/*
MIT License

Copyright (c) 2019 - 2024 Advanced Micro Devices, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#ifndef GUARD_RPP_HIPOC_KERNEL_HPP
#define GUARD_RPP_HIPOC_KERNEL_HPP

#include <array>
#include <cassert>
#include <vector>
#include <memory.h>

#include "rpp/errors.hpp"
#include "rpp/hipoc_program.hpp"
#include "rpp/stringutils.hpp"
#include "rpp/op_kernel_args.hpp"

namespace rpp {

using HipEventPtr = RPP_MANAGE_PTR(hipEvent_t, hipEventDestroy);
inline HipEventPtr make_hip_event()
{
    hipEvent_t result = nullptr;
    hipEventCreate(&result);
    return HipEventPtr{result};
}

#if 1

#if 1
template <class T, class U>
struct KernelArgsPair
{
    static const int alignment    = sizeof(U);
    static const int padding      = (alignment - (sizeof(T) % alignment)) % alignment;
    static const int second_index = sizeof(T) + padding;
    KernelArgsPair(T x, U y)
    {
        new(buffer) T(x);
        new(buffer + second_index) U(y);
    }
    char buffer[second_index + sizeof(U)] = {};
};
#else
template <class T, class U>
struct KernelArgsPair
{
    KernelArgsPair(T x, U y) : first(x), second(y) {}
    T first;
    U second;
};
#endif

template <class... Ts>
struct KernelArgsPack;

template <class T, class U, class... Ts>
struct KernelArgsPack<T, U, Ts...>
{
    using data_t = KernelArgsPack<KernelArgsPair<T, U>, Ts...>;
    KernelArgsPack(T x, U y, Ts... xs) : data(KernelArgsPair<T, U>(x, y), xs...) {}
    data_t data;
};

template <class T>
struct KernelArgsPack<T>
{
    KernelArgsPack(T x) : head(x) {}
    T head;
};

#else

template <class... Ts>
struct KernelArgsPack;

template <class T, class... Ts>
struct KernelArgsPack<T, Ts...>
{
    KernelArgsPack(T x, Ts... xs) : head(x), tail(xs...) {}
    T head;
    KernelArgsPack<Ts...> tail;
};

template <>
struct KernelArgsPack<>
{
};

#endif
template <class... Ts>
struct KernelArgs
{
    KernelArgs(Ts... xs) : pack(xs...) { std::fill(std::begin(hidden), std::end(hidden), 0); }
    KernelArgsPack<Ts...> pack;
    uint64_t hidden[6] = {};
};

struct HIPOCKernelInvoke
{
    hipStream_t stream = nullptr;
    hipFunction_t fun  = nullptr;
    std::array<size_t, 3> ldims = {};
    std::array<size_t, 3> gdims = {};
    std::string name;
    std::function<void(hipEvent_t, hipEvent_t)> callback;

    // Workaround for aggregate types in c++11
    HIPOCKernelInvoke() {}
    HIPOCKernelInvoke(hipStream_t pstream,
                      hipFunction_t pfun,
                      std::array<size_t, 3> pldims,
                      std::array<size_t, 3> pgdims,
                      std::string pname,
                      std::function<void(hipEvent_t, hipEvent_t)> pcallback)
        : stream(pstream), fun(pfun), ldims(pldims), gdims(pgdims), name(pname), callback(pcallback)
    {
    }
    void operator()(std::vector<OpKernelArg>& any_args) const
    {
        char hip_args[256] = {0};
        auto sz_left       = any_args[0].size();

        memcpy(hip_args, &(any_args[0].buffer[0]), any_args[0].size());
        //        copy_arg(any_args[0], hip_args, 0);

        for(unsigned long idx = 1; idx < any_args.size(); idx++)
        {
            auto& any_arg              = any_args[idx];
            unsigned long alignment    = any_arg.size();
            unsigned long padding      = (alignment - (sz_left % alignment)) % alignment;
            unsigned long second_index = sz_left + padding;
            memcpy(hip_args + second_index, &(any_arg.buffer[0]), any_arg.size());
            // copy_arg(any_arg, hip_args, second_index);
            sz_left = second_index + alignment;
        }
        // std::cout<<"Invoking run on hip_args\n";
        run(hip_args, sz_left);
    }

    template <class... Ts>
    void operator()(Ts... xs) const
    {
        // std::cout<<"Invoking run on Kernelargs\n";
        KernelArgs<Ts...> args{xs...};
        run(&args, sizeof(args));
    }

    void run(void* args, std::size_t size) const;

    const std::string& GetName() const { return name; }
};

struct HIPOCKernel
{
    HIPOCProgram program;
    std::string name;
    std::array<size_t, 3> ldims = {};
    std::array<size_t, 3> gdims = {};
    std::string kernel_module;
    hipFunction_t fun = nullptr;

    HIPOCKernel() {}
    HIPOCKernel(HIPOCProgram p,
                const std::string kernel_name,
                std::vector<size_t> local_dims,
                std::vector<size_t> global_dims
                )
        : program(p), name(kernel_name)
    {
        assert(!local_dims.empty() && local_dims.size() <= 3);
        assert(!global_dims.empty() && global_dims.size() <= 3);
        ldims.fill(1);
        gdims.fill(1);
        std::copy(local_dims.begin(), local_dims.end(), ldims.begin());
        std::copy(global_dims.begin(), global_dims.end(), gdims.begin());

        kernel_module = name;
#if defined(HSACOO) || defined(HIPRTC)
            auto status   = hipModuleGetFunction(&fun, program.GetModule(), kernel_module.c_str());
            if(hipSuccess != status)
                RPP_THROW_HIP_STATUS(status,
                                    "Failed to get function: " + kernel_module + " from " +
                                        program.GetBinary().string());
#endif

    }

    HIPOCKernelInvoke Invoke(hipStream_t stream,
                             std::function<void(hipEvent_t, hipEvent_t)> callback = nullptr);
};

} // namespace rpp

#endif
