LearnGodot/Models/ItemGroup.cs

using System.Collections.Generic;
using System.Linq;

namespace Learn.Models;

public class ItemGroup(IEnumerable<Item> items)
{
    public IEnumerable<string> GetKeys()
    {
        IEnumerable<string> inter = null;
        foreach (var item in items)
        {
            if (inter == null)
            {
                inter = item.Info.Keys;
            }
            else
            {
                inter = inter.Intersect(item.Info.Keys);
            }
        }
        if(inter == null) return new List<string>();
        return inter.ToList();
    }

    public bool TryGetValue(string key, out string value, out bool isSame)
    {
        value = null;
        isSame = true;
        
        if (!GetKeys().Contains(key)) return false;
        
        bool isFirst = true;
        foreach (var item in items)
        {
            if (isFirst)
            {
                isFirst = false;
            }
            else
            {
                isSame = value == item.Info[key];
                if(!isSame) return true;
            }
            value = item.Info[key];
        }
        return true;
    }

    public void SetValue(string key, string value)
    {
        foreach (var item in items)
        {
            item.Info[key] = value;
        }
    }

    public bool Remove(string key)
    {
        if (!GetKeys().Contains(key)) return false;
        foreach (var item in items)
        {
            item.Info.Remove(key);
        }
        return true;
    }

    private bool AnyContains(string key)
    {
        return items.Any(item => item.Info.Keys.Contains(key));
    }
    
    public bool TryAdd(string key, string value)
    {
        if (AnyContains(key)) return false;
        foreach (var item in items)
        {
            item.Info.Add(key, value);
        }
        return true;
    }
}