/*
 * SPDX-FileCopyrightText: Copyright (c) 1993-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * SPDX-License-Identifier: Apache-2.0
 *
 * 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.
 */

#ifndef TRT_SELECTIVE_SCAN_PLUGIN_H
#define TRT_SELECTIVE_SCAN_PLUGIN_H
#include "tensorrt_llm/kernels/selectiveScan.h"
#include "tensorrt_llm/plugins/common/plugin.h"
#include <cassert>

namespace tensorrt_llm::plugins
{
// batch_size = num_ctx_requests or num_gen_requests
// num_ctx_requests = number of context requests (single sequence per request).
// num_gen_requests = number of generation requests (single sequences per request).
// can not support beam search

// inputs
//     0.  input_tensor [batch_size, dim, seq_len]
//     1.  state [batch_size, dim, dstate]
//     2.  delta [batch_size, dim, seq_len]
//     3.  delta_bias [dim]
//     4.  A [dim, seq_len]
//     5.  B [batch_size, dstate, seq_len]
//     6.  C [batch_size, dstate, seq_len]
//     7.  D [dim]
//     8.  z [batch_size, dim, seq_len]
//     9.  host_request_types [batch_size] int32. 0: context; 1: generation; 2: none.
// outputs
//     0. output_tensor [batch_size, dim, seq_len]
//     1. state [batch_size, dim, dstate]

class SelectiveScanPlugin : public BasePlugin
{
public:
    SelectiveScanPlugin(
        int dim, int dstate, bool isVariableB, bool isVariableC, bool deltaSoftplus, nvinfer1::DataType type);

    SelectiveScanPlugin(const void* data, size_t length);

    ~SelectiveScanPlugin() override = default;

    // IPluginV2DynamicExt Methods
    nvinfer1::IPluginV2DynamicExt* clone() const noexcept override;
    nvinfer1::DimsExprs getOutputDimensions(int outputIndex, const nvinfer1::DimsExprs* inputs, int nbInputs,
        nvinfer1::IExprBuilder& exprBuilder) noexcept override;
    bool supportsFormatCombination(
        int pos, const nvinfer1::PluginTensorDesc* inOut, int nbInputs, int nbOutputs) noexcept override;
    void configurePlugin(const nvinfer1::DynamicPluginTensorDesc* in, int nbInputs,
        const nvinfer1::DynamicPluginTensorDesc* out, int nbOutputs) noexcept override;
    size_t getWorkspaceSize(const nvinfer1::PluginTensorDesc* inputs, int nbInputs,
        const nvinfer1::PluginTensorDesc* outputs, int nbOutputs) const noexcept override;
    int enqueue(const nvinfer1::PluginTensorDesc* inputDesc, const nvinfer1::PluginTensorDesc* outputDesc,
        const void* const* inputs, void* const* outputs, void* workspace, cudaStream_t stream) noexcept override;
    template <typename T>
    int enqueueImpl(const nvinfer1::PluginTensorDesc* inputDesc, const nvinfer1::PluginTensorDesc* outputDesc,
        const void* const* inputs, void* const* outputs, void* workspace, cudaStream_t stream);

    // IPluginV2Ext Methods
    nvinfer1::DataType getOutputDataType(
        int index, const nvinfer1::DataType* inputTypes, int nbInputs) const noexcept override;

    // IPluginV2 Methods
    const char* getPluginType() const noexcept override;
    const char* getPluginVersion() const noexcept override;
    int getNbOutputs() const noexcept override;
    int initialize() noexcept override;
    void terminate() noexcept override;
    size_t getSerializationSize() const noexcept override;
    void serialize(void* buffer) const noexcept override;
    void destroy() noexcept override;

    enum class RequestType : int32_t
    {
        kCONTEXT = 0,
        kGENERATION = 1
    };

private:
    using IndexType = std::int32_t;

    IndexType getInputTensorIdx() const
    {
        return 0;
    };

    IndexType getStateIdx() const
    {
        return 1;
    };

    IndexType getDeltaIdx() const
    {
        return 2;
    };

    IndexType getDeltaBiasIdx() const
    {
        return 3;
    };

    IndexType getAIdx() const
    {
        return 4;
    };

    IndexType getBIdx() const
    {
        return 5;
    };

    IndexType getCIdx() const
    {
        return 6;
    };

    IndexType getDIdx() const
    {
        return 7;
    };

    IndexType getZIdx() const
    {
        return 8;
    };

    IndexType getHostRequestTypesIdx() const
    {
        return 9;
    };

    void setSSMParams(tensorrt_llm::kernels::SSMParamsBase& params,
        // sizes
        const size_t batch, const size_t dim, const size_t seqLen, const size_t dstate, const size_t nChunks,
        const bool isVariableB, const bool isVariableC,
        // device pointers
        void* statePtr, const void* x, const void* delta, const void* deltaBias, const void* A, const void* B,
        const void* C, const void* D, const void* z, void* out,
        // strides
        const size_t strideXBatch, const size_t strideDtBatch, const size_t strideADim, const size_t strideBBatch,
        const size_t strideCBatch, const size_t strideZBatch, const size_t strideOutBatch,
        const size_t strideStateBatch, const size_t strideStateDim, bool deltaSoftplus);

private:
    int mDim;
    int mDState;
    bool mIsVariableB;
    bool mIsVariableC;
    bool mDeltaSoftplus;
    nvinfer1::DataType mType;
};

class SelectiveScanPluginCreator : public BaseCreator
{
public:
    SelectiveScanPluginCreator();

    const char* getPluginName() const noexcept override;

    const char* getPluginVersion() const noexcept override;

    const nvinfer1::PluginFieldCollection* getFieldNames() noexcept override;

    nvinfer1::IPluginV2* createPlugin(const char* name, const nvinfer1::PluginFieldCollection* fc) noexcept override;

    nvinfer1::IPluginV2* deserializePlugin(
        const char* name, const void* serialData, size_t serialLength) noexcept override;

private:
    static nvinfer1::PluginFieldCollection mFC;
    static std::vector<nvinfer1::PluginField> mPluginAttributes;
};

} // namespace tensorrt_llm::plugins

#endif // TRT_SELECTIVE_SCAN_PLUGIN_H