Thor/Thor.Shared/Grid.cs

using System.Collections;

namespace Thor.Shared;

public class Grid
{
    public string Identifier { get; set; }
    public string Name { get; set; }

    protected HashSet<ItemTitle> Titles { get; set; } = new();
    protected HashSet<ItemVerification> Verifications { get; set; } = new();

    public Item? GetItem(string id)
    {
        var title = Titles.Where(t => t.Identifier == id).FirstOrDefault();
        if (title is not null)
            return title;

        var verification = Verifications.Where(v => v.Identifier == id).FirstOrDefault();
        if(verification is not null) 
            return verification;

        return null;
    }

    public IEnumerable<Item> GetItems(IEnumerable<string> ids)
    {
        var lst = ids.ToHashSet();
        foreach (var i
            in GetItems()
                .Where(
                    t => lst.Contains(t.Identifier)))
        {
            yield return i;
        }
    }

    public IEnumerable<Item> GetItems()
    {
        return Enumerable.Union<Item>(Titles, Verifications).OrderBy(x => x.OrderId);
    }

    public IEnumerable<Item> GetChildren(IEnumerable<string> parentsid)
    {
        var lst = parentsid.ToHashSet();
        foreach (var i
            in  Titles
                .Where(
                    i => lst.Contains(i.ParentId)))
        {
            yield return i;
        }
    }

    public IEnumerable<Item> GetChildren(string id)
    {
        List<string> toExplore = new();
        HashSet<Item> toReturn = new();

        toExplore.Add(id);

        while (toExplore.Any())
        {
            var items = GetItems(toExplore);
            toExplore.Clear();
            foreach (var item in items)
            {
                if (toReturn.Contains(item))
                    continue;
                toReturn.Add(item);

                if(item is ItemTitle title)
                {
                    var children = GetChildren(title.Identifier);
                    foreach (var child in children)
                        if(!toReturn.Contains(child))
                            toExplore.Add(child.Identifier);
                }
            }
        }

        return toReturn;
    }


    public void AddItem(Item item)
    {
        if (item is ItemTitle title)
            Titles.Add(title);
        else if (item is ItemVerification verification)
            Verifications.Add(verification);
        else throw new NotImplementedException();
    }

    public void AddItems(params Item[] items)
    {
        foreach (var i in items)
            AddItem(i);
    }
}