using System;

using Org.BouncyCastle.Asn1.Oiw;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1.Ess
{
	[Obsolete("Use version in Asn1.Esf instead")]
	public class OtherCertID
		: Asn1Encodable
	{
		private Asn1Encodable otherCertHash;
		private IssuerSerial issuerSerial;

		public static OtherCertID GetInstance(
			object o)
		{
			if (o == null || o is OtherCertID)
			{
				return (OtherCertID) o;
			}

			if (o is Asn1Sequence)
			{
				return new OtherCertID((Asn1Sequence) o);
			}

			throw new ArgumentException(
				"unknown object in 'OtherCertID' factory : "
                + Platform.GetTypeName(o) + ".");
		}

		/**
		 * constructor
		 */
		public OtherCertID(
			Asn1Sequence seq)
		{
			if (seq.Count < 1 || seq.Count > 2)
			{
				throw new ArgumentException("Bad sequence size: " + seq.Count);
			}

			if (seq[0].ToAsn1Object() is Asn1OctetString)
			{
				otherCertHash = Asn1OctetString.GetInstance(seq[0]);
			}
			else
			{
				otherCertHash = DigestInfo.GetInstance(seq[0]);
			}

			if (seq.Count > 1)
			{
				issuerSerial = IssuerSerial.GetInstance(Asn1Sequence.GetInstance(seq[1]));
			}
		}

		public OtherCertID(
			AlgorithmIdentifier	algId,
			byte[]				digest)
		{
			this.otherCertHash = new DigestInfo(algId, digest);
		}

		public OtherCertID(
			AlgorithmIdentifier	algId,
			byte[]				digest,
			IssuerSerial		issuerSerial)
		{
			this.otherCertHash = new DigestInfo(algId, digest);
			this.issuerSerial = issuerSerial;
		}

		public AlgorithmIdentifier AlgorithmHash
		{
			get
			{
				if (otherCertHash.ToAsn1Object() is Asn1OctetString)
				{
					// SHA-1
					return new AlgorithmIdentifier(OiwObjectIdentifiers.IdSha1);
				}

				return DigestInfo.GetInstance(otherCertHash).AlgorithmID;
			}
		}

		public byte[] GetCertHash()
		{
			if (otherCertHash.ToAsn1Object() is Asn1OctetString)
			{
				// SHA-1
				return ((Asn1OctetString) otherCertHash.ToAsn1Object()).GetOctets();
			}

			return DigestInfo.GetInstance(otherCertHash).GetDigest();
		}

		public IssuerSerial IssuerSerial
		{
			get { return issuerSerial; }
		}

		/**
		 * <pre>
		 * OtherCertID ::= SEQUENCE {
		 *     otherCertHash    OtherHash,
		 *     issuerSerial     IssuerSerial OPTIONAL }
		 *
		 * OtherHash ::= CHOICE {
		 *     sha1Hash     OCTET STRING,
		 *     otherHash    OtherHashAlgAndValue }
		 *
		 * OtherHashAlgAndValue ::= SEQUENCE {
		 *     hashAlgorithm    AlgorithmIdentifier,
		 *     hashValue        OCTET STRING }
		 *
		 * </pre>
		 */
		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector(otherCertHash);

			if (issuerSerial != null)
			{
				v.Add(issuerSerial);
			}

			return new DerSequence(v);
		}
	}
}