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

    File: auMemoryModel.hpp
    Date: 2022-2-1
    File: AuroraUtils.hpp
    File: auROXTLUtils.hpp
    Date: 2021-6-9
    Author: Reece
***/
#pragma once

#include "auTypes.hpp"

struct AuHeap;

namespace __audetail
{
    extern AuHeap *gDefaultDiscontiguousHeap;
}

namespace Aurora::Memory
{
    struct ProxyHeap;
}

#if !defined(AURORA_RUNTIME_AU_SHARED_PTR)
    #define AURORA_RUNTIME_AU_SHARED_PTR std::shared_ptr
#endif

#if !defined(AURORA_RUNTIME_AU_WEAK_PTR)
    #define AURORA_RUNTIME_AU_WEAK_PTR std::weak_ptr
#endif

template <class T>
using AuWPtr = AURORA_RUNTIME_AU_WEAK_PTR<T>;

#if !defined(AURORA_RUNTIME_AU_UNIQUE_PTR)
    #define AURORA_RUNTIME_AU_UNIQUE_PTR AuUniquePointer
#endif

#include <auROXTL/MemoryModel/auUniquePointer.hpp>
#include "STLShims/ExtendStlLikeSharedPtr.hpp"

template <class T>
using AuSPtr = typename Aurora::Memory::ExSharedPtr<T, AURORA_RUNTIME_AU_SHARED_PTR<T>>;

template <class T>
using AuSSPtr = typename AURORA_RUNTIME_AU_SHARED_PTR<T>;

template <class T, typename Deleter_t = void(*)(T *)>
using AuUPtr = AURORA_RUNTIME_AU_UNIQUE_PTR<T, Deleter_t>;

#if !defined(AU_AuEnableSharedFromThis)
#define AU_AuEnableSharedFromThis

template <class X>
struct AuEnableSharedFromThis : Aurora::Memory::ExSharedFromThis<X, std::enable_shared_from_this<X>>
{};

#endif

#if !defined(AURORA_RUNTIME_MAKE_SHARED)
    #define AURORA_RUNTIME_MAKE_SHARED std::make_shared
#endif

static inline AU_NORETURN void SysPanic(const char *pMsg);

static auline void AuMemoryPanic(const char *msg)
{
    #if defined(AURORA_RUNTIME_MEMORY_PANIC)
        AURORA_RUNTIME_MEMORY_PANIC(msg);
    #else
        SysPanic(msg);
    #endif
}

#include "MemoryModel/auArraySize.hpp"
#include "MemoryModel/auSizeOf.hpp"
#include "MemoryModel/auOffsetOf.hpp"


template <typename T>
static auto AuTryLockMemoryType(T weak) -> decltype(weak.lock())
{
    if (weak.expired())
    {
        return {};
    }

    AUROXTL_COMMODITY_TRY
    {
        return weak.lock();
    }
    AUROXTL_COMMODITY_CATCH
    {
        return {};
    }
}

template <class Z, typename T>
static void auline AuSafeDelete(T *in)
{
    static_assert(AuIsBaseOf_v<T, AuRemovePointer_t<Z>>, "Couldn't not safe delete from type T because it is not derived from Z");

    if (in == nullptr)
    {
        return;
    }

    delete static_cast<Z>(in);
}

#if !defined(AURORA_RUNTIME_AU_DEFAULT_DELETER)
    #define AURORA_RUNTIME_AU_DEFAULT_DELETER std::default_delete
#endif

template <class T>
struct AuPMRAllocator;

namespace Aurora::Memory
{
    template <class T>
    struct CppHeapWrapper;
    

#if defined(AURORA_ROXTL_ALLOCATORS_USE_STD)

    template<typename T>
    using PrimitiveArrayAllocator =  std::allocator<T>;
    
    template<typename T>
    using ClassArrayAllocator     =  std::allocator<T>;
    
    template<typename T>
    using StringAllocator         =  std::allocator<T>;
    
#else

    static void *__FAlloc(Types::size_t length, Types::size_t align);
    static void  __Free(void *buffer);
    static AuUInt  __SizeOf(void *pHead);

    template <class T>
    struct BaseAuroraRuntimeAllocator
    {
        typedef T value_type;

