using System;
using System.Collections;
using System.IO;

using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.Collections;

namespace Org.BouncyCastle.Bcpg.OpenPgp
{
	/// <remarks>
	/// Often a PGP key ring file is made up of a succession of master/sub-key key rings.
	/// If you want to read an entire public key file in one hit this is the class for you.
	/// </remarks>
    public class PgpPublicKeyRingBundle
    {
        private readonly IDictionary pubRings;
        private readonly IList order;

		private PgpPublicKeyRingBundle(
            IDictionary	pubRings,
            IList       order)
        {
            this.pubRings = pubRings;
            this.order = order;
        }

		public PgpPublicKeyRingBundle(
            byte[] encoding)
            : this(new MemoryStream(encoding, false))
        {
        }

		/// <summary>Build a PgpPublicKeyRingBundle from the passed in input stream.</summary>
		/// <param name="inputStream">Input stream containing data.</param>
		/// <exception cref="IOException">If a problem parsing the stream occurs.</exception>
		/// <exception cref="PgpException">If an object is encountered which isn't a PgpPublicKeyRing.</exception>
		public PgpPublicKeyRingBundle(
            Stream inputStream)
			: this(new PgpObjectFactory(inputStream).AllPgpObjects())
		{
        }

		public PgpPublicKeyRingBundle(
            IEnumerable e)
        {
			this.pubRings = Platform.CreateHashtable();
			this.order = Platform.CreateArrayList();

			foreach (object obj in e)
            {
				PgpPublicKeyRing pgpPub = obj as PgpPublicKeyRing;

				if (pgpPub == null)
				{
					throw new PgpException(obj.GetType().FullName + " found where PgpPublicKeyRing expected");
				}

				long key = pgpPub.GetPublicKey().KeyId;
                pubRings.Add(key, pgpPub);
				order.Add(key);
            }
        }

		[Obsolete("Use 'Count' property instead")]
		public int Size
		{
			get { return order.Count; }
		}

		/// <summary>Return the number of key rings in this collection.</summary>
        public int Count
        {
			get { return order.Count; }
        }

		/// <summary>Allow enumeration of the public key rings making up this collection.</summary>
        public IEnumerable GetKeyRings()
        {
			return new EnumerableProxy(pubRings.Values);
        }

		/// <summary>Allow enumeration of the key rings associated with the passed in userId.</summary>
		/// <param name="userId">The user ID to be matched.</param>
		/// <returns>An <c>IEnumerable</c> of key rings which matched (possibly none).</returns>
		public IEnumerable GetKeyRings(
			string userId)
		{
			return GetKeyRings(userId, false, false);
		}

		/// <summary>Allow enumeration of the key rings associated with the passed in userId.</summary>
		/// <param name="userId">The user ID to be matched.</param>
		/// <param name="matchPartial">If true, userId need only be a substring of an actual ID string to match.</param>
		/// <returns>An <c>IEnumerable</c> of key rings which matched (possibly none).</returns>
        public IEnumerable GetKeyRings(
            string	userId,
            bool	matchPartial)
        {
			return GetKeyRings(userId, matchPartial, false);
        }

		/// <summary>Allow enumeration of the key rings associated with the passed in userId.</summary>
		/// <param name="userId">The user ID to be matched.</param>
		/// <param name="matchPartial">If true, userId need only be a substring of an actual ID string to match.</param>
		/// <param name="ignoreCase">If true, case is ignored in user ID comparisons.</param>
		/// <returns>An <c>IEnumerable</c> of key rings which matched (possibly none).</returns>
		public IEnumerable GetKeyRings(
			string	userId,
			bool	matchPartial,
			bool	ignoreCase)
		{
			IList rings = Platform.CreateArrayList();

			if (ignoreCase)
			{
                userId = Platform.ToLowerInvariant(userId);
			}

			foreach (PgpPublicKeyRing pubRing in GetKeyRings())
			{
				foreach (string nextUserID in pubRing.GetPublicKey().GetUserIds())
				{
					string next = nextUserID;
					if (ignoreCase)
					{
                        next = Platform.ToLowerInvariant(next);
                    }

					if (matchPartial)
					{
						if (next.IndexOf(userId) > -1)
						{
							rings.Add(pubRing);
						}
					}
					else
					{
						if (next.Equals(userId))
						{
							rings.Add(pubRing);
						}
					}
				}
			}

