// Copyright (c) 2017-2025 Advanced Micro Devices, Inc. All rights reserved.
//
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// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
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//
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
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// THE SOFTWARE.

#include <gtest/gtest.h>
#include <stdio.h>

#include <cmath>
#include <type_traits>
#include <vector>

#include <hip/hip_runtime.h>

#include <rocrand/rocrand.h>
#include <rocrand/rocrand_kernel.h>

#include "test_common.hpp"
#include "test_rocrand_common.hpp"

template<class GeneratorState>
__global__
void rocrand_init_kernel(GeneratorState*    states,
                         const size_t       states_size,
                         unsigned long long seed,
                         unsigned long long offset)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int subsequence = state_id;
    if(state_id < states_size)
    {
        GeneratorState state;
        rocrand_init(seed, subsequence, offset, &state);
        states[state_id] = state;
    }
}

template<class GeneratorState>
__global__
void rocrand_kernel(unsigned int* output, const size_t size)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int global_size = gridDim.x * blockDim.x;

    GeneratorState     state;
    const unsigned int subsequence = state_id;
    rocrand_init(0, subsequence, 123ULL, &state);

    unsigned int index = state_id;
    while(index < size)
    {
        output[index] = rocrand(&state);
        index += global_size;
    }
}

template<class GeneratorState>
__global__
void rocrand_uniform_kernel(float* output, const size_t size)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int global_size = gridDim.x * blockDim.x;

    GeneratorState     state;
    const unsigned int subsequence = state_id;
    rocrand_init(0, subsequence, 234ULL, &state);

    unsigned int index = state_id;
    while(index < size)
    {
        output[index] = rocrand_uniform(&state);
        index += global_size;
    }
}

template<class GeneratorState>
__global__
void rocrand_normal_kernel(float* output, const size_t size)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int global_size = gridDim.x * blockDim.x;

    GeneratorState     state;
    const unsigned int subsequence = state_id;
    rocrand_init(0, subsequence, 345ULL, &state);

    unsigned int index = state_id;
    while(index < size)
    {
        if(index % 3 == 0)
            output[index] = rocrand_normal2(&state).x;
        else if(index % 3 == 1)
            output[index] = rocrand_normal2(&state).y;
        else
            output[index] = rocrand_normal(&state);
        index += global_size;
    }
}

template<class GeneratorState>
__global__
void rocrand_log_normal_kernel(float* output, const size_t size)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int global_size = gridDim.x * blockDim.x;

    GeneratorState     state;
    const unsigned int subsequence = state_id;
    rocrand_init(0, subsequence, 456ULL, &state);

    unsigned int index = state_id;
    while(index < size)
    {
        if(index % 3 == 0)
            output[index] = rocrand_log_normal2(&state, 1.6f, 0.25f).x;
        else if(index % 3 == 1)
            output[index] = rocrand_log_normal2(&state, 1.6f, 0.25f).y;
        else
            output[index] = rocrand_log_normal(&state, 1.6f, 0.25f);
        index += global_size;
    }
}

template<class GeneratorState>
__global__
void rocrand_poisson_kernel(unsigned int* output, const size_t size, double lambda)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int global_size = gridDim.x * blockDim.x;

    GeneratorState     state;
    const unsigned int subsequence = state_id;
    rocrand_init(0, subsequence, 234ULL, &state);

    unsigned int index = state_id;
    while(index < size)
    {
        output[index] = rocrand_poisson(&state, lambda);
        index += global_size;
    }
}

template<class GeneratorState>
__global__
void rocrand_discrete_kernel(unsigned int*                 output,
                             const size_t                  size,
                             rocrand_discrete_distribution discrete_distribution)
{
    const unsigned int state_id    = blockIdx.x * blockDim.x + threadIdx.x;
    const unsigned int global_size = gridDim.x * blockDim.x;

    GeneratorState     state;
    const unsigned int subsequence = state_id;
    rocrand_init(0, subsequence, 234ULL, &state);

    unsigned int index = state_id;
    while(index < size)
    {
        output[index] = rocrand_discrete(&state, discrete_distribution);
        index += global_size;
    }
}

TEST(rocrand_kernel_xorwow, rocrand_state_xorwow_type)
{
    typedef rocrand_state_xorwow state_type;
    EXPECT_EQ(sizeof(state_type), 10 * sizeof(unsigned int));
    EXPECT_EQ(sizeof(state_type[32]), 32 * sizeof(rocrand_state_xorwow));
    EXPECT_TRUE(std::is_trivially_copyable<state_type>::value);
    EXPECT_TRUE(std::is_trivially_destructible<state_type>::value);
}

