using System;
using System.Threading;
using System.Threading.Tasks;
using HN.Domain;
using MediatR;

namespace HN.Application
{
  public sealed class CommentLinkCommandHandler : IRequestHandler<CommentLinkCommand, Guid>
  {
    private readonly ILinkRepository _linkRepository;
    private readonly ICommentRepository _commentRepository;
    private readonly IExecutingUserProvider _executingUserProvider;

    public CommentLinkCommandHandler(ILinkRepository linkRepository, ICommentRepository commentRepository, IExecutingUserProvider executingUserProvider)
    {
      _linkRepository = linkRepository;
      _commentRepository = commentRepository;
      _executingUserProvider = executingUserProvider;
    }

    public async Task<Guid> Handle(CommentLinkCommand request, CancellationToken cancellationToken)
    {
      var link = await _linkRepository.GetByIdAsync(request.LinkId);
      var comment = link.AddComment(_executingUserProvider.GetCurrentUserId(), request.Content);

      await _commentRepository.AddAsync(comment);

      return comment.Id;
    }
  }
}