the file still
					// exists (network shares issue: https://github.com/Microsoft/vscode/issues/13665).
					// Since we do not want to close an editor without reason, we have to check if the
					// file is really gone and not just a faulty file event.
					// This only applies to external file events, so we need to check for the isExternal
					// flag.
					let exists = false;
					if (isExternal && this.fileService.canHandleResource(resource)) {
						await timeout(100);
						exists = await this.fileService.exists(resource);
					}

					if (!exists && !editor.isDisposed()) {
						editor.dispose();
					} else if (this.environmentService.verbose) {
						console.warn(`File exists even though we received a delete event: ${resource.toString()}`);
					}
				}
			})();
		}
	}

	private getAllNonDirtyEditors(options: { includeUntitled: boolean, supportSideBySide: boolean }): IEditorInput[] {
		const editors: IEditorInput[] = [];

		function conditionallyAddEditor(editor: IEditorInput): void {
			if (editor.isUntitled() && !options.includeUntitled) {
				return;
			}

			if (editor.isDirty()) {
				return;
			}

			editors.push(editor);
		}

		for (const editor of this.editors) {
			if (options.supportSideBySide && editor instanceof SideBySideEditorInput) {
				conditionallyAddEditor(editor.master);
				conditionallyAddEditor(editor.details);
			} else {
				conditionallyAddEditor(editor);
			}
		}

		return editors;
	}

	//#endregion

	//#region Editor accessors

	private readonly editorsObserver = this._register(this.instantiationService.createInstance(EditorsObserver));

	get activeControl(): IVisibleEditor | undefined {
		return this.editorGroupService.activeGroup?.activeControl;
	}

	get activeTextEditorWidget(): ICodeEditor | IDiffEditor | undefined {
		const activeControl = this.activeControl;
		if (activeControl) {
			const activeControlWidget = activeControl.getControl();
			if (isCodeEditor(activeControlWidget) || isDiffEditor(activeControlWidget)) {
				return activeControlWidget;
			}
		}

		return undefined;
	}

	get activeTextEditorMode(): string | undefined {
		let activeCodeEditor: ICodeEditor | undefined = undefined;

		const activeTextEditorWidget = this.activeTextEditorWidget;
		if (isDiffEditor(activeTextEditorWidget)) {
			activeCodeEditor = activeTextEditorWidget.getModifiedEditor();
		} else {
			activeCodeEditor = activeTextEditorWidget;
		}

		return activeCodeEditor?.getModel()?.getLanguageIdentifier().language;
	}

	get count(): number {
		return this.editorsObserver.count;
	}

	get editors(): IEditorInput[] {
		return this.getEditors(EditorsOrder.SEQUENTIAL).map(({ editor }) => editor);
	}

	getEditors(order: EditorsOrder): ReadonlyArray<IEditorIdentifier> {
		if (order === EditorsOrder.MOST_RECENTLY_ACTIVE) {
			return this.editorsObserver.editors;
		}

		const editors: IEditorIdentifier[] = [];

		this.editorGroupService.getGroups(GroupsOrder.GRID_APPEARANCE).forEach(group => {
			editors.push(...group.getEditors(EditorsOrder.SEQUENTIAL).map(editor => ({ editor, groupId: group.id })));
		});

		return editors;
	}

	get activeEditor(): IEditorInput | undefined {
		const activeGroup = this.editorGroupService.activeGroup;

		return activeGroup ? withNullAsUndefined(activeGroup.activeEditor) : undefined;
	}

	get visibleControls(): IVisibleEditor[] {
		return coalesce(this.editorGroupService.groups.map(group => group.activeControl));
	}

	get visibleTextEditorWidgets(): Array<ICodeEditor | IDiffEditor> {
		return this.visibleControls.map(control => control.getControl() as ICodeEditor | IDiffEditor).filter(widget => isCodeEditor(widget) || isDiffEditor(widget));
	}

	get visibleEditors(): IEditorInput[] {
		return coalesce(this.editorGroupService.groups.map(group => group.activeEditor));
	}

