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

    File: auAtomic.hpp
    Date: 2022-2-1
    Author: Reece
***/
#pragma once

template<typename T>
struct AuAtomicUtils
{
    /**
     * @brief Sets bit offset in in
     * @return original value 
    */
    static T    Set(T *in, AuUInt8 offset);

    /**
     * @brief Adds addend to in
     * @return updated value 
    */
    static T    Add(T *in, T addend);

    /**
     * @brief Subtracts the minuend from in
     * @return updated value
    */
    static T    Sub(T *in, T minuend);

    /**
     * @brief Generic bitwise compare exchange
     * @param replace replacement value for in if in matches compare
     * @param compare required reference value
     * @return original value 
    */
    static T    CompareExchange(T *in, T replace, T compare);
};

#if defined(AURORA_COMPILER_MSVC)

template<>
inline auline AuUInt64 AuAtomicUtils<AuUInt64>::CompareExchange(AuUInt64 *in, AuUInt64 replace, AuUInt64 compare)
{
    return static_cast<AuUInt64>(_InterlockedCompareExchange64(reinterpret_cast<long long volatile *>(in), static_cast<long long>(replace), static_cast<long long>(compare)));
}

template<>
inline auline AuUInt32 AuAtomicUtils<AuUInt32>::CompareExchange(AuUInt32 *in, AuUInt32 replace, AuUInt32 compare)
{
    return static_cast<AuUInt32>(_InterlockedCompareExchange(reinterpret_cast<long volatile *>(in), static_cast<long>(replace), static_cast<long>(compare)));
}

template<>
inline auline AuUInt16 AuAtomicUtils<AuUInt16>::CompareExchange(AuUInt16 *in, AuUInt16 replace, AuUInt16 compare)
{
    return static_cast<AuUInt16>(_InterlockedCompareExchange16(reinterpret_cast<short volatile *>(in), static_cast<short>(replace), static_cast<short>(compare)));
}

template<>
inline auline AuInt64 AuAtomicUtils<AuInt64>::CompareExchange(AuInt64 *in, AuInt64 replace, AuInt64 compare)
{
    return _InterlockedCompareExchange64(reinterpret_cast<long long volatile *>(in), static_cast<long long>(replace), static_cast<long long>(compare));
}

template<>
inline auline AuInt32 AuAtomicUtils<AuInt32>::CompareExchange(AuInt32 *in, AuInt32 replace, AuInt32 compare)
{
    return _InterlockedCompareExchange(reinterpret_cast<long volatile *>(in), static_cast<long>(replace), static_cast<long>(compare));
}

template<>
inline auline AuInt16 AuAtomicUtils<AuInt16>::CompareExchange(AuInt16 *in, AuInt16 replace, AuInt16 compare)
{
    return _InterlockedCompareExchange16(reinterpret_cast<short volatile *>(in), static_cast<short>(replace), static_cast<short>(compare));
}

template<>
inline auline AuUInt64 AuAtomicUtils<AuUInt64>::Add(AuUInt64 *in, AuUInt64 addend)
{
    return static_cast<AuUInt64>(_InterlockedExchangeAdd64(reinterpret_cast<long long volatile *>(in), static_cast<long long>(addend)) + static_cast<long long>(addend));
}

template<>
inline auline AuUInt32 AuAtomicUtils<AuUInt32>::Add(AuUInt32 *in, AuUInt32 addend)
{
    return static_cast<AuUInt32>(_InterlockedExchangeAdd(reinterpret_cast<long volatile *>(in), static_cast<long>(addend)) + static_cast<long>(addend));
}

template<>
inline auline AuInt64 AuAtomicUtils<AuInt64>::Add(AuInt64 *in, AuInt64 addend)
{
    return _InterlockedExchangeAdd64(reinterpret_cast<long long volatile *>(in), static_cast<long long>(addend)) + static_cast<long long>(addend);
}

template<>
inline auline AuInt32 AuAtomicUtils<AuInt32>::Add(AuInt32 *in, AuInt32 addend)
{
    return _InterlockedExchangeAdd(reinterpret_cast<long volatile *>(in), static_cast<long>(addend)) + static_cast<long>(addend);
}

