/*
 * SPDX-FileCopyrightText: Copyright (c) 2022-2024 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.
 */

#include "tensorrt_llm/batch_manager/GptManager.h"
#include "tensorrt_llm/batch_manager/inferenceRequest.h"
#include "tensorrt_llm/batch_manager/namedTensor.h"
#include "tensorrt_llm/common/assert.h"
#include "tensorrt_llm/common/logger.h"
#include "tensorrt_llm/common/mpiUtils.h"
#include "tensorrt_llm/common/stringUtils.h"
#include "tensorrt_llm/executor/executor.h"
#include "tensorrt_llm/plugins/api/tllmPlugin.h"
#include "tensorrt_llm/runtime/common.h"
#include "tensorrt_llm/runtime/tllmLogger.h"
#include "tensorrt_llm/runtime/worldConfig.h"

#include <chrono>
#include <cstdint>
#include <cxxopts.hpp>
#include <iostream>
#include <nlohmann/json.hpp>
#include <string>
#include <thread>
#include <utility>

using namespace tensorrt_llm::batch_manager;
using namespace tensorrt_llm::runtime;

namespace tc = tensorrt_llm::common;
namespace texec = tensorrt_llm::executor;
namespace mpi = tensorrt_llm::mpi;
namespace trt = nvinfer1;

namespace
{

struct BenchmarkParams
{
    std::optional<SizeType> maxTokensInPagedKvCache = std::nullopt;
    std::optional<float> freeGpuMemoryFraction = std::nullopt;
    bool enableTrtOverlap = false;
    bool enableBlockReuse = false;
    bool enableChunkedContext = false;
    bool streaming = false;
};
} // namespace

// Class holding all infos regarding a single work item.
// This includes the original request, associated response factor
// and state.
class WorkItem
{
public:
    WorkItem(std::shared_ptr<InferenceRequest> inferenceRequest, uint64_t requestId)
        : mInferenceRequest(std::move(inferenceRequest))
        , mRequestId(requestId)
    {
    }

    [[nodiscard]] uint64_t requestId() const
    {
        return mRequestId;
    }

    [[nodiscard]] std::shared_ptr<InferenceRequest> getInferenceRequest() const
    {
        return mInferenceRequest;
    }

private:
    std::shared_ptr<InferenceRequest> mInferenceRequest;
    uint64_t mRequestId;
};

/// @brief Thread-safe queue of work items
class WorkItemsQueue
{
public:
    void clear()
    {
        std::lock_guard<std::mutex> lock(mMutex);
        mPendingWorkItems.clear();
        mPendingWorkItemsReqIds.clear();
        mInProgressWorkItems.clear();
    }

    // Note: this function only be called under a lock
    bool hasInProgressReqId(const uint64_t reqId) const
    {
        return (mInProgressWorkItems.find(reqId) != mInProgressWorkItems.end());
    }

    // Note: this function only be called under a lock
    bool hasPendingReqId(const uint64_t reqId) const
    {
        return (mPendingWorkItemsReqIds.find(reqId) != mPendingWorkItemsReqIds.end());
    }

    bool empty() const
    {
        return mPendingWorkItems.empty() && mInProgressWorkItems.empty() && mPendingWorkItemsReqIds.empty();
    }

    /// @brief Add a new work item to the queue
    /// Throws an error if requestId already exists

    void push(std::shared_ptr<InferenceRequest> request, uint64_t requestId)
    {
        std::lock_guard<std::mutex> lock(mMutex);
        TLLM_CHECK_WITH_INFO(!hasInProgressReqId(requestId) && !hasPendingReqId(requestId),
            "requestId %lu is already in progress, request is ignored.", requestId);

        auto workItem = std::make_shared<WorkItem>(request, requestId);
        mPendingWorkItems.push_back(workItem);
        mPendingWorkItemsReqIds.insert(workItem->requestId());
    }

    /// @brief Get a new work item from the queue, and move it to the list of
    /// in progress work items if it hasn't been stopped
    /// @return A tuple of the workItem and a boolean flag indicating if the work item
    /// has been marked in progress
    std::tuple<std::shared_ptr<WorkItem>, bool> pop()
    {
        std::lock_guard<std::mutex> lock(mMutex);

        auto workItem = mPendingWorkItems.front();
        mPendingWorkItems.pop_front();
        mPendingWorkItemsReqIds.erase(workItem->requestId());

        bool markedInProgress = false;
        mInProgressWorkItems.emplace(workItem->requestId(), workItem);
        markedInProgress = true;

        return {workItem, markedInProgress};
    }

    size_t numPendingWorkItems() const
    {
        std::lock_guard<std::mutex> lock(mMutex);
        return mPendingWorkItems.size();
    }

    size_t numInProgressWorkItems() const
    {
        std::lock_guard<std::mutex> lock(mMutex);
        return mInProgressWorkItems.size();
    }

    size_t size() const
    {
        std::lock_guard<std::mutex> lock(mMutex);
        return mPendingWorkItems.size() + mInProgressWorkItems.size();
    }

    /// @brief  Mark a request as being finished
    /// @param requestId
    void markFinished(const uint64_t requestId)
    {
        std::lock_guard<std::mutex> lock(mMutex);
        if (hasInProgressReqId(requestId))
        {
            mInProgressWorkItems.erase(requestId);
        }
    }

private:
    /// Queue of work items
    std::list<std::shared_ptr<WorkItem>> mPendingWorkItems;
    /// requestIds of work items in the queue
    std::set<uint64_t> mPendingWorkItemsReqIds;