	//#endregion

	//#region preventOpenEditor()

	private readonly openEditorHandlers: IOpenEditorOverrideHandler[] = [];

	overrideOpenEditor(handler: IOpenEditorOverrideHandler): IDisposable {
		this.openEditorHandlers.push(handler);

		return toDisposable(() => {
			const index = this.openEditorHandlers.indexOf(handler);
			if (index >= 0) {
				this.openEditorHandlers.splice(index, 1);
			}
		});
	}

	private onGroupWillOpenEditor(group: IEditorGroup, event: IEditorOpeningEvent): void {
		if (event.options && event.options.ignoreOverrides) {
			return;
		}

		for (const handler of this.openEditorHandlers) {
			const result = handler(event.editor, event.options, group);
			const override = result?.override;
			if (override) {
				event.prevent((() => override.then(editor => withNullAsUndefined(editor))));
				break;
			}
		}
	}

	//#endregion

	//#region openEditor()

	openEditor(editor: IEditorInput, options?: IEditorOptions | ITextEditorOptions, group?: OpenInEditorGroup): Promise<IEditor | undefined>;
	openEditor(editor: IResourceInput | IUntitledTextResourceInput, group?: OpenInEditorGroup): Promise<ITextEditor | undefined>;
	openEditor(editor: IResourceDiffInput, group?: OpenInEditorGroup): Promise<ITextDiffEditor | undefined>;
	openEditor(editor: IResourceSideBySideInput, group?: OpenInEditorGroup): Promise<ITextSideBySideEditor | undefined>;
	async openEditor(editor: IEditorInput | IResourceEditor, optionsOrGroup?: IEditorOptions | ITextEditorOptions | OpenInEditorGroup, group?: OpenInEditorGroup): Promise<IEditor | undefined> {
		const result = this.doResolveEditorOpenRequest(editor, optionsOrGroup, group);
		if (result) {
			const [resolvedGroup, resolvedEditor, resolvedOptions] = result;

			return withNullAsUndefined(await resolvedGroup.openEditor(resolvedEditor, resolvedOptions));
		}

		return undefined;
	}

	doResolveEditorOpenRequest(editor: IEditorInput | IResourceEditor, optionsOrGroup?: IEditorOptions | ITextEditorOptions | OpenInEditorGroup, group?: OpenInEditorGroup): [IEditorGroup, EditorInput, EditorOptions | undefined] | undefined {
		let resolvedGroup: IEditorGroup | undefined;
		let candidateGroup: OpenInEditorGroup | undefined;

		let typedEditor: EditorInput | undefined;
		let typedOptions: EditorOptions | undefined;

		// Typed Editor Support
		if (editor instanceof EditorInput) {
			typedEditor = editor;
			typedOptions = this.toOptions(optionsOrGroup as IEditorOptions);

			candidateGroup = group;
			resolvedGroup = this.findTargetGroup(typedEditor, typedOptions, candidateGroup);
		}

		// Untyped Text Editor Support
		else {
			const textInput = <IResourceEditor>editor;
			typedEditor = this.createInput(textInput);
			if (typedEditor) {
				typedOptions = TextEditorOptions.from(textInput);

				candidateGroup = optionsOrGroup as OpenInEditorGroup;
				resolvedGroup = this.findTargetGroup(typedEditor, typedOptions, candidateGroup);
			}
		}

		if (typedEditor && resolvedGroup) {
			if (
				this.editorGroupService.activeGroup !== resolvedGroup && 	// only if target group is not already active
				typedOptions && !typedOptions.inactive &&					// never for inactive editors
				typedOptions.preserveFocus &&								// only if preserveFocus
				typeof typedOptions.activation !== 'number' &&				// only if activation is not already defined (either true or false)
				candidateGroup !== SIDE_GROUP								// never for the SIDE_GROUP
			) {
				// If the resolved group is not the active one, we typically
				// want the group to become active. There are a few cases
				// where we stay away from encorcing this, e.g. if the caller
				// is already providing `activation`.
				//
				// Specifically for historic reasons we do not activate a
				// group is it is opened as `SIDE_GROUP` with `preserveFocus:true`.
				// repeated Alt-clicking of files in the explorer always open
				// into the same side group and not cause a group to be created each time.
				typedOptions.overwrite({ activation: EditorActivation.ACTIVATE });
			}

