using System;

using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Math;

namespace Org.BouncyCastle.Asn1.Cms
{
    public class IssuerAndSerialNumber
        : Asn1Encodable
    {
        public static IssuerAndSerialNumber GetInstance(object obj)
        {
            if (obj == null)
                return null;
            if (obj is IssuerAndSerialNumber issuerAndSerialNumber)
                return issuerAndSerialNumber;
            return new IssuerAndSerialNumber(Asn1Sequence.GetInstance(obj));
        }

        public static IssuerAndSerialNumber GetInstance(Asn1TaggedObject taggedObject, bool declaredExplicit)
        {
            return new IssuerAndSerialNumber(Asn1Sequence.GetInstance(taggedObject, declaredExplicit));
        }

        private X509Name m_name;
        private DerInteger m_serialNumber;

        private IssuerAndSerialNumber(Asn1Sequence seq)
        {
            int count = seq.Count;
            if (count != 2)
                throw new ArgumentException("Bad sequence size: " + count, nameof(seq));

            m_name = X509Name.GetInstance(seq[0]);
            m_serialNumber = DerInteger.GetInstance(seq[1]);
        }

        public IssuerAndSerialNumber(X509Name name, BigInteger serialNumber)
        {
            m_name = name;
            m_serialNumber = new DerInteger(serialNumber);
        }

        public IssuerAndSerialNumber(X509Name name, DerInteger serialNumber)
        {
            m_name = name;
            m_serialNumber = serialNumber;
        }

        public IssuerAndSerialNumber(X509CertificateStructure x509CertificateStructure)
        {
            m_name = x509CertificateStructure.Issuer;
            m_serialNumber = x509CertificateStructure.SerialNumber;
        }

        public X509Name Name => m_name;

        public DerInteger SerialNumber => m_serialNumber;

        public override Asn1Object ToAsn1Object() => new DerSequence(m_name, m_serialNumber);
    }
}