/* F07AR_T1W_F C++ Header Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 * Mark 27, 2019.
 */

#include <dco_light.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 << "F07AR_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, *work=0;
  nagad_t1w_w_rtype *a_r=0, *a_i=0;
  Complex           *ar=0, *drda=0, *dida=0;
  Integer           *ipiv=0;
  Integer           lwork = 64*n;
  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];
  work = new nagad_t1w_w_ctype [lwork];
  ipiv = new Integer [n];
  ar   = new Complex [n*n];
  drda = new Complex [n*n];
  dida = 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) {
      Integer k = i + j*n;
      cin >> dr >> di;
      a_r[k] = dr;
      a_i[k] = di;
      ar[k].re = dr;
      ar[k].im = di;
    }
  }

  // Print matrix A
  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<2*n; ++i) {
    Integer k;
    double inc = 1.0;
    if (i<n) {
      k = i*(n+1);
      nagad_t1w_inc_derivative(&a_r[k],inc);
    } else {
      k = (i-n)*(n+1);
      nagad_t1w_inc_derivative(&a_i[k],inc);
    }
    for (int j=0; j<n*n; ++j) {
      a[j].real(a_r[j]);
      a[j].imag(a_i[j]);
    }
    // Factorize the matrix A
    ifail = 0;
    f07ar_t1w_f_(ad_handle,n,n,a,n,ipiv,ifail);

    // Invert A
    ifail = 0;
    f07aw_t1w_f_(ad_handle,n,a,n,ipiv,work,lwork,ifail);
  
    double zero = 0.0;
    if (i<n) {
      nagad_t1w_set_derivative(&a_r[k],zero);
    } else {
      nagad_t1w_set_derivative(&a_i[k],zero);
    }

    for (int j=0; j<n; j++) {
      nagad_t1w_w_rtype dar, dai;
      Integer p = j + j*n;
      dar = real(a[p]);
      dai = imag(a[p]);
      double da = nagad_t1w_get_derivative(dar);
      double di = nagad_t1w_get_derivative(dai);
      if (i<n) {
        Integer l = j + i*n;
        drda[l].re = da;
        drda[l].im = di;
      } else {
        Integer l = j + (i-n)*n;
        dida[l].re = da;
        dida[l].im = di;
      }
    }
  }
    
  // Print Inverse
  for (int i = 0; i<n*n; i++) {
    nagad_t1w_w_rtype akr, aki;
    akr = real(a[i]);
    aki = imag(a[i]);
    ar[i].re = nagad_t1w_get_value(akr);
    ar[i].im = nagad_t1w_get_value(aki);
  }
  cout << endl;
  // NagError  fail;
  INIT_FAIL(fail);
  x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,ar,n,
         "  Inverse",0,&fail);

  cout << "\n\n Derivatives calculated: First order adjoints\n";
  cout << " Computational mode    : algorithmic\n";
  cout << "\n Derivatives of inverse diagonal w.r.t diagonal of A:\n";
  
  // Print derivatives
  cout << endl;
  INIT_FAIL(fail);
  x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,drda,n,
         "   d(real(ai(i,i)))/da(j,j)",0,&fail);

  cout << endl;
  INIT_FAIL(fail);
  x04dac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,n,dida,n,
         "   d(real(ai(i,i)))/da(j,j)",0,&fail);

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

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