			return [resolvedGroup, typedEditor, typedOptions];
		}

		return undefined;
	}

	private findTargetGroup(input: IEditorInput, options?: IEditorOptions, group?: OpenInEditorGroup): IEditorGroup {
		let targetGroup: IEditorGroup | undefined;

		// Group: Instance of Group
		if (group && typeof group !== 'number') {
			targetGroup = group;
		}

		// Group: Side by Side
		else if (group === SIDE_GROUP) {
			targetGroup = this.findSideBySideGroup();
		}

		// Group: Specific Group
		else if (typeof group === 'number' && group >= 0) {
			targetGroup = this.editorGroupService.getGroup(group);
		}

		// Group: Unspecified without a specific index to open
		else if (!options || typeof options.index !== 'number') {
			const groupsByLastActive = this.editorGroupService.getGroups(GroupsOrder.MOST_RECENTLY_ACTIVE);

			// Respect option to reveal an editor if it is already visible in any group
			if (options?.revealIfVisible) {
				for (const group of groupsByLastActive) {
					if (group.isActive(input)) {
						targetGroup = group;
						break;
					}
				}
			}

			// Respect option to reveal an editor if it is open (not necessarily visible)
			// Still prefer to reveal an editor in a group where the editor is active though.
			if (!targetGroup) {
				if (options?.revealIfOpened || this.configurationService.getValue<boolean>('workbench.editor.revealIfOpen')) {
					let groupWithInputActive: IEditorGroup | undefined = undefined;
					let groupWithInputOpened: IEditorGroup | undefined = undefined;

					for (const group of groupsByLastActive) {
						if (group.isOpened(input)) {
							if (!groupWithInputOpened) {
								groupWithInputOpened = group;
							}

							if (!groupWithInputActive && group.isActive(input)) {
								groupWithInputActive = group;
							}
						}

						if (groupWithInputOpened && groupWithInputActive) {
							break; // we found all groups we wanted
						}
					}

					// Prefer a target group where the input is visible
					targetGroup = groupWithInputActive || groupWithInputOpened;
				}
			}
		}

		// Fallback to active group if target not valid
		if (!targetGroup) {
			targetGroup = this.editorGroupService.activeGroup;
		}

		return targetGroup;
	}

	private findSideBySideGroup(): IEditorGroup {
		const direction = preferredSideBySideGroupDirection(this.configurationService);

		let neighbourGroup = this.editorGroupService.findGroup({ direction });
		if (!neighbourGroup) {
			neighbourGroup = this.editorGroupService.addGroup(this.editorGroupService.activeGroup, direction);
		}

		return neighbourGroup;
	}

	private toOptions(options?: IEditorOptions | ITextEditorOptions | EditorOptions): EditorOptions {
		if (!options || options instanceof EditorOptions) {
			return options as EditorOptions;
		}

		const textOptions: ITextEditorOptions = options;
		if (textOptions.selection || textOptions.viewState) {
			return TextEditorOptions.create(options);
		}

		return EditorOptions.create(options);
	}

	//#endregion

	//#region openEditors()

	openEditors(editors: IEditorInputWithOptions[], group?: OpenInEditorGroup): Promise<IEditor[]>;
	openEditors(editors: IResourceEditor[], group?: OpenInEditorGroup): Promise<IEditor[]>;
	async openEditors(editors: Array<IEditorInputWithOptions | IResourceEditor>, group?: OpenInEditorGroup): Promise<IEditor[]> {

