// @HEADER
// *****************************************************************************
//     Compadre: COMpatible PArticle Discretization and REmap Toolkit
//
// Copyright 2018 NTESS and the Compadre contributors.
// SPDX-License-Identifier: BSD-2-Clause
// *****************************************************************************
// @HEADER
#include "Compadre_LinearAlgebra_Definitions.hpp"

#include "KokkosBatched_UTV_Decl.hpp"
#include "KokkosBatched_SolveUTV_Decl_Compadre.hpp"

using namespace KokkosBatched;

namespace Compadre{
namespace GMLS_LinearAlgebra {

  template<typename DeviceType,
           typename AlgoTagType,
           typename MatrixViewType_A,
           typename MatrixViewType_B,
           typename MatrixViewType_X>
  struct Functor_TestBatchedTeamVectorSolveUTV {
    MatrixViewType_A _a;
    MatrixViewType_B _b;

    int _pm_getTeamScratchLevel_0;
    int _pm_getTeamScratchLevel_1;
    int _M, _N, _NRHS;
    bool _implicit_RHS;

    KOKKOS_INLINE_FUNCTION
    Functor_TestBatchedTeamVectorSolveUTV(
                      const int M,
                      const int N,
                      const int NRHS,
                      const MatrixViewType_A &a,
                      const MatrixViewType_B &b,
                      const bool implicit_RHS)
      : _a(a), _b(b), _M(M), _N(N), _NRHS(NRHS), _implicit_RHS(implicit_RHS) 
        { _pm_getTeamScratchLevel_0 = 0; _pm_getTeamScratchLevel_1 = 0; }

    template<typename MemberType>
    KOKKOS_INLINE_FUNCTION
    void operator()(const MemberType &member) const {

      const int k = member.league_rank();

      // workspace vectors
      scratch_vector_type ww_fast(member.team_scratch(_pm_getTeamScratchLevel_0), 3*_M);
      scratch_vector_type ww_slow(member.team_scratch(_pm_getTeamScratchLevel_1), _N*_NRHS);

      scratch_matrix_right_type aa(_a.data() + TO_GLOBAL(k)*TO_GLOBAL(_a.extent(1))*TO_GLOBAL(_a.extent(2)), 
              _a.extent(1), _a.extent(2));
      scratch_matrix_right_type bb(_b.data() + TO_GLOBAL(k)*TO_GLOBAL(_b.extent(1))*TO_GLOBAL(_b.extent(2)), 
              _b.extent(1), _b.extent(2));
      scratch_matrix_right_type xx(_b.data() + TO_GLOBAL(k)*TO_GLOBAL(_b.extent(1))*TO_GLOBAL(_b.extent(2)), 
              _b.extent(1), _b.extent(2));

      // if sizes don't match extents, then copy to a view with extents matching sizes
      if ((size_t)_M!=_a.extent(1) || (size_t)_N!=_a.extent(2)) {
        scratch_matrix_right_type tmp(ww_slow.data(), _M, _N);
        auto aaa = scratch_matrix_right_type(_a.data() + TO_GLOBAL(k)*TO_GLOBAL(_a.extent(1))*TO_GLOBAL(_a.extent(2)), _M, _N);
        // copy A to W, then back to A
        Kokkos::parallel_for(Kokkos::TeamThreadRange(member,0,_M),[&](const int &i) {
          Kokkos::parallel_for(Kokkos::ThreadVectorRange(member,0,_N),[&](const int &j) {
              tmp(i,j) = aa(i,j);
          });
        });
        member.team_barrier();
        Kokkos::parallel_for(Kokkos::TeamThreadRange(member,0,_M),[&](const int &i) {
          Kokkos::parallel_for(Kokkos::ThreadVectorRange(member,0,_N),[&](const int &j) {
              aaa(i,j) = tmp(i,j);
          });
        });
        member.team_barrier();
        aa = aaa;
      }

      if (std::is_same<typename MatrixViewType_B::array_layout, layout_left>::value) {
        scratch_matrix_right_type tmp(ww_slow.data(), _N, _NRHS);
        // coming from LU
        // then copy B to W, then back to B
        auto bb_left = 
            scratch_matrix_left_type(_b.data() + TO_GLOBAL(k)*TO_GLOBAL(_b.extent(1))*TO_GLOBAL(_b.extent(2)), 
                    _b.extent(1), _b.extent(2));
        Kokkos::parallel_for(Kokkos::TeamThreadRange(member,0,_N),[&](const int &i) {
          Kokkos::parallel_for(Kokkos::ThreadVectorRange(member,0,_NRHS),[&](const int &j) {
              tmp(i,j) = bb_left(i,j);
          });
        });
        member.team_barrier();
        Kokkos::parallel_for(Kokkos::TeamThreadRange(member,0,_N),[&](const int &i) {
          Kokkos::parallel_for(Kokkos::ThreadVectorRange(member,0,_NRHS),[&](const int &j) {
              bb(i,j) = tmp(i,j);
          });
        });
      }

      scratch_matrix_right_type uu(member.team_scratch(_pm_getTeamScratchLevel_1), _M, _N /* only N columns of U are filled, maximum */);
      scratch_matrix_right_type vv(member.team_scratch(_pm_getTeamScratchLevel_1), _N, _N);
      scratch_local_index_type pp(member.team_scratch(_pm_getTeamScratchLevel_0), _N);

      bool do_print = false;
      if (do_print) {
        Kokkos::single(Kokkos::PerTeam(member), [&] () {
          using Kokkos::printf;
          //print a
          printf("a=zeros(%lu,%lu);\n", aa.extent(0), aa.extent(1));
              for (size_t i=0; i<aa.extent(0); ++i) {
                  for (size_t j=0; j<aa.extent(1); ++j) {
                      printf("a(%lu,%lu)= %f;\n", i+1,j+1, aa(i,j));
                  }
              }
          //print b
          printf("b=zeros(%lu,%lu);\n", bb.extent(0), bb.extent(1));
              for (size_t i=0; i<bb.extent(0); ++i) {
                  for (size_t j=0; j<bb.extent(1); ++j) {
                      printf("b(%lu,%lu)= %f;\n", i+1,j+1, bb(i,j));
                  }
              }
        });
      }
      do_print = false;

