Files
gongxue-base/apps/server/src/notifications/notifications.service.ts

101 lines
3.2 KiB
TypeScript

import { BadRequestException, Injectable, NotFoundException } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Subject, Observable } from 'rxjs';
import { EventEmitter2 } from '@nestjs/event-emitter';
import { Notification } from '../entities/notification.entity';
import { CreateNotificationDto } from './dto/notification.dto';
@Injectable()
export class NotificationsService {
private subjects = new Map<number, Subject<Notification>>();
private subscriberCounts = new Map<number, number>();
constructor(
@InjectRepository(Notification)
private repo: Repository<Notification>,
private eventEmitter: EventEmitter2,
) {}
async create(dto: CreateNotificationDto): Promise<Notification[]> {
const recipientIds = [...new Set(dto.recipientIds)];
if (recipientIds.length === 0) throw new BadRequestException('通知接收人不能为空');
const notifications = recipientIds.map((recipientId) => ({
recipientId,
type: dto.type,
title: dto.title,
content: dto.content ?? '',
link: dto.link,
}));
const saved = await this.repo.save(notifications);
// Push SSE + emit event
for (const n of saved) {
this.subjects.get(n.recipientId)?.next(n);
this.eventEmitter.emit('notification.created', n);
}
return saved;
}
async findByUser(userId: number, after?: number, limit: number = 20): Promise<Notification[]> {
const safeLimit = Math.min(Math.max(limit, 1), 100);
const qb = this.repo
.createQueryBuilder('n')
.where('n.recipientId = :userId', { userId })
.orderBy('n.createdAt', 'DESC')
.take(safeLimit);
if (after !== undefined) {
qb.andWhere('n.id < :after', { after });
}
return qb.getMany();
}
async getUnreadCount(userId: number): Promise<number> {
return this.repo.count({
where: { recipientId: userId, isRead: false },
});
}
async markRead(id: number, userId: number): Promise<void> {
const notification = await this.repo.findOne({ where: { id, recipientId: userId } });
if (!notification) throw new NotFoundException('通知不存在');
if (notification.isRead) return;
await this.repo.update({ id, recipientId: userId }, { isRead: true, readAt: new Date() });
}
async markAllRead(userId: number): Promise<void> {
await this.repo.update(
{ recipientId: userId, isRead: false },
{ isRead: true, readAt: new Date() },
);
}
subscribe(userId: number): Observable<Notification> {
if (!this.subjects.has(userId)) {
this.subjects.set(userId, new Subject<Notification>());
this.subscriberCounts.set(userId, 0);
}
this.subscriberCounts.set(userId, (this.subscriberCounts.get(userId) ?? 0) + 1);
return this.subjects.get(userId)!.asObservable();
}
unsubscribe(userId: number): void {
const count = (this.subscriberCounts.get(userId) ?? 0) - 1;
if (count > 0) {
this.subscriberCounts.set(userId, count);
return;
}
// Last subscriber gone → complete + clean up
this.subscriberCounts.delete(userId);
const subj = this.subjects.get(userId);
if (subj) {
subj.complete();
this.subjects.delete(userId);
}
}
}