using System;
using System.Collections.Generic;

namespace HN.Domain
{
  public sealed class Link
  {
    public Guid Id { get; }
    public string Url { get; }
    public DateTime CreatedAt { get; }
    private List<Vote> _votes;
    public IReadOnlyList<Vote> Votes => _votes;

    private Link(string url)
    {
      this.Id = Guid.NewGuid();
      this.CreatedAt = DateTime.UtcNow;
      this.Url = url;
      this._votes = new List<Vote>();
    }

    public static Link FromUrl(string url)
    {
      return new Link(url);
    }

    public void Upvote()
    {
      _votes.Add(new Vote(VoteType.Up));
    }

    public void Downvote()
    {
      _votes.Add(new Vote(VoteType.Down));
    }

    public Comment AddComment(string content)
    {
      return new Comment(Id, content);
    }
  }
}