Asn1SyntaxException.cs

using System;
using System.Collections.Generic;
using System.Text;
 
namespace Waher.Content.Asn1.Exceptions
{
    public class Asn1SyntaxException : Asn1Exception
    {
        private readonly string text;
        private readonly int pos;
 
        public Asn1SyntaxException(string Message, string Text, int Position)
            : base(Format(Message, Text, Position))
        {
            this.text = Text;
            this.pos = Position;
        }
 
        public string Text => this.text;
 
        public int Position => this.pos;
 
        private static string Format(string Message, string Text, int Position)
        {
            int Pos = Position - 100;
            int End = Pos + 200;
            int NewPos = 100;
 
            if (Pos < 0)
            {
                NewPos += Pos;
                Pos = 0;
            }
 
            if (End > Text.Length)
                End = Text.Length;
 
            string s = Text.Substring(Pos, End - Pos);
            s = s.Insert(NewPos, "^^^-------- " + Message + " -----");
 
            return Message + "\r\n\r\n" + s;
        }
    }
}