/**
 * Copyright (c) 2020-present, Goldman Sachs
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { guaranteeNonNullable } from '@finos/legend-shared';
import {
  UserManager,
  type UserManagerSettings,
  type User,
  WebStorageStateStore,
} from 'oidc-client-ts';

export class SecondaryOAuthClient {
  private userManager: UserManager;
  private user: User | null = null;

  constructor(config: UserManagerSettings) {
    this.userManager = new UserManager({
      ...config,
      userStore: new WebStorageStateStore({ store: window.localStorage }),
      scope: config.extraQueryParams?.scope as string,
    });
  }

  /** Get current token, refresh if needed */
  public async getToken(): Promise<string> {
    this.user = this.user ?? (await this.userManager.getUser());
    if (this.user) {
      const exp = this.user.expires_at ? this.user.expires_at * 1000 : 0;
      if (Date.now() < exp - 10 * 60 * 1000) {
        return this.user.access_token;
      } else {
        await this.userManager.removeUser();
      }
    }
    this.user = guaranteeNonNullable(await this.userManager.signinSilent());
    return this.user.access_token;
  }
}