/// @file
/// Test creation, action, and destruction for mass matrix operator
/// \test Test creation, action, and destruction for mass matrix operator
#include <ceed.h>
#include <stdlib.h>
#include <math.h>
#include "t320-basis.h"
#include "t510-operator.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 = 12, dim = 2, P = 6, Q = 4;
  CeedInt nx = 3, ny = 2;
  CeedInt row, col, offset;
  CeedInt num_dofs = (nx*2+1)*(ny*2+1), num_qpts = num_elem*Q;
  CeedInt indx[num_elem*P];
  CeedScalar x[dim*num_dofs];
  CeedScalar q_ref[dim*Q], q_weight[Q];
  CeedScalar interp[P*Q], grad[dim*P*Q];
  CeedScalar sum;

  CeedInit(argv[1], &ceed);

  for (CeedInt i=0; i<num_dofs; i++) {
    x[i] = (1. / (nx*2)) * (CeedScalar) (i % (nx*2+1));
    x[i+num_dofs] = (1. / (ny*2)) * (CeedScalar) (i / (nx*2+1));
  }
  for (CeedInt i=0; i<num_elem/2; i++) {
    col = i % nx;
    row = i / nx;
    offset = col*2 + row*(nx*2+1)*2;

    indx[i*2*P +  0] =  2 + offset;
    indx[i*2*P +  1] =  9 + offset;
    indx[i*2*P +  2] = 16 + offset;
    indx[i*2*P +  3] =  1 + offset;
    indx[i*2*P +  4] =  8 + offset;
    indx[i*2*P +  5] =  0 + offset;

    indx[i*2*P +  6] = 14 + offset;
    indx[i*2*P +  7] =  7 + offset;
    indx[i*2*P +  8] =  0 + offset;
    indx[i*2*P +  9] = 15 + offset;
    indx[i*2*P + 10] =  8 + offset;
    indx[i*2*P + 11] = 16 + offset;
  }

  // Restrictions
  CeedElemRestrictionCreate(ceed, num_elem, P, dim, num_dofs, dim*num_dofs,
                            CEED_MEM_HOST, CEED_USE_POINTER, indx, &elem_restr_x);

  CeedElemRestrictionCreate(ceed, num_elem, P, 1, 1, num_dofs, CEED_MEM_HOST,
                            CEED_USE_POINTER, indx, &elem_restr_u);
  CeedInt strides_qd[3] = {1, Q, Q};
  CeedElemRestrictionCreateStrided(ceed, num_elem, Q, 1, num_qpts, strides_qd,
                                   &elem_restr_qd_i);

  // Bases
  buildmats(q_ref, q_weight, interp, grad);
  CeedBasisCreateH1(ceed, CEED_TRIANGLE, dim, P, Q, interp, grad, q_ref,
                    q_weight, &basis_x);

  buildmats(q_ref, q_weight, interp, grad);
  CeedBasisCreateH1(ceed, CEED_TRIANGLE, 1, P, Q, interp, grad, q_ref,
                    q_weight, &basis_u);

  // QFunctions
  CeedQFunctionCreateInterior(ceed, 1, setup, setup_loc, &qf_setup);
  CeedQFunctionAddInput(qf_setup, "_weight", 1, CEED_EVAL_WEIGHT);
  CeedQFunctionAddInput(qf_setup, "x", dim*dim, 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);

  // Operators
  CeedOperatorCreate(ceed, qf_setup, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
                     &op_setup);

  CeedOperatorCreate(ceed, qf_mass, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
                     &op_mass);

  CeedVectorCreate(ceed, dim*num_dofs, &X);
  CeedVectorSetArray(X, CEED_MEM_HOST, CEED_USE_POINTER, x);
  CeedVectorCreate(ceed, num_qpts, &q_data);

  CeedOperatorSetField(op_setup, "_weight", CEED_ELEMRESTRICTION_NONE, basis_x,
                       CEED_VECTOR_NONE);
  CeedOperatorSetField(op_setup, "x", elem_restr_x, basis_x, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_setup, "rho", elem_restr_qd_i, CEED_BASIS_COLLOCATED,
                       CEED_VECTOR_ACTIVE);

  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);

  CeedOperatorApply(op_setup, X, q_data, CEED_REQUEST_IMMEDIATE);

  CeedVectorCreate(ceed, num_dofs, &U);
  CeedVectorSetValue(U, 1.0);
  CeedVectorCreate(ceed, num_dofs, &V);

  CeedOperatorApply(op_mass, U, V, CEED_REQUEST_IMMEDIATE);

  // Check output
  CeedVectorGetArrayRead(V, CEED_MEM_HOST, &hv);
  sum = 0.;
  for (CeedInt i=0; i<num_dofs; i++)
    sum += hv[i];
  if (fabs(sum-1.)>1000.*CEED_EPSILON)
    // LCOV_EXCL_START
    printf("Computed Area: %f != True Area: 1.0\n", sum);
  // LCOV_EXCL_STOP
  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;
}