    /// work items currently in progress
    std::unordered_map<uint64_t, std::shared_ptr<WorkItem>> mInProgressWorkItems;

    mutable std::mutex mMutex;
};

struct BenchInfo
{
    BenchInfo() = default;

    BenchInfo(int _inputLength, int _outputLength, std::chrono::time_point<std::chrono::steady_clock> _start)
        : inputLength(_inputLength)
        , outputLength(_outputLength)
        , start(_start)
        , latency()
    {
    }

    int inputLength;
    int outputLength;
    std::chrono::time_point<std::chrono::steady_clock> start;
    std::chrono::time_point<std::chrono::steady_clock> end;
    float latency; // millisecond
};

class Recorder
{
public:
    explicit Recorder(std::string opCsvFile)
        : mOpCsvFile(std::move(opCsvFile))
    {
    }

    void initialize()
    {
        mStart = std::chrono::steady_clock::now();
    }

    void finalize()
    {
        mEnd = std::chrono::steady_clock::now();
    }

    void recordStart(std::shared_ptr<InferenceRequest> request, uint64_t requestId)
    {
        auto const inputLength = request->getInputIds()->getSize();
        auto const maxNewTokens = request->getMaxNewTokensNamed();
        auto const& outputLengthTensor = maxNewTokens.tensor;
        TLLM_CHECK_WITH_INFO(outputLengthTensor != nullptr && outputLengthTensor->getSize() > 0,
            "Undefined scalar vector for %s", maxNewTokens.name.c_str());
        auto const outputLength = *bufferCast<SizeType>(*outputLengthTensor);
        auto const start = std::chrono::steady_clock::now();
        mRequestBenchInfos[requestId] = BenchInfo(inputLength, outputLength, start);
    }

    void recordStart(SizeType inputLength, SizeType maxNewTokens, uint64_t requestId,
        std::chrono::time_point<std::chrono::steady_clock> const& start)
    {
        mRequestBenchInfos[requestId] = BenchInfo(inputLength, maxNewTokens, start);
    }

    void recordEnd(uint64_t requestId)
    {
        mRequestBenchInfos[requestId].end = std::chrono::steady_clock::now();
        mRequestBenchInfos[requestId].latency = std::chrono::duration<float, std::milli>(
            mRequestBenchInfos[requestId].end - mRequestBenchInfos[requestId].start)
                                                    .count();
    }

    void calculateMetrics()
    {
        mNumSamples = mRequestBenchInfos.size();
        mTotalLatency = std::chrono::duration<float, std::milli>(mEnd - mStart).count();
        mSeqThroughput = mNumSamples / (mTotalLatency / 1000);
        mAvgSeqLatency = 0;
        int totalOutputTokens = 0;
        for (auto reqInfo : mRequestBenchInfos)
        {
            mAvgSeqLatency += reqInfo.second.latency;
            totalOutputTokens += reqInfo.second.outputLength;
        }
        mAvgSeqLatency /= mNumSamples;
        mTokenThroughput = totalOutputTokens / (mTotalLatency / 1000);
    }

    void report()
    {
        printf("[BENCHMARK] num_samples %d\n", mNumSamples);
        printf("[BENCHMARK] total_latency(ms) %.2f\n", mTotalLatency);
        printf("[BENCHMARK] seq_throughput(seq/sec) %.2f\n", mSeqThroughput);
        printf("[BENCHMARK] avg_sequence_latency(ms) %.2f\n", mAvgSeqLatency);
        printf("[BENCHMARK] token_throughput(token/sec) %.2f\n", mTokenThroughput);
    }

    void writeOpMetricsToCsv()
    {
        if (!mOpCsvFile.empty())
        {
            std::vector<std::string> headers = {"num_samples", "total_latency(ms)", "seq_throughput(seq/sec)",
                "avg_sequence_latency(ms)", "token_throughput(token/sec)"};

            std::ofstream outputFile(mOpCsvFile);

            if (outputFile.is_open())
            {
                for (auto const& header : headers)
                {
                    outputFile << header << ",";
                }
                outputFile << "\n";
                outputFile << mNumSamples << "," << mTotalLatency << "," << mSeqThroughput << "," << mAvgSeqLatency
                           << "," << mTokenThroughput;
                outputFile << "\n";
            }
            else
            {
                std::cerr << "Error opening file '" << mOpCsvFile << "' for writing.\n";
            }
        }
    }

private:
    std::unordered_map<uint64_t, BenchInfo> mRequestBenchInfos;

    std::chrono::time_point<std::chrono::steady_clock> mStart;
    std::chrono::time_point<std::chrono::steady_clock> mEnd;
    int mNumSamples{};
    float mTotalLatency{};
    float mSeqThroughput{};
    float mAvgSeqLatency{};
    float mTokenThroughput{};
    std::string mOpCsvFile;
}; // class Recorder

class ExecutorServer
{
public:
    ExecutorServer(std::filesystem::path const& trtEnginePath, TrtGptModelType modelType, int32_t maxBeamWidth,
        batch_scheduler::SchedulerPolicy schedulerPolicy, BenchmarkParams const& benchmarkParams,
        std::shared_ptr<Recorder> recorder, std::chrono::milliseconds waitSleep,
        std::optional<uint64_t> const staticEmulatedBatchSize, bool logIterationData)
        : mRecorder(std::move(recorder))
        , mWaitSleep(waitSleep)
        , mStaticEmulatedBatchSize(staticEmulatedBatchSize)
        , mActiveCount(0)
    {

