/***
    Copyright (C) 2022 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: CBC.cpp
    Date: 2022-10-08
    Author: Reece
***/
#include <Source/RuntimeInternal.hpp>
#include "../Crypto.hpp"
#include "CBC.hpp"

namespace Aurora::Crypto::CBC
{
    bool CBCContext::Initialize(const Memory::MemoryViewRead &key,
                                const Memory::MemoryViewRead &iv)
    {
        if (iv.length > 32)
        {
            SysPushErrorArg();
            return false;
        }

        if (!iv.ptr)
        {
            SysPushErrorArg();
            return false;
        }

        if (!key.ptr)
        {
            SysPushErrorArg();
            return false;
        }

        if (key.length > AuArraySize(this->streamKey_))
        {
            SysPushErrorArg();
            return false;
        }

        AuMemcpy(this->cbc_.IV, iv.ptr, iv.length);
        this->iIVLength = iv.length;
        this->iKeyLength = key.length;

        AuMemcpy(this->streamKey_, key.ptr, key.length);
        return true;
    }

    bool CBCContext::GetIV(const Memory::MemoryViewWrite &writeView)
    {
        if (!writeView.ptr)
        {
            SysPushErrorArg();
            return false;
        }

        if (writeView.length != this->cbc_.blocklen)
        {
            return {};
        }

        AuMemcpy(writeView.ptr, this->cbc_.IV, this->cbc_.blocklen);
        return true;
    }

    bool CBCContext::SetIV(const Memory::MemoryViewRead &readView)
    {
        if (!readView.ptr)
        {
            SysPushErrorArg();
            return false;
        }

        if (readView.length != this->cbc_.blocklen)
        {
            return {};
        }

        AuMemcpy(this->cbc_.IV, readView.ptr, this->cbc_.blocklen);
        return true;
    }

    bool CBCContext::TryInit(int iCipher)
    {
        char iv[32];
        int iRet {};

        if (this->iLastCipher_ != -1)
        {
            return this->iLastCipher_ == iCipher;
        }

        AuMemcpy(iv, this->cbc_.IV, 32);

        iRet = ::cbc_start(iCipher,
                           AuReinterpretCast<const unsigned char *>(iv),
                           AuReinterpretCast<const unsigned char *>(this->streamKey_),
                           this->iKeyLength,
                           0,
                           &this->cbc_);
        if (iRet != CRYPT_OK)
        {
            SysPushErrorCrypt("{}", iRet);
            return {};
        }

        this->iLastCipher_ = iCipher;
        return true;
    }

    bool CBCContext::Decrypt(int iCipher,
                             const Memory::MemoryViewWrite &memoryView)
    {
        int iRet {};
        if (!TryInit(iCipher))
        {
            return false;
        }

        iRet = ::cbc_decrypt(AuReinterpretCast<const unsigned char *>(memoryView.ptr),
                             AuReinterpretCast<unsigned char *>(memoryView.ptr),
                             memoryView.length,
                             &this->cbc_);
        if (iRet != CRYPT_OK)
        {
            SysPushErrorCrypt("{}", iRet);
            return false;
        }

        return true;
    }

    bool CBCContext::Encrypt(int iCipher,
                             const Memory::MemoryViewWrite &memoryView)
    {
        int iRet {};

        if (!TryInit(iCipher))
        {
            return false;
        }

        iRet = ::cbc_encrypt(AuReinterpretCast<const unsigned char *>(memoryView.ptr),
                             AuReinterpretCast<unsigned char *>(memoryView.ptr),
                             memoryView.length,
                             &this->cbc_);
        if (iRet != CRYPT_OK)
        {
            SysPushErrorCrypt("{}", iRet);
            return false;
        }

        return true;
    }

    AUKN_SYM ICBCContext *NewContextNew()
    {
        return  _new CBCContext();
    }

    AUKN_SYM void NewContextRelease(ICBCContext *pContext)
    {
        AuSafeDelete<CBCContext *>(pContext);
    }
}