		// Convert to typed editors and options
		const typedEditors: IEditorInputWithOptions[] = [];
		editors.forEach(editor => {
			if (isEditorInputWithOptions(editor)) {
				typedEditors.push(editor);
			} else {
				typedEditors.push({ editor: this.createInput(editor), options: TextEditorOptions.from(editor) });
			}
		});

		// Find target groups to open
		const mapGroupToEditors = new Map<IEditorGroup, IEditorInputWithOptions[]>();
		if (group === SIDE_GROUP) {
			mapGroupToEditors.set(this.findSideBySideGroup(), typedEditors);
		} else {
			typedEditors.forEach(typedEditor => {
				const targetGroup = this.findTargetGroup(typedEditor.editor, typedEditor.options, group);

				let targetGroupEditors = mapGroupToEditors.get(targetGroup);
				if (!targetGroupEditors) {
					targetGroupEditors = [];
					mapGroupToEditors.set(targetGroup, targetGroupEditors);
				}

				targetGroupEditors.push(typedEditor);
			});
		}

		// Open in target groups
		const result: Promise<IEditor | null>[] = [];
		mapGroupToEditors.forEach((editorsWithOptions, group) => {
			result.push(group.openEditors(editorsWithOptions));
		});

		return coalesce(await Promise.all(result));
	}

	//#endregion

	//#region isOpen()

	isOpen(editor: IEditorInput): boolean {
		return this.editorGroupService.groups.some(group => group.isOpened(editor));
	}

	//#endregion

	//#region replaceEditors()

	replaceEditors(editors: IResourceEditorReplacement[], group: IEditorGroup | GroupIdentifier): Promise<void>;
	replaceEditors(editors: IEditorReplacement[], group: IEditorGroup | GroupIdentifier): Promise<void>;
	replaceEditors(editors: Array<IEditorReplacement | IResourceEditorReplacement>, group: IEditorGroup | GroupIdentifier): Promise<void> {
		const typedEditors: IEditorReplacement[] = [];

		editors.forEach(replaceEditorArg => {
			if (replaceEditorArg.editor instanceof EditorInput) {
				const replacementArg = replaceEditorArg as IEditorReplacement;

				typedEditors.push({
					editor: replacementArg.editor,
					replacement: replacementArg.replacement,
					options: this.toOptions(replacementArg.options)
				});
			} else {
				const replacementArg = replaceEditorArg as IResourceEditorReplacement;

				typedEditors.push({
					editor: this.createInput(replacementArg.editor),
					replacement: this.createInput(replacementArg.replacement),
					options: this.toOptions(replacementArg.replacement.options)
				});
			}
		});

		const targetGroup = typeof group === 'number' ? this.editorGroupService.getGroup(group) : group;
		if (targetGroup) {
			return targetGroup.replaceEditors(typedEditors);
		}

		return Promise.resolve();
	}

	//#endregion

	//#region invokeWithinEditorContext()

	invokeWithinEditorContext<T>(fn: (accessor: ServicesAccessor) => T): T {
		const activeTextEditorWidget = this.activeTextEditorWidget;
		if (isCodeEditor(activeTextEditorWidget)) {
			return activeTextEditorWidget.invokeWithinContext(fn);
		}

		const activeGroup = this.editorGroupService.activeGroup;
		if (activeGroup) {
			return activeGroup.invokeWithinContext(fn);
		}

		return this.instantiationService.invokeFunction(fn);
	}

	//#endregion

	//#region createInput()

	private readonly editorInputCache = new ResourceMap<CachedEditorInput>();

	createInput(input: IEditorInputWithOptions | IEditorInput | IResourceEditor): EditorInput {

		// Typed Editor Input Support (EditorInput)
		if (input instanceof EditorInput) {
			return input;
		}

		// Typed Editor Input Support (IEditorInputWithOptions)
		const editorInputWithOptions = input as IEditorInputWithOptions;
		if (editorInputWithOptions.editor instanceof EditorInput) {
			return editorInputWithOptions.editor;
		}

