DigitalData.Core/DigitalData.Core.Security/Cryptographer/RSACryptographerList.cs

using DigitalData.Core.Abstractions.Security;
using System.Collections;

namespace DigitalData.Core.Security.Cryptographer
{
    public class RSACryptographerList<TRSACryptographer> : IEnumerable<TRSACryptographer> where TRSACryptographer : IRSACryptographer
    {
        private readonly Func<TRSACryptographer, string> _keyGenerator;

        private readonly IEnumerable<TRSACryptographer> _cryptographers;

        internal RSACryptographerList(Func<TRSACryptographer, string> keyGenerator, IEnumerable<TRSACryptographer> cryptographers)
        {
            _keyGenerator = keyGenerator;
            _cryptographers = cryptographers;            
        }

        public TRSACryptographer? this[string key] => _cryptographers.SingleOrDefault(crypt => _keyGenerator(crypt) == key);

        public IEnumerator<TRSACryptographer> GetEnumerator() => _cryptographers.GetEnumerator();

        IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
    }
}