/* F08AE_T1W_F C++ Header Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 * Mark 27, 2019.
 */

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

// typedef DCO_TYPE nagad_t1w_w_rtype
typedef double DCO_BASE_TYPE;
typedef dco::gt1s<DCO_BASE_TYPE> DCO_MODE;
typedef DCO_MODE::type DCO_TYPE;

int main(void)
{
  /* Scalars */
  Integer  exit_status = 0;
#ifdef NAG_LOAD_FP
  /* The following line is needed to force the Microsoft linker
     to load floating point support */
  float force_loading_of_ms_float_support = 0;
#endif /* NAG_LOAD_FP */

  cout << "F08AE_T1W_F C++ Header Example Program Results\n\n";

  void    *ad_handle = 0;
  Integer ifail = 0;
  x10aa_t1w_f_(ad_handle,ifail);

  // Skip heading in data file
  string mystr;
  getline (cin, mystr);
  
  Integer m, n;
  cin >> m; cin >> n;

  Integer pda = m;
  Integer lwork = 64 * n;

  Integer tau_len;
  if (m<n) {
    tau_len = m;
  } else {
    tau_len = n;
  }

  // Allocate arrays
  // nagad_t1w_w_rtype *a = 0, *tau = 0, *a_in = 0, *work = 0;
  DCO_TYPE *a = 0, *tau = 0, *work = 0, *a_in = 0;
  double   *r = 0, *drda = 0;
  a    = new DCO_TYPE [m * n];
  a_in = new DCO_TYPE [m * n];
  tau  = new DCO_TYPE [tau_len];
  work = new DCO_TYPE [lwork];
  r    = new double [n * n];
  drda = new double [n * m];

  // Read A from data file
  double   tmp;
  for (int i = 0; i < m; ++i) {
    for (int j = 0; j < n; ++j){
      cin >> tmp;
      a_in[i+j*m] = tmp;
    }
  }

  double d_zero = 0.0;
  for (int i = 0; i < m * n; i++) {
    // nagad_t1w_set_derivative(&a_in[i],d_zero);
    dco::derivative(a_in[i]) = d_zero;
    a[i] = a_in[i];
  }

  double d_one = 1.0;
  for (int j  = 0;  j < m; j++) {
    // nagad_t1w_set_derivative(&a[j],d_one);
    dco::derivative(a[j]) = d_one;

    f08ae_t1w_f_(ad_handle, m, n, a, pda, tau, work, lwork, ifail);
    if (ifail != 0) {
      printf("Error from f08ae_t1w_f_ .\n%" NAG_IFMT  " ", ifail);
      exit_status = 1;
      goto END;
    }
    if (j==0) {
      for (int k = 0; k < n; ++k) {
        for (int i = 0; i < n; ++i) {
          // r[i+k*n] = a[i+k*m].value
          r[i+k*n] = dco::value(a[i+k*m]);
        }
      }
    }
    for (int i = 0; i < n; i++) {
      int l = i*(m+1);
      int k = j*n + i;
      // drda[k] = a[l].tangent
      drda[k] = dco::derivative(a[l]);
    }

    for (int i = 0; i < m * n; i++)
      a[i] = a_in[i];
  }

  NagError  fail;
  INIT_FAIL(fail);
  x04cac(Nag_ColMajor,Nag_UpperMatrix,Nag_NonUnitDiag,n,n,r,n,
         "R from Q factorization of A",0,&fail);
  printf("\nDerivatives of diagonal of R w.r.t. first col of A\n");
  x04cac(Nag_ColMajor,Nag_GeneralMatrix,Nag_NonUnitDiag,n,m,drda,n,
         "dR_ii/dA_j1",0,&fail);

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

  delete [] a;
  delete [] a_in;
  delete [] tau;
  delete [] r;
  delete [] drda;
  delete [] work;

  return exit_status;
}