using System;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1;

public class DerEnumerated : Asn1Object
{
	private readonly byte[] bytes;

	private static readonly DerEnumerated[] cache = new DerEnumerated[12];

	public BigInteger Value => new BigInteger(bytes);

	public static DerEnumerated GetInstance(object obj)
	{
		if (obj == null || obj is DerEnumerated)
		{
			return (DerEnumerated)obj;
		}
		throw new ArgumentException("illegal object in GetInstance: " + Platform.GetTypeName(obj));
	}

	public static DerEnumerated GetInstance(Asn1TaggedObject obj, bool isExplicit)
	{
		Asn1Object asn1Object = obj.GetObject();
		if (isExplicit || asn1Object is DerEnumerated)
		{
			return GetInstance(asn1Object);
		}
		return FromOctetString(((Asn1OctetString)asn1Object).GetOctets());
	}

	public DerEnumerated(int val)
	{
		bytes = BigInteger.ValueOf(val).ToByteArray();
	}

	public DerEnumerated(BigInteger val)
	{
		bytes = val.ToByteArray();
	}

	public DerEnumerated(byte[] bytes)
	{
		if (bytes.Length > 1 && ((bytes[0] == 0 && (bytes[1] & 0x80) == 0) || (bytes[0] == byte.MaxValue && (bytes[1] & 0x80) != 0)) && !DerInteger.AllowUnsafe())
		{
			throw new ArgumentException("malformed enumerated");
		}
		this.bytes = Arrays.Clone(bytes);
	}

	internal override void Encode(DerOutputStream derOut)
	{
		derOut.WriteEncoded(10, bytes);
	}

	protected override bool Asn1Equals(Asn1Object asn1Object)
	{
		if (!(asn1Object is DerEnumerated derEnumerated))
		{
			return false;
		}
		return Arrays.AreEqual(bytes, derEnumerated.bytes);
	}

	protected override int Asn1GetHashCode()
	{
		return Arrays.GetHashCode(bytes);
	}

	internal static DerEnumerated FromOctetString(byte[] enc)
	{
		if (enc.Length == 0)
		{
			throw new ArgumentException("ENUMERATED has zero length", "enc");
		}
		if (enc.Length == 1)
		{
			int num = enc[0];
			if (num < cache.Length)
			{
				DerEnumerated derEnumerated = cache[num];
				if (derEnumerated != null)
				{
					return derEnumerated;
				}
				return cache[num] = new DerEnumerated(Arrays.Clone(enc));
			}
		}
		return new DerEnumerated(Arrays.Clone(enc));
	}
}