Vector.cs

using System;
using System.Collections;
using System.Text;
 
namespace NeuroAccess.Nfc.TravelDocuments.Security
{
    public class Vector(Array Elements, byte[] SubSection) : IEnumerable
    {
        public Array Elements { get; } = Elements;
 
        public byte[] SubSection { get; } = SubSection;
 
        public int Length => this.Elements.Length;
 
        public object? FirstElement => this[0];
 
        public object? LastElement => this[this.Length - 1];
 
        public object? FirstElementNested
        {
            get
            {
                object? First = this.FirstElement;
                if (First is not byte[] Binary)
                    return First;
 
                if (ASN1.TryDecodeDer(Binary, out object? Decoded))
                {
                    this.Elements.SetValue(Decoded, 0);
                    return Decoded;
                }
 
                return First;
            }
        }
 
        public object? LastElementNested
        {
            get
            {
                object? Last = this.LastElement;
 
                if (Last is not byte[] Binary)
                    return Last;
 
                if (ASN1.TryDecodeDer(Binary, out object? Decoded))
                {
                    this.Elements.SetValue(Decoded, this.Length - 1);
                    return Decoded;
                }
 
                return Last;
            }
        }
 
        public object? this[int Index]
        {
            get
            {
                if (Index < 0 || Index >= this.Elements.Length)
                    return null;
                else
                    return this.Elements.GetValue(Index);
            }
        }
 
        public override string ToString()
        {
            StringBuilder sb = new();
            bool First = true;
 
            sb.Append(this.GetType().Name);
            sb.Append('(');
 
            foreach (object? Item in this)
            {
                if (First)
                    First = false;
                else
                    sb.Append(',');
 
                sb.Append(Item?.ToString() ?? "null");
            }
 
            sb.Append(')');
 
            return sb.ToString();
        }
 
        public IEnumerator GetEnumerator()
        {
            return this.Elements.GetEnumerator();
        }
    }
}