using DigitalData.Core.Abstractions.Security;
using DigitalData.Core.Security.Extensions;
using System.Runtime.Serialization;

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

        public bool IsEncrypted => Password is not null;

        public IRSAEncryptor Encryptor
        {
            get
            {
                return new RSAEncryptor()
                {
                    Pem = _rsa.ExportRSAPublicKeyPem(),
                    Padding = Padding
                };
            }
        }

        internal RSADecryptor() { }

        [OnDeserialized]
        private void OnDeserialized(StreamingContext context) => Init();

        private IRSADecryptor Init()
        {
            if (string.IsNullOrWhiteSpace(Pem))
                throw new InvalidOperationException("Pem cannot be null or empty.");

            if (Password is null)
                _rsa.ImportFromPem(Pem);
            else
                _rsa.ImportFromEncryptedPem(Pem, Password.AsSpan());

            return this;
        }

        public byte[] Decrypt(byte[] data) => _rsa.Decrypt(data, Padding);

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