using System;
using Org.BouncyCastle.Asn1;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Utilities.Collections;

namespace Org.BouncyCastle.X509;

public abstract class X509ExtensionBase : IX509Extension
{
	protected abstract X509Extensions GetX509Extensions();

	protected virtual ISet GetExtensionOids(bool critical)
	{
		X509Extensions x509Extensions = GetX509Extensions();
		if (x509Extensions != null)
		{
			HashSet hashSet = new HashSet();
			{
				foreach (DerObjectIdentifier extensionOid in x509Extensions.ExtensionOids)
				{
					X509Extension extension = x509Extensions.GetExtension(extensionOid);
					if (extension.IsCritical == critical)
					{
						hashSet.Add(extensionOid.Id);
					}
				}
				return hashSet;
			}
		}
		return null;
	}

	public virtual ISet GetNonCriticalExtensionOids()
	{
		return GetExtensionOids(critical: false);
	}

	public virtual ISet GetCriticalExtensionOids()
	{
		return GetExtensionOids(critical: true);
	}

	[Obsolete("Use version taking a DerObjectIdentifier instead")]
	public Asn1OctetString GetExtensionValue(string oid)
	{
		return GetExtensionValue(new DerObjectIdentifier(oid));
	}

	public virtual Asn1OctetString GetExtensionValue(DerObjectIdentifier oid)
	{
		X509Extensions x509Extensions = GetX509Extensions();
		if (x509Extensions != null)
		{
			X509Extension extension = x509Extensions.GetExtension(oid);
			if (extension != null)
			{
				return extension.Value;
			}
		}
		return null;
	}
}