// Copyright (c) 2017-2022 Advanced Micro Devices, Inc. All rights reserved.
//
// 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.

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

#include <hip/hip_runtime.h>
#include <rocrand/rocrand.h>

#include <rng/generator_type.hpp>
#include <rng/generators.hpp>

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

TEST(rocrand_xorwow_prng_tests, init_test)
{
    rocrand_xorwow generator; // offset = 0
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());

    generator.set_offset(1);
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());

    generator.set_offset(1337);
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());

    generator.set_offset(1048576);
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());

    generator.set_offset(1 << 24);
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());

    generator.set_offset(1 << 28);
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());

    generator.set_offset((1ULL << 36) + 1234567ULL);
    ROCRAND_CHECK(generator.init());
    HIP_CHECK(hipDeviceSynchronize());
}

TEST(rocrand_xorwow_prng_tests, uniform_uint_test)
{
    const size_t size = 1313;
    unsigned int * data;
    HIP_CHECK(hipMallocHelper(reinterpret_cast<void**>(&data), sizeof(unsigned int) * size));

    rocrand_xorwow g;
    ROCRAND_CHECK(g.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int host_data[size];
    HIP_CHECK(hipMemcpy(host_data, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned long long sum = 0;
    for(size_t i = 0; i < size; i++)
    {
        sum += host_data[i];
    }
    const unsigned int mean = sum / size;
    ASSERT_NEAR(mean, UINT_MAX / 2, UINT_MAX / 20);

    HIP_CHECK(hipFree(data));
}

TEST(rocrand_xorwow_prng_tests, uniform_float_test)
{
    const size_t size = 1313;
    float * data;
    hipMallocHelper(reinterpret_cast<void**>(&data), sizeof(float) * size);

    rocrand_xorwow g;
    ROCRAND_CHECK(g.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    float host_data[size];
    HIP_CHECK(hipMemcpy(host_data, data, sizeof(float) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    double sum = 0;
    for(size_t i = 0; i < size; i++)
    {
        ASSERT_GT(host_data[i], 0.0f);
        ASSERT_LE(host_data[i], 1.0f);
        sum += host_data[i];
    }
    const float mean = sum / size;
    ASSERT_NEAR(mean, 0.5f, 0.05f);

    HIP_CHECK(hipFree(data));
}

// Check if the numbers generated by first generate() call are different from
// the numbers generated by the 2nd call (same generator)
TEST(rocrand_xorwow_prng_tests, state_progress_test)
{
    // Device data
    const size_t size = 1025;
    unsigned int * data;
    HIP_CHECK(hipMallocHelper(reinterpret_cast<void**>(&data), sizeof(unsigned int) * size));

    // Generator
    rocrand_xorwow g0;

    // Generate using g0 and copy to host
    ROCRAND_CHECK(g0.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int host_data1[size];
    HIP_CHECK(hipMemcpy(host_data1, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    // Generate using g0 and copy to host
    ROCRAND_CHECK(g0.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int host_data2[size];
    HIP_CHECK(hipMemcpy(host_data2, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    size_t same = 0;
    for(size_t i = 0; i < size; i++)
    {
        if(host_data1[i] == host_data2[i]) same++;
    }
    // It may happen that numbers are the same, so we
    // just make sure that most of them are different.
    EXPECT_LT(same, static_cast<size_t>(0.01f * size));

    HIP_CHECK(hipFree(data));
}

// Checks if generators with the same seed and in the same state
// generate the same numbers
TEST(rocrand_xorwow_prng_tests, same_seed_test)
{
    const unsigned long long seed = 0xdeadbeefdeadbeefULL;

    // Device side data
    const size_t size = 1024;
    unsigned int * data;
    HIP_CHECK(hipMallocHelper(reinterpret_cast<void**>(&data), sizeof(unsigned int) * size));

    // Generators
    rocrand_xorwow g0, g1;
    // Set same seeds
    g0.set_seed(seed);
    g1.set_seed(seed);

    // Generate using g0 and copy to host
    ROCRAND_CHECK(g0.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int g0_host_data[size];
    HIP_CHECK(hipMemcpy(g0_host_data, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    // Generate using g1 and copy to host
    ROCRAND_CHECK(g1.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int g1_host_data[size];
    HIP_CHECK(hipMemcpy(g1_host_data, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    // Numbers generated using same generator with same
    // seed should be the same
    for(size_t i = 0; i < size; i++)
    {
        ASSERT_EQ(g0_host_data[i], g1_host_data[i]);
    }

