#include <thrust/fill.h>
#include <thrust/iterator/discard_iterator.h>
#include <thrust/iterator/retag.h>
#include <thrust/iterator/zip_iterator.h>

#include <algorithm>

#include <unittest/unittest.h>

_CCCL_DIAG_PUSH
_CCCL_DIAG_SUPPRESS_MSVC(4244 4267) // possible loss of data

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

  Vector v{0, 1, 2, 3, 4};

  thrust::fill(v.begin() + 1, v.begin() + 4, (T) 7);

  Vector ref{0, 7, 7, 7, 4};
  ASSERT_EQUAL(v, ref);

  thrust::fill(v.begin() + 0, v.begin() + 3, (T) 8);

  ref = {8, 8, 8, 7, 4};
  ASSERT_EQUAL(v, ref);

  thrust::fill(v.begin() + 2, v.end(), (T) 9);

  ref = {8, 8, 9, 9, 9};
  ASSERT_EQUAL(v, ref);

  thrust::fill(v.begin(), v.end(), (T) 1);

  ref = Vector(5, 1);
  ASSERT_EQUAL(v, ref);
}
DECLARE_VECTOR_UNITTEST(TestFillSimple);

void TestFillDiscardIterator()
{
  // there's no result to check because fill returns void
  thrust::fill(
    thrust::discard_iterator<thrust::host_system_tag>(), thrust::discard_iterator<thrust::host_system_tag>(10), 13);

  thrust::fill(
    thrust::discard_iterator<thrust::device_system_tag>(), thrust::discard_iterator<thrust::device_system_tag>(10), 13);
}
DECLARE_UNITTEST(TestFillDiscardIterator);

template <class Vector>
void TestFillMixedTypes()
{
  Vector v(4);

  thrust::fill(v.begin(), v.end(), bool(true));

  Vector ref(4, 1);
  ASSERT_EQUAL(v, ref);

  thrust::fill(v.begin(), v.end(), char(20));

  ref = Vector(4, 20);
  ASSERT_EQUAL(v, ref);
}
DECLARE_VECTOR_UNITTEST(TestFillMixedTypes);

template <typename T>
void TestFill(size_t n)
{
  thrust::host_vector<T> h_data   = unittest::random_integers<T>(n);
  thrust::device_vector<T> d_data = h_data;

  thrust::fill(h_data.begin() + std::min((size_t) 1, n), h_data.begin() + std::min((size_t) 3, n), (T) 0);
  thrust::fill(d_data.begin() + std::min((size_t) 1, n), d_data.begin() + std::min((size_t) 3, n), (T) 0);

  ASSERT_EQUAL(h_data, d_data);

  thrust::fill(h_data.begin() + std::min((size_t) 117, n), h_data.begin() + std::min((size_t) 367, n), (T) 1);
  thrust::fill(d_data.begin() + std::min((size_t) 117, n), d_data.begin() + std::min((size_t) 367, n), (T) 1);

  ASSERT_EQUAL(h_data, d_data);

  thrust::fill(h_data.begin() + std::min((size_t) 8, n), h_data.begin() + std::min((size_t) 259, n), (T) 2);
  thrust::fill(d_data.begin() + std::min((size_t) 8, n), d_data.begin() + std::min((size_t) 259, n), (T) 2);

  ASSERT_EQUAL(h_data, d_data);

  thrust::fill(h_data.begin() + std::min((size_t) 3, n), h_data.end(), (T) 3);
  thrust::fill(d_data.begin() + std::min((size_t) 3, n), d_data.end(), (T) 3);

  ASSERT_EQUAL(h_data, d_data);

  thrust::fill(h_data.begin(), h_data.end(), (T) 4);
  thrust::fill(d_data.begin(), d_data.end(), (T) 4);

  ASSERT_EQUAL(h_data, d_data);
}
DECLARE_VARIABLE_UNITTEST(TestFill);

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

  Vector v{0, 1, 2, 3, 4};

  typename Vector::iterator iter = thrust::fill_n(v.begin() + 1, 3, (T) 7);

  Vector ref{0, 7, 7, 7, 4};
  ASSERT_EQUAL(v, ref);

  ASSERT_EQUAL_QUIET(v.begin() + 4, iter);

  iter = thrust::fill_n(v.begin() + 0, 3, (T) 8);

  ref = {8, 8, 8, 7, 4};
  ASSERT_EQUAL(v, ref);

  ASSERT_EQUAL_QUIET(v.begin() + 3, iter);

  iter = thrust::fill_n(v.begin() + 2, 3, (T) 9);

  ref = {8, 8, 9, 9, 9};
  ASSERT_EQUAL(v, ref);

