/*
 * Copyright (c) 2020-2023, NVIDIA CORPORATION.  All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// Ignore CUTLASS warnings about type punning
#ifdef __GNUC__ // Check if the compiler is GCC or Clang
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
#endif

#include "cutlass/array.h"
#include "cutlass/numeric_conversion.h"

#include "cutlass/gemm/device/gemm_grouped.h"
#include "cutlass/gemm/kernel/default_gemm_grouped.h"

#include "cutlass/cutlass.h"

#include "cute/tensor.hpp"

#include "cutlass/epilogue/collective/collective_builder.hpp"
#include "cutlass/epilogue/collective/default_epilogue.hpp"
#include "cutlass/epilogue/thread/linear_combination.h"
#include "cutlass/gemm/collective/collective_builder.hpp"
#include "cutlass/gemm/device/gemm_universal_adapter.h"
#include "cutlass/gemm/dispatch_policy.hpp"
#include "cutlass/gemm/group_array_problem_shape.hpp"
#include "cutlass/gemm/kernel/gemm_universal.hpp"
#include "cutlass/tensor_ref.h"

#include "cutlass_extensions/compute_occupancy.h"
#include "cutlass_extensions/epilogue_helpers.h"
#include "cutlass_extensions/gemm/kernel/default_fpA_intB_traits.h"
#include "cutlass_extensions/gemm/kernel/moe_cutlass_kernel.h"
#include "cutlass_extensions/gemm/threadblock/default_mma.h"

#ifdef __GNUC__ // Check if the compiler is GCC or Clang
#pragma GCC diagnostic pop
#endif

#include "tensorrt_llm/common/assert.h"
#include "tensorrt_llm/common/cudaUtils.h"
#include "tensorrt_llm/kernels/cutlass_kernels/cutlass_heuristic.h"
#include "tensorrt_llm/kernels/cutlass_kernels/cutlass_type_conversion.h"

#include "../include/moe_gemm_kernels.h"
#include "./launchers/moe_gemm_tma_ws_launcher.h"
#include "./moe_tma_warp_specialized_traits.h"

#include <cuda.h>
#include <cuda_fp16.h>
#include <math.h>
#include <sstream>

namespace tensorrt_llm::kernels::cutlass_kernels
{
using EpilogueFusion = TmaWarpSpecializedGroupedGemmInput::EpilogueFusion;

template <typename Arch, typename T, typename WeightType, typename OutputType, typename EpilogueTag,
    EpilogueFusion FUSION, typename TileShape, typename ClusterShape>
void dispatchMoeGemmSelectBiasTmaWarpSpecialized(TmaWarpSpecializedGroupedGemmInput hopper_input, int num_experts,
    int multi_processor_count, cudaStream_t stream, int* occupancy, size_t* workspace_size)
{
    static_assert((Arch::kMinComputeCapability == 90
                      && kernels::cutlass_kernels::isValidHopperMOESpecialisation<T, WeightType, EpilogueTag>())
            || (Arch::kMinComputeCapability >= 100
                && kernels::cutlass_kernels::isValidBlackwellMOESpecialisation<T, WeightType, EpilogueTag>()),
        "Invalid TMA WS configuration invoked, fallback to Sm80");

    TLLM_CHECK_WITH_INFO(
        workspace_size || hopper_input.isValid(), "Hopper specialisation is missing additional input information");

    //            auto func = hopper_input.ptr_c ?
    //            kernels::cutlass_kernels::genericMoeGemmKernelLauncherHopper<T, WeightType,
    //                            cutlass::arch::Sm90, EpilogueTag, true>
    //                                           :
    //                                           kernels::cutlass_kernels::genericMoeGemmKernelLauncherHopper<T,
    //                                           WeightType,
    //                                               cutlass::arch::Sm90, EpilogueTag, false>;
    // TODO Re-enable bias when CUTLASS supports it