        texec::SchedulerConfig schedulerConfig(batch_scheduler::batchManagerToExecSchedPolicy(schedulerPolicy));
        texec::KvCacheConfig kvCacheConfig(benchmarkParams.enableBlockReuse, benchmarkParams.maxTokensInPagedKvCache,
            std::nullopt, std::nullopt, benchmarkParams.freeGpuMemoryFraction, false);
        texec::ExecutorConfig executorConfig(maxBeamWidth, schedulerConfig, kvCacheConfig,
            benchmarkParams.enableChunkedContext, true, benchmarkParams.enableTrtOverlap);

        mExecutor = std::make_shared<texec::Executor>(trtEnginePath, texec::ModelType::kDECODER_ONLY, executorConfig);
    }

    void enqueue(std::vector<texec::Request> requests, bool warmup = false)
    {
        try
        {
            std::vector<SizeType> inputLengths;
            std::vector<SizeType> maxNewTokens;
            for (auto const& request : requests)
            {
                inputLengths.push_back(request.getInputTokenIds().size());
                maxNewTokens.push_back(request.getMaxNewTokens());
            }
            auto const start = std::chrono::steady_clock::now();
            auto reqIds = mExecutor->enqueueRequests(std::move(requests));
            for (int req = 0; req < reqIds.size(); ++req)
            {
                if (!warmup)
                {
                    mRecorder->recordStart(inputLengths.at(req), maxNewTokens.at(req), reqIds.at(req), start);
                }
                mActiveCount++;
            }
        }
        catch (std::exception const& e)
        {
            TLLM_THROW("%s", e.what());
        }
    }

    void waitForResponses(std::optional<SizeType> numRequests, bool warmup = false)
    {
        SizeType numFinished = 0;
        while (mActiveCount || (numRequests && numFinished < numRequests.value()))
        {
            auto responses = mExecutor->awaitResponses(std::nullopt, mWaitSleep);
            for (auto const& response : responses)
            {
                if (response.hasError())
                {
                    // This request failed for some reason, get error msg
                    std::string errStr = "Request id " + std::to_string(response.getRequestId()) + " failed with err "
                        + response.getErrorMsg();
                    TLLM_THROW(errStr);
                }
                else if (response.getResult().isFinal)
                {
                    auto reqId = response.getRequestId();
                    mActiveCount--;
                    numFinished++;
                    if (!warmup)
                    {
                        mRecorder->recordEnd(reqId);
                    }
                }
            }
        }
    }

    void shutdown()
    {
        mExecutor->shutdown();
    }

private:
    std::shared_ptr<texec::Executor> mExecutor;
    std::shared_ptr<Recorder> mRecorder;
    std::chrono::milliseconds mWaitSleep;
    std::optional<int> mStaticEmulatedBatchSize;
    std::atomic<uint64_t> mActiveCount;
}; // class ExecutorServer

class GptServer
{
public:
    GptServer(std::filesystem::path const& trtEnginePath, TrtGptModelType modelType, SizeType maxBeamWidth,
        batch_scheduler::SchedulerPolicy schedulerPolicy, TrtGptModelOptionalParams const& optionalParams,
        std::shared_ptr<Recorder> recorder, std::optional<uint64_t> terminateReqId, std::chrono::milliseconds waitSleep,
        std::optional<SizeType> const staticEmulatedBatchSize,
        std::optional<std::chrono::milliseconds> const batchTimeout, bool logIterationData)
        : mRecorder(std::move(recorder))
        , mTerminateReqId(terminateReqId)
        , mWaitSleep(waitSleep)
        , mStaticEmulatedBatchSize(staticEmulatedBatchSize)
        , mBatchTimeout(batchTimeout.value_or(std::chrono::milliseconds{0}))
        , mActiveCount(0)
    {
        ReturnBatchManagerStatsCallback iterationDataCallback = [this, logIterationData](std::string const& log)
        {
            if (logIterationData)
            {
                TLLM_LOG_INFO(log);
            }

            if (mStaticEmulatedBatchSize)
            {
                auto const json = nlohmann::json::parse(log);
                auto const activeRequests = json["Active Request Count"];
                TLLM_CHECK(activeRequests <= mStaticEmulatedBatchSize.value());
            }
        };

        mBatchManager = std::make_shared<GptManager>(
            trtEnginePath, modelType, maxBeamWidth, schedulerPolicy,
            [this](int max_num_requests) { return getInferenceRequests(max_num_requests); },
            [this](uint64_t requestId, std::list<NamedTensor> const& response_tensors, bool final_response,
                std::string const& errMsg)
            { return sendResponse(requestId, response_tensors, final_response, errMsg); },
            nullptr, iterationDataCallback, optionalParams, terminateReqId);
    }

    ~GptServer()
    {
        mWorkItemsQueue.clear();
    }

    void enqueue(std::shared_ptr<InferenceRequest> const& request)
    {
        TLLM_CHECK(request != nullptr);
        auto const requestId = request->getRequestId();
        if (requestId == mTerminateReqId)
        {
            mWorkItemsQueue.push(request, requestId);
            return;
        }

