#include <thrust/extrema.h>
#include <thrust/functional.h>
#include <thrust/iterator/retag.h>
#include <thrust/set_operations.h>
#include <thrust/sort.h>

#include <unittest/unittest.h>

template <typename InputIterator1, typename InputIterator2, typename OutputIterator>
OutputIterator set_symmetric_difference(
  my_system& system, InputIterator1, InputIterator1, InputIterator2, InputIterator2, OutputIterator result)
{
  system.validate_dispatch();
  return result;
}

void TestSetSymmetricDifferenceDispatchExplicit()
{
  thrust::device_vector<int> vec(1);

  my_system sys(0);
  thrust::set_symmetric_difference(sys, vec.begin(), vec.begin(), vec.begin(), vec.begin(), vec.begin());

  ASSERT_EQUAL(true, sys.is_valid());
}
DECLARE_UNITTEST(TestSetSymmetricDifferenceDispatchExplicit);

template <typename InputIterator1, typename InputIterator2, typename OutputIterator>
OutputIterator
set_symmetric_difference(my_tag, InputIterator1, InputIterator1, InputIterator2, InputIterator2, OutputIterator result)
{
  *result = 13;
  return result;
}

void TestSetSymmetricDifferenceDispatchImplicit()
{
  thrust::device_vector<int> vec(1);

  thrust::set_symmetric_difference(
    thrust::retag<my_tag>(vec.begin()),
    thrust::retag<my_tag>(vec.begin()),
    thrust::retag<my_tag>(vec.begin()),
    thrust::retag<my_tag>(vec.begin()),
    thrust::retag<my_tag>(vec.begin()));

  ASSERT_EQUAL(13, vec.front());
}
DECLARE_UNITTEST(TestSetSymmetricDifferenceDispatchImplicit);

template <typename Vector>
void TestSetSymmetricDifferenceSimple()
{
  using Iterator = typename Vector::iterator;

  Vector a{0, 2, 4, 6}, b{0, 3, 3, 4, 7};

  Vector ref{2, 3, 3, 6, 7};
  Vector result(5);

  Iterator end = thrust::set_symmetric_difference(a.begin(), a.end(), b.begin(), b.end(), result.begin());

  ASSERT_EQUAL_QUIET(result.end(), end);
  ASSERT_EQUAL(ref, result);
}
DECLARE_VECTOR_UNITTEST(TestSetSymmetricDifferenceSimple);

template <typename T>
void TestSetSymmetricDifference(const size_t n)
{
  size_t sizes[]   = {0, 1, n / 2, n, n + 1, 2 * n};
  size_t num_sizes = sizeof(sizes) / sizeof(size_t);

  thrust::host_vector<T> random =
    unittest::random_integers<unittest::int8_t>(n + *thrust::max_element(sizes, sizes + num_sizes));

  thrust::host_vector<T> h_a(random.begin(), random.begin() + n);
  thrust::host_vector<T> h_b(random.begin() + n, random.end());

  thrust::stable_sort(h_a.begin(), h_a.end());
  thrust::stable_sort(h_b.begin(), h_b.end());

  thrust::device_vector<T> d_a = h_a;
  thrust::device_vector<T> d_b = h_b;

  for (size_t i = 0; i < num_sizes; i++)
  {
    size_t size = sizes[i];

    thrust::host_vector<T> h_result(n + size);
    thrust::device_vector<T> d_result(n + size);

    typename thrust::host_vector<T>::iterator h_end;
    typename thrust::device_vector<T>::iterator d_end;

    h_end = thrust::set_symmetric_difference(h_a.begin(), h_a.end(), h_b.begin(), h_b.begin() + size, h_result.begin());
    h_result.resize(h_end - h_result.begin());

    d_end = thrust::set_symmetric_difference(d_a.begin(), d_a.end(), d_b.begin(), d_b.begin() + size, d_result.begin());
    d_result.resize(d_end - d_result.begin());