    if constexpr (Arch::kMinComputeCapability < 90)
    {
        TLLM_THROW("Invalid architecture instantiated");
    }
#ifndef COMPILE_HOPPER_TMA_GROUPED_GEMMS
    else if constexpr (Arch::kMinComputeCapability >= 90 && Arch::kMinComputeCapability < 100)
    {
        TLLM_THROW("Please recompile with support for hopper by passing 90-real as an arch to build_wheel.py.");
    }
#endif
#ifndef COMPILE_BLACKWELL_TMA_GROUPED_GEMMS
    else if constexpr (Arch::kMinComputeCapability >= 100 && Arch::kMinComputeCapability < 120)
    {
        TLLM_THROW("Please recompile with support for blackwell by passing 100-real as an arch to build_wheel.py.");
    }
#endif
#ifndef COMPILE_BLACKWELL_SM120_TMA_GROUPED_GEMMS
    else if constexpr (Arch::kMinComputeCapability >= 120)
    {
        TLLM_THROW("Please recompile with support for blackwell by passing 120-real as an arch to build_wheel.py.");
    }
#endif
    else
    {
        auto getFunc = [&]()
        {
            if constexpr (std::is_same_v<T, __nv_fp8_e4m3> && std::is_same_v<WeightType, __nv_fp4_e2m1>)
            {
                TLLM_CHECK_WITH_INFO(hopper_input.fpX_block_scaling_type
                        == TmaWarpSpecializedGroupedGemmInput::FpXBlockScalingType::MXFPX,
                    "MXFPX is the only supported scaling type for WFP4AFP8");
                return &kernels::cutlass_kernels::tma_warp_specialized_generic_moe_gemm_kernelLauncher<Arch, T,
                    WeightType, OutputType, EpilogueTag, FUSION, TileShape, ClusterShape, true, false>;
            }
            else
            {
                TLLM_CHECK_WITH_INFO(hopper_input.fpX_block_scaling_type
                        != TmaWarpSpecializedGroupedGemmInput::FpXBlockScalingType::MXFPX,
                    "MXFPX is not supported for the selected weight combination");
                return &kernels::cutlass_kernels::tma_warp_specialized_generic_moe_gemm_kernelLauncher<Arch, T,
                    WeightType, OutputType, EpilogueTag, FUSION, TileShape, ClusterShape, false, false>;
            }
        };
        getFunc()(hopper_input, num_experts, multi_processor_count, stream, occupancy, workspace_size);
    }
}

template <typename ClusterTileShape, typename ClusterShape, typename DataType, typename WeightType>
constexpr bool are_tile_shapes_supported_sm100()
{
    using namespace cute;
    using CtaShape = decltype(shape_div(ClusterTileShape{}, ClusterShape{}));
    // This is the epilogue shape. The MMA shape will be twice this for 2SM
    constexpr auto TileM = size<0>(CtaShape{});
    constexpr auto TileN = size<1>(CtaShape{});

    if constexpr (TileM != 64 && TileM != 128)
    {
        return false;
    }

#ifdef ENABLE_FP4
    if constexpr (std::is_same_v<DataType, __nv_fp4_e2m1> || std::is_same_v<WeightType, __nv_fp4_e2m1>)
    {
        // if (TileN % 64 != 0 || TileN < 128)
        // {
        //     return false;
        // }
        if ((TileN != 64 && TileN != 128) || TileM != 128)
        {
            return false;
        }
    }
#endif

    if constexpr (std::is_same_v<DataType, __nv_fp8_e4m3>)
    {
        if constexpr ((TileN == 16 || TileN == 8) && cute::size<0>(ClusterShape{}) == 1
            && cute::size<1>(ClusterShape{}) == 1)
        {
            return true;
        }
    }

    if constexpr (TileN % 32 != 0 || TileN < 32 || TileN > 256)
    {
        return false;
    }

    if constexpr (cute::size<0>(ClusterShape{}) % 2 == 0 && TileN % 64 != 0)
    {
        return false;
    }

    return true;
}

template <typename ClusterTileShape, typename ClusterShape, typename DataType>
constexpr bool are_tile_shapes_supported_sm120()
{
    using namespace cute;
    if constexpr (cute::size<0>(ClusterShape{}) != 1 || cute::size<1>(ClusterShape{}) != 1
        || cute::size<2>(ClusterShape{}) != 1)
    {
        return false;
    }
    using CtaShape = decltype(shape_div(ClusterTileShape{}, ClusterShape{}));
    // This is the epilogue shape. The MMA shape will be twice this for 2SM
    constexpr auto TileM = size<0>(CtaShape{});
    constexpr auto TileN = size<1>(CtaShape{});
    constexpr auto TileK = size<2>(CtaShape{});

    return (TileM == 128 && TileN == 128 && TileK == 128) || (TileM == 128 && TileN == 128 && TileK == 256)
        || (TileM == 128 && TileN == 256 && TileK == 128) || (TileM == 256 && TileN == 128 && TileK == 128);
}

/*
    1x1x1 cluster shape is are supported for any tile shape.

    2x1x1 cluster shape is only supported for when the M tile is at least 128.

    1x2x1 cluster shape is only supported when the N tile is at least 128.

    2x2x1 cluster shape is only supported when both the M and N tiles are at least 128.

