/// \author Kyungjoo Kim (kyukim@sandia.gov)

#include "gtest/gtest.h"
#include "Kokkos_Core.hpp"
#include "Kokkos_Random.hpp"

//#include "KokkosBatched_Vector.hpp"

#include "KokkosBatched_Gemv_Decl.hpp"
#include "KokkosBatched_Gemv_Serial_Impl.hpp"

#include "KokkosKernels_TestUtils.hpp"

using namespace KokkosBatched;

namespace Test {
namespace Gemv {

template <typename T>
struct ParamTag {
  typedef T trans;
};

template <typename DeviceType, typename ViewType, typename ScalarType,
          typename ParamTagType, typename AlgoTagType>
struct Functor_TestBatchedSerialGemv {
  ViewType _a, _b, _c;

  ScalarType _alpha, _beta;

  KOKKOS_INLINE_FUNCTION
  Functor_TestBatchedSerialGemv(const ScalarType alpha, const ViewType &a,
                                const ViewType &b, const ScalarType beta,
                                const ViewType &c)
      : _a(a), _b(b), _c(c), _alpha(alpha), _beta(beta) {}

  KOKKOS_INLINE_FUNCTION
  void operator()(const ParamTagType &, const int k) const {
    auto aa = Kokkos::subview(_a, k, Kokkos::ALL(), Kokkos::ALL());
    auto bb = Kokkos::subview(_b, k, Kokkos::ALL(), 0);
    auto cc = Kokkos::subview(_c, k, Kokkos::ALL(), 0);

    SerialGemv<typename ParamTagType::trans, AlgoTagType>::invoke(
        _alpha, aa, bb, _beta, cc);
  }

  inline void run() {
    typedef typename ViewType::value_type value_type;
    std::string name_region("KokkosBatched::Test::SerialGemv");
    const std::string name_value_type = Test::value_type_name<value_type>();
    std::string name                  = name_region + name_value_type;
    Kokkos::Profiling::pushRegion(name.c_str());
    Kokkos::RangePolicy<DeviceType, ParamTagType> policy(0, _c.extent(0));
    Kokkos::parallel_for(name.c_str(), policy, *this);
    Kokkos::Profiling::popRegion();
  }
};

template <typename DeviceType, typename ViewType, typename ScalarType,
          typename ParamTagType, typename AlgoTagType>
void impl_test_batched_gemv(const int N, const int BlkSize) {
  typedef typename ViewType::value_type value_type;
  typedef Kokkos::Details::ArithTraits<value_type> ats;

  /// randomized input testing views
  ScalarType alpha = 1.5, beta = 3.0;

  ViewType a0("a0", N, BlkSize, BlkSize), a1("a1", N, BlkSize, BlkSize),
      b0("b0", N, BlkSize, 1), b1("b1", N, BlkSize, 1), c0("c0", N, BlkSize, 1),
      c1("c1", N, BlkSize, 1);

  Kokkos::Random_XorShift64_Pool<typename DeviceType::execution_space> random(
      13718);
  Kokkos::fill_random(a0, random, value_type(1.0));
  Kokkos::fill_random(b0, random, value_type(1.0));
  Kokkos::fill_random(c0, random, value_type(1.0));

  Kokkos::fence();

  Kokkos::deep_copy(a1, a0);
  Kokkos::deep_copy(b1, b0);
  Kokkos::deep_copy(c1, c0);

  /// test body
  Functor_TestBatchedSerialGemv<DeviceType, ViewType, ScalarType, ParamTagType,
                                Algo::Gemv::Unblocked>(alpha, a0, b0, beta, c0)
      .run();
  Functor_TestBatchedSerialGemv<DeviceType, ViewType, ScalarType, ParamTagType,
                                AlgoTagType>(alpha, a1, b1, beta, c1)
      .run();

  Kokkos::fence();

  /// for comparison send it to host
  typename ViewType::HostMirror c0_host = Kokkos::create_mirror_view(c0);
  typename ViewType::HostMirror c1_host = Kokkos::create_mirror_view(c1);

  Kokkos::deep_copy(c0_host, c0);
  Kokkos::deep_copy(c1_host, c1);

  /// check c0 = c1 ; this eps is about 10^-14
  typedef typename ats::mag_type mag_type;
  mag_type sum(1), diff(0);
  const mag_type eps = 1.0e3 * ats::epsilon();

  for (int k = 0; k < N; ++k)
    for (int i = 0; i < BlkSize; ++i)
      for (int j = 0; j < 1; ++j) {
        sum += ats::abs(c0_host(k, i, j));
        diff += ats::abs(c0_host(k, i, j) - c1_host(k, i, j));
      }
  EXPECT_NEAR_KK(diff / sum, 0, eps);
}
}  // namespace Gemv
}  // namespace Test

template <typename DeviceType, typename ValueType, typename ScalarType,
          typename ParamTagType, typename AlgoTagType>
int test_batched_gemv() {
#if defined(KOKKOSKERNELS_INST_LAYOUTLEFT)
  {
    typedef Kokkos::View<ValueType ***, Kokkos::LayoutLeft, DeviceType>
        ViewType;
    Test::Gemv::impl_test_batched_gemv<DeviceType, ViewType, ScalarType,
                                       ParamTagType, AlgoTagType>(0, 10);
    for (int i = 0; i < 10; ++i) {
      // printf("Testing: LayoutLeft,  Blksize %d\n", i);
      Test::Gemv::impl_test_batched_gemv<DeviceType, ViewType, ScalarType,
                                         ParamTagType, AlgoTagType>(1024, i);
    }
  }
#endif
#if defined(KOKKOSKERNELS_INST_LAYOUTRIGHT)
  {
    typedef Kokkos::View<ValueType ***, Kokkos::LayoutRight, DeviceType>
        ViewType;
    Test::Gemv::impl_test_batched_gemv<DeviceType, ViewType, ScalarType,
                                       ParamTagType, AlgoTagType>(0, 10);
    for (int i = 0; i < 10; ++i) {
      // printf("Testing: LayoutRight, Blksize %d\n", i);
      Test::Gemv::impl_test_batched_gemv<DeviceType, ViewType, ScalarType,
                                         ParamTagType, AlgoTagType>(1024, i);
    }
  }
#endif

  return 0;
}