  ASSERT_EQUAL_QUIET(v.end(), iter);

  iter = thrust::fill_n(v.begin(), v.size(), (T) 1);

  ref = Vector(5, 1);
  ASSERT_EQUAL(v, ref);

  ASSERT_EQUAL_QUIET(v.end(), iter);
}
DECLARE_VECTOR_UNITTEST(TestFillNSimple);

void TestFillNDiscardIterator()
{
  thrust::discard_iterator<thrust::host_system_tag> h_result =
    thrust::fill_n(thrust::discard_iterator<thrust::host_system_tag>(), 10, 13);

  thrust::discard_iterator<thrust::device_system_tag> d_result =
    thrust::fill_n(thrust::discard_iterator<thrust::device_system_tag>(), 10, 13);

  thrust::discard_iterator<> reference(10);

  ASSERT_EQUAL_QUIET(reference, h_result);
  ASSERT_EQUAL_QUIET(reference, d_result);
}
DECLARE_UNITTEST(TestFillNDiscardIterator);

template <class Vector>
void TestFillNMixedTypes()
{
  Vector v(4);

  typename Vector::iterator iter = thrust::fill_n(v.begin(), v.size(), bool(true));

  Vector ref(4, 1);
  ASSERT_EQUAL(v, ref);
  ASSERT_EQUAL_QUIET(v.end(), iter);

  iter = thrust::fill_n(v.begin(), v.size(), char(20));

  ref = Vector(4, 20);
  ASSERT_EQUAL(v, ref);
  ASSERT_EQUAL_QUIET(v.end(), iter);
}
DECLARE_VECTOR_UNITTEST(TestFillNMixedTypes);

template <typename T>
void TestFillN(size_t n)
{
  thrust::host_vector<T> h_data   = unittest::random_integers<T>(n);
  thrust::device_vector<T> d_data = h_data;

  size_t begin_offset = std::min<size_t>(1, n);
  thrust::fill_n(h_data.begin() + begin_offset, std::min((size_t) 3, n) - begin_offset, (T) 0);
  thrust::fill_n(d_data.begin() + begin_offset, std::min((size_t) 3, n) - begin_offset, (T) 0);

  ASSERT_EQUAL(h_data, d_data);

  begin_offset = std::min<size_t>(117, n);
  thrust::fill_n(h_data.begin() + begin_offset, std::min((size_t) 367, n) - begin_offset, (T) 1);
  thrust::fill_n(d_data.begin() + begin_offset, std::min((size_t) 367, n) - begin_offset, (T) 1);

  ASSERT_EQUAL(h_data, d_data);

  begin_offset = std::min<size_t>(8, n);
  thrust::fill_n(h_data.begin() + begin_offset, std::min((size_t) 259, n) - begin_offset, (T) 2);
  thrust::fill_n(d_data.begin() + begin_offset, std::min((size_t) 259, n) - begin_offset, (T) 2);

  ASSERT_EQUAL(h_data, d_data);

  begin_offset = std::min<size_t>(3, n);
  thrust::fill_n(h_data.begin() + begin_offset, h_data.size() - begin_offset, (T) 3);
  thrust::fill_n(d_data.begin() + begin_offset, d_data.size() - begin_offset, (T) 3);

  ASSERT_EQUAL(h_data, d_data);

  thrust::fill_n(h_data.begin(), h_data.size(), (T) 4);
  thrust::fill_n(d_data.begin(), d_data.size(), (T) 4);

  ASSERT_EQUAL(h_data, d_data);
}
DECLARE_VARIABLE_UNITTEST(TestFillN);

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

  Vector v1(3, T(0));
  Vector v2(3, T(0));
  Vector v3(3, T(0));

  thrust::fill(thrust::make_zip_iterator(v1.begin(), v2.begin(), v3.begin()),
               thrust::make_zip_iterator(v1.end(), v2.end(), v3.end()),
               cuda::std::tuple<T, T, T>(4, 7, 13));

  Vector ref1{4, 4, 4};
  ASSERT_EQUAL(ref1, v1);

  Vector ref2{7, 7, 7};
  ASSERT_EQUAL(ref2, v2);

  Vector ref3{13, 13, 13};
  ASSERT_EQUAL(ref3, v3);
};
DECLARE_VECTOR_UNITTEST(TestFillZipIterator);

void TestFillTuple()
{
  using T     = int;
  using Tuple = cuda::std::tuple<T, T>;

  thrust::host_vector<Tuple> h(3, Tuple(0, 0));
  thrust::device_vector<Tuple> d(3, Tuple(0, 0));

  thrust::fill(h.begin(), h.end(), Tuple(4, 7));
  thrust::fill(d.begin(), d.end(), Tuple(4, 7));