		// Side by Side Support
		const resourceSideBySideInput = input as IResourceSideBySideInput;
		if (resourceSideBySideInput.masterResource && resourceSideBySideInput.detailResource) {
			const masterInput = this.createInput({ resource: resourceSideBySideInput.masterResource, forceFile: resourceSideBySideInput.forceFile });
			const detailInput = this.createInput({ resource: resourceSideBySideInput.detailResource, forceFile: resourceSideBySideInput.forceFile });

			return new SideBySideEditorInput(
				resourceSideBySideInput.label || this.toSideBySideLabel(detailInput, masterInput, '-'),
				resourceSideBySideInput.description,
				detailInput,
				masterInput
			);
		}

		// Diff Editor Support
		const resourceDiffInput = input as IResourceDiffInput;
		if (resourceDiffInput.leftResource && resourceDiffInput.rightResource) {
			const leftInput = this.createInput({ resource: resourceDiffInput.leftResource, forceFile: resourceDiffInput.forceFile });
			const rightInput = this.createInput({ resource: resourceDiffInput.rightResource, forceFile: resourceDiffInput.forceFile });

			return new DiffEditorInput(
				resourceDiffInput.label || this.toSideBySideLabel(leftInput, rightInput, '↔'),
				resourceDiffInput.description,
				leftInput,
				rightInput
			);
		}

		// Untitled file support
		const untitledInput = input as IUntitledTextResourceInput;
		if (untitledInput.forceUntitled || !untitledInput.resource || (untitledInput.resource && untitledInput.resource.scheme === Schemas.untitled)) {
			const untitledOptions = {
				mode: untitledInput.mode,
				initialValue: untitledInput.contents,
				encoding: untitledInput.encoding
			};

			// Untitled resource: use as hint for an existing untitled editor
			let untitledModel: IUntitledTextEditorModel;
			if (untitledInput.resource?.scheme === Schemas.untitled) {
				untitledModel = this.untitledTextEditorService.create({ untitledResource: untitledInput.resource, ...untitledOptions });
			}

			// Other resource: use as hint for associated filepath
			else {
				untitledModel = this.untitledTextEditorService.create({ associatedResource: untitledInput.resource, ...untitledOptions });
			}

			return this.createOrGetCached(untitledModel.resource, () => {

				// Factory function for new untitled editor
				const input = this.instantiationService.createInstance(UntitledTextEditorInput, untitledModel);

				// We dispose the untitled model once the editor
				// is being disposed. Even though we may have not
				// created the model initially, the lifecycle for
				// untitled is tightly coupled with the editor
				// lifecycle for now.
				Event.once(input.onDispose)(() => untitledModel.dispose());

				return input;
			}) as EditorInput;
		}

		// Resource Editor Support
		const resourceInput = input as IResourceInput;
		if (resourceInput.resource instanceof URI) {
			let label = resourceInput.label;
			if (!label) {
				label = basename(resourceInput.resource); // derive the label from the path
			}

			return this.createOrGetCached(resourceInput.resource, () => {

				// File
				if (resourceInput.forceFile /* fix for https://github.com/Microsoft/vscode/issues/48275 */ || this.fileService.canHandleResource(resourceInput.resource)) {
					return this.fileInputFactory.createFileInput(resourceInput.resource, resourceInput.encoding, resourceInput.mode, this.instantiationService);
				}

				// Resource
				return this.instantiationService.createInstance(ResourceEditorInput, resourceInput.label, resourceInput.description, resourceInput.resource, resourceInput.mode);
			}, cachedInput => {

				// Untitled
				if (cachedInput instanceof UntitledTextEditorInput) {
					return;
				}

				// Files
				else if (!(cachedInput instanceof ResourceEditorInput)) {
					if (resourceInput.encoding) {
						cachedInput.setPreferredEncoding(resourceInput.encoding);
					}

					if (resourceInput.mode) {
						cachedInput.setPreferredMode(resourceInput.mode);
					}
				}

