/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: AuRNG.cpp
    Date: 2021-6-11
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "AuRNG.hpp"
#include "AuRNGEntropy.hpp"
#include "AuWELL.hpp"

namespace Aurora::RNG
{
    static WELLRand gWellRand;
    RandomUnique_t gFastDevice;

    AUKN_SYM void ReadSecureRNG(void *pBuffer, AuUInt32 uBytes)
    {
        AuUInt32 offset;
        AuUInt8 *headPtr;

        SysAssert(pBuffer, "Null RNG out buffer");

        headPtr = reinterpret_cast<AuUInt8 *>(pBuffer);
        offset  = 0;

        while (offset != uBytes)
        {
            auto req   = uBytes - offset;
            auto bytes = RngGetBytes(headPtr + offset, req);
            SysAssertExp(bytes, "Couldn't consume {} RNG bytes", req);
            offset += bytes;
        }
    }

    AUKN_SYM void ReadFastRNG(void *pBuffer, AuUInt32 uBytes)
    {
        SysAssert(pBuffer, "Null RNG out buffer");

        WELL_NextBytes(&gWellRand, pBuffer, uBytes);
    }

    static void InitFastRng()
    {
        AuArray<AuUInt8, 64> maxEntropy;
        RngFillArray<false, AuUInt8>(maxEntropy.data(), 64);
        gWellRand = WELL_SeedRandBig64(maxEntropy);
        RandomDef fast;
        fast.SetQuickRng();
        gFastDevice = RandomUnique(fast);
    }

    void Init()
    {
        EntropyInit();
        InitFastRng();
    }

    void Release()
    {
        EntropyDeinit();
    }
}