  ASSERT_EQUAL_QUIET(h, d);
};
DECLARE_UNITTEST(TestFillTuple);

struct TypeWithTrivialAssigment
{
  int x, y, z;
};

void TestFillWithTrivialAssignment()
{
  using T = TypeWithTrivialAssigment;

  thrust::host_vector<T> h(1);
  thrust::device_vector<T> d(1);

  ASSERT_EQUAL(h[0].x, 0);
  ASSERT_EQUAL(h[0].y, 0);
  ASSERT_EQUAL(h[0].z, 0);
  ASSERT_EQUAL(static_cast<T>(d[0]).x, 0);
  ASSERT_EQUAL(static_cast<T>(d[0]).y, 0);
  ASSERT_EQUAL(static_cast<T>(d[0]).z, 0);

  T val;
  val.x = 10;
  val.y = 20;
  val.z = -1;

  thrust::fill(h.begin(), h.end(), val);
  thrust::fill(d.begin(), d.end(), val);

  ASSERT_EQUAL(h[0].x, 10);
  ASSERT_EQUAL(h[0].y, 20);
  ASSERT_EQUAL(h[0].z, -1);
  ASSERT_EQUAL(static_cast<T>(d[0]).x, 10);
  ASSERT_EQUAL(static_cast<T>(d[0]).y, 20);
  ASSERT_EQUAL(static_cast<T>(d[0]).z, -1);
};
DECLARE_UNITTEST(TestFillWithTrivialAssignment);

struct TypeWithNonTrivialAssigment
{
  int x{0}, y{0}, z{0};

  TypeWithNonTrivialAssigment() = default;

  TypeWithNonTrivialAssigment(const TypeWithNonTrivialAssigment&) = default;

  _CCCL_HOST_DEVICE TypeWithNonTrivialAssigment& operator=(const TypeWithNonTrivialAssigment& t)
  {
    x = t.x;
    y = t.y;
    z = t.x + t.y;
    return *this;
  }

  _CCCL_HOST_DEVICE bool operator==(const TypeWithNonTrivialAssigment& t) const
  {
    return x == t.x && y == t.y && z == t.z;
  }
};

void TestFillWithNonTrivialAssignment()
{
  using T = TypeWithNonTrivialAssigment;

  thrust::host_vector<T> h(1);
  thrust::device_vector<T> d(1);

  ASSERT_EQUAL(h[0].x, 0);
  ASSERT_EQUAL(h[0].y, 0);
  ASSERT_EQUAL(h[0].z, 0);
  ASSERT_EQUAL(static_cast<T>(d[0]).x, 0);
  ASSERT_EQUAL(static_cast<T>(d[0]).y, 0);
  ASSERT_EQUAL(static_cast<T>(d[0]).z, 0);

  T val;
  val.x = 10;
  val.y = 20;
  val.z = -1;

  thrust::fill(h.begin(), h.end(), val);
  thrust::fill(d.begin(), d.end(), val);

  ASSERT_EQUAL(h[0].x, 10);
  ASSERT_EQUAL(h[0].y, 20);
  ASSERT_EQUAL(h[0].z, 30);
  ASSERT_EQUAL(static_cast<T>(d[0]).x, 10);
  ASSERT_EQUAL(static_cast<T>(d[0]).y, 20);
  ASSERT_EQUAL(static_cast<T>(d[0]).z, 30);
};
DECLARE_UNITTEST(TestFillWithNonTrivialAssignment);

template <typename ForwardIterator, typename T>
void fill(my_system& system, ForwardIterator /*first*/, ForwardIterator, const T&)
{
  system.validate_dispatch();
}

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

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

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

template <typename ForwardIterator, typename T>
void fill(my_tag, ForwardIterator first, ForwardIterator, const T&)
{
  *first = 13;
}

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

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

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

template <typename OutputIterator, typename Size, typename T>
OutputIterator fill_n(my_system& system, OutputIterator first, Size, const T&)
{
  system.validate_dispatch();
  return first;
}

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

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

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

template <typename OutputIterator, typename Size, typename T>
OutputIterator fill_n(my_tag, OutputIterator first, Size, const T&)
{
  *first = 13;
  return first;
}

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

  thrust::fill_n(thrust::retag<my_tag>(vec.begin()), vec.size(), 0);

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

_CCCL_DIAG_POP