#include <thrust/binary_search.h>
#include <thrust/detail/allocator/allocator_system.h>
#include <thrust/iterator/discard_iterator.h>
#include <thrust/iterator/retag.h>
#include <thrust/sequence.h>
#include <thrust/sort.h>

#include <unittest/unittest.h>

//////////////////////
// Vector Functions //
//////////////////////

// convert xxx_vector<T1> to xxx_vector<T2>
template <class ExampleVector, typename NewType>
struct vector_like
{
  using alloc        = typename ExampleVector::allocator_type;
  using alloc_traits = typename cuda::std::allocator_traits<alloc>;
  using new_alloc    = typename alloc_traits::template rebind_alloc<NewType>;
  using type         = thrust::detail::vector_base<NewType, new_alloc>;
};

template <class Vector>
void TestVectorLowerBoundSimple()
{
  Vector vec{0, 2, 5, 7, 8};

  Vector input(10);
  thrust::sequence(input.begin(), input.end());

  using int_type  = typename Vector::difference_type;
  using IntVector = typename vector_like<Vector, int_type>::type;

  // test with integral output type
  IntVector integral_output(10);
  thrust::lower_bound(vec.begin(), vec.end(), input.begin(), input.end(), integral_output.begin());

  typename IntVector::iterator output_end =
    thrust::lower_bound(vec.begin(), vec.end(), input.begin(), input.end(), integral_output.begin());

  ASSERT_EQUAL((output_end - integral_output.begin()), 10);

  IntVector ref{0, 1, 1, 2, 2, 2, 3, 3, 4, 5};
  ASSERT_EQUAL(integral_output, ref);

  //    // test with iterator output type
  //    using IteratorVector = typename vector_like<Vector, typename Vector::iterator>::type;
  //    IteratorVector iterator_output(10);
  //    thrust::lower_bound(vec.begin(), vec.end(), input.begin(), input.end(), iterator_output.begin());
  //
  //    ASSERT_EQUAL(iterator_output[0] - vec.begin(), 0);
  //    ASSERT_EQUAL(iterator_output[1] - vec.begin(), 1);
  //    ASSERT_EQUAL(iterator_output[2] - vec.begin(), 1);
  //    ASSERT_EQUAL(iterator_output[3] - vec.begin(), 2);
  //    ASSERT_EQUAL(iterator_output[4] - vec.begin(), 2);
  //    ASSERT_EQUAL(iterator_output[5] - vec.begin(), 2);
  //    ASSERT_EQUAL(iterator_output[6] - vec.begin(), 3);
  //    ASSERT_EQUAL(iterator_output[7] - vec.begin(), 3);
  //    ASSERT_EQUAL(iterator_output[8] - vec.begin(), 4);
  //    ASSERT_EQUAL(iterator_output[9] - vec.begin(), 5);
}
DECLARE_VECTOR_UNITTEST(TestVectorLowerBoundSimple);

template <typename ForwardIterator, typename InputIterator, typename OutputIterator>
OutputIterator
lower_bound(my_system& system, ForwardIterator, ForwardIterator, InputIterator, InputIterator, OutputIterator output)
{
  system.validate_dispatch();
  return output;
}

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

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

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

template <typename ForwardIterator, typename InputIterator, typename OutputIterator>
OutputIterator lower_bound(my_tag, ForwardIterator, ForwardIterator, InputIterator, InputIterator, OutputIterator output)
{
  *output = 13;
  return output;
}

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

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

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

template <class Vector>
void TestVectorUpperBoundSimple()
{
  Vector vec{0, 2, 5, 7, 8};

  Vector input(10);
  thrust::sequence(input.begin(), input.end());

  using int_type  = typename Vector::difference_type;
  using IntVector = typename vector_like<Vector, int_type>::type;

  // test with integral output type
  IntVector integral_output(10);
  typename IntVector::iterator output_end =
    thrust::upper_bound(vec.begin(), vec.end(), input.begin(), input.end(), integral_output.begin());

  ASSERT_EQUAL((output_end - integral_output.begin()), 10);

  IntVector ref{1, 1, 2, 2, 2, 3, 3, 4, 5, 5};
  ASSERT_EQUAL(integral_output, ref);