    ASSERT_EQUAL(h_result, d_result);
  }
}
DECLARE_VARIABLE_UNITTEST(TestSetSymmetricDifference);

template <typename T>
void TestSetSymmetricDifferenceEquivalentRanges(const size_t n)
{
  thrust::host_vector<T> temp = unittest::random_integers<T>(n);
  thrust::host_vector<T> h_a  = temp;
  thrust::sort(h_a.begin(), h_a.end());
  thrust::host_vector<T> h_b = h_a;

  thrust::device_vector<T> d_a = h_a;
  thrust::device_vector<T> d_b = h_b;

  thrust::host_vector<T> h_result(h_a.size() + h_b.size());
  thrust::device_vector<T> d_result(h_result.size());

  typename thrust::host_vector<T>::iterator h_end;
  typename thrust::device_vector<T>::iterator d_end;

  h_end = thrust::set_symmetric_difference(h_a.begin(), h_a.end(), h_b.begin(), h_b.end(), h_result.begin());
  h_result.erase(h_end, h_result.end());

  d_end = thrust::set_symmetric_difference(d_a.begin(), d_a.end(), d_b.begin(), d_b.end(), d_result.begin());
  d_result.erase(d_end, d_result.end());

  ASSERT_EQUAL(h_result, d_result);
}
DECLARE_VARIABLE_UNITTEST(TestSetSymmetricDifferenceEquivalentRanges);

template <typename T>
void TestSetSymmetricDifferenceMultiset(const size_t n)
{
  thrust::host_vector<T> vec = unittest::random_integers<int>(2 * n);

  // restrict elements to [min,13)
  for (typename thrust::host_vector<T>::iterator i = vec.begin(); i != vec.end(); ++i)
  {
    int temp = static_cast<int>(*i);
    temp %= 13;
    *i = temp;
  }

  thrust::host_vector<T> h_a(vec.begin(), vec.begin() + n);
  thrust::host_vector<T> h_b(vec.begin() + n, vec.end());

  thrust::sort(h_a.begin(), h_a.end());
  thrust::sort(h_b.begin(), h_b.end());

  thrust::device_vector<T> d_a = h_a;
  thrust::device_vector<T> d_b = h_b;

  thrust::host_vector<T> h_result(h_a.size() + h_b.size());
  thrust::device_vector<T> d_result(h_result.size());

  typename thrust::host_vector<T>::iterator h_end;
  typename thrust::device_vector<T>::iterator d_end;

  h_end = thrust::set_difference(h_a.begin(), h_a.end(), h_b.begin(), h_b.end(), h_result.begin());
  h_result.erase(h_end, h_result.end());

  d_end = thrust::set_difference(d_a.begin(), d_a.end(), d_b.begin(), d_b.end(), d_result.begin());
  d_result.erase(d_end, d_result.end());

  ASSERT_EQUAL(h_result, d_result);
}
DECLARE_VARIABLE_UNITTEST(TestSetSymmetricDifferenceMultiset);

template <typename U>
void TestSetSymmetricDifferenceKeyValue(size_t n)
{
  using T = key_value<U, U>;

  thrust::host_vector<U> h_keys_a   = unittest::random_integers<U>(n);
  thrust::host_vector<U> h_values_a = unittest::random_integers<U>(n);

  thrust::host_vector<U> h_keys_b   = unittest::random_integers<U>(n);
  thrust::host_vector<U> h_values_b = unittest::random_integers<U>(n);

  thrust::host_vector<T> h_a(n), h_b(n);
  for (size_t i = 0; i < n; ++i)
  {
    h_a[i] = T(h_keys_a[i], h_values_a[i]);
    h_b[i] = T(h_keys_b[i], h_values_b[i]);
  }

  thrust::stable_sort(h_a.begin(), h_a.end());
  thrust::stable_sort(h_b.begin(), h_b.end());

  thrust::device_vector<T> d_a = h_a;
  thrust::device_vector<T> d_b = h_b;

  thrust::host_vector<T> h_result(h_a.size() + h_b.size());
  thrust::device_vector<T> d_result(h_result.size());

  typename thrust::host_vector<T>::iterator h_end;
  typename thrust::device_vector<T>::iterator d_end;

  h_end = thrust::set_symmetric_difference(h_a.begin(), h_a.end(), h_b.begin(), h_b.end(), h_result.begin());
  h_result.erase(h_end, h_result.begin());

  d_end = thrust::set_symmetric_difference(d_a.begin(), d_a.end(), d_b.begin(), d_b.end(), d_result.begin());

  d_result.erase(d_end, d_result.begin());

  ASSERT_EQUAL_QUIET(h_result, d_result);
}
DECLARE_VARIABLE_UNITTEST(TestSetSymmetricDifferenceKeyValue);