Thor/Thor.Shared/Register.cs

namespace Thor.Shared;

public class Register
{
    List<Entry> Entries = new();

    public void Add(Entry entry)
    {        
        Entries.Add(entry);
    }

    public void Clear()
    {
        Entries.Clear(); 
    }

    public List<Entry> GetEntriesOrdered(string itemid)
    {
        var entries = Entries
            .Where(e => e.Target == itemid)
            .ToList();
        entries.Sort((a, b) => a.When.CompareTo(b.When));

        return entries;
    }

    public ItemAnswer ForgeItemAnswer(string itemid)
    {
        var entries = GetEntriesOrdered(itemid);

        ItemAnswer ret = new();
        ret.TargetId = itemid;

        // fastpass ☺
        if (entries.Count == 0)
            return ret;

        foreach (var entry in entries)
        {
            if (entry.Type == Entry.EntryType.Set)
            {
                if (!entry.State.HasValue)
                    throw new Exception("Entry typed Set send without any State.");

                ret.CurrentState = entry.State.Value;
            }
            else 
                throw new NotImplementedException();

            Entries.Add(entry);
        }

        return ret;
    }

    public ItemAnswer.State GetItemState(string itemid)
    {
        var entries = Entries
            .Where(e
                => e.Target == itemid
                && e.Type == Entry.EntryType.Set)
            .OrderByDescending(e => e.When)
            .ToList();

        if(entries.Count == 0)
            return default(ItemAnswer.State);

        var firstEntryState = entries.First().State;

        return firstEntryState ?? default(ItemAnswer.State);
    }
}