import {join} from 'path';
import {promises as fs} from 'fs';
import {promisify} from 'util';
import {google} from 'googleapis';


// If modifying these scopes, delete token.json.
const SCOPES = ['https://www.googleapis.com/auth/drive.metadata.readonly'];
// The file token.json stores the user's access and refresh tokens, and is
// created automatically when the authorization flow completes for the first
// time.
const TOKEN_PATH = join(__dirname, '..', 'token.json');

class GoogleAuth extends EventEmitter {
  constructor() {
    super();
  }

  async authorize(credentials) {
    let token;
    const {client_secret, client_id} = credentials;
    const oAuth2Client = new google.auth.OAuth2(client_id, client_secret, `http://localhost:${port}`);
    try {
      token = JSON.parse(await fs.readFile(TOKEN_PATH));
    } catch (e) {
      const authUrl = oAuth2Client.generateAuthUrl({
        access_type: 'offline',
        scope: SCOPES,
      });
      this.emit('auth', authUrl);
      const code = await promisify(this.once).bind(this)('token');
      token = await oAuth2Client.getToken(code);
      await fs.writeFile(TOKEN_PATH, JSON.stringify(token));
    } finally {
      await oAuth2Client.setCredentials(token);
    }
  }

  token(code) {
    this.emit('token', code);
  }
}

class GoogleDrive extends GoogleAuth {
  constructor() {
    super();
    this.path = '/drive/api';
  }

  async getFolderID(path) {

  }

  async infoFile(path) {

  }

  async folderList(path) {

  }

  async downloadFile(path) {

  }

  async uploadFile(path) {

  }
}

export {
  GoogleAuth,
  GoogleDrive,
};