#if !STELLAOPS_CRYPTO_SODIUM
using System;
using System.Text;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;

namespace StellaOps.Cryptography;

/// <summary>
/// Managed Argon2id implementation powered by BouncyCastle.Cryptography.
/// </summary>
public sealed partial class Argon2idPasswordHasher
{
    private static partial byte[] DeriveHashCore(string password, ReadOnlySpan<byte> salt, PasswordHashOptions options)
    {
        var passwordBytes = Encoding.UTF8.GetBytes(password);

        var parameters = new Argon2Parameters.Builder(Argon2Parameters.Argon2id)
            .WithSalt(salt.ToArray())
            .WithParallelism(options.Parallelism)
            .WithIterations(options.Iterations)
            .WithMemoryAsKB(options.MemorySizeInKib)
            .Build();

        var generator = new Argon2BytesGenerator();
        generator.Init(parameters);

        var result = new byte[HashLengthBytes];
        generator.GenerateBytes(passwordBytes, result);

        return result;
    }
}
#endif