using System;

using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1.X509
{
	/// <remarks>
	/// <pre>
	/// PrivateKeyUsagePeriod ::= SEQUENCE
	/// {
	/// notBefore       [0]     GeneralizedTime OPTIONAL,
	/// notAfter        [1]     GeneralizedTime OPTIONAL }
	/// </pre>
	/// </remarks>
	public class PrivateKeyUsagePeriod
		: Asn1Encodable
	{
		public static PrivateKeyUsagePeriod GetInstance(
			object obj)
		{
			if (obj is PrivateKeyUsagePeriod)
			{
				return (PrivateKeyUsagePeriod) obj;
			}

			if (obj is Asn1Sequence)
			{
				return new PrivateKeyUsagePeriod((Asn1Sequence) obj);
			}

			if (obj is X509Extension)
			{
				return GetInstance(X509Extension.ConvertValueToObject((X509Extension) obj));
			}

			throw new ArgumentException("unknown object in GetInstance: " + Platform.GetTypeName(obj), "obj");
		}

		private DerGeneralizedTime _notBefore, _notAfter;

		private PrivateKeyUsagePeriod(
			Asn1Sequence seq)
		{
			foreach (Asn1TaggedObject tObj in seq)
			{
				if (tObj.TagNo == 0)
				{
					_notBefore = DerGeneralizedTime.GetInstance(tObj, false);
				}
				else if (tObj.TagNo == 1)
				{
					_notAfter = DerGeneralizedTime.GetInstance(tObj, false);
				}
			}
		}

		public DerGeneralizedTime NotBefore
		{
			get { return _notBefore; }
		}

		public DerGeneralizedTime NotAfter
		{
			get { return _notAfter; }
		}

		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector();

			if (_notBefore != null)
			{
				v.Add(new DerTaggedObject(false, 0, _notBefore));
			}

			if (_notAfter != null)
			{
				v.Add(new DerTaggedObject(false, 1, _notAfter));
			}

			return new DerSequence(v);
		}
	}
}