/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *  Modifications Copyright© 2019-2025 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/binary_search.h>
#include <thrust/iterator/retag.h>
#include <thrust/sequence.h>
#include <thrust/sort.h>

#include <unittest/unittest.h>

THRUST_DIAG_PUSH
THRUST_DIAG_SUPPRESS_MSVC(4244 4267) // possible loss of data

//////////////////////
// Scalar Functions //
//////////////////////

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

  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 0) - vec.begin(), 0);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 1) - vec.begin(), 1);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 2) - vec.begin(), 1);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 3) - vec.begin(), 2);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 4) - vec.begin(), 2);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 5) - vec.begin(), 2);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 6) - vec.begin(), 3);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 7) - vec.begin(), 3);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 8) - vec.begin(), 4);
  ASSERT_EQUAL(thrust::lower_bound(vec.begin(), vec.end(), 9) - vec.begin(), 5);
}
DECLARE_VECTOR_UNITTEST(TestScalarLowerBoundSimple);

template <typename ForwardIterator, typename LessThanComparable>
ForwardIterator
lower_bound(my_system& system, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  system.validate_dispatch();
  return first;
}

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

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

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

template <typename ForwardIterator, typename LessThanComparable>
ForwardIterator lower_bound(my_tag, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  *first = 13;
  return first;
}

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

  thrust::lower_bound(thrust::retag<my_tag>(vec.begin()), thrust::retag<my_tag>(vec.end()), 0);

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

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

  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 0) - vec.begin(), 1);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 1) - vec.begin(), 1);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 2) - vec.begin(), 2);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 3) - vec.begin(), 2);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 4) - vec.begin(), 2);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 5) - vec.begin(), 3);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 6) - vec.begin(), 3);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 7) - vec.begin(), 4);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 8) - vec.begin(), 5);
  ASSERT_EQUAL(thrust::upper_bound(vec.begin(), vec.end(), 9) - vec.begin(), 5);
}
DECLARE_VECTOR_UNITTEST(TestScalarUpperBoundSimple);

template <typename ForwardIterator, typename LessThanComparable>
ForwardIterator
upper_bound(my_system& system, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  system.validate_dispatch();
  return first;
}

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

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

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

template <typename ForwardIterator, typename LessThanComparable>
ForwardIterator upper_bound(my_tag, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  *first = 13;
  return first;
}

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

  thrust::upper_bound(thrust::retag<my_tag>(vec.begin()), thrust::retag<my_tag>(vec.end()), 0);

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

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

  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 0), true);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 1), false);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 2), true);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 3), false);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 4), false);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 5), true);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 6), false);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 7), true);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 8), true);
  ASSERT_EQUAL(thrust::binary_search(vec.begin(), vec.end(), 9), false);
}
DECLARE_VECTOR_UNITTEST(TestScalarBinarySearchSimple);

template <typename ForwardIterator, typename LessThanComparable>
bool binary_search(
  my_system& system, ForwardIterator /*first*/, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  system.validate_dispatch();
  return false;
}

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

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

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

template <typename ForwardIterator, typename LessThanComparable>
bool binary_search(my_tag, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  *first = 13;
  return false;
}

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

  thrust::binary_search(thrust::retag<my_tag>(vec.begin()), thrust::retag<my_tag>(vec.end()), 0);

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

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

  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 0).first - vec.begin(), 0);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 1).first - vec.begin(), 1);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 2).first - vec.begin(), 1);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 3).first - vec.begin(), 2);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 4).first - vec.begin(), 2);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 5).first - vec.begin(), 2);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 6).first - vec.begin(), 3);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 7).first - vec.begin(), 3);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 8).first - vec.begin(), 4);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 9).first - vec.begin(), 5);

  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 0).second - vec.begin(), 1);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 1).second - vec.begin(), 1);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 2).second - vec.begin(), 2);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 3).second - vec.begin(), 2);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 4).second - vec.begin(), 2);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 5).second - vec.begin(), 3);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 6).second - vec.begin(), 3);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 7).second - vec.begin(), 4);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 8).second - vec.begin(), 5);
  ASSERT_EQUAL(thrust::equal_range(vec.begin(), vec.end(), 9).second - vec.begin(), 5);
}
DECLARE_VECTOR_UNITTEST(TestScalarEqualRangeSimple);

template <typename ForwardIterator, typename LessThanComparable>
thrust::pair<ForwardIterator, ForwardIterator>
equal_range(my_system& system, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  system.validate_dispatch();
  return thrust::make_pair(first, first);
}

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

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

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

template <typename ForwardIterator, typename LessThanComparable>
thrust::pair<ForwardIterator, ForwardIterator>
equal_range(my_tag, ForwardIterator first, ForwardIterator /*last*/, const LessThanComparable& /*value*/)
{
  *first = 13;
  return thrust::make_pair(first, first);
}

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

  thrust::equal_range(thrust::retag<my_tag>(vec.begin()), thrust::retag<my_tag>(vec.end()), 0);

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

THRUST_DIAG_POP

void TestBoundsWithBigIndexesHelper(int magnitude)
{
  thrust::counting_iterator<long long> begin(1);
  thrust::counting_iterator<long long> end = begin + (1ll << magnitude);
  ASSERT_EQUAL(thrust::distance(begin, end), 1ll << magnitude);

  thrust::detail::intmax_t distance_low_value =
    thrust::distance(begin, thrust::lower_bound(thrust::device, begin, end, 17));

  thrust::detail::intmax_t distance_high_value =
    thrust::distance(begin, thrust::lower_bound(thrust::device, begin, end, (1ll << magnitude) - 17));

  ASSERT_EQUAL(distance_low_value, 16);
  ASSERT_EQUAL(distance_high_value, (1ll << magnitude) - 18);

  distance_low_value = thrust::distance(begin, thrust::upper_bound(thrust::device, begin, end, 17));

  distance_high_value =
    thrust::distance(begin, thrust::upper_bound(thrust::device, begin, end, (1ll << magnitude) - 17));

  ASSERT_EQUAL(distance_low_value, 17);
  ASSERT_EQUAL(distance_high_value, (1ll << magnitude) - 17);
}

void TestBoundsWithBigIndexes()
{
  TestBoundsWithBigIndexesHelper(30);
  TestBoundsWithBigIndexesHelper(31);
  TestBoundsWithBigIndexesHelper(32);
  TestBoundsWithBigIndexesHelper(33);
}
DECLARE_UNITTEST(TestBoundsWithBigIndexes);
