/* F03BN_T1W_F C++ Header Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 * Mark 27, 2019.
 */

#include <dco.hpp>
#include <nag.h>
#include <nagx04.h>
#include <nagad.h>
#include <stdio.h>
#include <string>
#include <iostream>
using namespace std;

int main(void)
{
  int       exit_status = 0;
  void      *ad_handle = 0;
  Integer   ifail = 0;

  cout << "F03BN_T1W_F C++ Header Example Program Results\n\n";
  // Skip heading in data file
  string mystr;
  getline (cin, mystr);

  // Read problem size and number of right-hand-sides 
  Integer n;
  cin >> n;

  // Allocate arrays containing A and its factorized form, B
  // and the solution X.
  nagad_t1w_w_ctype *a=0, *a_in=0;
  nagad_t1w_w_rtype *a_r=0, *a_i=0;
  Complex           *ar=0;
  Integer           *ipiv=0;
  a    =  new nagad_t1w_w_ctype [n*n];  
  a_in =  new nagad_t1w_w_ctype [n*n];
  a_r  =  new nagad_t1w_w_rtype [n*n];
  a_i  =  new nagad_t1w_w_rtype [n*n];
  ipiv =  new Integer           [n];  
  ar   =  new Complex           [n*n];
  
  // Read the matrix A, register and copy
  double dr, di;
  for (int i = 0; i<n; ++i) {
    for (int j = 0; j<n; ++j) {
      cin >> dr >> di;
      Integer k = i + j*n;
      a_r[k] = dr;
      a_i[k] = di;
      ar[k].re = dr;
      ar[k].im = di;
    }
  }

  // Print matrix A
  cout << endl;
  NagError  fail;
  INIT_FAIL(fail);
  x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
         "  A",0,&fail);

  // Create AD configuration data object
  ifail = 0;
  x10aa_t1w_f_(ad_handle,ifail);

  for (int i=0; i<n; i++) {
    for (int j=0; j<n; j++) {
      Integer k = i + j*n;

      for (int r=0; r<2; ++r) {
        double inc = 1.0;
        if (r==0) {
          nagad_t1w_inc_derivative(&a_r[k],inc);
        } else {
          nagad_t1w_inc_derivative(&a_i[k],inc);
        }

        for (int p = 0; p<n; ++p) {
          for (int q = 0; q<n; ++q) {
            Integer l = p + q*n;
            a[l].real(a_r[l]);
            a[l].imag(a_i[l]);
          }
        }
        // Factorize the matrix A
        ifail = 0;
        f07ar_t1w_f_(ad_handle,n,n,a,n,ipiv,ifail);

        if (i==0 && j==0 && r==0) {
          // Print Factorization of A
          for (int p = 0; p<n; p++) {
            for (int q = 0; q<n; q++) {
              int l = p + q*n;
              
              nagad_t1w_w_rtype akr, aki;
              akr = real(a[l]);
              aki = imag(a[l]);
              ar[l].re = nagad_t1w_get_value(akr);
              ar[l].im = nagad_t1w_get_value(aki);
            }
          }
          cout << endl;
          // NagError  fail;
          INIT_FAIL(fail);
          x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
                 "  Array A after factorization",0,&fail);
        }

        nagad_t1w_w_ctype d;
        Integer           id[2];
        d = 0;
        ifail = 0;
        f03bn_t1w_f_(ad_handle,n,a,n,ipiv,d,id,ifail);

        if (i==0 && j==0 && r==0) {
          nagad_t1w_w_rtype dcr, dci;
          dcr = real(d);
          dci = imag(d);
          dr = nagad_t1w_get_value(dcr);
          di = nagad_t1w_get_value(dci);
          cout << " d = (" << dr << "," << di << ") id = ";
          cout << id[0] << ", " << id[1];
          dr = dr*pow(2.0,id[0]);
          di = di*pow(2.0,id[1]);
          cout << "\n\n value of determinant = (" << dr << "," << di << ")";
          cout << endl;
        }

        // Obtain derivatives
        nagad_t1w_w_rtype dt;
        dt = real(d);
        double ddr = nagad_t1w_get_derivative(dt);
        double zero = 0.0;
        if (r==0) {
          ar[k].re = ddr;
          nagad_t1w_set_derivative(&a_r[k],zero);
        } else {
          ar[k].im = ddr;
          nagad_t1w_set_derivative(&a_i[k],zero);
        }
      }
    }
  }

  cout << "\n\n Derivatives calculated: First order tangents\n";
  cout << " Computational mode    : algorithmic\n";
  cout << "\n Derivatives of real(d) w.r.t A:\n";

  // Print derivatives
  cout << endl;
  INIT_FAIL(fail);
  x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
         "           d(dreal)/da(i,j)",0,&fail);

 END:
  // Remove computational data object
  ifail = 0;
  x10ab_t1w_f_(ad_handle,ifail);

  delete [] a;
  delete [] a_in;
  delete [] a_r;
  delete [] a_i;
  delete [] ipiv;
  delete [] ar;
  
  return exit_status;
}