using AutoMapper;
using Chatbot.Api.Application.Commands;
using Chatbot.Api.Application.Events;
using Chatbot.Api.Domain.Entities;
using Chatbot.Api.Domain.Repositories;
using MediatR;
using Microsoft.Extensions.Logging;
using System;
using System.Threading;
using System.Threading.Tasks;

namespace Chatbot.Api.Application.CommandHandlers
{
    public class SaveChatMessageHandler : IRequestHandler<SaveChatMessage, ChatMessageSaved>
    {
        private readonly ILogger<SaveChatMessageHandler> _logger;
        private readonly IMapper _mapper;
        private readonly IChatRepository _chatRepository;

        public SaveChatMessageHandler(ILogger<SaveChatMessageHandler> logger, IMapper mapper, IChatRepository chatRepository)
        {
            _logger = logger;
            _mapper = mapper;
            _chatRepository = chatRepository;
        }

        public async Task<ChatMessageSaved> Handle(SaveChatMessage request, CancellationToken cancellationToken)
        {
            try
            {
                var message = _mapper.Map<ChatMessage>(request);
                await _chatRepository.Add(message);

                return new ChatMessageSaved(true, null);
            }
            catch (Exception ex)
            {
                var correlationIdMsg = $"CorrelationId: {request.Metadata.CorrelationId}";
                _logger.LogError(ex, $"An unexpected error has occurred. {correlationIdMsg}");
                return new ChatMessageSaved(false, $"{ex.Message} {correlationIdMsg}");
            }
        }
    }
}