    We make the above restrictions are to improve compilation speed in TRT-LLM by pruning kernels
    that may not be very useful in practice.
 */
template <typename Arch, typename CTAShape, typename ClusterShape, typename DataType, typename WeightType>
constexpr bool are_tile_shapes_supported()
{
    if constexpr (Arch::kMinComputeCapability >= 100 && Arch::kMinComputeCapability < 120)
    {
        return are_tile_shapes_supported_sm100<CTAShape, ClusterShape, DataType, WeightType>();
    }
    else if constexpr (Arch::kMinComputeCapability == 120)
    {
        return are_tile_shapes_supported_sm120<CTAShape, ClusterShape, DataType>();
    }

    using namespace cute;
    [[maybe_unused]] constexpr int cta_m = get<0>(CTAShape{});
    [[maybe_unused]] constexpr int cta_n = get<1>(CTAShape{});
    constexpr int cga_m = get<0>(ClusterShape{});
    constexpr int cga_n = get<1>(ClusterShape{});

    if constexpr (cga_m == _1{} && cga_n == _1{})
    {
        return true;
    }
    else if constexpr (cga_m == _2{} && cga_n == _1{} && cta_m >= _128{})
    {
        return true;
    }
    else if constexpr (cga_m == _1{} && cga_n == _2{} && cta_n >= _128{})
    {
        return true;
    }
    else if constexpr (cga_m == _2{} && cga_n == _2{} && cta_m >= _128{} && cta_n >= _128{})
    {
        return true;
    }
    else
    {
        return false;
    }
}

template <typename Arch, typename T, typename WeightType, typename OutputType, typename EpilogueTag,
    EpilogueFusion FUSION, typename TileShape>
void dispatchMoeGemmSelectClusterShapeTmaWarpSpecialized(TmaWarpSpecializedGroupedGemmInput hopper_input,
    int num_experts, cutlass_extensions::CutlassGemmConfig gemm_config, int multi_processor_count, cudaStream_t stream,
    int* occupancy, size_t* workspace_size)
{
    using namespace cute;
    switch (gemm_config.cluster_shape)
    {
#define SHAPE_CASE(M, N, K)                                                                                            \
    case cutlass_extensions::ClusterShape::ClusterShape_##M##x##N##x##K:                                               \
    {                                                                                                                  \
        using ClusterShape = Shape<_##M, _##N, _##K>;                                                                  \
        if constexpr (are_tile_shapes_supported<Arch, TileShape, ClusterShape, T, WeightType>())                       \
        {                                                                                                              \
            dispatchMoeGemmSelectBiasTmaWarpSpecialized<Arch, T, WeightType, OutputType, EpilogueTag, FUSION,          \
                TileShape, ClusterShape>(                                                                              \
                hopper_input, num_experts, multi_processor_count, stream, occupancy, workspace_size);                  \
            break;                                                                                                     \
        }                                                                                                              \
        else                                                                                                           \
        {                                                                                                              \
            TLLM_THROW(                                                                                                \
                "%s\nUnsupported tile (%d, %d, %d) and cluster (%d, %d, %d) shape combination for arch %d.\nConfig "   \
                "was %s",                                                                                              \
                __PRETTY_FUNCTION__, (int) cute::get<0>(TileShape{}), (int) cute::get<1>(TileShape{}),                 \
                (int) cute::get<2>(TileShape{}), M, N, K, (int) Arch::kMinComputeCapability,                           \
                gemm_config.toString().c_str());                                                                       \
        }                                                                                                              \
    }

        SHAPE_CASE(1, 1, 1)
        SHAPE_CASE(1, 2, 1)

        SHAPE_CASE(2, 1, 1)
        SHAPE_CASE(2, 2, 1)

#undef SHAPE_CASE
    default: TLLM_THROW("Unsupported config %d for MoE gemm.", (int) gemm_config.cluster_shape);
    }
} // namespace tensorrt_llm

template <typename T, typename WeightType, typename OutputType, typename EpilogueTag, EpilogueFusion FUSION>
void dispatchMoeGemmSelectTileShapeTmaWarpSpecialized(TmaWarpSpecializedGroupedGemmInput hopper_input, int num_experts,
    cutlass_extensions::CutlassGemmConfig gemm_config, int multi_processor_count, cudaStream_t stream, int* occupancy,
    size_t* workspace_size)
{
    using namespace cute;

