SignerInformationStore.cs

using System.Collections.Generic;

using Org.BouncyCastle.Utilities.Collections;

namespace Org.BouncyCastle.Cms
{
    public class SignerInformationStore
        : IEnumerable<SignerInformation>
    {
        private readonly List<SignerInformation> m_all;
        private readonly Dictionary<SignerID, List<SignerInformation>> m_table =
            new Dictionary<SignerID, List<SignerInformation>>();

        /**
         * Create a store containing a single SignerInformation object.
         *
         * @param signerInfo the signer information to contain.
         */
        public SignerInformationStore(SignerInformation signerInfo)
        {
            m_all = new List<SignerInformation>(1){ signerInfo };
            m_table[signerInfo.SignerID] = m_all;
        }

        /**
         * Create a store containing a collection of SignerInformation objects.
         *
         * @param signerInfos a collection of signer information objects to contain.
         */
        public SignerInformationStore(IEnumerable<SignerInformation> signerInfos)
        {
            m_all = new List<SignerInformation>(signerInfos);

            foreach (SignerInformation signer in m_all)
            {
                SignerID sid = signer.SignerID;

                if (!m_table.TryGetValue(sid, out var list))
                {
                    list = new List<SignerInformation>(1);
                    m_table[sid] = list;
                }

                list.Add(signer);
            }
        }

        public SignerInformation this[SignerID selector] => GetFirstSigner(selector);

        /**
         * Return the first SignerInformation object that matches the
         * passed in selector. Null if there are no matches.
         *
         * @param selector to identify a signer
         * @return a single SignerInformation object. Null if none matches.
         */
        public SignerInformation GetFirstSigner(SignerID selector)
        {
            if (m_table.TryGetValue(selector, out var list))
                return list[0];

            return null;
        }

        /// <summary>The number of signers in the collection.</summary>
        public int Count => m_all.Count;

        /// <returns>A list of all signers in the collection</returns>
        public IList<SignerInformation> GetSigners() => new List<SignerInformation>(m_all);

        /**
         * Return possible empty collection with signers matching the passed in SignerID
         *
         * @param selector a signer id to select against.
         * @return a collection of SignerInformation objects.
         */
        public IList<SignerInformation> GetSigners(SignerID selector)
        {
            if (m_table.TryGetValue(selector, out var list))
                return new List<SignerInformation>(list);

            return new List<SignerInformation>(0);
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => GetEnumerator();

        public IEnumerator<SignerInformation> GetEnumerator()
        {
            IEnumerable<SignerInformation> e = CollectionUtilities.Proxy(m_all);
            return e.GetEnumerator();
        }

        internal List<SignerInformation> SignersInternal => m_all;
    }
}