IM/backend/IM_API/Application/EventHandlers/SignalREventHandler.cs

using AutoMapper;
using IM_API.Application.Interfaces;
using IM_API.Domain.Events;
using IM_API.Dtos;
using IM_API.Hubs;
using IM_API.Models;
using IM_API.Tools;
using Microsoft.AspNetCore.SignalR;

namespace IM_API.Application.EventHandlers
{
    public class SignalREventHandler : IEventHandler<MessageCreatedEvent>
    {
        private readonly IHubContext<ChatHub> _hub;
        private readonly IMapper _mapper;
        public SignalREventHandler(IHubContext<ChatHub> hub, IMapper mapper)
        {
            _hub = hub;
            _mapper = mapper;
        }

        public async Task Handle(MessageCreatedEvent @event)
        {
            if(@event.ChatType == Models.ChatType.PRIVATE)
            {
                MessageBaseDto messageBaseDto = _mapper.Map<MessageBaseDto>(_mapper.Map<Message>(@event));
                await _hub.Clients.Users(@event.MsgRecipientId.ToString()).SendAsync("ReceiveMessage", messageBaseDto);
            }
        }
    }
}