        AU_COPY_MOVE(BaseAuroraRuntimeAllocator)

        constexpr BaseAuroraRuntimeAllocator() noexcept
        { }

        template <class U>
        constexpr BaseAuroraRuntimeAllocator(const BaseAuroraRuntimeAllocator <U> &) noexcept
        { }

        void *allocate_bytes(std::size_t nbytes,
                             std::size_t alignment = alignof(std::max_align_t))
        {
            if (auto pRet = __FAlloc(nbytes, alignment))
            {
                return pRet;
            }
            else
            {
                throw std::bad_alloc();
            }
        }

        void deallocate_bytes(void *p,
                              std::size_t nbytes,
                              std::size_t alignment = alignof(std::max_align_t))
        {
            return __Free(p);
        }
        
    #if defined(AU_LANG_CPP_23)
        constexpr std::allocation_result<T *> allocate_at_least(const size_t count)
        {
            auto pThat = this->allocate(count);
            return { (T *)pThat, __SizeOf(pThat) / sizeof(T) };
        }
    #endif
        
        template <class U, class... Args >
        void construct(U *p, Args&&... args)
        {
            new ((void *)p) U(AuForward<Args>(args)...);
        }

        template <class U, class... Args >
        void construct_at(U *p, Args&&... args)
        {
            new ((void *)p) U(AuForward<Args>(args)...);
        }

        void deallocate(const T *pType,
                                  const size_t count)
        {
            this->deallocate_bytes((void *)pType, 0, 0);
        }

        AU_ALLOC T *allocate(const size_t count)
        {
            if (!count)
            {
                return nullptr;
            }
            
            return (T *)this->allocate_bytes(count * sizeof(T), alignof(T));
        }

        template <class U>
        U *allocate_object(std::size_t n = 1)
        {
            return (U *)this->allocate_bytes(sizeof(U) * n, alignof(U));
        }

        template <class U>
        void deallocate_object(U *p, std::size_t n = 1)
        {
            this->deallocate_bytes(p, 0, 0);
        }

        template <class U, class... CtorArgs>
        U *new_object(CtorArgs&&... args)
        {
            U *p = this->allocate_object<U>();
            try
            {
                this->construct(p, AuForward<CtorArgs>(args)...);
            }
            catch (...)
            {
                this->deallocate_object(p);
                throw;
            }
            return p;
        }

        template <class U>
        void delete_object(U *p)
        {
            if constexpr (AuIsClass_v<U> &&
                          !AuIsTriviallyDestructible_v<U>)
            {
                p->~U();
            }

            this->deallocate_object(p);
        }

        template <class Z>
        inline constexpr bool operator==(const Aurora::Memory::BaseAuroraRuntimeAllocator<Z> &rhs) noexcept
        {
            return true;
        }
    };
    
    template<typename T>
    using PrimitiveArrayAllocator     =  BaseAuroraRuntimeAllocator<T>;
    
    template<typename T>
    using ClassArrayAllocator         =  BaseAuroraRuntimeAllocator<T>;

    template<typename T>
    using StringAllocator             =  BaseAuroraRuntimeAllocator<T>;

    template<typename T>
    using SharedControlBlockAllocator = BaseAuroraRuntimeAllocator<T>;

    template <class T>
    struct DefaultRuntimeDeleter
    {
        constexpr DefaultRuntimeDeleter() noexcept = default;

        template <class Z>
        DefaultRuntimeDeleter(const DefaultRuntimeDeleter<Z> &) noexcept
        { }

        void operator()(T *pThat) const
        {
            if constexpr (AuIsClass_v<T> &&
                          !AuIsTriviallyDestructible_v<T>)
            {
                pThat->~T();
            }

            Aurora::Memory::__Free(pThat);
        }
    };
    
    template <class T>
    struct DefaultRuntimeDeleter<T[]>
    {
        constexpr DefaultRuntimeDeleter() noexcept = default;

        template <class Z>
        DefaultRuntimeDeleter(const DefaultRuntimeDeleter<Z> &) noexcept
        { }

        template <class Z>
        void operator()(Z *pThat) const
        {
            AURORA_RUNTIME_AU_DEFAULT_DELETER<T[]>()(pThat);
        }
    };

#endif
}

#if defined(AURORA_ROXTL_ALLOCATORS_USE_STD)

    template <class T>
    using AuDefaultDeleter = AURORA_RUNTIME_AU_DEFAULT_DELETER<T>;

#else

    template <class T>
    using AuDefaultDeleter = Aurora::Memory::DefaultRuntimeDeleter<T>;