  //    // test with iterator output type
  //    using IteratorVector = typename vector_like<Vector, typename Vector::iterator>::type;
  //    IteratorVector iterator_output(10);
  //    thrust::lower_bound(vec.begin(), vec.end(), input.begin(), input.end(), iterator_output.begin());
  //
  //    ASSERT_EQUAL(iterator_output[0] - vec.begin(), 1);
  //    ASSERT_EQUAL(iterator_output[1] - vec.begin(), 1);
  //    ASSERT_EQUAL(iterator_output[2] - vec.begin(), 2);
  //    ASSERT_EQUAL(iterator_output[3] - vec.begin(), 2);
  //    ASSERT_EQUAL(iterator_output[4] - vec.begin(), 2);
  //    ASSERT_EQUAL(iterator_output[5] - vec.begin(), 3);
  //    ASSERT_EQUAL(iterator_output[6] - vec.begin(), 3);
  //    ASSERT_EQUAL(iterator_output[7] - vec.begin(), 4);
  //    ASSERT_EQUAL(iterator_output[8] - vec.begin(), 5);
  //    ASSERT_EQUAL(iterator_output[9] - vec.begin(), 5);
}
DECLARE_VECTOR_UNITTEST(TestVectorUpperBoundSimple);

template <typename ForwardIterator, typename InputIterator, typename OutputIterator>
OutputIterator
upper_bound(my_system& system, ForwardIterator, ForwardIterator, InputIterator, InputIterator, OutputIterator output)
{
  system.validate_dispatch();
  return output;
}

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

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

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

template <typename ForwardIterator, typename InputIterator, typename OutputIterator>
OutputIterator upper_bound(my_tag, ForwardIterator, ForwardIterator, InputIterator, InputIterator, OutputIterator output)
{
  *output = 13;
  return output;
}

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

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

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

template <class Vector>
void TestVectorBinarySearchSimple()
{
  Vector vec{0, 2, 5, 7, 8};

  Vector input(10);
  thrust::sequence(input.begin(), input.end());

  using BoolVector = typename vector_like<Vector, bool>::type;
  using int_type   = typename Vector::difference_type;
  using IntVector  = typename vector_like<Vector, int_type>::type;

  // test with boolean output type
  BoolVector bool_output(10);
  typename BoolVector::iterator bool_output_end =
    thrust::binary_search(vec.begin(), vec.end(), input.begin(), input.end(), bool_output.begin());

  ASSERT_EQUAL((bool_output_end - bool_output.begin()), 10);

  BoolVector bool_ref{true, false, true, false, false, true, false, true, true, false};
  ASSERT_EQUAL(bool_output, bool_ref);

  // test with integral output type
  IntVector integral_output(10, 2);
  typename IntVector::iterator int_output_end =
    thrust::binary_search(vec.begin(), vec.end(), input.begin(), input.end(), integral_output.begin());

  ASSERT_EQUAL((int_output_end - integral_output.begin()), 10);

  IntVector int_ref{1, 0, 1, 0, 0, 1, 0, 1, 1, 0};
  ASSERT_EQUAL(integral_output, int_ref);
}
DECLARE_VECTOR_UNITTEST(TestVectorBinarySearchSimple);

template <typename ForwardIterator, typename InputIterator, typename OutputIterator>
OutputIterator
binary_search(my_system& system, ForwardIterator, ForwardIterator, InputIterator, InputIterator, OutputIterator output)
{
  system.validate_dispatch();
  return output;
}

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

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

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

template <typename ForwardIterator, typename InputIterator, typename OutputIterator>
OutputIterator
binary_search(my_tag, ForwardIterator, ForwardIterator, InputIterator, InputIterator, OutputIterator output)
{
  *output = 13;
  return output;
}

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

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

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

template <typename T>
struct TestVectorLowerBound
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_vec = unittest::random_integers<T>(n);
    thrust::sort(h_vec.begin(), h_vec.end());
    thrust::device_vector<T> d_vec = h_vec;

    thrust::host_vector<T> h_input   = unittest::random_integers<T>(2 * n);
    thrust::device_vector<T> d_input = h_input;

    using int_type = typename thrust::host_vector<T>::difference_type;
    thrust::host_vector<int_type> h_output(2 * n);
    thrust::device_vector<int_type> d_output(2 * n);

    thrust::lower_bound(h_vec.begin(), h_vec.end(), h_input.begin(), h_input.end(), h_output.begin());
    thrust::lower_bound(d_vec.begin(), d_vec.end(), d_input.begin(), d_input.end(), d_output.begin());

    ASSERT_EQUAL(h_output, d_output);
  }
};
VariableUnitTest<TestVectorLowerBound, SignedIntegralTypes> TestVectorLowerBoundInstance;

template <typename T>
struct TestVectorUpperBound
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_vec = unittest::random_integers<T>(n);
    thrust::sort(h_vec.begin(), h_vec.end());
    thrust::device_vector<T> d_vec = h_vec;

    thrust::host_vector<T> h_input   = unittest::random_integers<T>(2 * n);
    thrust::device_vector<T> d_input = h_input;

    using int_type = typename thrust::host_vector<T>::difference_type;
    thrust::host_vector<int_type> h_output(2 * n);
    thrust::device_vector<int_type> d_output(2 * n);

    thrust::upper_bound(h_vec.begin(), h_vec.end(), h_input.begin(), h_input.end(), h_output.begin());
    thrust::upper_bound(d_vec.begin(), d_vec.end(), d_input.begin(), d_input.end(), d_output.begin());

