/**
	 * DeleteAnnotationsByUser — soft-delete all annotation layers + annotations
	 * created by a specific user within the given rooms.
	 * Used when canceling/switching a user's assignment on a transmittal.
	 * Caller should resolve room IDs via getRoomByDocument first.
	 */
	async deleteAnnotationsByUser(request: DeleteAnnotationsByUserRequest): Promise<DeleteAnnotationsByUserResponse> {
		const roomIds = request.roomIds ?? [];
		if (roomIds.length === 0) {
			return { deletedAnnotations: 0, deletedLayers: 0 };
		}

		const hard = request.hardDelete === true;
		let layerResult: { count: number };
		let annotationResult: { count: number };

		if (hard) {
			// Hard-delete layers + annotations
			annotationResult = await this.prisma.annotations.deleteMany({
				where: {
					layer: { room_id: { in: roomIds } },
					created_by: request.userId,
				},
			});
			layerResult = await this.prisma.annotationLayers.deleteMany({
				where: {
					room_id: { in: roomIds },
					created_by: request.userId,
				},
			});
		} else {
			// Soft-delete
			const now = new Date();
			annotationResult = await this.prisma.annotations.updateMany({
				where: {
					layer: { room_id: { in: roomIds } },
					created_by: request.userId,
					deleted_at: null,
				},
				data: { deleted_at: now },
			});
			layerResult = await this.prisma.annotationLayers.updateMany({
				where: {
					room_id: { in: roomIds },
					created_by: request.userId,
					deleted_at: null,
				},
				data: { deleted_at: now },
			});
		}

		this.logger.log(
			`${hard ? 'Hard' : 'Soft'}-deleted ${annotationResult.count} annotations / ${layerResult.count} layers ` +
				`for user ${request.userId} in ${roomIds.length} room(s)`
		);

		return { deletedAnnotations: annotationResult.count, deletedLayers: layerResult.count };
	}