				// Resources
				else {
					if (label) {
						cachedInput.setName(label);
					}

					if (resourceInput.description) {
						cachedInput.setDescription(resourceInput.description);
					}

					if (resourceInput.mode) {
						cachedInput.setPreferredMode(resourceInput.mode);
					}
				}
			}) as EditorInput;
		}

		throw new Error('Unknown input type');
	}

	private createOrGetCached(resource: URI, factoryFn: () => CachedEditorInput, cachedFn?: (input: CachedEditorInput) => void): CachedEditorInput {

		// Return early if already cached
		let input = this.editorInputCache.get(resource);
		if (input) {
			if (cachedFn) {
				cachedFn(input);
			}

			return input;
		}

		// Otherwise create and add to cache
		input = factoryFn();
		this.editorInputCache.set(resource, input);
		Event.once(input.onDispose)(() => this.editorInputCache.delete(resource));

		return input;
	}

	private toSideBySideLabel(leftInput: EditorInput, rightInput: EditorInput, divider: string): string | undefined {
		const leftResource = leftInput.resource;
		const rightResource = rightInput.resource;

		// Without any resource, do not try to compute a label
		if (!leftResource || !rightResource) {
			return undefined;
		}

		// If both editors are file inputs, we produce an optimized label
		// by adding the relative path of both inputs to the label. This
		// makes it easier to understand a file-based comparison.
		if (this.fileInputFactory.isFileInput(leftInput) && this.fileInputFactory.isFileInput(rightInput)) {
			return `${this.labelService.getUriLabel(leftResource, { relative: true })} ${divider} ${this.labelService.getUriLabel(rightResource, { relative: true })}`;
		}

		// Signal back that the label should be computed from within the editor
		return undefined;
	}

	//#endregion

	//#region save/revert

	async save(editors: IEditorIdentifier | IEditorIdentifier[], options?: ISaveEditorsOptions): Promise<boolean> {

		// Convert to array
		if (!Array.isArray(editors)) {
			editors = [editors];
		}

		// Split editors up into a bucket that is saved in parallel
		// and sequentially. Unless "Save As", all non-untitled editors
		// can be saved in parallel to speed up the operation. Remaining
		// editors are potentially bringing up some UI and thus run
		// sequentially.
		const editorsToSaveParallel: IEditorIdentifier[] = [];
		const editorsToSaveSequentially: IEditorIdentifier[] = [];
		if (options?.saveAs) {
			editorsToSaveSequentially.push(...editors);
		} else {
			for (const { groupId, editor } of editors) {
				if (editor.isUntitled()) {
					editorsToSaveSequentially.push({ groupId, editor });
				} else {
					editorsToSaveParallel.push({ groupId, editor });
				}
			}
		}

		// Editors to save in parallel
		await Promise.all(editorsToSaveParallel.map(({ groupId, editor }) => {

			// Use save as a hint to pin the editor if used explicitly
			if (options?.reason === SaveReason.EXPLICIT) {
				this.editorGroupService.getGroup(groupId)?.pinEditor(editor);
			}

			// Save
			return editor.save(groupId, options);
		}));

		// Editors to save sequentially
		for (const { groupId, editor } of editorsToSaveSequentially) {
			if (editor.isDisposed()) {
				continue; // might have been disposed from the save already
			}

			// Preserve view state by opening the editor first if the editor
			// is untitled or we "Save As". This also allows the user to review
			// the contents of the editor before making a decision.
			let viewState: IEditorViewState | undefined = undefined;
			const control = await this.openEditor(editor, undefined, groupId);
			if (isTextEditor(control)) {
				viewState = control.getViewState();
			}

			const result = options?.saveAs ? await editor.saveAs(groupId, options) : await editor.save(groupId, options);
			if (!result) {
				return false; // failed or cancelled, abort
			}

