using Isopoh.Cryptography.Argon2;
using Isopoh.Cryptography.SecureArray;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;

namespace Akari.Prototype.Server.Utils
{
    public static class Security
    {
        public const int HashLength = 32;
        public const int SaltLength = 12;

        public static string Argon2idHash(byte[] password)
        {
            var salt = new byte[8];

            RandomNumberGenerator.Fill(salt);

            var config = new Argon2Config()
            {
                HashLength = 32,
                Lanes = Environment.ProcessorCount / 2,
                Threads = Environment.ProcessorCount / 2,
                Password = password,
                Salt = salt,
                Type = Argon2Type.HybridAddressing,
                Version = Argon2Version.Nineteen
            };

            return Argon2.Hash(config);
        }

        public static SecureArray<byte> Argon2idDeriveBytes(byte[] password, byte[] salt, int length, bool clear = false, int? threads = null)
        {
            int t = threads ?? Environment.ProcessorCount / 2;

            if (t < 1)
            {
                t = 1;
            }

            var config = new Argon2Config()
            {
                HashLength = length,
                Password = password,
                Salt = salt,
                Lanes = t,
                Threads = t,
                ClearPassword = clear,
                ClearSecret = clear,
                Type = Argon2Type.HybridAddressing,
                Version = Argon2Version.Nineteen
            };

            return new Argon2(config).Hash();
        }
        public static SecureArray<byte> Argon2idDeriveBytes(string password, string salt, int length, bool clear = false, int? threads = null)
        {
            return Argon2idDeriveBytes(Encoding.UTF8.GetBytes(password), Encoding.UTF8.GetBytes(salt), length, clear, threads);
        }
    }
}