feat: add WebSocket notifications for new comments

- Introduced enriched comment retrieval with user information and like statistics.
- Implemented WebSocket notifications to notify users of new comments on content.
- Updated dependency injection to include `EventsGateway` and `RealtimeModule`.

backend/src/comments/comments.service.ts

@@ -3,6 +3,7 @@ import {
 	Injectable,
 	NotFoundException,
 } from "@nestjs/common";
+import { EventsGateway } from "../realtime/events.gateway";
 import { S3Service } from "../s3/s3.service";
 import type { CreateCommentDto } from "./dto/create-comment.dto";
 import { CommentLikesRepository } from "./repositories/comment-likes.repository";
@@ -14,6 +15,7 @@ export class CommentsService {
 		private readonly commentsRepository: CommentsRepository,
 		private readonly commentLikesRepository: CommentLikesRepository,
 		private readonly s3Service: S3Service,
+		private readonly eventsGateway: EventsGateway,
 	) {}
 
 	async create(userId: string, contentId: string, dto: CreateCommentDto) {
@@ -24,11 +26,36 @@ export class CommentsService {
 			parentId: dto.parentId,
 		});
 
-		// Enrichir le commentaire créé (pour le retour API)
+		// Récupérer le commentaire avec les infos utilisateur pour le WebSocket
+		const enrichedComment = await this.findOneEnriched(comment.id, userId);
+
+		// Notifier les autres utilisateurs sur ce contenu
+		this.eventsGateway.sendToContent(contentId, "new_comment", enrichedComment);
+
+		return enrichedComment;
+	}
+
+	async findOneEnriched(commentId: string, currentUserId?: string) {
+		const comment = await this.commentsRepository.findOneEnriched(commentId);
+		if (!comment) return null;
+
+		const [likesCount, isLiked] = await Promise.all([
+			this.commentLikesRepository.countByCommentId(comment.id),
+			currentUserId
+				? this.commentLikesRepository.isLikedByUser(comment.id, currentUserId)
+				: Promise.resolve(false),
+		]);
+
 		return {
 			...comment,
-			likesCount: 0,
-			isLiked: false,
+			likesCount,
+			isLiked,
+			user: {
+				...comment.user,
+				avatarUrl: comment.user.avatarUrl
+					? this.s3Service.getPublicUrl(comment.user.avatarUrl)
+					: null,
+			},
 		};
 	}