        // Enqueue
        try
        {
            mRecorder->recordStart(request, requestId);
            mWorkItemsQueue.push(request, requestId);
        }
        catch (tc::TllmException const& e)
        {
            throw;
        }
        catch (std::exception const& e)
        {
            TLLM_THROW("%s", e.what());
        }
    }

    void resetBatchDeadline()
    {
        mBatchDeadline = (std::chrono::steady_clock::now() + mBatchTimeout).time_since_epoch();
    }

    void waitForEmpty() const
    {
        while (!mWorkItemsQueue.empty())
        {
            std::this_thread::sleep_for(mWaitSleep);
        }
    }

    void waitBatchManager() const
    {
        mBatchManager->waitUntilTerminate();
    }

    void shutdown() const
    {
        mBatchManager->shutdown();
    }

    // Return up to max_num_requests inference requests.
    std::list<std::shared_ptr<InferenceRequest>> getInferenceRequests(int const max_num_requests)
    {
        std::list<std::shared_ptr<InferenceRequest>> inferenceRequests;
        auto& comm = COMM_SESSION;
        if (max_num_requests > 0)
        {
            auto world_size = comm.getSize();
            auto rank = comm.getRank();
            if (rank == 0)
            {
                auto const numNewWorkItems = std::min(static_cast<int64_t>(mWorkItemsQueue.numPendingWorkItems()),
                    static_cast<int64_t>(max_num_requests));

                bool const timeout = std::chrono::steady_clock::now().time_since_epoch() > mBatchDeadline.load();
                bool readyForNextBatch = numNewWorkItems > 0 && timeout;
                if (mStaticEmulatedBatchSize)
                {
                    if (numNewWorkItems > 0)
                    {
                        bool const previousBatchFinished = mActiveCount == 0;
                        bool const haveEnoughForNextBatch = numNewWorkItems >= mStaticEmulatedBatchSize.value();
                        readyForNextBatch = previousBatchFinished && (timeout || haveEnoughForNextBatch);
                    }
                    if (numNewWorkItems == 0 || readyForNextBatch)
                    {
                        // Timeout should only begin once we have at least 1 pending request.
                        // Reset timeout when no requests are pending or we submit a new batch.
                        resetBatchDeadline();
                    }
                }

                if (readyForNextBatch)
                {
                    // Only add a single batch at a time when emulating static batching
                    auto const numItemsToAdd = std::min(
                        numNewWorkItems, static_cast<int64_t>(mStaticEmulatedBatchSize.value_or(numNewWorkItems)));
                    mActiveCount += numItemsToAdd;
                    while (inferenceRequests.size() < numItemsToAdd)
                    {
                        auto [workItem, markedInProgress] = mWorkItemsQueue.pop();

                        if (markedInProgress)
                        {
                            inferenceRequests.emplace_back(workItem->getInferenceRequest());
                        }
                        else
                        {
                            auto warnStr = tc::fmtstr(
                                "request Id %lu has been stopped. Request is ignored.", workItem->requestId());
                            TLLM_LOG_WARNING(warnStr);
                            sendResponse(workItem->requestId(), {}, true, warnStr);
                        }
                    }
                }
                if (world_size > 1)
                {
                    auto numNewWorkItems = static_cast<int64_t>(inferenceRequests.size());
                    comm.bcast(&numNewWorkItems, 1, mpi::MpiType::kINT64, 0);
                    if (numNewWorkItems > 0)
                    {
                        std::vector<int64_t> packed;
                        for (auto const& infReq : inferenceRequests)
                        {
                            auto vpacked = infReq->serialize();
                            packed.push_back(static_cast<int64_t>(vpacked.size()));
                            packed.insert(
                                packed.end(), std::move_iterator(vpacked.begin()), std::move_iterator(vpacked.end()));
                        }
                        comm.bcast(packed, 0);
                    }
                }
            }
            else
            {
                // subordinate ranks hang until master rank sends work
                int64_t numNewWorkItems = 0;
                comm.bcast(&numNewWorkItems, 1, mpi::MpiType::kINT64, 0);
                if (numNewWorkItems > 0)
                {
                    std::vector<int64_t> packed;
                    comm.bcast(packed, 0);
                    int64_t* packed_ptr = packed.data();
                    for (int64_t count = 0; count < numNewWorkItems; ++count)
                    {
                        int64_t n = *(packed_ptr++);
                        auto infReq = InferenceRequest::deserialize(packed_ptr);
                        packed_ptr += n;
                        inferenceRequests.emplace_back(infReq);
                    }
                }
            }
        }
        return inferenceRequests;
    }

    void sendResponse(uint64_t requestId, [[maybe_unused]] std::list<NamedTensor> const& response_tensors,
        bool final_response, [[maybe_unused]] std::string const& errMsg)
    {
        // `response_tensors` contains `outputIds, sequenceLength, [contextLogits, generationLogits], logProbs,
        // cumLogProbs`. `contextLogits, generationLogits` are optional, only contained when `gather_context_logits` and
        // `gather_generation_logits` are enabled respectively. Or enable 'gather_all_token_logits' to enable both of
        // them.
        try
        {
            if (final_response)
            {
                mWorkItemsQueue.markFinished(requestId);
                mRecorder->recordEnd(requestId);
                mActiveCount--;
            }
        }
        catch (std::exception const& e)
        {
            TLLM_LOG_ERROR("Failed to send response for requestId %lu\n%s", requestId, e.what());
        }
    }

private:
    std::shared_ptr<GptManager> mBatchManager;
    std::shared_ptr<Recorder> mRecorder;
    WorkItemsQueue mWorkItemsQueue;
    std::optional<uint64_t> mTerminateReqId;
    std::chrono::milliseconds mWaitSleep;
    std::optional<SizeType> mStaticEmulatedBatchSize;
    std::chrono::milliseconds mBatchTimeout;
    std::atomic<std::chrono::steady_clock::time_point::duration> mBatchDeadline;
    std::atomic<uint64_t> mActiveCount;