			// Replace editor preserving viewstate (either across all groups or
			// only selected group) if the resulting editor is different from the
			// current one.
			if (!result.matches(editor)) {
				const targetGroups = editor.isUntitled() ? this.editorGroupService.groups.map(group => group.id) /* untitled replaces across all groups */ : [groupId];
				for (const group of targetGroups) {
					await this.replaceEditors([{ editor, replacement: result, options: { pinned: true, viewState } }], group);
				}
			}
		}

		return true;
	}

	saveAll(options?: ISaveAllEditorsOptions): Promise<boolean> {
		return this.save(this.getAllDirtyEditors(options), options);
	}

	async revert(editors: IEditorIdentifier | IEditorIdentifier[], options?: IRevertOptions): Promise<boolean> {

		// Convert to array
		if (!Array.isArray(editors)) {
			editors = [editors];
		}

		const result = await Promise.all(editors.map(async ({ groupId, editor }) => {
			if (editor.isDisposed()) {
				return true; // might have been disposed from from the revert already
			}

			// Use revert as a hint to pin the editor
			this.editorGroupService.getGroup(groupId)?.pinEditor(editor);

			return editor.revert(groupId, options);
		}));

		return result.every(success => !!success);
	}

	async revertAll(options?: IRevertAllEditorsOptions): Promise<boolean> {
		return this.revert(this.getAllDirtyEditors(options), options);
	}

	private getAllDirtyEditors(options?: IBaseSaveRevertAllEditorOptions): IEditorIdentifier[] {
		const editors: IEditorIdentifier[] = [];

		for (const group of this.editorGroupService.getGroups(GroupsOrder.MOST_RECENTLY_ACTIVE)) {
			for (const editor of group.getEditors(EditorsOrder.MOST_RECENTLY_ACTIVE)) {
				if (editor.isDirty() && (!editor.isUntitled() || !!options?.includeUntitled)) {
					editors.push({ groupId: group.id, editor });
				}
			}
		}

		return editors;
	}

	//#endregion

	dispose(): void {
		super.dispose();

		// Dispose remaining watchers if any
		this.activeOutOfWorkspaceWatchers.forEach(disposable => dispose(disposable));
		this.activeOutOfWorkspaceWatchers.clear();
	}
}

export interface IEditorOpenHandler {
	(
		delegate: (group: IEditorGroup, editor: IEditorInput, options?: IEditorOptions) => Promise<IEditor | null>,
		group: IEditorGroup,
		editor: IEditorInput,
		options?: IEditorOptions | ITextEditorOptions
	): Promise<IEditor | null>;
}

/**
 * The delegating workbench editor service can be used to override the behaviour of the openEditor()
 * method by providing a IEditorOpenHandler. All calls are being delegated to the existing editor
 * service otherwise.
 */
export class DelegatingEditorService implements IEditorService {

	_serviceBrand: undefined;

	constructor(
		private editorOpenHandler: IEditorOpenHandler,
		@IEditorService private editorService: EditorService
	) { }

	openEditor(editor: IEditorInput, options?: IEditorOptions | ITextEditorOptions, group?: OpenInEditorGroup): Promise<IEditor | undefined>;
	openEditor(editor: IResourceInput | IUntitledTextResourceInput, group?: OpenInEditorGroup): Promise<ITextEditor | undefined>;
	openEditor(editor: IResourceDiffInput, group?: OpenInEditorGroup): Promise<ITextDiffEditor | undefined>;
	openEditor(editor: IResourceSideBySideInput, group?: OpenInEditorGroup): Promise<ITextSideBySideEditor | undefined>;
	async openEditor(editor: IEditorInput | IResourceEditor, optionsOrGroup?: IEditorOptions | ITextEditorOptions | OpenInEditorGroup, group?: OpenInEditorGroup): Promise<IEditor | undefined> {
		const result = this.editorService.doResolveEditorOpenRequest(editor, optionsOrGroup, group);
		if (result) {
			const [resolvedGroup, resolvedEditor, resolvedOptions] = result;

