#include <thrust/functional.h>
#include <thrust/iterator/discard_iterator.h>
#include <thrust/iterator/retag.h>
#include <thrust/unique.h>

#include <cuda/std/array>

#include <unittest/unittest.h>

template <typename ForwardIterator>
ForwardIterator unique(my_system& system, ForwardIterator first, ForwardIterator)
{
  system.validate_dispatch();
  return first;
}

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

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

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

template <typename ForwardIterator>
ForwardIterator unique(my_tag, ForwardIterator first, ForwardIterator)
{
  *first = 13;
  return first;
}

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

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

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

template <typename InputIterator, typename OutputIterator>
OutputIterator unique_copy(my_system& system, InputIterator, InputIterator, OutputIterator result)
{
  system.validate_dispatch();
  return result;
}

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

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

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

template <typename InputIterator, typename OutputIterator>
OutputIterator unique_copy(my_tag, InputIterator, InputIterator, OutputIterator result)
{
  *result = 13;
  return result;
}

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

  thrust::unique_copy(
    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(TestUniqueCopyDispatchImplicit);

template <typename ForwardIterator>
typename ::cuda::std::iterator_traits<ForwardIterator>::difference_type
unique_count(my_system& system, ForwardIterator, ForwardIterator)
{
  system.validate_dispatch();
  return 0;
}

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

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

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

template <typename ForwardIterator>
typename ::cuda::std::iterator_traits<ForwardIterator>::difference_type
unique_count(my_tag, ForwardIterator, ForwardIterator)
{
  return 13;
}

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

  auto result = thrust::unique_count(thrust::retag<my_tag>(vec.begin()), thrust::retag<my_tag>(vec.begin()));

  ASSERT_EQUAL(13, result);
}
DECLARE_UNITTEST(TestUniqueCountDispatchImplicit);

template <typename T>
struct is_equal_div_10_unique
{
  _CCCL_HOST_DEVICE bool operator()(const T x, const T& y) const
  {
    return ((int) x / 10) == ((int) y / 10);
  }
};

template <typename Vector>
void TestUniqueSimple()
{
  using T = typename Vector::value_type;

  Vector data{11, 11, 12, 20, 29, 21, 21, 31, 31, 37};

  typename Vector::iterator new_last;

  new_last = thrust::unique(data.begin(), data.end());

  ASSERT_EQUAL(new_last - data.begin(), 7);
  data.resize(7);
  Vector ref{11, 12, 20, 29, 21, 31, 37};
  ASSERT_EQUAL(data, ref);

  new_last = thrust::unique(data.begin(), new_last, is_equal_div_10_unique<T>());

  ASSERT_EQUAL(new_last - data.begin(), 3);
  ref.resize(3);
  data.resize(3);
  ref = {11, 20, 31};
  ASSERT_EQUAL(data, ref);
}
DECLARE_INTEGRAL_VECTOR_UNITTEST(TestUniqueSimple);

template <typename T>
struct TestUnique
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_data   = unittest::random_integers<bool>(n);
    thrust::device_vector<T> d_data = h_data;

    typename thrust::host_vector<T>::iterator h_new_last;
    typename thrust::device_vector<T>::iterator d_new_last;

    h_new_last = thrust::unique(h_data.begin(), h_data.end());
    d_new_last = thrust::unique(d_data.begin(), d_data.end());

    ASSERT_EQUAL(h_new_last - h_data.begin(), d_new_last - d_data.begin());

    h_data.resize(h_new_last - h_data.begin());
    d_data.resize(d_new_last - d_data.begin());

    ASSERT_EQUAL(h_data, d_data);
  }
};
VariableUnitTest<TestUnique, IntegralTypes> TestUniqueInstance;

template <typename Vector>
void TestUniqueCopySimple()
{
  using T = typename Vector::value_type;

  Vector data{11, 11, 12, 20, 29, 21, 21, 31, 31, 37};
  Vector output(10, -1);

  typename Vector::iterator new_last;

  new_last = thrust::unique_copy(data.begin(), data.end(), output.begin());