// TODO:
#if 0
template<>
inline auline AuUInt16 AuAtomicUtils<AuUInt16>::Add(AuUInt16 *in, AuUInt16 addend)
{
    return {};
}
#endif


template<>
inline auline AuUInt64 AuAtomicUtils<AuUInt64>::Sub(AuUInt64 *in, AuUInt64 minuend)
{
    return Add(in, AuUInt64(0) - minuend);
}

template<>
inline auline AuUInt32 AuAtomicUtils<AuUInt32>::Sub(AuUInt32 *in, AuUInt32 minuend)
{
    return Add(in, AuUInt32(0) - minuend);
}

// TODO:
#if 0
template<>
inline auline AuUInt16 AuAtomicUtils<AuUInt16>::Sub(AuUInt16 *in, AuUInt16 minuend)
{
    return {};
}

#endif

template<>
inline auline AuUInt64 AuAtomicUtils<AuUInt64>::Set(AuUInt64 *in, AuUInt8 offset)
{
    return _InterlockedOr64(reinterpret_cast<long long volatile *>(in), AuUInt64(1) << offset);
}

template<>
inline auline AuUInt32 AuAtomicUtils<AuUInt32>::Set(AuUInt32 *in, AuUInt8 offset)
{
    return _InterlockedOr(reinterpret_cast<long volatile *>(in), 1 << offset);
}

template<>
inline auline AuUInt16 AuAtomicUtils<AuUInt16>::Set(AuUInt16 *in, AuUInt8 offset)
{
    return _InterlockedOr16(reinterpret_cast<short volatile *>(in), 1 << offset);
}


template<>
inline auline AuInt64 AuAtomicUtils<AuInt64>::Set(AuInt64 *in, AuUInt8 offset)
{
    return _InterlockedOr64(reinterpret_cast<long long volatile *>(in), AuUInt64(1) << offset);
}

template<>
inline auline AuInt32 AuAtomicUtils<AuInt32>::Set(AuInt32 *in, AuUInt8 offset)
{
    return _InterlockedOr(reinterpret_cast<long volatile *>(in), 1 << offset);
}

template<>
inline auline long AuAtomicUtils<long>::Set(long *in, AuUInt8 offset)
{
    return _InterlockedOr(reinterpret_cast<long volatile *>(in), 1 << offset);
}

template<>
inline auline unsigned long AuAtomicUtils<unsigned long>::Set(unsigned long *in, AuUInt8 offset)
{
    return _InterlockedOr(reinterpret_cast<long volatile *>(in), 1 << offset);
}

template<>
inline auline AuInt16 AuAtomicUtils<AuInt16>::Set(AuInt16 *in, AuUInt8 offset)
{
    return _InterlockedOr16(reinterpret_cast<short volatile *>(in), 1 << offset);
}

#elif defined(AURORA_COMPILER_CLANG) || defined(AURORA_COMPILER_GCC)

template<typename T>
inline auline T AuAtomicUtils<T>::CompareExchange(T *in, T replace, T compare)
{
    return __sync_val_compare_and_swap(in, compare, replace);
}

template<typename T>
inline auline T AuAtomicUtils<T>::Add(T *in, T addend)
{
    return __sync_add_and_fetch(in, addend);
}

template<typename T>
inline auline T AuAtomicUtils<T>::Sub(T *in, T minuend)
{
    return __sync_sub_and_fetch(in, minuend);
}

template<typename T>
inline auline T AuAtomicUtils<T>::Set(T *in, AuUInt8 offset)
{
    return __sync_fetch_and_or(in, T(1) << offset);
}

#endif

template<typename T>
auline 
T    AuAtomicSet(T *in, AuUInt8 offset)
{
    return AuAtomicUtils<T>::Set(in, offset);
}

template<typename T>
auline
T    AuAtomicAdd(T *in, T addend)
{
    return AuAtomicUtils<T>::Add(in, addend);
}

template<typename T>
auline
T    AuAtomicSub(T *in, T minuend)
{
    return AuAtomicUtils<T>::Sub(in, minuend);
}

template<typename T>
auline
T    AuAtomicCompareExchange(T *in, T replace, T compare)
{
    return AuAtomicUtils<T>::CompareExchange(in, replace, compare);
}