#endif

template <class T, typename... Args>
AuSPtr<T> AuMakeShared(Args&&... args);

template <class T, typename... Args>
static auline AuSPtr<T> AuMakeSharedPanic(Args&&... args)
{
#if defined(AURORA_ROXTL_ALLOCATORS_USE_STD)
    try
    {
        auto pShared = AURORA_RUNTIME_MAKE_SHARED<T>(AuForward<Args>(args)...);
        if (!pShared)
        {
            AuMemoryPanic("Failed to allocate <X>"); // TODO: non-rtti typename
        }

        return pShared;
    }
    catch (...)
    {
        AuMemoryPanic("Failed to allocate <X>"); // TODO: non-rtti typename
        return {};
    }
#else
    auto pShared = AuMakeShared<T>(AuForward<Args>(args)...);
    if (!pShared)
    {
        AuMemoryPanic("Failed to allocate <X>"); // TODO: non-rtti typename
    }

    return pShared;
#endif
}

template <class T, typename... Args>
static auline AuSPtr<T> AuMakeSharedThrow(Args&&... args)
{
#if defined(AURORA_ROXTL_ALLOCATORS_USE_STD)
    try
    {
        auto pShared = AURORA_RUNTIME_MAKE_SHARED<T>(AuForward<Args>(args)...);
        if (!pShared)
        {
            // TODO: Agnostic SysPushErrorMemory
            AU_THROW_STRING("Failed to allocate <X>"); // TODO: non-rtti typename
        }

        return pShared;
    }
    catch (...)
    {
        // TODO: Agnostic SysPushErrorCatch
        AU_THROW_STRING("Failed to allocate <X>"); // TODO: non-rtti typename
        return {};
    }
#else
    auto pShared = AuMakeShared<T>(AuForward<Args>(args)...);
    if (!pShared)
    {
        AU_THROW_STRING("Failed to allocate <X>"); // TODO: non-rtti typename
    }

    return pShared;
#endif
}

template <class T>
static auline AuSPtr<T> AuMakeSharedArray(AuUInt count)
{
    try
    {
    #if defined(AU_LANG_CPP_20) && 0
        return AURORA_RUNTIME_AU_SHARED_PTR<T[]>(count);
    #else
        return AURORA_RUNTIME_AU_SHARED_PTR<T>(new T[count], AURORA_RUNTIME_AU_DEFAULT_DELETER<T[]>());
    #endif
    }
    catch (...)
    {
        return {};
    }
}

namespace __audetail
{
    struct Dummy
    {
        char a;
    };

    inline AuSPtr<Dummy> gDummy;

    inline AuSPtr<Dummy> GetDummyDeleter()
    {
        if (!gDummy)
        {
        #if defined(AURORA_COMPILER_MSVC)
            return gDummy;
        #endif
            gDummy = AuMakeShared<Dummy>();
        }
        return gDummy;
    }
}

template <class T>
static AuSPtr<T> AuUnsafeRaiiToShared(T *in)
{
    return AuSPtr<T>(__audetail::GetDummyDeleter(), in);
}

template <class T, class Z>
static AuSPtr<T> AuUnsafeRaiiToShared(const AuUPtr<T, Z> &in)
{
    return AuUnsafeRaiiToShared(in.get());
}

template <class T, class Z>
inline constexpr bool operator==(const Aurora::Memory::BaseAuroraRuntimeAllocator<T> &lhs,
                                 const Aurora::Memory::BaseAuroraRuntimeAllocator<Z> &rhs) noexcept
{
    return true;
}

template <class T, class Z>
inline constexpr bool operator!=(const Aurora::Memory::BaseAuroraRuntimeAllocator<T> &lhs,
                                 const Aurora::Memory::BaseAuroraRuntimeAllocator<Z> &rhs) noexcept
{
    return false;
}

#include <auROXTL/MemoryModel/auSetAllocator.hpp>

#include <auROXTL/MemoryModel/auPMRAllocator.hpp>

#include <auROXTL/MemoryModel/auHeapStats.hpp>
#include <auROXTL/MemoryModel/auHeap.hpp>
#include <auROXTL/MemoryModel/auHeapAccessor.hpp>

#include <auROXTL/MemoryModel/auDummyHeap.hpp>

#include <auROXTL/MemoryModel/auMemoryAllocate.hpp>