/* clang-format off */
//ff-c++-LIBRARY-dep: cxx11
//ff-c++-cpp-dep:
/* clang-format on */

// -*- C++ -*-
// Time-stamp: "2018-07-05 14:34:38 fujiwara"
// $Id$
// Author: fujiwara@acs.i.kyoto-u.ac.jp
//----------------------------------------------------------------------
//  Get Linear Equation from FreeFem++ in the HB (Harwell-Boeing) format
//  Japan SIAM, Nagoya, Sept. 2018
//----------------------------------------------------------------------
#include <iostream>
#include <cstdlib>
#include <fstream>
#include <complex>
#include <type_traits>

#include "ff++.hpp"
#include "AFunction_ext.hpp"

void output_matrix_entries(ofstream &fout, const int N, const double *const ccs_val,
                           const int nnzero, const double *const b) {
  for (int i = 0; i < nnzero; i++) {

    fout << setw(20) << setprecision(17) << setiosflags(ios::scientific) << ccs_val[i];

    if ((i + 1) % 4 == 0) fout << std::endl;
  }
  if (nnzero % 4 != 0) fout << std::endl;

  for (int i = 0; i < N; i++) {

    fout << setw(20) << setprecision(17) << setiosflags(ios::scientific) << b[i];

    if ((i + 1) % 4 == 0) fout << std::endl;
  }
  if (N % 4 != 0) fout << std::endl;

  return;
}

void output_matrix_entries(ofstream &fout, const int N, const complex< double > *const ccs_val,
                           const int nnzero, const complex< double > *const b) {
  for (int i = 0; i < nnzero; i++) {

    fout << setw(20) << setprecision(17) << setiosflags(ios::scientific) << ccs_val[i].real( )
         << setw(20) << setprecision(17) << setiosflags(ios::scientific) << ccs_val[i].imag( );

    if ((i + 1) % 2 == 0) fout << std::endl;
  }
  if (nnzero % 2 != 0) fout << std::endl;

  for (int i = 0; i < N; i++) {

    fout << setw(20) << setprecision(17) << setiosflags(ios::scientific) << b[i].real( ) << setw(20)
         << setprecision(17) << setiosflags(ios::scientific) << b[i].imag( );

    if ((i + 1) % 2 == 0) fout << std::endl;
  }
  if (N % 2 != 0) fout << std::endl;

  return;
}

template< typename R >
long SaveHB(std::string *const &hb_filename, Matrice_Creuse< R > *const &sparse_mat,
            KN_< R > const &b, std::string *const &hb_title) {
  MatriceMorse< R > *A = sparse_mat->pHM( );

  const bool isDouble = sizeof(R) == sizeof(double);    // std::is_floating_point<R>::value;

  if (!A) return 1;    // error

  // A->M = A->N : size of problem
  // A->nbcoef   : # of non-zero entries in the matrix A
  // A->a[i]     : CRS, entry, 0 <= i < A->nbcoef
  // A->cl[i]    : CRS, column indexes, 0 <= i < A->nbcoef
  // A->lg[r]    : CRS, row starting location, 0 <= r < A->m
  // A->lg[A->M] : # of non-zero elements ( == A->nbcoef)

  // b->N()      : size
  // b[i]        : i-th element

  const int N = A->N;
  const int M = A->M;
  if (N != M) return 1;

  std::cout << "SaveHB : # of unknowns = " << N << std::endl;

  const int nnzero = A->nnz;

  std::cout << "SaveHB : # of non-zero entries in A = " << nnzero << std::endl;
  int *col_ptr, *row_ind;
  R *ccs_val;
  A->setfortran(true);
  A->CSC(col_ptr, row_ind, ccs_val);

  //--------------------------------------------------
  // File
  //--------------------------------------------------
  std::ofstream fout(hb_filename->c_str( ));
  if (!fout) {
    std::cerr << "Cannot open the file : " << hb_filename->c_str( ) << std::endl;
    std::exit(1);
  }

  std::cout << "SaveHB : filename = " << hb_filename->c_str( ) << std::endl;

