using DigitalData.Core.Abstractions.Security;
using DigitalData.Core.Security.Extensions;
using System.Security.Cryptography;

namespace DigitalData.Core.Security
{
    public class RSADecryptor : RSACryptographer, IRSADecryptor, IRSACryptographer
    {
        public string? Password { get; init; }

        public bool HasEncryptedPem => Password is not null;

        public bool IsEncrypted => Password is not null;

        private readonly Lazy<IRSAEncryptor> _lazyEncryptor;

        public IRSAEncryptor Encryptor => _lazyEncryptor.Value;

        private readonly Lazy<RSA> lazyRSA;

        protected override RSA RSA => lazyRSA.Value;

        public RSADecryptor() 
        {
            _lazyEncryptor = new(() => new RSAEncryptor()
            {
                Pem = RSA.ExportRSAPublicKeyPem(),
                Padding = Padding
            });

            lazyRSA = new(() =>
            {
                var rsa = RSA.Create();
                if (Password is null)
                    RSA.ImportFromPem(Pem);
                else
                    RSA.ImportFromEncryptedPem(Pem, Password.AsSpan());

                return rsa;
            });
        }
        
        public byte[] Decrypt(byte[] data) => RSA.Decrypt(data, Padding);

        public string Decrypt(string data) => RSA.Decrypt(data.Base64ToByte(), Padding).BytesToString();
    }
}