using DigitalData.Core.Abstractions.Security;
using Microsoft.IdentityModel.Tokens;
using System.Reflection;
using System.Security.Cryptography;

namespace DigitalData.Core.Security.Cryptographer
{
    //TODO: Abstract RSA for future updates (using ECC, El Gamal or Lattice-based Cryptography)
    public class RSACryptographer : IRSACryptographer
    {
        public virtual string Pem { get; init; }
                
        public RSAEncryptionPadding Padding { get; init; } = RSAEncryptionPadding.OaepSHA256;

        // TODO: add as json converter to IConfigurIConfiguration.Config
        public string PaddingName
        {
            get => Padding.ToString();
            init => Padding = typeof(RSAEncryptionPadding).GetProperty(value, BindingFlags.Public | BindingFlags.Static)?.GetValue(null) as RSAEncryptionPadding ?? throw new ArgumentException($"Padding '{value}' not found.");
        }

        protected virtual RSA RSA { get; } = RSA.Create();

        public string Issuer { get; init; } = string.Empty;

        public string Audience { get; init; } = string.Empty;

        private readonly Lazy<RsaSecurityKey> _lazyRsaSecurityKey;

        public RsaSecurityKey RsaSecurityKey => _lazyRsaSecurityKey.Value;

#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
        internal RSACryptographer()
        {
            _lazyRsaSecurityKey = new(() => new RsaSecurityKey(RSA));
        }
#pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
    }
}