			return new EnumerableProxy(rings);
		}

		/// <summary>Return the PGP public key associated with the given key id.</summary>
		/// <param name="keyId">The ID of the public key to return.</param>
        public PgpPublicKey GetPublicKey(
            long keyId)
        {
            foreach (PgpPublicKeyRing pubRing in GetKeyRings())
            {
                PgpPublicKey pub = pubRing.GetPublicKey(keyId);

				if (pub != null)
                {
                    return pub;
                }
            }

			return null;
        }

		/// <summary>Return the public key ring which contains the key referred to by keyId</summary>
		/// <param name="keyId">key ID to match against</param>
        public PgpPublicKeyRing GetPublicKeyRing(
            long keyId)
        {
            if (pubRings.Contains(keyId))
            {
                return (PgpPublicKeyRing)pubRings[keyId];
            }

			foreach (PgpPublicKeyRing pubRing in GetKeyRings())
            {
                PgpPublicKey pub = pubRing.GetPublicKey(keyId);

                if (pub != null)
                {
                    return pubRing;
                }
            }

			return null;
        }

		/// <summary>
		/// Return true if a key matching the passed in key ID is present, false otherwise.
		/// </summary>
		/// <param name="keyID">key ID to look for.</param>
		public bool Contains(
			long keyID)
		{
			return GetPublicKey(keyID) != null;
		}

		public byte[] GetEncoded()
        {
            MemoryStream bOut = new MemoryStream();

			Encode(bOut);

			return bOut.ToArray();
        }

		public void Encode(
            Stream outStr)
        {
			BcpgOutputStream bcpgOut = BcpgOutputStream.Wrap(outStr);

			foreach (long key in order)
            {
                PgpPublicKeyRing sec = (PgpPublicKeyRing) pubRings[key];

				sec.Encode(bcpgOut);
            }
        }

		/// <summary>
		/// Return a new bundle containing the contents of the passed in bundle and
		/// the passed in public key ring.
		/// </summary>
		/// <param name="bundle">The <c>PgpPublicKeyRingBundle</c> the key ring is to be added to.</param>
		/// <param name="publicKeyRing">The key ring to be added.</param>
		/// <returns>A new <c>PgpPublicKeyRingBundle</c> merging the current one with the passed in key ring.</returns>
		/// <exception cref="ArgumentException">If the keyId for the passed in key ring is already present.</exception>
        public static PgpPublicKeyRingBundle AddPublicKeyRing(
            PgpPublicKeyRingBundle  bundle,
            PgpPublicKeyRing        publicKeyRing)
        {
            long key = publicKeyRing.GetPublicKey().KeyId;

			if (bundle.pubRings.Contains(key))
            {
                throw new ArgumentException("Bundle already contains a key with a keyId for the passed in ring.");
            }

			IDictionary newPubRings = Platform.CreateHashtable(bundle.pubRings);
            IList newOrder = Platform.CreateArrayList(bundle.order);

			newPubRings[key] = publicKeyRing;

			newOrder.Add(key);

			return new PgpPublicKeyRingBundle(newPubRings, newOrder);
        }

		/// <summary>
		/// Return a new bundle containing the contents of the passed in bundle with
		/// the passed in public key ring removed.
		/// </summary>
		/// <param name="bundle">The <c>PgpPublicKeyRingBundle</c> the key ring is to be removed from.</param>
		/// <param name="publicKeyRing">The key ring to be removed.</param>
		/// <returns>A new <c>PgpPublicKeyRingBundle</c> not containing the passed in key ring.</returns>
		/// <exception cref="ArgumentException">If the keyId for the passed in key ring is not present.</exception>
        public static PgpPublicKeyRingBundle RemovePublicKeyRing(
            PgpPublicKeyRingBundle	bundle,
            PgpPublicKeyRing		publicKeyRing)
        {
            long key = publicKeyRing.GetPublicKey().KeyId;

			if (!bundle.pubRings.Contains(key))
            {
                throw new ArgumentException("Bundle does not contain a key with a keyId for the passed in ring.");
            }

			IDictionary newPubRings = Platform.CreateHashtable(bundle.pubRings);
            IList newOrder = Platform.CreateArrayList(bundle.order);

			newPubRings.Remove(key);
			newOrder.Remove(key);

			return new PgpPublicKeyRingBundle(newPubRings, newOrder);
        }
    }
}