			// Pass on to editor open handler
			const control = await this.editorOpenHandler(
				(group: IEditorGroup, editor: IEditorInput, options?: IEditorOptions) => group.openEditor(editor, options),
				resolvedGroup,
				resolvedEditor,
				resolvedOptions
			);

			if (control) {
				return control; // the opening was handled, so return early
			}

			return withNullAsUndefined(await resolvedGroup.openEditor(resolvedEditor, resolvedOptions));
		}

		return undefined;
	}

	//#region Delegate to IEditorService

	get onDidActiveEditorChange(): Event<void> { return this.editorService.onDidActiveEditorChange; }
	get onDidVisibleEditorsChange(): Event<void> { return this.editorService.onDidVisibleEditorsChange; }

	get activeEditor(): IEditorInput | undefined { return this.editorService.activeEditor; }
	get activeControl(): IVisibleEditor | undefined { return this.editorService.activeControl; }
	get activeTextEditorWidget(): ICodeEditor | IDiffEditor | undefined { return this.editorService.activeTextEditorWidget; }
	get activeTextEditorMode(): string | undefined { return this.editorService.activeTextEditorMode; }
	get visibleEditors(): ReadonlyArray<IEditorInput> { return this.editorService.visibleEditors; }
	get visibleControls(): ReadonlyArray<IVisibleEditor> { return this.editorService.visibleControls; }
	get visibleTextEditorWidgets(): ReadonlyArray<ICodeEditor | IDiffEditor> { return this.editorService.visibleTextEditorWidgets; }
	get editors(): ReadonlyArray<IEditorInput> { return this.editorService.editors; }
	get count(): number { return this.editorService.count; }

	getEditors(order: EditorsOrder): ReadonlyArray<IEditorIdentifier> { return this.editorService.getEditors(order); }

	openEditors(editors: IEditorInputWithOptions[], group?: OpenInEditorGroup): Promise<IEditor[]>;
	openEditors(editors: IResourceEditor[], group?: OpenInEditorGroup): Promise<IEditor[]>;
	openEditors(editors: Array<IEditorInputWithOptions | IResourceEditor>, group?: OpenInEditorGroup): Promise<IEditor[]> {
		return this.editorService.openEditors(editors, group);
	}

	replaceEditors(editors: IResourceEditorReplacement[], group: IEditorGroup | GroupIdentifier): Promise<void>;
	replaceEditors(editors: IEditorReplacement[], group: IEditorGroup | GroupIdentifier): Promise<void>;
	replaceEditors(editors: Array<IEditorReplacement | IResourceEditorReplacement>, group: IEditorGroup | GroupIdentifier): Promise<void> {
		return this.editorService.replaceEditors(editors as IResourceEditorReplacement[] /* TS fail */, group);
	}

	isOpen(editor: IEditorInput): boolean { return this.editorService.isOpen(editor); }

	overrideOpenEditor(handler: IOpenEditorOverrideHandler): IDisposable { return this.editorService.overrideOpenEditor(handler); }

	invokeWithinEditorContext<T>(fn: (accessor: ServicesAccessor) => T): T { return this.editorService.invokeWithinEditorContext(fn); }

	createInput(input: IResourceEditor): IEditorInput { return this.editorService.createInput(input); }

	save(editors: IEditorIdentifier | IEditorIdentifier[], options?: ISaveEditorsOptions): Promise<boolean> { return this.editorService.save(editors, options); }
	saveAll(options?: ISaveAllEditorsOptions): Promise<boolean> { return this.editorService.saveAll(options); }

	revert(editors: IEditorIdentifier | IEditorIdentifier[], options?: IRevertOptions): Promise<boolean> { return this.editorService.revert(editors, options); }
	revertAll(options?: IRevertAllEditorsOptions): Promise<boolean> { return this.editorService.revertAll(options); }

	//#endregion
}

registerSingleton(IEditorService, EditorService);