zod-backend/src/common/modules/notification/services/firebase.service.ts

import { Injectable, Logger } from '@nestjs/common';
import { ConfigService } from '@nestjs/config';
import * as admin from 'firebase-admin';
@Injectable()
export class FirebaseService {
  private readonly logger = new Logger(FirebaseService.name);
  constructor(private readonly configService: ConfigService) {
    admin.initializeApp({
      credential: admin.credential.cert({
        projectId: this.configService.get('FIREBASE_PROJECT_ID'),
        clientEmail: this.configService.get('FIREBASE_CLIENT_EMAIL'),
        privateKey: this.configService.get('FIREBASE_PRIVATE_KEY').replace(/\\n/g, '\n'),
      }),
    });
  }

  sendNotification(tokens: string | string[], title: string, body: string) {
    this.logger.log(`Sending push notification to ${tokens}`);
    const message = {
      notification: {
        title,
        body,
      },
      tokens: Array.isArray(tokens) ? tokens : [tokens],
    };

    admin.messaging().sendEachForMulticast(message);
  }
}