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

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

#include "KokkosBatched_Trsm_Decl.hpp"
#include "KokkosBatched_Trsm_Serial_Impl.hpp"

#include "KokkosKernels_TestUtils.hpp"

using namespace KokkosBatched;

namespace Test {
namespace Trsm {

template <typename S, typename U, typename T, typename D>
struct ParamTag {
  typedef S side;
  typedef U uplo;
  typedef T trans;
  typedef D diag;
};

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

  ScalarType _alpha;

  KOKKOS_INLINE_FUNCTION
  Functor_TestBatchedSerialTrsm(const ScalarType alpha, const ViewType &a,
                                const ViewType &b)
      : _a(a), _b(b), _alpha(alpha) {}

  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(), Kokkos::ALL());

    SerialTrsm<typename ParamTagType::side, typename ParamTagType::uplo,
               typename ParamTagType::trans, typename ParamTagType::diag,
               AlgoTagType>::invoke(_alpha, aa, bb);
  }

  inline void run() {
    typedef typename ViewType::value_type value_type;
    std::string name_region("KokkosBatched::Test::SerialTrsm");
    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, _b.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_trsm(const int N, const int BlkSize, const int NumCols) {
  typedef typename ViewType::value_type value_type;
  typedef Kokkos::Details::ArithTraits<value_type> ats;

  /// randomized input testing views
  ScalarType alpha(1.0);

  const bool is_side_right =
      std::is_same<typename ParamTagType::side, Side::Right>::value;
  const int b_nrows = is_side_right ? NumCols : BlkSize;
  const int b_ncols = is_side_right ? BlkSize : NumCols;
  ViewType a0("a0", N, BlkSize, BlkSize), a1("a1", N, BlkSize, BlkSize),
      b0("b0", N, b_nrows, b_ncols), b1("b1", N, b_nrows, b_ncols);

  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::fence();

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

  Functor_TestBatchedSerialTrsm<DeviceType, ViewType, ScalarType, ParamTagType,
                                Algo::Trsm::Unblocked>(alpha, a0, b0)
      .run();
  Functor_TestBatchedSerialTrsm<DeviceType, ViewType, ScalarType, ParamTagType,
                                AlgoTagType>(alpha, a1, b1)
      .run();

  Kokkos::fence();

  /// for comparison send it to host
  typename ViewType::HostMirror b0_host = Kokkos::create_mirror_view(b0);
  typename ViewType::HostMirror b1_host = Kokkos::create_mirror_view(b1);

  Kokkos::deep_copy(b0_host, b0);
  Kokkos::deep_copy(b1_host, b1);

  /// check b0 = b1 ; 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 < b_nrows; ++i)
      for (int j = 0; j < b_ncols; ++j) {
        sum += ats::abs(b0_host(k, i, j));
        diff += ats::abs(b0_host(k, i, j) - b1_host(k, i, j));
      }
  EXPECT_NEAR_KK(diff / sum, 0.0, eps);
}
}  // namespace Trsm
}  // namespace Test

template <typename DeviceType, typename ValueType, typename ScalarType,
          typename ParamTagType, typename AlgoTagType>
int test_batched_trsm() {
#if defined(KOKKOSKERNELS_INST_LAYOUTLEFT)
  {
    typedef Kokkos::View<ValueType ***, Kokkos::LayoutLeft, DeviceType>
        ViewType;
    Test::Trsm::impl_test_batched_trsm<DeviceType, ViewType, ScalarType,
                                       ParamTagType, AlgoTagType>(0, 10, 4);
    for (int i = 0; i < 10; ++i) {
      // printf("Testing: LayoutLeft,  Blksize %d\n", i);
      Test::Trsm::impl_test_batched_trsm<DeviceType, ViewType, ScalarType,
                                         ParamTagType, AlgoTagType>(1024, i, 4);
      Test::Trsm::impl_test_batched_trsm<DeviceType, ViewType, ScalarType,
                                         ParamTagType, AlgoTagType>(1024, i, 1);
    }
  }
#endif
#if defined(KOKKOSKERNELS_INST_LAYOUTRIGHT)
  {
    typedef Kokkos::View<ValueType ***, Kokkos::LayoutRight, DeviceType>
        ViewType;
    Test::Trsm::impl_test_batched_trsm<DeviceType, ViewType, ScalarType,
                                       ParamTagType, AlgoTagType>(0, 10, 4);
    for (int i = 0; i < 10; ++i) {
      // printf("Testing: LayoutRight, Blksize %d\n", i);
      Test::Trsm::impl_test_batched_trsm<DeviceType, ViewType, ScalarType,
                                         ParamTagType, AlgoTagType>(1024, i, 4);
      Test::Trsm::impl_test_batched_trsm<DeviceType, ViewType, ScalarType,
                                         ParamTagType, AlgoTagType>(1024, i, 1);
    }
  }
#endif

  return 0;
}
