import DBService  from './db.js';
import { Subscription } from './Subscription.js';

export interface SubscriptionData {
  endpoint: string;
  keys: {
    p256dh: string;
    auth: string;
  };
}

class SubscriptionService {
  private static instance: SubscriptionService;
  private dbService: DBService = DBService.getInstance();

  private constructor() {
  }


  public static getInstance(): SubscriptionService {
    if (!SubscriptionService.instance) {
      SubscriptionService.instance = new SubscriptionService();
    }
    return SubscriptionService.instance;
  }


  async addSubscription(subscription: SubscriptionData): Promise<void> {
    await this.dbService.saveSubscription(
      subscription.endpoint,
      subscription.keys.p256dh,
      subscription.keys.auth
    );
  }


  async fetchSubscriptions(): Promise<Subscription[]> {
    return this.dbService.getSubscriptions();
  }
}

export default SubscriptionService;