}; // class GptServer

namespace
{

struct Sample
{
    std::vector<int32_t> inputIds;
    int32_t outputLen;
    float delay;
};

using Samples = std::vector<Sample>;

Samples parseWorkloadJson(std::filesystem::path const& datasetPath, int maxNumSamples)
{
    auto constexpr allowExceptions = true;
    auto constexpr ignoreComments = true;
    TLLM_CHECK_WITH_INFO(std::filesystem::exists(datasetPath), "File does not exist: %s", datasetPath.c_str());
    std::ifstream jsonStream(datasetPath);
    auto json = nlohmann::json::parse(jsonStream, nullptr, allowExceptions, ignoreComments);

    Samples samples;

    for (auto const& sample : json["samples"])
    {
        if (samples.size() >= maxNumSamples)
            break;
        samples.emplace_back(Sample{sample["input_ids"], sample["output_len"], sample["delay"]});
    }
    return samples;
}

std::shared_ptr<InferenceRequest> makeRequest(std::uint64_t reqId, Sample const& sample,
    ITensor::SharedPtr const& beamWidthTensor, ITensor::SharedPtr const& eosId, ITensor::SharedPtr const& padId,
    BufferManager const& bufferManager, ITensor::SharedPtr const& returnContextLogits = nullptr,
    ITensor::SharedPtr const& returnGenerationLogits = nullptr)
{
    auto request = std::make_shared<InferenceRequest>(reqId);
    auto const& inputIds = sample.inputIds;
    request->setInputIds(bufferManager.copyFrom(
        inputIds, ITensor::makeShape({static_cast<SizeType>(inputIds.size())}), MemoryType::kCPU));
    auto const requestOutputLen = sample.outputLen;
    request->setMaxNewTokens(bufferManager.copyFrom(&requestOutputLen, ITensor::makeShape({1, 1}), MemoryType::kCPU));
    request->setBeamWidth(beamWidthTensor);
    if (eosId != nullptr)
    {
        request->setEndId(eosId);
    }
    if (padId != nullptr)
    {
        request->setPadId(padId);
    }
    if (returnContextLogits)
    {
        request->setReturnContextLogits(returnContextLogits);
    }
    if (returnGenerationLogits)
    {
        request->setReturnGenerationLogits(returnGenerationLogits);
    }
    return request;
}

texec::Request makeExecutorRequest(Sample const& sample, SizeType const& beamWidth,
    std::optional<SizeType> const& eosId, std::optional<SizeType> const& padId, bool streaming = false,
    bool const& returnContextLogits = false, bool const& returnGenerationLogits = false)
{
    auto samplingConfig = texec::SamplingConfig{beamWidth};
    auto outputConfig = texec::OutputConfig{false, returnContextLogits, returnGenerationLogits, false};
    return {sample.inputIds, sample.outputLen, streaming, samplingConfig, outputConfig, eosId, padId};
}

void benchmarkGptManager(std::filesystem::path const& engineDir, TrtGptModelType modelType,
    std::string const& datasetPath, std::string const& opCsvFile, int maxNumSamples, int beamWidth, int warmUp,
    std::optional<TokenIdType> const& eosId, std::optional<TokenIdType> const& padId,
    BenchmarkParams const& benchmarkParams, batch_scheduler::SchedulerPolicy schedulerPolicy,
    std::chrono::milliseconds waitSleep, bool returnContextLogits, bool returnGenerationLogits,
    std::optional<SizeType> const staticEmulatedBatchSize, std::optional<std::chrono::milliseconds> const batchTimeout,
    bool logIterationData)
{
    auto const worldConfig = WorldConfig::mpi();

    TrtGptModelOptionalParams optionalParams;

    if (benchmarkParams.maxTokensInPagedKvCache)
    {
        optionalParams.kvCacheConfig.maxTokens = benchmarkParams.maxTokensInPagedKvCache;
    }
    if (benchmarkParams.freeGpuMemoryFraction)
    {
        optionalParams.kvCacheConfig.freeGpuMemoryFraction = benchmarkParams.freeGpuMemoryFraction;
    }
    optionalParams.kvCacheConfig.enableBlockReuse = benchmarkParams.enableBlockReuse;
    optionalParams.enableChunkedContext = benchmarkParams.enableChunkedContext;
    optionalParams.enableTrtOverlap = benchmarkParams.enableTrtOverlap;

    BufferManager bufferManager{std::make_shared<CudaStream>()}; // the stream is not used

    ITensor::SharedPtr beamWidthTensor{
        bufferManager.copyFrom(&beamWidth, ITensor::makeShape({1}), MemoryType::kPINNED)};

    // Load dataset
    auto const samples = parseWorkloadJson(datasetPath, maxNumSamples);
    auto const numSamples = samples.size();

    int const maxBeamWidth = beamWidth;
    auto recorder = std::make_shared<Recorder>(opCsvFile);
    uint64_t terminateReqId = numSamples + 1;
    auto gptServer = std::make_shared<GptServer>(engineDir, modelType, maxBeamWidth, schedulerPolicy, optionalParams,
        recorder, terminateReqId, waitSleep, staticEmulatedBatchSize, batchTimeout, logIterationData);

    ITensor::SharedPtr eosIdTensor{
        eosId ? bufferManager.copyFrom(&eosId.value(), ITensor::makeShape({1}), MemoryType::kPINNED) : nullptr};
    ITensor::SharedPtr padIdTensor{
        padId ? bufferManager.copyFrom(&padId.value(), ITensor::makeShape({1}), MemoryType::kPINNED) : nullptr};

