/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *  Modifications Copyright© 2019-2023 Advanced Micro Devices, Inc. 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.
 */

#include <thrust/copy.h>
#include <thrust/functional.h>
#include <thrust/iterator/counting_iterator.h>
#include <thrust/iterator/transform_iterator.h>
#include <thrust/reduce.h>
#include <thrust/sequence.h>

#include "test_header.hpp"

TESTS_DEFINE(TransformIteratorTests, FullTestsParams);
TESTS_DEFINE(PrimitiveTransformIteratorTests, NumericalTestsParams);

TEST(TransformIteratorTests, UsingHip)
{
    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    ASSERT_EQ(THRUST_DEVICE_SYSTEM, THRUST_DEVICE_SYSTEM_HIP);
}

TYPED_TEST(TransformIteratorTests, TransformIterator)
{
    using Vector = typename TestFixture::input_type;
    using Policy = typename TestFixture::execution_policy;
    using T      = typename Vector::value_type;

    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    using UnaryFunction = thrust::negate<T>;
    using Iterator      = typename Vector::iterator;

    Vector input(4);
    Vector output(4);

    // initialize input
    thrust::sequence(Policy{}, input.begin(), input.end(), 1);

    // construct transform_iterator
    thrust::transform_iterator<UnaryFunction, Iterator> iter(input.begin(), UnaryFunction());

    thrust::copy(Policy{}, iter, iter + 4, output.begin());

    ASSERT_EQ(output[0], (T)-1);
    ASSERT_EQ(output[1], (T)-2);
    ASSERT_EQ(output[2], (T)-3);
    ASSERT_EQ(output[3], (T)-4);
}

TYPED_TEST(TransformIteratorTests, MakeTransformIterator)
{
    using Vector = typename TestFixture::input_type;
    using Policy = typename TestFixture::execution_policy;
    using T      = typename Vector::value_type;

    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    using UnaryFunction = thrust::negate<T>;
    using Iterator      = typename Vector::iterator;

    Vector input(4);
    Vector output(4);

    // initialize input
    thrust::sequence(Policy{}, input.begin(), input.end(), 1);

    // construct transform_iterator
    thrust::transform_iterator<UnaryFunction, Iterator> iter(input.begin(), UnaryFunction());

    thrust::copy(Policy{},
                 thrust::make_transform_iterator(input.begin(), UnaryFunction()),
                 thrust::make_transform_iterator(input.end(), UnaryFunction()),
                 output.begin());

    ASSERT_EQ(output[0], (T)-1);
    ASSERT_EQ(output[1], (T)-2);
    ASSERT_EQ(output[2], (T)-3);
    ASSERT_EQ(output[3], (T)-4);
}

TYPED_TEST(PrimitiveTransformIteratorTests, TransformIteratorReduce)
{
    using T = typename TestFixture::input_type;

    SCOPED_TRACE(testing::Message() << "with device_id= " << test::set_device_from_ctest());

    for(auto size : get_sizes())
    {
        SCOPED_TRACE(testing::Message() << "with size= " << size);

        T error_margin = (T)0.01 * size;

        for(auto seed : get_seeds())
        {
            SCOPED_TRACE(testing::Message() << "with seed= " << seed);

            thrust::host_vector<T>   h_data = get_random_data<T>(size, 0, 10, seed);
            thrust::device_vector<T> d_data = h_data;

            // run on host
            T h_result = thrust::reduce(
                thrust::make_transform_iterator(h_data.begin(), thrust::negate<T>()),
                thrust::make_transform_iterator(h_data.end(), thrust::negate<T>()));

            // run on device
            T d_result = thrust::reduce(
                thrust::make_transform_iterator(d_data.begin(), thrust::negate<T>()),
                thrust::make_transform_iterator(d_data.end(), thrust::negate<T>()));

            ASSERT_NEAR(h_result, d_result, error_margin);
        }
    }
}

struct ExtractValue{
    int operator()(std::unique_ptr<int> const& n){
        return *n;
    }
};

TEST(TransformIteratorTests, TestTransformIteratorNonCopyable)
{
    thrust::host_vector<std::unique_ptr<int>> hv(4);
    hv[0].reset(new int{1});
    hv[1].reset(new int{2});
    hv[2].reset(new int{3});
    hv[3].reset(new int{4});

    auto transformed = thrust::make_transform_iterator(hv.begin(), ExtractValue{});
    ASSERT_EQ(transformed[0], 1);
    ASSERT_EQ(transformed[1], 2);
    ASSERT_EQ(transformed[2], 3);
    ASSERT_EQ(transformed[3], 4);
}

struct DeviceOp
{
    __device__ int operator()(int)
    {
        return int {};
    }
};

/// Tests compilation of device-only operators.
TEST(TransformIteratorTests, TestDeviceOperator)
{
    thrust::device_vector<int> dv(1);
    auto                       iter = thrust::make_transform_iterator(dv.begin(), DeviceOp {});
    THRUST_UNUSED_VAR(iter);
}
