using System;

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

namespace Org.BouncyCastle.Asn1.Esf
{
	/// <summary>
	/// Summary description for OtherHashAlgAndValue.
	/// </summary>
	/// <remarks>
	/// <code>
	/// OtherHashAlgAndValue ::= SEQUENCE {
	///		hashAlgorithm	AlgorithmIdentifier,
	/// 	hashValue		OtherHashValue
	/// }
	/// 
	/// OtherHashValue ::= OCTET STRING
	/// </code>
	/// </remarks>
	public class OtherHashAlgAndValue
		: Asn1Encodable
	{
		private readonly AlgorithmIdentifier	hashAlgorithm;
		private readonly Asn1OctetString		hashValue;

		public static OtherHashAlgAndValue GetInstance(
			object obj)
		{
			if (obj == null || obj is OtherHashAlgAndValue)
				return (OtherHashAlgAndValue) obj;

			if (obj is Asn1Sequence)
				return new OtherHashAlgAndValue((Asn1Sequence) obj);

			throw new ArgumentException(
				"Unknown object in 'OtherHashAlgAndValue' factory: "
                    + Platform.GetTypeName(obj),
				"obj");
		}

		private OtherHashAlgAndValue(
			Asn1Sequence seq)
		{
			if (seq == null)
				throw new ArgumentNullException("seq");
			if (seq.Count != 2)
				throw new ArgumentException("Bad sequence size: " + seq.Count, "seq");

			this.hashAlgorithm = AlgorithmIdentifier.GetInstance(seq[0].ToAsn1Object());
			this.hashValue = (Asn1OctetString) seq[1].ToAsn1Object();
		}

		public OtherHashAlgAndValue(
			AlgorithmIdentifier	hashAlgorithm,
			byte[]				hashValue)
		{
			if (hashAlgorithm == null)
				throw new ArgumentNullException("hashAlgorithm");
			if (hashValue == null)
				throw new ArgumentNullException("hashValue");

			this.hashAlgorithm = hashAlgorithm;
			this.hashValue = new DerOctetString(hashValue);
		}

		public OtherHashAlgAndValue(
			AlgorithmIdentifier	hashAlgorithm,
			Asn1OctetString		hashValue)
		{
			if (hashAlgorithm == null)
				throw new ArgumentNullException("hashAlgorithm");
			if (hashValue == null)
				throw new ArgumentNullException("hashValue");

			this.hashAlgorithm = hashAlgorithm;
			this.hashValue = hashValue;
		}

		public AlgorithmIdentifier HashAlgorithm
		{
			get { return hashAlgorithm; }
		}

		public byte[] GetHashValue()
		{
			return hashValue.GetOctets();
		}

		public override Asn1Object ToAsn1Object()
		{
			return new DerSequence(hashAlgorithm, hashValue);
		}
	}
}