/// @file
/// Test creation, action, and destruction for mass matrix operator
/// \test Test creation, action, and destruction for mass matrix operator
#include "t500-operator.h"

#include <ceed.h>
#include <math.h>
#include <stdlib.h>

int main(int argc, char **argv) {
  Ceed                ceed;
  CeedElemRestriction elem_restr_x, elem_restr_u, elem_restr_qd_i;
  CeedBasis           basis_x, basis_u;
  CeedQFunction       qf_setup, qf_mass;
  CeedOperator        op_setup, op_mass;
  CeedVector          q_data, X, U, V;
  const CeedScalar   *hv;
  CeedInt             num_elem = 15, P = 5, Q = 8;
  CeedInt             num_nodes_x = num_elem + 1, num_nodes_u = num_elem * (P - 1) + 1;
  CeedInt             ind_x[num_elem * 2], ind_u[num_elem * P];
  CeedScalar          x[num_nodes_x];

  //! [Ceed Init]
  CeedInit(argv[1], &ceed);
  //! [Ceed Init]
  for (CeedInt i = 0; i < num_nodes_x; i++) x[i] = (CeedScalar)i / (num_nodes_x - 1);
  for (CeedInt i = 0; i < num_elem; i++) {
    ind_x[2 * i + 0] = i;
    ind_x[2 * i + 1] = i + 1;
  }
  //! [ElemRestr Create]
  CeedElemRestrictionCreate(ceed, num_elem, 2, 1, 1, num_nodes_x, CEED_MEM_HOST, CEED_USE_POINTER, ind_x, &elem_restr_x);
  //! [ElemRestr Create]

  for (CeedInt i = 0; i < num_elem; i++) {
    for (CeedInt j = 0; j < P; j++) {
      ind_u[P * i + j] = i * (P - 1) + j;
    }
  }
  //! [ElemRestrU Create]
  CeedElemRestrictionCreate(ceed, num_elem, P, 1, 1, num_nodes_u, CEED_MEM_HOST, CEED_USE_POINTER, ind_u, &elem_restr_u);
  CeedInt strides_qd[3] = {1, Q, Q};
  CeedElemRestrictionCreateStrided(ceed, num_elem, Q, 1, Q * num_elem, strides_qd, &elem_restr_qd_i);
  //! [ElemRestrU Create]

  //! [Basis Create]
  CeedBasisCreateTensorH1Lagrange(ceed, 1, 1, 2, Q, CEED_GAUSS, &basis_x);
  CeedBasisCreateTensorH1Lagrange(ceed, 1, 1, P, Q, CEED_GAUSS, &basis_u);
  //! [Basis Create]

  //! [QFunction Create]
  CeedQFunctionCreateInterior(ceed, 1, setup, setup_loc, &qf_setup);
  CeedQFunctionAddInput(qf_setup, "weight", 1, CEED_EVAL_WEIGHT);
  CeedQFunctionAddInput(qf_setup, "dx", 1, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_setup, "rho", 1, CEED_EVAL_NONE);

  CeedQFunctionCreateInterior(ceed, 1, mass, mass_loc, &qf_mass);
  CeedQFunctionAddInput(qf_mass, "rho", 1, CEED_EVAL_NONE);
  CeedQFunctionAddInput(qf_mass, "u", 1, CEED_EVAL_INTERP);
  CeedQFunctionAddOutput(qf_mass, "v", 1, CEED_EVAL_INTERP);
  //! [QFunction Create]

  //! [Setup Create]
  CeedOperatorCreate(ceed, qf_setup, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE, &op_setup);
  //! [Setup Create]

  //! [Operator Create]
  CeedOperatorCreate(ceed, qf_mass, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE, &op_mass);
  //! [Operator Create]

  CeedVectorCreate(ceed, num_nodes_x, &X);
  CeedVectorSetArray(X, CEED_MEM_HOST, CEED_USE_POINTER, x);
  CeedVectorCreate(ceed, num_elem * Q, &q_data);

  //! [Setup Set]
  CeedOperatorSetField(op_setup, "weight", CEED_ELEMRESTRICTION_NONE, basis_x, CEED_VECTOR_NONE);
  CeedOperatorSetField(op_setup, "dx", elem_restr_x, basis_x, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_setup, "rho", elem_restr_qd_i, CEED_BASIS_COLLOCATED, CEED_VECTOR_ACTIVE);
  //! [Setup Set]

  //! [Operator Set]
  CeedOperatorSetField(op_mass, "rho", elem_restr_qd_i, CEED_BASIS_COLLOCATED, q_data);
  CeedOperatorSetField(op_mass, "u", elem_restr_u, basis_u, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_mass, "v", elem_restr_u, basis_u, CEED_VECTOR_ACTIVE);
  //! [Operator Set]

  //! [Setup Apply]
  CeedOperatorApply(op_setup, X, q_data, CEED_REQUEST_IMMEDIATE);
  //! [Setup Apply]

  CeedVectorCreate(ceed, num_nodes_u, &U);
  CeedVectorSetValue(U, 0.0);
  CeedVectorCreate(ceed, num_nodes_u, &V);
  //! [Operator Apply]
  CeedOperatorApply(op_mass, U, V, CEED_REQUEST_IMMEDIATE);
  //! [Operator Apply]

  CeedVectorGetArrayRead(V, CEED_MEM_HOST, &hv);
  for (CeedInt i = 0; i < num_nodes_u; i++) {
    if (fabs(hv[i]) > 1e-14) printf("[%" CeedInt_FMT "] v %g != 0.0\n", i, hv[i]);
  }
  CeedVectorRestoreArrayRead(V, &hv);

  CeedQFunctionDestroy(&qf_setup);
  CeedQFunctionDestroy(&qf_mass);
  CeedOperatorDestroy(&op_setup);
  CeedOperatorDestroy(&op_mass);
  CeedElemRestrictionDestroy(&elem_restr_u);
  CeedElemRestrictionDestroy(&elem_restr_x);
  CeedElemRestrictionDestroy(&elem_restr_qd_i);
  CeedBasisDestroy(&basis_u);
  CeedBasisDestroy(&basis_x);
  CeedVectorDestroy(&X);
  CeedVectorDestroy(&U);
  CeedVectorDestroy(&V);
  CeedVectorDestroy(&q_data);
  CeedDestroy(&ceed);
  return 0;
}