    ASSERT_EQUAL(h_output, d_output);
  }
};
VariableUnitTest<TestVectorUpperBound, SignedIntegralTypes> TestVectorUpperBoundInstance;

template <typename T>
struct TestVectorBinarySearch
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_vec = unittest::random_integers<T>(n);
    thrust::sort(h_vec.begin(), h_vec.end());
    thrust::device_vector<T> d_vec = h_vec;

    thrust::host_vector<T> h_input   = unittest::random_integers<T>(2 * n);
    thrust::device_vector<T> d_input = h_input;

    using int_type = typename thrust::host_vector<T>::difference_type;
    thrust::host_vector<int_type> h_output(2 * n);
    thrust::device_vector<int_type> d_output(2 * n);

    thrust::binary_search(h_vec.begin(), h_vec.end(), h_input.begin(), h_input.end(), h_output.begin());
    thrust::binary_search(d_vec.begin(), d_vec.end(), d_input.begin(), d_input.end(), d_output.begin());

    ASSERT_EQUAL(h_output, d_output);
  }
};
VariableUnitTest<TestVectorBinarySearch, SignedIntegralTypes> TestVectorBinarySearchInstance;

template <typename T>
struct TestVectorLowerBoundDiscardIterator
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_vec = unittest::random_integers<T>(n);
    thrust::sort(h_vec.begin(), h_vec.end());
    thrust::device_vector<T> d_vec = h_vec;

    thrust::host_vector<T> h_input   = unittest::random_integers<T>(2 * n);
    thrust::device_vector<T> d_input = h_input;

    thrust::discard_iterator<> h_result =
      thrust::lower_bound(h_vec.begin(), h_vec.end(), h_input.begin(), h_input.end(), thrust::make_discard_iterator());
    thrust::discard_iterator<> d_result =
      thrust::lower_bound(d_vec.begin(), d_vec.end(), d_input.begin(), d_input.end(), thrust::make_discard_iterator());

    thrust::discard_iterator<> reference(static_cast<std::ptrdiff_t>(2 * n));

    ASSERT_EQUAL_QUIET(reference, h_result);
    ASSERT_EQUAL_QUIET(reference, d_result);
  }
};
VariableUnitTest<TestVectorLowerBoundDiscardIterator, SignedIntegralTypes> TestVectorLowerBoundDiscardIteratorInstance;

template <typename T>
struct TestVectorUpperBoundDiscardIterator
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_vec = unittest::random_integers<T>(n);
    thrust::sort(h_vec.begin(), h_vec.end());
    thrust::device_vector<T> d_vec = h_vec;

    thrust::host_vector<T> h_input   = unittest::random_integers<T>(2 * n);
    thrust::device_vector<T> d_input = h_input;

    thrust::discard_iterator<> h_result =
      thrust::upper_bound(h_vec.begin(), h_vec.end(), h_input.begin(), h_input.end(), thrust::make_discard_iterator());
    thrust::discard_iterator<> d_result =
      thrust::upper_bound(d_vec.begin(), d_vec.end(), d_input.begin(), d_input.end(), thrust::make_discard_iterator());

    thrust::discard_iterator<> reference(static_cast<std::ptrdiff_t>(2 * n));

    ASSERT_EQUAL_QUIET(reference, h_result);
    ASSERT_EQUAL_QUIET(reference, d_result);
  }
};
VariableUnitTest<TestVectorUpperBoundDiscardIterator, SignedIntegralTypes> TestVectorUpperBoundDiscardIteratorInstance;

template <typename T>
struct TestVectorBinarySearchDiscardIterator
{
  void operator()(const size_t n)
  {
    thrust::host_vector<T> h_vec = unittest::random_integers<T>(n);
    thrust::sort(h_vec.begin(), h_vec.end());
    thrust::device_vector<T> d_vec = h_vec;

    thrust::host_vector<T> h_input   = unittest::random_integers<T>(2 * n);
    thrust::device_vector<T> d_input = h_input;

    thrust::discard_iterator<> h_result = thrust::binary_search(
      h_vec.begin(), h_vec.end(), h_input.begin(), h_input.end(), thrust::make_discard_iterator());
    thrust::discard_iterator<> d_result = thrust::binary_search(
      d_vec.begin(), d_vec.end(), d_input.begin(), d_input.end(), thrust::make_discard_iterator());

    thrust::discard_iterator<> reference(static_cast<std::ptrdiff_t>(2 * n));

    ASSERT_EQUAL_QUIET(reference, h_result);
    ASSERT_EQUAL_QUIET(reference, d_result);
  }
};
VariableUnitTest<TestVectorBinarySearchDiscardIterator, SignedIntegralTypes>
  TestVectorBinarySearchDiscardIteratorInstance;