    ITensor::SharedPtr returnContextLogitsFlagTensor{returnContextLogits
            ? bufferManager.copyFrom(&returnContextLogits, ITensor::makeShape({1}), MemoryType::kPINNED)
            : nullptr};

    ITensor::SharedPtr returnGenerationLogitsFlagTensor{returnGenerationLogits
            ? bufferManager.copyFrom(&returnGenerationLogits, ITensor::makeShape({1}), MemoryType::kPINNED)
            : nullptr};

    if (worldConfig.getRank() == 0)
    {
        // Warm up
        gptServer->resetBatchDeadline();
        SizeType reqId = 0;
        for (auto i = 0; i < warmUp; ++i)
        {
            ++reqId;
            if (i == terminateReqId)
                ++reqId;
            auto request = makeRequest(reqId, samples[0], beamWidthTensor, eosIdTensor, padIdTensor, bufferManager);
            gptServer->enqueue(request);
        }
        gptServer->waitForEmpty();

        // Benchmark
        recorder->initialize();
        gptServer->resetBatchDeadline();
        for (std::size_t i = 0; i < numSamples; ++i)
        {
            auto request = makeRequest(i + 1, samples[i], beamWidthTensor, eosIdTensor, padIdTensor, bufferManager,
                returnContextLogitsFlagTensor, returnGenerationLogitsFlagTensor);
            gptServer->enqueue(request);
            auto delayInMs = static_cast<int>(samples[i].delay * 1000);

            if (delayInMs != 0)
            {
                std::chrono::milliseconds delay(delayInMs);
                std::this_thread::sleep_for(delay);
            }
        }
        gptServer->waitForEmpty();
        recorder->finalize();
        recorder->calculateMetrics();
        recorder->report();
        recorder->writeOpMetricsToCsv();
        // Send terminateReqId to terminate servers on all ranks
        // Server on rank 0 will broadcast the terminate signal to other servers on multi-GPU cases
        gptServer->enqueue(std::make_shared<InferenceRequest>(terminateReqId));
    }
    // Wait until benchmarking is done and batch manager is terminated
    gptServer->waitBatchManager();
}

void benchmarkExecutor(std::filesystem::path const& engineDir, TrtGptModelType modelType,
    std::string const& datasetPath, std::string const& opCsvFile, int maxNumSamples, int beamWidth, int warmUp,
    std::optional<int32_t> const& eosId, std::optional<int32_t> const& padId, BenchmarkParams const& benchmarkParams,
    batch_scheduler::SchedulerPolicy schedulerPolicy, std::chrono::milliseconds waitSleep, bool returnContextLogits,
    bool returnGenerationLogits, std::optional<int> const staticEmulatedBatchSize, bool logIterationData)
{
    auto const& world = tensorrt_llm::mpi::MpiComm::world();
    auto worldRank = world.getRank();

    // Load dataset
    auto const samples = parseWorkloadJson(datasetPath, maxNumSamples);
    auto const numSamples = samples.size();

    auto recorder = std::make_shared<Recorder>(opCsvFile);

    auto executorServer = std::make_shared<ExecutorServer>(engineDir, modelType, beamWidth, schedulerPolicy,
        benchmarkParams, recorder, waitSleep, staticEmulatedBatchSize, logIterationData);

    if (worldRank == 0)
    {
        // Warm up
        {
            std::vector<texec::Request> requests;
            for (auto i = 0; i < warmUp; ++i)
            {
                requests.emplace_back(makeExecutorRequest(samples[0], beamWidth, eosId, padId,
                    benchmarkParams.streaming, returnContextLogits, returnGenerationLogits));
            }
            executorServer->enqueue(std::move(requests), true);
            executorServer->waitForResponses(warmUp, true);
        }

        // Benchmark
        {
            // Create requests
            recorder->initialize();
            std::vector<texec::Request> requests;
            std::vector<int> delays;
            for (std::size_t i = 0; i < numSamples; ++i)
            {
                requests.emplace_back(makeExecutorRequest(samples[i], beamWidth, eosId, padId,
                    benchmarkParams.streaming, returnContextLogits, returnGenerationLogits));
                delays.push_back(static_cast<int>(samples[i].delay * 1000));
            }

            bool hasDelay = std::any_of(delays.begin(), delays.end(), [](auto const& delay) { return delay > 0; });
            if (hasDelay && staticEmulatedBatchSize)
            {
                TLLM_THROW("Executor benchmark doesn't support delays with emulated static batch sizes");
            }

            if (!hasDelay)
            {
                if (!staticEmulatedBatchSize)
                {
                    executorServer->enqueue(std::move(requests));
                    executorServer->waitForResponses(numSamples);
                }
                else
                {
                    SizeType numRequests = requests.size();
                    SizeType maxBatchSize = staticEmulatedBatchSize.value();
                    for (SizeType req = 0; req < numRequests; req += maxBatchSize)
                    {
                        auto batchSize = std::min(maxBatchSize, numRequests - req);

