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

using System;

namespace Org.BouncyCastle.Asn1.Ocsp
{
    public class TbsRequest
        : Asn1Encodable
    {
		private static readonly DerInteger V1 = new DerInteger(0);

		private readonly DerInteger      version;
        private readonly GeneralName     requestorName;
        private readonly Asn1Sequence    requestList;
        private readonly X509Extensions  requestExtensions;

		private bool versionSet;

		public static TbsRequest GetInstance(
			Asn1TaggedObject	obj,
			bool				explicitly)
		{
			return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
		}

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

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

			throw new ArgumentException("unknown object in factory: " + obj.GetType().Name, "obj");
		}

		public TbsRequest(
            GeneralName     requestorName,
            Asn1Sequence    requestList,
            X509Extensions  requestExtensions)
        {
            this.version = V1;
            this.requestorName = requestorName;
            this.requestList = requestList;
            this.requestExtensions = requestExtensions;
        }

		private TbsRequest(
            Asn1Sequence seq)
        {
            int index = 0;

			Asn1Encodable enc = seq[0];
			if (enc is Asn1TaggedObject)
            {
                Asn1TaggedObject o = (Asn1TaggedObject) enc;

				if (o.TagNo == 0)
                {
					versionSet = true;
					version = DerInteger.GetInstance(o, true);
                    index++;
                }
                else
                {
                    version = V1;
                }
            }
            else
            {
                version = V1;
            }

			if (seq[index] is Asn1TaggedObject)
            {
                requestorName = GeneralName.GetInstance((Asn1TaggedObject) seq[index++], true);
            }

			requestList = (Asn1Sequence) seq[index++];

			if (seq.Count == (index + 1))
            {
                requestExtensions = X509Extensions.GetInstance((Asn1TaggedObject) seq[index], true);
            }
        }

		public DerInteger Version
		{
			get { return version; }
		}

		public GeneralName RequestorName
		{
			get { return requestorName; }
		}

		public Asn1Sequence RequestList
		{
			get { return requestList; }
		}

		public X509Extensions RequestExtensions
		{
			get { return requestExtensions; }
		}

		/**
         * Produce an object suitable for an Asn1OutputStream.
         * <pre>
         * TBSRequest      ::=     Sequence {
         *     version             [0]     EXPLICIT Version DEFAULT v1,
         *     requestorName       [1]     EXPLICIT GeneralName OPTIONAL,
         *     requestList                 Sequence OF Request,
         *     requestExtensions   [2]     EXPLICIT Extensions OPTIONAL }
         * </pre>
         */
        public override Asn1Object ToAsn1Object()
        {
            Asn1EncodableVector v = new Asn1EncodableVector();

			//
			// if default don't include - unless explicitly provided. Not strictly correct
			// but required for some requests
			//
			if (!version.Equals(V1) || versionSet)
			{
                v.Add(new DerTaggedObject(true, 0, version));
            }

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

			v.Add(requestList);

			if (requestExtensions != null)
            {
                v.Add(new DerTaggedObject(true, 2, requestExtensions));
            }

			return new DerSequence(v);
        }
    }
}