#define SHAPE_CASE(SMVERSION, M, N, K)                                                                                 \
    case cutlass_extensions::CutlassTileConfigSM##SMVERSION::CtaShape##M##x##N##x##K##B:                               \
    {                                                                                                                  \
        constexpr int KtileBytes = (K * 8)                                                                             \
            / cutlass::sizeof_bits<typename kernels::cutlass_kernels::TllmToCutlassTypeAdapter<T>::type>::value;       \
        using KTileDim = Int<KtileBytes>;                                                                              \
        using TileShape = Shape<_##M, _##N, KTileDim>;                                                                 \
        dispatchMoeGemmSelectClusterShapeTmaWarpSpecialized<cutlass::arch::Sm##SMVERSION, T, WeightType, OutputType,   \
            EpilogueTag, FUSION, TileShape>(                                                                           \
            hopper_input, num_experts, gemm_config, multi_processor_count, stream, occupancy, workspace_size);         \
        break;                                                                                                         \
    }
#define DEFAULT_CASE(SMVERSION)                                                                                        \
    case cutlass_extensions::CutlassTileConfigSM##SMVERSION::Undefined: TLLM_THROW("GEMM config undefined."); break;   \
    case cutlass_extensions::CutlassTileConfigSM##SMVERSION::ChooseWithHeuristic:                                      \
        TLLM_THROW("GEMM config should have already been set by heuristic.");                                          \
        break;                                                                                                         \
    default: TLLM_THROW("Unsupported config %d for MoE gemm.", (int) gemm_config.tile_config_sm##SMVERSION); break;

    if (gemm_config.sm_version == 90)
    {
        if constexpr (kernels::cutlass_kernels::isValidHopperMOESpecialisation<T, WeightType, EpilogueTag, FUSION>())
        {
            switch (gemm_config.tile_config_sm90)
            {
                SHAPE_CASE(90, 128, 16, 128)
                SHAPE_CASE(90, 128, 32, 128)
                SHAPE_CASE(90, 128, 64, 128)
                SHAPE_CASE(90, 128, 128, 128)
                SHAPE_CASE(90, 128, 256, 128)
                SHAPE_CASE(90, 256, 128, 128)
                DEFAULT_CASE(90)
            }
        }
        else
        {
            TLLM_THROW("Unsupported SM90 configuration requested");
        }
    }
    else if (gemm_config.sm_version >= 100 && gemm_config.sm_version < 120)
    {
        if constexpr (kernels::cutlass_kernels::isValidBlackwellMOESpecialisation<T, WeightType, EpilogueTag, FUSION>())
        {
            switch (gemm_config.tile_config_sm100)
            {
                SHAPE_CASE(100, 64, 64, 128)
                SHAPE_CASE(100, 64, 128, 128)
                SHAPE_CASE(100, 64, 256, 128)

                SHAPE_CASE(100, 128, 16, 128)
                SHAPE_CASE(100, 128, 32, 128)
                SHAPE_CASE(100, 128, 64, 128)
                SHAPE_CASE(100, 128, 128, 128)
                SHAPE_CASE(100, 128, 256, 128)

                SHAPE_CASE(100, 256, 64, 128)
                SHAPE_CASE(100, 256, 128, 128)
                SHAPE_CASE(100, 256, 256, 128)

                // SHAPE_CASE(100, 128, 128, 64)
                // SHAPE_CASE(100, 128, 256, 64)
                // SHAPE_CASE(100, 256, 256, 64)
                DEFAULT_CASE(100)
            }
        }
        else
        {
            TLLM_THROW("Unsupported SM100 configuration requested");
        }
    }
    else if (gemm_config.sm_version == 120)
    {
        TLLM_LOG_TRACE("At %s, SM120 config=%d", __PRETTY_FUNCTION__, (int) gemm_config.tile_config_sm120);
        if constexpr (kernels::cutlass_kernels::isValidSM120MOESpecialisation<T, WeightType, EpilogueTag, FUSION>())
        {
            switch (gemm_config.tile_config_sm120)
            {
                SHAPE_CASE(120, 128, 128, 64)
                SHAPE_CASE(120, 128, 128, 128)
                SHAPE_CASE(120, 128, 256, 64)
                SHAPE_CASE(120, 256, 128, 64)
                DEFAULT_CASE(120)
            }
        }
    }
#undef SHAPE_CASE
}

template <typename T, typename WeightType, typename OutputType, EpilogueFusion FUSION>
size_t calcMaxWorkspaceSizeTmaWarpSpecialized(int num_experts, cutlass_extensions::CutlassGemmConfig gemm_config,
    int multi_processor_count, TmaWarpSpecializedGroupedGemmInput::FpXBlockScalingType fpX_block_scaling_type)
{
    size_t count = 0;
    TmaWarpSpecializedGroupedGemmInput input{};
    input.fpX_block_scaling_type = fpX_block_scaling_type;
    // Most of the values are ignored for WS size calculation. We reuse the function to reduce the template bloat
    dispatchMoeGemmSelectTileShapeTmaWarpSpecialized<T, WeightType, OutputType, cutlass_extensions::EpilogueOpDefault,
        FUSION>(input, num_experts, gemm_config, multi_processor_count, cudaStream_t{0}, nullptr, &count);
    return count;
}

} // namespace tensorrt_llm::kernels::cutlass_kernels
