#include <thrust/iterator/zip_iterator.h>
#include <thrust/scan.h>

#include <unittest/unittest.h>

#if THRUST_DEVICE_SYSTEM == THRUST_DEVICE_SYSTEM_CUDA
#  include <unittest/cuda/testframework.h>
#endif

using namespace unittest;

template <typename Tuple>
struct TuplePlus
{
  _CCCL_HOST_DEVICE Tuple operator()(Tuple x, Tuple y) const
  {
    return cuda::std::make_tuple(
      cuda::std::get<0>(x) + cuda::std::get<0>(y), cuda::std::get<1>(x) + cuda::std::get<1>(y));
  }
}; // end SumTuple

template <typename T>
struct TestZipIteratorScan
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_data0 = unittest::random_samples<T>(n);
    thrust::host_vector<T> h_data1 = unittest::random_samples<T>(n);

    thrust::device_vector<T> d_data0 = h_data0;
    thrust::device_vector<T> d_data1 = h_data1;

    using Tuple = cuda::std::tuple<T, T>;

    thrust::host_vector<Tuple> h_result(n);
    thrust::device_vector<Tuple> d_result(n);

    // inclusive_scan (tuple output)
    thrust::inclusive_scan(
      thrust::make_zip_iterator(h_data0.begin(), h_data1.begin()),
      thrust::make_zip_iterator(h_data0.end(), h_data1.end()),
      h_result.begin(),
      TuplePlus<Tuple>());
    thrust::inclusive_scan(
      thrust::make_zip_iterator(d_data0.begin(), d_data1.begin()),
      thrust::make_zip_iterator(d_data0.end(), d_data1.end()),
      d_result.begin(),
      TuplePlus<Tuple>());
    ASSERT_EQUAL_QUIET(h_result, d_result);

    // exclusive_scan (tuple output)
    thrust::exclusive_scan(
      thrust::make_zip_iterator(h_data0.begin(), h_data1.begin()),
      thrust::make_zip_iterator(h_data0.end(), h_data1.end()),
      h_result.begin(),
      cuda::std::make_tuple<T, T>(0, 0),
      TuplePlus<Tuple>());
    thrust::exclusive_scan(
      thrust::make_zip_iterator(d_data0.begin(), d_data1.begin()),
      thrust::make_zip_iterator(d_data0.end(), d_data1.end()),
      d_result.begin(),
      cuda::std::make_tuple<T, T>(0, 0),
      TuplePlus<Tuple>());
    ASSERT_EQUAL_QUIET(h_result, d_result);

    thrust::host_vector<T> h_result0(n);
    thrust::host_vector<T> h_result1(n);
    thrust::device_vector<T> d_result0(n);
    thrust::device_vector<T> d_result1(n);

    // inclusive_scan (zip_iterator output)
    thrust::inclusive_scan(
      thrust::make_zip_iterator(h_data0.begin(), h_data1.begin()),
      thrust::make_zip_iterator(h_data0.end(), h_data1.end()),
      thrust::make_zip_iterator(h_result0.begin(), h_result1.begin()),
      TuplePlus<Tuple>());
    thrust::inclusive_scan(
      thrust::make_zip_iterator(d_data0.begin(), d_data1.begin()),
      thrust::make_zip_iterator(d_data0.end(), d_data1.end()),
      thrust::make_zip_iterator(d_result0.begin(), d_result1.begin()),
      TuplePlus<Tuple>());
    ASSERT_EQUAL_QUIET(h_result0, d_result0);
    ASSERT_EQUAL_QUIET(h_result1, d_result1);

    // exclusive_scan (zip_iterator output)
    thrust::exclusive_scan(
      thrust::make_zip_iterator(h_data0.begin(), h_data1.begin()),
      thrust::make_zip_iterator(h_data0.end(), h_data1.end()),
      thrust::make_zip_iterator(h_result0.begin(), h_result1.begin()),
      cuda::std::make_tuple<T, T>(0, 0),
      TuplePlus<Tuple>());
    thrust::exclusive_scan(
      thrust::make_zip_iterator(d_data0.begin(), d_data1.begin()),
      thrust::make_zip_iterator(d_data0.end(), d_data1.end()),
      thrust::make_zip_iterator(d_result0.begin(), d_result1.begin()),
      cuda::std::make_tuple<T, T>(0, 0),
      TuplePlus<Tuple>());
    ASSERT_EQUAL_QUIET(h_result0, d_result0);
    ASSERT_EQUAL_QUIET(h_result1, d_result1);
  }
};
VariableUnitTest<TestZipIteratorScan, SignedIntegralTypes> TestZipIteratorScanInstance;