// Copyright (c) Microsoft Corporation. All rights reserved.

// Licensed under the MIT License.

import { inject, injectable } from 'inversify';

import { DocumentSelector, Event, EventEmitter, workspace } from 'vscode';

import type { notebook, NotebookConcatTextDocument, NotebookDocument } from 'vscode-proposed';

import { UseProposedApi } from '../constants';

import { IApplicationEnvironment, IVSCodeNotebook } from './types';

@injectable()

export class VSCodeNotebook implements IVSCodeNotebook {

public get onDidOpenNotebookDocument(): Event<NotebookDocument> {

const onDidOpenNotebookDocument =

this.notebook.onDidOpenNotebookDocument ?? (workspace as any).onDidOpenNotebookDocument;

return this.canUseNotebookApi ? onDidOpenNotebookDocument : new EventEmitter<NotebookDocument>().event;

}

public get onDidCloseNotebookDocument(): Event<NotebookDocument> {

const onDidCloseNotebookDocument =

this.notebook.onDidCloseNotebookDocument ?? (workspace as any).onDidCloseNotebookDocument;

return this.canUseNotebookApi ? onDidCloseNotebookDocument : new EventEmitter<NotebookDocument>().event;

}

public get notebookDocuments(): ReadonlyArray<NotebookDocument> {

const notebookDocuments = this.notebook.notebookDocuments ?? (workspace as any).notebookDocuments;

return this.canUseNotebookApi ? notebookDocuments : [];

}

private get notebook() {

if (!this._notebook) {

this._notebook = require('vscode').notebook ?? require('vscode').notebooks;

}

return this._notebook!;

}

private _notebook?: typeof notebook;

private readonly canUseNotebookApi?: boolean;

constructor(

@inject(UseProposedApi) private readonly useProposedApi: boolean,

@inject(IApplicationEnvironment) readonly env: IApplicationEnvironment,

) {

if (this.useProposedApi) {

this.canUseNotebookApi = true;

}

}

public createConcatTextDocument(doc: NotebookDocument, selector?: DocumentSelector): NotebookConcatTextDocument {

if (this.useProposedApi) {

return this.notebook.createConcatTextDocument(doc, selector) as any; // Types of Position are different for some reason. Fix this later.

}

throw new Error('createConcatDocument not supported');

}

}