  //--------------------------------------------------
  // Header of the HB format
  //--------------------------------------------------
  const int bufsize = 1024;
  char buf[bufsize];

  // Line 1
  const int HB_TITLE_LENGTH = 72;
  memset(buf, '\0', bufsize);
  strncpy(buf, hb_title->c_str( ), HB_TITLE_LENGTH - 1);
  std::cout << "SaveHB : title = " << buf << std::endl;

  for (int i = 0; i < HB_TITLE_LENGTH - strlen(hb_title->c_str( )); i++) strcat(buf, " ");

  strcat(buf, "     KEY");
  fout << buf << std::endl;

  // Line 2
  int ptrcrd = (N + 1) / 8;    // #lines for pointers
  if ((N + 1) % 8 != 0) ptrcrd += 1;

  int indcrd = nnzero / 8;    // #lines for row (or variable) indices
  if (nnzero % 8 != 0) indcrd += 1;

  int valcrd = (isDouble) ? nnzero / 4 : (2 * nnzero) / 4;    // #lines for numerical values
  if (nnzero % 4 != 0) valcrd += 1;

  int rhscrd = (isDouble) ? N / 4 : (2 * N / 4);    // #lines for right-hand sides
  if (N % 4 != 0) rhscrd += 1;

  // #data lines excluding header
  int totcrd = ptrcrd + indcrd + valcrd + rhscrd;
  snprintf(buf, bufsize, "%14d%14d%14d%14d%14d", totcrd, ptrcrd, indcrd, valcrd, rhscrd);
  fout << buf << std::endl;

  // Line 3 : MXTYPE, NROW, NCOL, NNZERO, NELTVL
  const int neltvl = 0;    // #elemental matrix entries, assembled matrix=0
  if (isDouble)
    snprintf(buf, bufsize, "RUA           %14d%14d%14d%14d", N, N, nnzero, neltvl);    // double
  else
    snprintf(buf, bufsize, "CUA           %14d%14d%14d%14d", N, N, nnzero, neltvl);    // complex<double>
  fout << buf << std::endl;

  // Line 4
  //   PTRFMT : Format for Pointers
  //   INDFMT : Format for row (or variable) indices
  //   VALFMT : Format for numerical values of coefficient matrix
  //   RHSFMT : Format for numerical values of right-hand side
  fout << "(8I10)          (8I10)          (4E20.12)           (4E20.12)" << std::endl;

  // Line 5
  //  F : Right-hand side type (full storage)
  //  NRHS : #right-hand sides
  //  NRHSIX : #row indices
  fout << "F                          1             0" << std::endl;

  //--------------------------------------------------
  // Body
  //--------------------------------------------------
  for (int i = 0; i <= N; i++) {
    fout << setw(10) << col_ptr[i];
    if ((i + 1) % 8 == 0) fout << std::endl;
  }
  if ((N + 1) % 8 != 0) fout << std::endl;

  for (int i = 0; i < nnzero; i++) {
    fout << setw(10) << row_ind[i];
    if ((i + 1) % 8 == 0) fout << std::endl;
  }
  if (nnzero % 8 != 0) fout << std::endl;

  output_matrix_entries(fout, N, ccs_val, nnzero, b);

  fout.close( );

  A->setfortran(false);
  return 0;
}

static void Load_Init( ) {    // le constructeur qui ajoute la fonction "splitmesh3"  a freefem++
  if (verbosity) {
    cout << " load: SaveHB  " << endl;
  }

  Global.Add(
    "SaveHB", "(",
    new OneOperator4_< long, string *, Matrice_Creuse< double > *, KN_< double >, string * >(
      SaveHB));
  Global.Add("SaveHB", "(",
             new OneOperator4_< long, string *, Matrice_Creuse< std::complex< double > > *,
                                KN_< std::complex< double > >, string * >(SaveHB));
}
LOADFUNC(Load_Init)
//----------------------------------------------------------------------
// End of file
//----------------------------------------------------------------------
