using System;
using System.Text;

using Org.BouncyCastle.Utilities;

namespace Org.BouncyCastle.Asn1.X509
{
    /**
     * The DistributionPoint object.
     * <pre>
     * DistributionPoint ::= Sequence {
     *      distributionPoint [0] DistributionPointName OPTIONAL,
     *      reasons           [1] ReasonFlags OPTIONAL,
     *      cRLIssuer         [2] GeneralNames OPTIONAL
     * }
     * </pre>
     */
    public class DistributionPoint
        : Asn1Encodable
    {
        internal readonly DistributionPointName	distributionPoint;
        internal readonly ReasonFlags			reasons;
        internal readonly GeneralNames			cRLIssuer;

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

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

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

            throw new ArgumentException("Invalid DistributionPoint: " + Platform.GetTypeName(obj));
        }

		private DistributionPoint(
            Asn1Sequence seq)
        {
            for (int i = 0; i != seq.Count; i++)
            {
				Asn1TaggedObject t = Asn1TaggedObject.GetInstance(seq[i]);

				switch (t.TagNo)
                {
                case 0:
                    distributionPoint = DistributionPointName.GetInstance(t, true);
                    break;
                case 1:
                    reasons = new ReasonFlags(DerBitString.GetInstance(t, false));
                    break;
                case 2:
                    cRLIssuer = GeneralNames.GetInstance(t, false);
                    break;
                }
            }
        }

		public DistributionPoint(
            DistributionPointName	distributionPointName,
            ReasonFlags				reasons,
            GeneralNames			crlIssuer)
        {
            this.distributionPoint = distributionPointName;
            this.reasons = reasons;
            this.cRLIssuer = crlIssuer;
        }

		public DistributionPointName DistributionPointName
        {
			get { return distributionPoint; }
        }

		public ReasonFlags Reasons
        {
			get { return reasons; }
        }

		public GeneralNames CrlIssuer
        {
			get { return cRLIssuer; }
        }

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

            // As this is a CHOICE it must be explicitly tagged
            v.AddOptionalTagged(true, 0, distributionPoint);

            v.AddOptionalTagged(false, 1, reasons);
            v.AddOptionalTagged(false, 2, cRLIssuer);
            return new DerSequence(v);
        }

		public override string ToString()
		{
			StringBuilder buf = new StringBuilder();
			buf.AppendLine("DistributionPoint: [");
			if (distributionPoint != null)
			{
                AppendObject(buf, "distributionPoint", distributionPoint.ToString());
			}
			if (reasons != null)
			{
                AppendObject(buf, "reasons", reasons.ToString());
			}
			if (cRLIssuer != null)
			{
                AppendObject(buf, "cRLIssuer", cRLIssuer.ToString());
			}
			buf.AppendLine("]");
			return buf.ToString();
		}

		private void AppendObject(StringBuilder buf, string name, string val)
		{
			string indent = "    ";
			buf.Append(indent);
			buf.Append(name);
			buf.AppendLine(":");
			buf.Append(indent);
			buf.Append(indent);
			buf.Append(val);
            buf.AppendLine();
		}
	}
}