                        std::vector<texec::Request> requestsBatch(std::make_move_iterator(requests.begin() + req),
                            std::make_move_iterator(requests.begin() + req + batchSize));
                        // Enqueue in batches
                        executorServer->enqueue(std::move(requestsBatch));
                        // Wait for current batch to be done
                        executorServer->waitForResponses(batchSize);
                    }
                }
            }
            else
            {
                // Launch a thread that will wait for responses
                std::thread waitThread(
                    [numSamples, executorServer]() { executorServer->waitForResponses(numSamples); });
                // Enqueue requests one by one
                for (std::size_t i = 0; i < numSamples; ++i)
                {
                    executorServer->enqueue({std::move(requests.at(i))});
                    std::this_thread::sleep_for(std::chrono::milliseconds(delays.at(i)));
                }
                waitThread.join();
            }
        }
        recorder->finalize();
        recorder->calculateMetrics();
        recorder->report();
        recorder->writeOpMetricsToCsv();
        // Send terminateReqId to terminate servers on all ranks
        // Sever on rank 0 will broadcast the terminate signal to other servers on multi-GPU cases
        // gptServer->enqueue(std::make_shared<InferenceRequest>(terminateReqId));
    }
}

} // namespace

int main(int argc, char* argv[])
{
    cxxopts::Options options(
        "TensorRT-LLM BatchManager Benchmark", "TensorRT-LLM BatchManager Benchmark for GPT and GPT-like models.");
    options.add_options()("h,help", "Print usage");
    options.add_options()("engine_dir", "Directory that store the engines.", cxxopts::value<std::string>());
    options.add_options()(
        "api", "API type: gptManager or executor.", cxxopts::value<std::string>()->default_value("gptManager"));
    options.add_options()(
        "type", "Batching type: IFB or V1(non-IFB) batching.", cxxopts::value<std::string>()->default_value("IFB"));
    options.add_options()("dataset", "Dataset that is used for benchmarking BatchManager.",
        cxxopts::value<std::string>()->default_value(""));
    options.add_options()(
        "output_csv", "Write output metrics to CSV", cxxopts::value<std::string>()->default_value(""));
    options.add_options()("max_num_samples", "maximum number of samples to use from dataset/generate",
        cxxopts::value<int>()->default_value("100000"));
    options.add_options()(
        "beam_width", "Specify beam width you want to benchmark.", cxxopts::value<int>()->default_value("1"));
    options.add_options()(
        "warm_up", "Specify warm up iterations before benchmark starts.", cxxopts::value<int>()->default_value("2"));
    options.add_options()(
        "eos_id", "Specify the end-of-sequence token id.", cxxopts::value<TokenIdType>()->default_value("-1"));
    options.add_options()("pad_id", "Specify the padding token id.", cxxopts::value<TokenIdType>());
    options.add_options()("max_tokens_in_paged_kvcache", "Max tokens in paged K-V Cache.", cxxopts::value<int>());
    options.add_options()(
        "kv_cache_free_gpu_mem_fraction", "K-V Cache Free Gpu Mem Fraction.", cxxopts::value<float>());
    options.add_options()("enable_trt_overlap", "Overlap TRT context preparation and execution",
        cxxopts::value<bool>()->default_value("false"));
    options.add_options()("streaming", "Operate in streaming mode", cxxopts::value<bool>()->default_value("false"));
    options.add_options()(
        "enable_kv_cache_reuse", "Enables the KV cache reuse.", cxxopts::value<bool>()->default_value("false"));
    options.add_options()("enable_chunked_context", "Whether to enable context chunking.",
        cxxopts::value<bool>()->default_value("false"));
    options.add_options()(
        "return_context_logits", "Whether to return context logits.", cxxopts::value<bool>()->default_value("false"));
    options.add_options()("return_generation_logits", "Whether to return generation logits.",
        cxxopts::value<bool>()->default_value("false"));

    options.add_options()("scheduler_policy", "Choose scheduler policy between max_utilization/guaranteed_no_evict.",
        cxxopts::value<std::string>()->default_value("guaranteed_no_evict"));

    options.add_options()("first_batch_delay",
        "Delay before submitting the first batch of requests. This can be used to increase the size of the first "
        "batch.",
        cxxopts::value<int32_t>());
    options.add_options()("static_emulated_batch_size",
        "Emulate static batching performance with the provided batch size.", cxxopts::value<SizeType>());
    options.add_options()("static_emulated_timeout",
        "Timeout (ms) before launching a partial batch in emulated static batching mode",
        cxxopts::value<int32_t>()->default_value("500"));
    options.add_options()("log_level", "Choose log level between verbose/info/warning/error/internal_error.",
        cxxopts::value<std::string>()->default_value("error"));
    options.add_options()("log_iteration_data", "On each decoder iteration, print batch state metadata.",
        cxxopts::value<bool>()->default_value("false"));
    options.add_options()("wait_sleep", "Specify how many milliseconds to sleep each iteration of waitForEmpty loop.",
        cxxopts::value<int>()->default_value("25"));

    auto result = options.parse(argc, argv);

    if (result.count("help"))
    {
        std::cout << options.help() << std::endl;
        return 0;
    }

    // Argument: Engine directory
    if (!result.count("engine_dir"))
    {
        std::cout << options.help() << std::endl;
        TLLM_LOG_ERROR("Please specify engine directory.");
        return 1;
    }

    // Argument: API
    auto const api = result["api"].as<std::string>();

    // Argument: Batching Type
    auto const type = result["type"].as<std::string>();
    TrtGptModelType modelType{TrtGptModelType::V1};
    if (type == "V1")
    {
        modelType = TrtGptModelType::V1;
    }
    else if (type == "IFB")
    {
        modelType = TrtGptModelType::InflightFusedBatching;
    }
    else
    {
        TLLM_LOG_ERROR("Unexpected batching type: %s", type.c_str());
        return 1;
    }

    // Argument: Dataset
    auto const datasetPath = result["dataset"].as<std::string>();
    auto const maxNumSamples = result["max_num_samples"].as<int>();

