using System;

using System.Collections.Generic;

using System.Runtime.Serialization;

using System.Linq;

using AutoMapper;

using Newtonsoft.Json;

public class Forum

{

    public Forum()

    {

        this.SubForums = new List<Forum>();

    }

    public Guid ID { get; set; }        

    public string Nome { get; set; }

    public Guid? ParentID { get; set; }

    public virtual Forum Parent { get; set; }

    public virtual ICollection<Forum> SubForums { get; set; }

}

​

/*[DataContract]*/

public class ForumDTO

{

    /*[DataMember]*/

    public Guid ID { get; set; }

    /*[DataMember]*/

    public string Nome { get; set; }

    /*[DataMember]*/

    public Guid? ParentID { get; set; }

    /*[DataMember]*/

    public ForumDTO Parent { get; set; }

    /*[DataMember]*/

    public IList<ForumDTO> SubForums { get; set; }

}

​

public class Program

{

    public static List<Forum> CriarForums(ref List<Forum> lista, Forum parent = null, int? hieraquia = 0)

    {

        var forums = new List<Forum>();

        if (hieraquia == 3)

        {

            return forums;

        }

        for (int indice = 0; indice < 3; indice++) 

        {

            var forum = new Forum();

            forum.ID = Guid.NewGuid();

            forum.Nome = Faker.NameFaker.Name();

            if (parent != default(Forum))

            {

                forum.ParentID = parent.ID;

                forum.Parent = parent;

            }

            forum.SubForums = Program.CriarForums(ref lista, forum, hieraquia + 1);

            forums.Add(forum);

            lista.Add(forum);

        }

        return forums;

    }

    public static void Main()

    {

        Mapper.CreateMap<Forum, ForumDTO>();

​

        var forums = new List<Forum>();

        CriarForums(ref forums);

        var dto = (

            from forum in forums

            where !forum.ParentID.HasValue

            select Mapper.Map<ForumDTO>(forum)

        ).ToList();

        var jsonSettings =  new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.Objects };

        Console.WriteLine(JsonConvert.SerializeObject(dto, Formatting.Indented, jsonSettings));

    }

}