// SPDX-License-Identifier: Apache-2.0
// 
// Copyright 2008-2016 Conrad Sanderson (https://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
// 
// 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
// https://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.
// ------------------------------------------------------------------------


//! \addtogroup op_dotext
//! @{



template<typename eT>
inline
eT
op_dotext::direct_rowvec_mat_colvec
  (
  const eT*      A_mem,
  const Mat<eT>& B,
  const eT*      C_mem
  )
  {
  arma_debug_sigprint();
  
  const uword cost_AB = B.n_cols;
  const uword cost_BC = B.n_rows;
  
  if(cost_AB <= cost_BC)
    {
    podarray<eT> tmp(B.n_cols);
    
    for(uword col=0; col<B.n_cols; ++col)
      {
      const eT* B_coldata = B.colptr(col);
      
      eT val = eT(0);
      for(uword i=0; i<B.n_rows; ++i)
        {
        val += A_mem[i] * B_coldata[i];
        }
        
      tmp[col] = val;
      }
    
    return op_dot::direct_dot(B.n_cols, tmp.mem, C_mem);
    }
  else
    {
    podarray<eT> tmp(B.n_rows);
    
    for(uword row=0; row<B.n_rows; ++row)
      {
      eT val = eT(0);
      for(uword col=0; col<B.n_cols; ++col)
        {
        val += B.at(row,col) * C_mem[col];
        }
      
      tmp[row] = val;
      }
    
    return op_dot::direct_dot(B.n_rows, A_mem, tmp.mem);
    }
  
  
  }



template<typename eT>
inline
eT
op_dotext::direct_rowvec_transmat_colvec
  (
  const eT*      A_mem,
  const Mat<eT>& B,
  const eT*      C_mem
  )
  {
  arma_debug_sigprint();
  
  const uword cost_AB = B.n_rows;
  const uword cost_BC = B.n_cols;
  
  if(cost_AB <= cost_BC)
    {
    podarray<eT> tmp(B.n_rows);
    
    for(uword row=0; row<B.n_rows; ++row)
      {
      eT val = eT(0);
      
      for(uword i=0; i<B.n_cols; ++i)
        {
        val += A_mem[i] * B.at(row,i);
        }
        
      tmp[row] = val;
      }
    
    return op_dot::direct_dot(B.n_rows, tmp.mem, C_mem);
    }
  else
    {
    podarray<eT> tmp(B.n_cols);
    
    for(uword col=0; col<B.n_cols; ++col)
      {
      const eT* B_coldata = B.colptr(col);
      
      eT val = eT(0);
      
      for(uword i=0; i<B.n_rows; ++i)
        {
        val += B_coldata[i] * C_mem[i];
        }
      
      tmp[col] = val;
      }
    
    return op_dot::direct_dot(B.n_cols, A_mem, tmp.mem);
    }
  
  
  }



template<typename eT>
inline
eT
op_dotext::direct_rowvec_diagmat_colvec
  (
  const eT*      A_mem,
  const Mat<eT>& B,
  const eT*      C_mem
  )
  {
  arma_debug_sigprint();
  
  eT val = eT(0);

  for(uword i=0; i<B.n_rows; ++i)
    {
    val += A_mem[i] * B.at(i,i) * C_mem[i];
    }

  return val;
  }



template<typename eT>
inline
eT
op_dotext::direct_rowvec_invdiagmat_colvec
  (
  const eT*      A_mem,
  const Mat<eT>& B,
  const eT*      C_mem
  )
  {
  arma_debug_sigprint();
  
  eT val = eT(0);

  for(uword i=0; i<B.n_rows; ++i)
    {
    val += (A_mem[i] * C_mem[i]) / B.at(i,i);
    }

  return val;
  }



template<typename eT>
inline
eT
op_dotext::direct_rowvec_invdiagvec_colvec
  (
  const eT*      A_mem,
  const Mat<eT>& B,
  const eT*      C_mem
  )
  {
  arma_debug_sigprint();
  
  const eT* B_mem = B.mem;
  
  eT val = eT(0);

  for(uword i=0; i<B.n_elem; ++i)
    {
    val += (A_mem[i] * C_mem[i]) / B_mem[i];
    }

  return val;
  }



//! @}