    HIP_CHECK(hipFree(data));
}

// Checks if generators with the same seed and in the same state generate
// the same numbers
TEST(rocrand_xorwow_prng_tests, different_seed_test)
{
    const unsigned long long seed0 = 0xdeadbeefdeadbeefULL;
    const unsigned long long seed1 = 0xbeefdeadbeefdeadULL;

    // Device side data
    const size_t size = 1024;
    unsigned int * data;
    HIP_CHECK(hipMallocHelper(reinterpret_cast<void**>(&data), sizeof(unsigned int) * size));

    // Generators
    rocrand_xorwow g0, g1;
    // Set different seeds
    g0.set_seed(seed0);
    g1.set_seed(seed1);
    ASSERT_NE(g0.get_seed(), g1.get_seed());

    // Generate using g0 and copy to host
    ROCRAND_CHECK(g0.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int g0_host_data[size];
    HIP_CHECK(hipMemcpy(g0_host_data, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    // Generate using g1 and copy to host
    ROCRAND_CHECK(g1.generate(data, size));
    HIP_CHECK(hipDeviceSynchronize());

    unsigned int g1_host_data[size];
    HIP_CHECK(hipMemcpy(g1_host_data, data, sizeof(unsigned int) * size, hipMemcpyDeviceToHost));
    HIP_CHECK(hipDeviceSynchronize());

    size_t same = 0;
    for(size_t i = 0; i < size; i++)
    {
        if(g1_host_data[i] == g0_host_data[i]) same++;
    }
    // It may happen that numbers are the same, so we
    // just make sure that most of them are different.
    EXPECT_LT(same, static_cast<size_t>(0.01f * size));

    HIP_CHECK(hipFree(data));
}

TEST(rocrand_xorwow_prng_tests, discard_test)
{
    const unsigned long long seed = 1234567890123ULL;
    rocrand_xorwow::engine_type engine1(seed, 0, 678ULL);
    rocrand_xorwow::engine_type engine2(seed, 0, 677ULL);

    (void)engine2.next();

    EXPECT_EQ(engine1(), engine2());

    const unsigned long long ds[] = {
        1ULL, 4ULL, 37ULL, 583ULL, 7452ULL,
        21032ULL, 35678ULL, 66778ULL, 10313475ULL, 82120230ULL
    };

    for (auto d : ds)
    {
        for (unsigned long long i = 0; i < d; i++)
        {
            (void)engine1.next();
        }
        engine2.discard(d);

        EXPECT_EQ(engine1(), engine2());
    }
}

TEST(rocrand_xorwow_prng_tests, discard_sequence_test)
{
    const unsigned long long seed = ~1234567890123ULL;
    rocrand_xorwow::engine_type engine1(seed, 0, 444ULL);
    rocrand_xorwow::engine_type engine2(seed, 123ULL, 444ULL);

    engine1.discard_subsequence(123ULL);

    EXPECT_EQ(engine1(), engine2());

    engine1.discard( 5356446450ULL);
    engine1.discard_subsequence(123ULL);
    engine1.discard(30000000006ULL);

    engine2.discard_subsequence(3ULL);
    engine2.discard(35356446456ULL);
    engine2.discard_subsequence(120ULL);

    EXPECT_EQ(engine1(), engine2());

    engine1.discard_subsequence(3456000ULL);
    engine1.discard_subsequence(1000005ULL);

    engine2.discard_subsequence(4456005ULL);

    EXPECT_EQ(engine1(), engine2());
}

template <typename T>
class rocrand_xorwow_prng_offset : public ::testing::Test {
public:
  using output_type = T;
};

using RocrandXorwowPrngOffsetTypes = ::testing::Types<unsigned int, float>;
TYPED_TEST_SUITE(rocrand_xorwow_prng_offset, RocrandXorwowPrngOffsetTypes);

TYPED_TEST(rocrand_xorwow_prng_offset, offsets_test)
{
    using T = typename TestFixture::output_type;
    const size_t size = 131313;

    constexpr size_t offsets[] = { 0, 1, 11, 112233 };

    for(const auto offset : offsets)
    {
        const size_t size0 = size;
        const size_t size1 = (size + offset);
        T* data0;
        T* data1;
        hipMalloc(reinterpret_cast<void**>(&data0), sizeof(T) * size0);
        hipMalloc(reinterpret_cast<void**>(&data1), sizeof(T) * size1);

        rocrand_xorwow g0;
        g0.set_offset(offset);
        g0.generate(data0, size0);
    
        rocrand_xorwow g1;
        g1.generate(data1, size1);