TEST(rocrand_kernel_xorwow, rocrand_init)
{
    // Just get access to internal state
    class rocrand_state_xorwow_test : public rocrand_state_xorwow
    {
        typedef rocrand_state_xorwow::xorwow_state internal_state_type;

    public:
        rocrand_state_xorwow_test() {}

        internal_state_type internal_state() const
        {
            return m_state;
        }
    };

    typedef rocrand_state_xorwow      state_type;
    typedef rocrand_state_xorwow_test state_type_test;

    unsigned long long seed   = 0xdeadbeefbeefdeadULL;
    unsigned long long offset = 345678ULL;

    const size_t states_size = 256;
    state_type*  states;
    HIP_CHECK(hipMallocHelper(&states, states_size * sizeof(state_type)));
    HIP_CHECK(hipDeviceSynchronize());

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_init_kernel),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       states,
                       states_size,
                       seed,
                       offset);
    HIP_CHECK(hipGetLastError());

    std::vector<state_type_test> states_host(states_size);
    HIP_CHECK(hipMemcpy(states_host.data(),
                        states,
                        states_size * sizeof(state_type),
                        hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(states));

    for(size_t si = 1; si < states_size; si++)
    {
        auto s0 = states_host[si - 1].internal_state();
        auto s1 = states_host[si].internal_state();
        EXPECT_NE(s0.x[0], s1.x[0]);
        EXPECT_NE(s0.x[1], s1.x[1]);
        EXPECT_NE(s0.x[2], s1.x[2]);
        EXPECT_NE(s0.x[3], s1.x[3]);
        EXPECT_NE(s0.x[4], s1.x[4]);

        // same values because d depends on seed and offset, but not subsequence
        EXPECT_EQ(s0.d, s1.d);
    }
}

TEST(rocrand_kernel_xorwow, rocrand)
{
    typedef rocrand_state_xorwow state_type;

    const size_t  output_size = 8192;
    unsigned int* output;
    HIP_CHECK(hipMallocHelper(&output, output_size * sizeof(unsigned int)));
    HIP_CHECK(hipDeviceSynchronize());

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_kernel<state_type>),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       output,
                       output_size);
    HIP_CHECK(hipGetLastError());

    std::vector<unsigned int> output_host(output_size);
    HIP_CHECK(hipMemcpy(output_host.data(),
                        output,
                        output_size * sizeof(unsigned int),
                        hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(output));

    double mean = 0;
    for(auto v : output_host)
    {
        mean += static_cast<double>(v) / UINT_MAX;
    }
    mean = mean / output_size;
    EXPECT_NEAR(mean, 0.5, 0.1);
}

TEST(rocrand_kernel_xorwow, rocrand_uniform)
{
    typedef rocrand_state_xorwow state_type;

    const size_t output_size = 8192;
    float*       output;
    HIP_CHECK(hipMallocHelper(&output, output_size * sizeof(float)));
    HIP_CHECK(hipDeviceSynchronize());

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_uniform_kernel<state_type>),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       output,
                       output_size);
    HIP_CHECK(hipGetLastError());

    std::vector<float> output_host(output_size);
    HIP_CHECK(
        hipMemcpy(output_host.data(), output, output_size * sizeof(float), hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(output));

    double mean = 0;
    for(auto v : output_host)
    {
        mean += static_cast<double>(v);
    }
    mean = mean / output_size;
    EXPECT_NEAR(mean, 0.5, 0.1);
}

TEST(rocrand_kernel_xorwow, rocrand_normal)
{
    typedef rocrand_state_xorwow state_type;

    const size_t output_size = 8192;
    float*       output;
    HIP_CHECK(hipMallocHelper(&output, output_size * sizeof(float)));
    HIP_CHECK(hipDeviceSynchronize());

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_normal_kernel<state_type>),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       output,
                       output_size);
    HIP_CHECK(hipGetLastError());

    std::vector<float> output_host(output_size);
    HIP_CHECK(
        hipMemcpy(output_host.data(), output, output_size * sizeof(float), hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(output));

    double mean = 0;
    for(auto v : output_host)
    {
        mean += static_cast<double>(v);
    }
    mean = mean / output_size;
    EXPECT_NEAR(mean, 0.0, 0.2);

    double stddev = 0;
    for(auto v : output_host)
    {
        stddev += std::pow(static_cast<double>(v) - mean, 2);
    }
    stddev = stddev / output_size;
    EXPECT_NEAR(stddev, 1.0, 0.2);
}