      /// Solving Ax = b using UTV transformation
      /// A P^T P x = b
      /// UTV P x = b;

      /// UTV = A P^T
      int matrix_rank(0);
      member.team_barrier();
      TeamVectorUTV<MemberType,AlgoTagType>
        ::invoke(member, aa, pp, uu, vv, ww_fast, matrix_rank);
      member.team_barrier();

      if (do_print) {
        Kokkos::single(Kokkos::PerTeam(member), [&] () {
        using Kokkos::printf;
        printf("matrix_rank: %d\n", matrix_rank);
        //print u
        printf("u=zeros(%lu,%lu);\n", uu.extent(0), uu.extent(1));
        for (size_t i=0; i<uu.extent(0); ++i) {
            for (size_t j=0; j<uu.extent(1); ++j) {
                printf("u(%lu,%lu)= %f;\n", i+1,j+1, uu(i,j));
            }
        }
        });
      }
      TeamVectorSolveUTVCompadre<MemberType,AlgoTagType>
        ::invoke(member, matrix_rank, _M, _N, _NRHS, uu, aa, vv, pp, bb, xx, ww_slow, ww_fast, _implicit_RHS);
      member.team_barrier();

    }

    inline
    void run(ParallelManager pm) {
      typedef typename MatrixViewType_A::non_const_value_type value_type;
      std::string name_region("KokkosBatched::Test::TeamVectorSolveUTVCompadre");
      std::string name_value_type = ( std::is_same<value_type,float>::value ? "::Float" :
                                      std::is_same<value_type,double>::value ? "::Double" :
                                      std::is_same<value_type,Kokkos::complex<float> >::value ? "::ComplexFloat" :
                                      std::is_same<value_type,Kokkos::complex<double> >::value ? "::ComplexDouble" : "::UnknownValueType" );
      std::string name = name_region + name_value_type;
      Kokkos::Profiling::pushRegion( name.c_str() );

      _pm_getTeamScratchLevel_0 = pm.getTeamScratchLevel(0);
      _pm_getTeamScratchLevel_1 = pm.getTeamScratchLevel(1);
      
      int scratch_size = scratch_matrix_right_type::shmem_size(_N, _N); // V
      scratch_size += scratch_matrix_right_type::shmem_size(_M, _N /* only N columns of U are filled, maximum */); // U
      scratch_size += scratch_vector_type::shmem_size(_N*_NRHS); // W (for SolveUTV)

      int l0_scratch_size = scratch_vector_type::shmem_size(_N); // P (temporary)
      l0_scratch_size += scratch_vector_type::shmem_size(3*_M); // W (for UTV)

      pm.clearScratchSizes();
      pm.setTeamScratchSize(0, l0_scratch_size);
      pm.setTeamScratchSize(1, scratch_size);

      pm.CallFunctorWithTeamThreadsAndVectors(*this, _a.extent(0));
      Kokkos::fence();

      Kokkos::Profiling::popRegion();
    }
  };



template <typename A_layout, typename B_layout, typename X_layout>
void batchQRPivotingSolve(ParallelManager pm, double *A, int lda, int nda, double *B, int ldb, int ndb, int M, int N, int NRHS, const int num_matrices, const bool implicit_RHS) {

    typedef Algo::UTV::Unblocked algo_tag_type;
    typedef Kokkos::View<double***, A_layout, Kokkos::MemoryTraits<Kokkos::Unmanaged> >
                    MatrixViewType_A;
    typedef Kokkos::View<double***, B_layout, Kokkos::MemoryTraits<Kokkos::Unmanaged> >
                    MatrixViewType_B;
    typedef Kokkos::View<double***, X_layout, Kokkos::MemoryTraits<Kokkos::Unmanaged> >
                    MatrixViewType_X;

    MatrixViewType_A mat_A(A, num_matrices, lda, nda);
    MatrixViewType_B mat_B(B, num_matrices, ldb, ndb);

    Functor_TestBatchedTeamVectorSolveUTV
      <device_execution_space, algo_tag_type, MatrixViewType_A, MatrixViewType_B, MatrixViewType_X>(M,N,NRHS,mat_A,mat_B,implicit_RHS).run(pm);

}

template void batchQRPivotingSolve<layout_right, layout_right, layout_right>(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_right, layout_right, layout_left >(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_right, layout_left , layout_right>(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_right, layout_left , layout_left >(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_left , layout_right, layout_right>(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_left , layout_right, layout_left >(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_left , layout_left , layout_right>(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);
template void batchQRPivotingSolve<layout_left , layout_left , layout_left >(ParallelManager,double*,int,int,double*,int,int,int,int,int,const int,const bool);

} // GMLS_LinearAlgebra
} // Compadre