        std::vector<T> host_data0(size0);
        std::vector<T> host_data1(size1);
        hipMemcpy(host_data0.data(), data0, sizeof(T) * size0, hipMemcpyDeviceToHost);
        hipMemcpy(host_data1.data(), data1, sizeof(T) * size1, hipMemcpyDeviceToHost);
        hipDeviceSynchronize();
    
        for(size_t i = 0; i < size; ++i)
        {
            ASSERT_EQ(host_data0[i], host_data1[i + offset]);
        }

        hipFree(data0);
        hipFree(data1);
    }
}

// Check that subsequent generations of different sizes produce one
// sequence without gaps, no matter how many values are generated per call.
template<typename T, typename GenerateFunc>
void continuity_test(GenerateFunc generate_func, unsigned int divisor = 1)
{
    std::vector<size_t> sizes0({ 100, 1, 24783, 3, 2, 776543 });
    std::vector<size_t> sizes1({ 1024, 55, 65536, 623456, 30, 111331 });
    if (divisor > 1)
    {
        for (size_t& s : sizes0) s = (s + divisor - 1) & ~static_cast<size_t>(divisor - 1);
        for (size_t& s : sizes1) s = (s + divisor - 1) & ~static_cast<size_t>(divisor - 1);
    }

    const auto size0 = std::accumulate(sizes0.cbegin(), sizes0.cend(), std::size_t{0});
    const auto size1 = std::accumulate(sizes1.cbegin(), sizes1.cend(), std::size_t{0});

    T * data0;
    T * data1;
    hipMalloc(reinterpret_cast<void**>(&data0), sizeof(T) * size0);
    hipMalloc(reinterpret_cast<void**>(&data1), sizeof(T) * size1);

    rocrand_xorwow g0;
    rocrand_xorwow g1;

    std::vector<T> host_data0(size0);
    std::vector<T> host_data1(size1);

    size_t current0 = 0;
    for (size_t s : sizes0)
    {
        generate_func(g0, data0, s);
        hipMemcpy(
            host_data0.data() + current0,
            data0,
            sizeof(T) * s, hipMemcpyDefault);
        current0 += s;
    }
    size_t current1 = 0;
    for (size_t s : sizes1)
    {
        generate_func(g1, data1, s);
        hipMemcpy(
            host_data1.data() + current1,
            data1,
            sizeof(T) * s, hipMemcpyDefault);
        current1 += s;
    }

    for(size_t i = 0; i < std::min(size0, size1); i++)
    {
        ASSERT_EQ(host_data0[i], host_data1[i]);
    }

    hipFree(data0);
    hipFree(data1);
}

TEST(rocrand_xorwow_prng_tests, continuity_uniform_uint_test)
{
    continuity_test<unsigned int>([](rocrand_xorwow& g, unsigned int * data, size_t s) { g.generate(data, s); });
}

TEST(rocrand_xorwow_prng_tests, continuity_uniform_char_test)
{
    continuity_test<unsigned char>([](rocrand_xorwow& g, unsigned char * data, size_t s) { g.generate(data, s); }, 4);
}

TEST(rocrand_xorwow_prng_tests, continuity_uniform_float_test)
{
    continuity_test<float>([](rocrand_xorwow& g, float * data, size_t s) { g.generate_uniform(data, s); });
}

TEST(rocrand_xorwow_prng_tests, continuity_uniform_double_test)
{
    continuity_test<double>([](rocrand_xorwow& g, double * data, size_t s) { g.generate_uniform(data, s); });
}

TEST(rocrand_xorwow_prng_tests, continuity_normal_float_test)
{
    continuity_test<float>([](rocrand_xorwow& g, float * data, size_t s) { g.generate_normal(data, s, 0.0f, 1.0f); }, 2);
}

TEST(rocrand_xorwow_prng_tests, continuity_normal_double_test)
{
    continuity_test<double>([](rocrand_xorwow& g, double * data, size_t s) { g.generate_normal(data, s, 0.0, 1.0); }, 2);
}

TEST(rocrand_xorwow_prng_tests, continuity_log_normal_float_test)
{
    continuity_test<float>([](rocrand_xorwow& g, float * data, size_t s) { g.generate_log_normal(data, s, 0.0f, 1.0f); }, 2);
}

TEST(rocrand_xorwow_prng_tests, continuity_log_normal_double_test)
{
    continuity_test<double>([](rocrand_xorwow& g, double * data, size_t s) { g.generate_log_normal(data, s, 0.0, 1.0); }, 2);
}

TEST(rocrand_xorwow_prng_tests, continuity_poisson_test)
{
    continuity_test<unsigned int>([](rocrand_xorwow& g, unsigned int * data, size_t s) { g.generate_poisson(data, s, 100.0); });
}