    // Argument: Output metrics CSV
    auto const opCsvFile = result["output_csv"].as<std::string>();

    // Argument: beam width
    auto const beamWidth = result["beam_width"].as<int>();

    // Argument: wait_sleep
    auto const waitSleep = std::chrono::milliseconds(result["wait_sleep"].as<int>());
    BenchmarkParams benchmarkParams;

    // Argument: Max tokens in paged K-V Cache
    if (result.count("max_tokens_in_paged_kvcache"))
    {
        benchmarkParams.maxTokensInPagedKvCache = result["max_tokens_in_paged_kvcache"].as<int>();
    }
    // Argument: K-V Cache Free Gpu Mem Fraction
    if (result.count("kv_cache_free_gpu_mem_fraction"))
    {
        benchmarkParams.freeGpuMemoryFraction = result["kv_cache_free_gpu_mem_fraction"].as<float>();
    }
    // Argument: Enable TRT overlap
    benchmarkParams.enableTrtOverlap = result["enable_trt_overlap"].as<bool>();

    // Argument: Enable KV cache reuse
    benchmarkParams.enableBlockReuse = result["enable_kv_cache_reuse"].as<bool>();

    // Argument: streaming
    benchmarkParams.streaming = result["streaming"].as<bool>();

    // Argument: Enable batch stats output
    bool logIterationData = result["log_iteration_data"].as<bool>();

    // Argument: Enable chunked context
    benchmarkParams.enableChunkedContext = result["enable_chunked_context"].as<bool>();

    // Argument: Enable return context logits
    bool returnContextLogits = result["return_context_logits"].as<bool>();

    // Argument: Enable return context logits
    bool returnGenerationLogits = result["return_generation_logits"].as<bool>();

    std::optional<TokenIdType> padId;
    // Argument: Padding token id
    if (result.count("pad_id"))
    {
        padId = result["pad_id"].as<TokenIdType>();
    }

    // Argument: End-of-sentence token id
    std::optional<TokenIdType> eosId = result["eos_id"].as<TokenIdType>();

    std::optional<std::chrono::milliseconds> batchTimeout;
    // Argument: first_batch_delay
    if (result.count("first_batch_delay"))
    {
        batchTimeout = std::chrono::milliseconds{result["first_batch_delay"].as<int32_t>()};
    }

    std::optional<SizeType> staticEmulatedBatchSize;
    // Argument: Static emulated batch size
    if (result.count("static_emulated_batch_size"))
    {
        staticEmulatedBatchSize = result["static_emulated_batch_size"].as<SizeType>();

        batchTimeout = std::chrono::milliseconds{result["static_emulated_timeout"].as<int32_t>()};
    }

    // Argument: Scheduler policy
    batch_scheduler::SchedulerPolicy schedulerPolicy;
    auto const schedulerPolicyArg = result["scheduler_policy"].as<std::string>();
    if (schedulerPolicyArg == "max_utilization")
    {
        schedulerPolicy = batch_scheduler::SchedulerPolicy::MAX_UTILIZATION;
    }
    else if (schedulerPolicyArg == "guaranteed_no_evict")
    {
        schedulerPolicy = batch_scheduler::SchedulerPolicy::GUARANTEED_NO_EVICT;
    }
    else
    {
        TLLM_LOG_ERROR("Unexpected scheduler policy: " + schedulerPolicyArg);
        return 1;
    }

    // Argument: Log level
    auto logger = std::make_shared<TllmLogger>();
    auto const logLevel = result["log_level"].as<std::string>();
    if (logLevel == "verbose")
    {
        logger->setLevel(trt::ILogger::Severity::kVERBOSE);
    }
    else if (logLevel == "info")
    {
        logger->setLevel(trt::ILogger::Severity::kINFO);
    }
    else if (logLevel == "warning")
    {
        logger->setLevel(trt::ILogger::Severity::kWARNING);
    }
    else if (logLevel == "error")
    {
        logger->setLevel(trt::ILogger::Severity::kERROR);
    }
    else if (logLevel == "internal_error")
    {
        logger->setLevel(trt::ILogger::Severity::kINTERNAL_ERROR);
    }
    else
    {
        TLLM_LOG_ERROR("Unexpected log level: " + logLevel);
        return 1;
    }

    initTrtLlmPlugins(logger.get());

    if (api == "gptManager")
    {
        try
        {
            benchmarkGptManager(result["engine_dir"].as<std::string>(), modelType, datasetPath, opCsvFile,
                maxNumSamples, beamWidth, result["warm_up"].as<int>(), eosId, padId, benchmarkParams, schedulerPolicy,
                waitSleep, returnContextLogits, returnGenerationLogits, staticEmulatedBatchSize, batchTimeout,
                logIterationData);
        }
        catch (std::exception const& e)
        {
            TLLM_LOG_ERROR(e.what());
            return 1;
        }
    }
    else if (api == "executor")
    {
        try
        {
            benchmarkExecutor(result["engine_dir"].as<std::string>(), modelType, datasetPath, opCsvFile, maxNumSamples,
                beamWidth, result["warm_up"].as<int>(), eosId, padId, benchmarkParams, schedulerPolicy, waitSleep,
                returnContextLogits, returnGenerationLogits, staticEmulatedBatchSize, logIterationData);
        }
        catch (std::exception const& e)
        {
            TLLM_LOG_ERROR(e.what());
            return 1;
        }
    }
    else
    {
        TLLM_LOG_ERROR("api parameter must be gptManager or executor");
        return 1;
    }

    return 0;
}