/*******************************************************************************
 *
 * TRIQS: a Toolbox for Research in Interacting Quantum Systems
 *
 * Copyright (C) 2012 by O. Parcollet
 *
 * TRIQS is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.
 *
 * TRIQS is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * TRIQS. If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/
#ifndef TRIQS_ARRAYS_BLAS_LAPACK_GER_H
#define TRIQS_ARRAYS_BLAS_LAPACK_GER_H
#include "./tools.hpp"
#include "./qcache.hpp"

namespace triqs { namespace arrays { namespace blas { 

 using namespace blas_lapack_tools;
 namespace f77 { // overload
  typedef std::complex<double> dcomplex;

  extern "C" { 
   void TRIQS_FORTRAN_MANGLING(dger)(const int &M, const int &N, const double &, const double [], const int &, const double [], const int &, double [], const int &);
   void TRIQS_FORTRAN_MANGLING(zgeru)(const int &M, const int &N, const dcomplex &, const dcomplex [], const int &, const dcomplex [], const int &, dcomplex [], const int &);
  }

  inline void ger (const int & M, const int & N, const double & alpha, const double* x, const int & incx, const double* Y, const int & incy, double* A, const int & LDA)  { 
   TRIQS_FORTRAN_MANGLING(dger)(M, N, alpha, x, incx, Y, incy, A, LDA);
  }
  inline void ger (const int & M, const int & N, const dcomplex & alpha, const dcomplex* x, const int & incx, const dcomplex* Y, const int & incy, dcomplex* A, const int & LDA)  { 
   TRIQS_FORTRAN_MANGLING(zgeru)(M, N, alpha, x, incx, Y, incy, A, LDA);
  }
 }

 /**
  * Calls ger : A += alpha * x * ty
  * Takes care of making temporary copies if necessary
  */
 template< typename VTX, typename VTY, typename MT> 
  typename std::enable_if< is_blas_lapack_type<typename VTX::value_type>::value && have_same_value_type< VTX, VTY, MT>::value >::type 
  ger (typename VTX::value_type alpha, VTX const & X, VTY const & Y, MT & A) { 
   static_assert( is_amv_value_or_view_class<MT>::value, "ger : A must be a matrix or a matrix_view");
   if (( first_dim(A) != Y.size()) || (second_dim(A) != X.size())) TRIQS_RUNTIME_ERROR << "Dimension mismatch in ger : A : "<< get_shape(A()) <<" while X : "<<get_shape(X())<<" and Y : "<<get_shape(Y());
   const_qcache<VTX> Cx(X); // mettre la condition a la main
   const_qcache<VTY> Cy(Y); // mettre la condition a la main
   reflexive_qcache<MT> Ca(A);
   if (Ca().memory_layout_is_c()) // tA += alpha y tx  
    f77::ger(get_n_rows(Ca()), get_n_cols(Ca()), alpha, Cy().data_start(), Cy().stride(), Cx().data_start(), Cx().stride(), Ca().data_start(), get_ld(Ca()));
   else
    f77::ger(get_n_rows(Ca()), get_n_cols(Ca()), alpha, Cx().data_start(), Cx().stride(), Cy().data_start(), Cy().stride(), Ca().data_start(), get_ld(Ca()));

  /* std::cerr << " Meme labout  C"<< Ca().memory_layout_is_c()  << "  "<<A.memory_layout_is_c()<<std::endl ;
   std::cerr<< " has_contiguous_data(A) : "<< has_contiguous_data(A) << std::endl;
   std::cerr<< Ca()<< std::endl;  
   std::cerr<< Ca()(0,0) <<  "  "<< Ca()(1,0) <<  "  "<< Ca()(0,1) <<  "  "<< Ca()(1,1) <<  "  "<< std::endl;  
   std::cerr<< Ca().data_start()[0]<< "  "<< Ca().data_start()[1]<< "  "<< Ca().data_start()[2]<< "  " << Ca().data_start()[3]<< "  "<<std::endl;
  
   std::cerr<< A<< std::endl;  
   std::cerr<< A(0,0) <<  "  "<< A(1,0) <<  "  "<< A(0,1) <<  "  "<< A(1,1) <<  "  "<< std::endl;  
   std::cerr<< A.data_start()[0]<< "  "<< A.data_start()[1]<< "  "<< A.data_start()[2]<< "  " << A.data_start()[3]<< "  "<<std::endl;
*/

  }

  // to allow ger (alpha, x,y, M(..., ...)) i.e. a temporary view, which is not matched by previos templates
 // which require an lvalue
 template< typename A, typename VTX, typename VTY, typename V, ull_t Opt, ull_t To, bool W> 
 void ger (A alpha, VTX const & x, VTY const & y, matrix_view<V,Opt,To,W> && r) { ger(alpha,x,y,r);}

}}}// namespace
#endif