TEST(rocrand_kernel_xorwow, rocrand_log_normal)
{
    typedef rocrand_state_xorwow state_type;

    const size_t output_size = 8192;
    float*       output;
    HIP_CHECK(hipMallocHelper(&output, output_size * sizeof(float)));
    HIP_CHECK(hipDeviceSynchronize());

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_log_normal_kernel<state_type>),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       output,
                       output_size);
    HIP_CHECK(hipGetLastError());

    std::vector<float> output_host(output_size);
    HIP_CHECK(
        hipMemcpy(output_host.data(), output, output_size * sizeof(float), hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(output));

    double mean = 0;
    for(auto v : output_host)
    {
        mean += static_cast<double>(v);
    }
    mean = mean / output_size;

    double stddev = 0;
    for(auto v : output_host)
    {
        stddev += std::pow(v - mean, 2);
    }
    stddev = std::sqrt(stddev / output_size);

    double logmean = std::log(mean * mean / std::sqrt(stddev + mean * mean));
    double logstd  = std::sqrt(std::log(1.0f + stddev / (mean * mean)));

    EXPECT_NEAR(1.6, logmean, 1.6 * 0.2);
    EXPECT_NEAR(0.25, logstd, 0.25 * 0.2);
}

class rocrand_kernel_xorwow_poisson : public ::testing::TestWithParam<double>
{};

TEST_P(rocrand_kernel_xorwow_poisson, rocrand_poisson)
{
    typedef rocrand_state_xorwow state_type;

    const double lambda = GetParam();

    const size_t  output_size = 8192;
    unsigned int* output;
    HIP_CHECK(hipMallocHelper(&output, output_size * sizeof(unsigned int)));
    HIP_CHECK(hipDeviceSynchronize());

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_poisson_kernel<state_type>),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       output,
                       output_size,
                       lambda);
    HIP_CHECK(hipGetLastError());

    std::vector<unsigned int> output_host(output_size);
    HIP_CHECK(hipMemcpy(output_host.data(),
                        output,
                        output_size * sizeof(unsigned int),
                        hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(output));

    double mean = 0;
    for(auto v : output_host)
    {
        mean += static_cast<double>(v);
    }
    mean = mean / output_size;

    double variance = 0;
    for(auto v : output_host)
    {
        variance += std::pow(v - mean, 2);
    }
    variance = variance / output_size;

    EXPECT_NEAR(mean, lambda, std::max(1.0, lambda * 1e-1));
    EXPECT_NEAR(variance, lambda, std::max(1.0, lambda * 1e-1));
}

TEST_P(rocrand_kernel_xorwow_poisson, rocrand_discrete)
{
    typedef rocrand_state_xorwow state_type;

    const double lambda = GetParam();

    const size_t  output_size = 8192;
    unsigned int* output;
    HIP_CHECK(hipMallocHelper(&output, output_size * sizeof(unsigned int)));
    HIP_CHECK(hipDeviceSynchronize());

    rocrand_discrete_distribution discrete_distribution;
    ROCRAND_CHECK(rocrand_create_poisson_distribution(lambda, &discrete_distribution));

    hipLaunchKernelGGL(HIP_KERNEL_NAME(rocrand_discrete_kernel<state_type>),
                       dim3(4),
                       dim3(64),
                       0,
                       0,
                       output,
                       output_size,
                       discrete_distribution);
    HIP_CHECK(hipGetLastError());

    std::vector<unsigned int> output_host(output_size);
    HIP_CHECK(hipMemcpy(output_host.data(),
                        output,
                        output_size * sizeof(unsigned int),
                        hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());
    HIP_CHECK(hipFree(output));
    ROCRAND_CHECK(rocrand_destroy_discrete_distribution(discrete_distribution));

    double mean = 0;
    for(auto v : output_host)
    {
        mean += static_cast<double>(v);
    }
    mean = mean / output_size;

    double variance = 0;
    for(auto v : output_host)
    {
        variance += std::pow(v - mean, 2);
    }
    variance = variance / output_size;

    EXPECT_NEAR(mean, lambda, std::max(1.0, lambda * 1e-1));
    EXPECT_NEAR(variance, lambda, std::max(1.0, lambda * 1e-1));
}

const double lambdas[] = {1.0, 5.5, 20.0, 100.0, 1234.5, 5000.0};

INSTANTIATE_TEST_SUITE_P(rocrand_kernel_xorwow_poisson,
                         rocrand_kernel_xorwow_poisson,
                         ::testing::ValuesIn(lambdas));