  ASSERT_EQUAL(new_last - output.begin(), 7);
  output.resize(7);
  Vector ref{11, 12, 20, 29, 21, 31, 37};
  ASSERT_EQUAL(output, ref);

  new_last = thrust::unique_copy(output.begin(), new_last, data.begin(), is_equal_div_10_unique<T>());

  ASSERT_EQUAL(new_last - data.begin(), 3);
  ref.resize(3);
  data.resize(3);
  ref = {11, 20, 31};
  ASSERT_EQUAL(data, ref);
}
DECLARE_INTEGRAL_VECTOR_UNITTEST(TestUniqueCopySimple);

template <typename T>
struct TestUniqueCopy
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_data   = unittest::random_integers<bool>(n);
    thrust::device_vector<T> d_data = h_data;

    thrust::host_vector<T> h_output(n);
    thrust::device_vector<T> d_output(n);

    typename thrust::host_vector<T>::iterator h_new_last;
    typename thrust::device_vector<T>::iterator d_new_last;

    h_new_last = thrust::unique_copy(h_data.begin(), h_data.end(), h_output.begin());
    d_new_last = thrust::unique_copy(d_data.begin(), d_data.end(), d_output.begin());

    ASSERT_EQUAL(h_new_last - h_output.begin(), d_new_last - d_output.begin());

    h_data.resize(h_new_last - h_output.begin());
    d_data.resize(d_new_last - d_output.begin());

    ASSERT_EQUAL(h_output, d_output);
  }
};
VariableUnitTest<TestUniqueCopy, IntegralTypes> TestUniqueCopyInstance;

template <typename T>
struct TestUniqueCopyToDiscardIterator
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_data   = unittest::random_integers<bool>(n);
    thrust::device_vector<T> d_data = h_data;

    thrust::host_vector<T> h_unique = h_data;
    h_unique.erase(thrust::unique(h_unique.begin(), h_unique.end()), h_unique.end());

    thrust::discard_iterator<> reference(h_unique.size());

    typename thrust::device_vector<T>::iterator d_new_last;

    thrust::discard_iterator<> h_result =
      thrust::unique_copy(h_data.begin(), h_data.end(), thrust::make_discard_iterator());

    thrust::discard_iterator<> d_result =
      thrust::unique_copy(d_data.begin(), d_data.end(), thrust::make_discard_iterator());

    ASSERT_EQUAL_QUIET(reference, h_result);
    ASSERT_EQUAL_QUIET(reference, d_result);
  }
};
VariableUnitTest<TestUniqueCopyToDiscardIterator, IntegralTypes> TestUniqueCopyToDiscardIteratorInstance;

template <typename Vector>
void TestUniqueCountSimple()
{
  using T = typename Vector::value_type;

  Vector data{11, 11, 12, 20, 29, 21, 21, 31, 31, 37};

  int count = thrust::unique_count(data.begin(), data.end());

  ASSERT_EQUAL(count, 7);

  int div_10_count = thrust::unique_count(data.begin(), data.end(), is_equal_div_10_unique<T>());

  ASSERT_EQUAL(div_10_count, 3);
}
DECLARE_INTEGRAL_VECTOR_UNITTEST(TestUniqueCountSimple);

template <typename T>
struct TestUniqueCount
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_data   = unittest::random_integers<bool>(n);
    thrust::device_vector<T> d_data = h_data;

    int h_count{};
    int d_count{};

    h_count = thrust::unique_count(h_data.begin(), h_data.end());
    d_count = thrust::unique_count(d_data.begin(), d_data.end());

    ASSERT_EQUAL(h_count, d_count);
  }
};
VariableUnitTest<TestUniqueCount, IntegralTypes> TestUniqueCountInstance;

template <typename T>
struct TestUniqueMemoryAccess
{
  void operator()()
  {
    thrust::device_vector<cuda::std::array<T, 100>> v(10);
    thrust::unique(v.begin(), v.end());
  }
};
SimpleUnitTest<TestUniqueMemoryAccess, unittest::type_list<int>> TestUniqueMemoryAccessInstance;