/// @file
/// Test creation, action, and destruction for diffusion matrix operator
/// \test Test creation, action, and destruction for diffusion matrix operator
#include <ceed.h>
#include <stdlib.h>
#include <math.h>
#include "t320-basis.h"
#include "t522-operator.h"

/* The mesh comprises of two rows of 3 quadralaterals followed by one row
     of 6 triangles:
   _ _ _
  |_|_|_|
  |_|_|_|
  |/|/|/|

*/

int main(int argc, char **argv) {
  Ceed ceed;
  CeedElemRestriction elem_restr_x_tet, elem_restr_u_tet,
                      elem_restr_qd_i_tet,
                      elem_restr_x_hex, elem_restr_u_hex,
                      elem_restr_qd_i_hex;
  CeedBasis basis_x_tet, basis_u_tet,
            basis_x_hex, basis_u_hex;
  CeedQFunction qf_setup_tet, qf_diff_tet,
                qf_setup_hex, qf_diff_hex;
  CeedOperator op_setup_tet, op_diff_tet,
               op_setup_hex, op_diff_hex,
               op_setup, op_diff;
  CeedVector q_data_tet, q_data_hex, X, U, V;
  const CeedScalar *hv;
  CeedInt num_elem_tet = 6, P_tet = 6, Q_tet = 4,
          num_elem_hex = 6, P_hex = 3, Q_hex = 4, dim = 2;
  CeedInt n_x = 3, n_y = 3,
          n_x_tet = 3, n_y_tet = 1, n_x_hex = 3;
  CeedInt row, col, offset;
  CeedInt num_dofs = (n_x*2+1)*(n_y*2+1),
          num_qpts_tet = num_elem_tet*Q_tet,
          num_qpts_hex = num_elem_hex*Q_hex*Q_hex;
  CeedInt ind_x_tet[num_elem_tet*P_tet],
          ind_x_hex[num_elem_hex*P_hex*P_hex];
  CeedScalar x[dim*num_dofs];
  CeedScalar q_ref[dim*Q_tet], q_weight[Q_tet];
  CeedScalar interp[P_tet*Q_tet], grad[dim*P_tet*Q_tet];

  CeedInit(argv[1], &ceed);

  // DoF Coordinates
  for (CeedInt i=0; i<n_y*2+1; i++)
    for (CeedInt j=0; j<n_x*2+1; j++) {
      x[i+j*(n_y*2+1)+0*num_dofs] = (CeedScalar) i / (2*n_y);
      x[i+j*(n_y*2+1)+1*num_dofs] = (CeedScalar) j / (2*n_x);
    }
  CeedVectorCreate(ceed, dim*num_dofs, &X);
  CeedVectorSetArray(X, CEED_MEM_HOST, CEED_USE_POINTER, x);

  // Qdata Vectors
  CeedVectorCreate(ceed, num_qpts_tet*dim*(dim+1)/2, &q_data_tet);
  CeedVectorCreate(ceed, num_qpts_hex*dim*(dim+1)/2, &q_data_hex);

  // Tet Elements
  for (CeedInt i=0; i<num_elem_tet/2; i++) {
    col = i % n_x_tet;
    row = i / n_x_tet;
    offset = col*2 + row*(n_x_tet*2+1)*2;

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

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

  // -- Restrictions
  CeedElemRestrictionCreate(ceed, num_elem_tet, P_tet, dim, num_dofs,
                            dim*num_dofs,
                            CEED_MEM_HOST, CEED_USE_POINTER, ind_x_tet,
                            &elem_restr_x_tet);

  CeedElemRestrictionCreate(ceed, num_elem_tet, P_tet, 1, 1, num_dofs,
                            CEED_MEM_HOST, CEED_USE_POINTER, ind_x_tet,
                            &elem_restr_u_tet);
  CeedInt strides_qd_tet[3] = {1, Q_tet, Q_tet *dim *(dim+1)/2};
  CeedElemRestrictionCreateStrided(ceed, num_elem_tet, Q_tet, dim*(dim+1)/2,
                                   dim*(dim+1)/2*num_qpts_tet, strides_qd_tet,
                                   &elem_restr_qd_i_tet);

  // -- Bases
  buildmats(q_ref, q_weight, interp, grad);
  CeedBasisCreateH1(ceed, CEED_TOPOLOGY_TRIANGLE, dim, P_tet, Q_tet, interp, grad,
                    q_ref, q_weight, &basis_x_tet);

  buildmats(q_ref, q_weight, interp, grad);
  CeedBasisCreateH1(ceed, CEED_TOPOLOGY_TRIANGLE, 1, P_tet, Q_tet, interp, grad,
                    q_ref, q_weight, &basis_u_tet);

  // -- QFunctions
  CeedQFunctionCreateInterior(ceed, 1, setup, setup_loc, &qf_setup_tet);
  CeedQFunctionAddInput(qf_setup_tet, "weight", 1, CEED_EVAL_WEIGHT);
  CeedQFunctionAddInput(qf_setup_tet, "dx", dim*dim, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_setup_tet, "rho", dim*(dim+1)/2, CEED_EVAL_NONE);

  CeedQFunctionCreateInterior(ceed, 1, diff, diff_loc, &qf_diff_tet);
  CeedQFunctionAddInput(qf_diff_tet, "rho", dim*(dim+1)/2, CEED_EVAL_NONE);
  CeedQFunctionAddInput(qf_diff_tet, "u", dim, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_diff_tet, "v", dim, CEED_EVAL_GRAD);

  // -- Operators
  // ---- Setup Tet
  CeedOperatorCreate(ceed, qf_setup_tet, CEED_QFUNCTION_NONE,
                     CEED_QFUNCTION_NONE, &op_setup_tet);
  CeedOperatorSetField(op_setup_tet, "weight", CEED_ELEMRESTRICTION_NONE,
                       basis_x_tet,
                       CEED_VECTOR_NONE);
  CeedOperatorSetField(op_setup_tet, "dx", elem_restr_x_tet, basis_x_tet,
                       CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_setup_tet, "rho", elem_restr_qd_i_tet,
                       CEED_BASIS_COLLOCATED, q_data_tet);
  // ---- diff Tet
  CeedOperatorCreate(ceed, qf_diff_tet, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
                     &op_diff_tet);
  CeedOperatorSetField(op_diff_tet, "rho", elem_restr_qd_i_tet,
                       CEED_BASIS_COLLOCATED, q_data_tet);
  CeedOperatorSetField(op_diff_tet, "u", elem_restr_u_tet, basis_u_tet,
                       CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_diff_tet, "v", elem_restr_u_tet, basis_u_tet,
                       CEED_VECTOR_ACTIVE);

  // Hex Elements
  for (CeedInt i=0; i<num_elem_hex; i++) {
    col = i % n_x_hex;
    row = i / n_x_hex;
    offset = (n_x_tet*2+1)*(n_y_tet*2)*(1+row) + col*2;
    for (CeedInt j=0; j<P_hex; j++)
      for (CeedInt k=0; k<P_hex; k++)
        ind_x_hex[P_hex*(P_hex*i+k)+j] = offset + k*(n_x_hex*2+1) + j;
  }

  // -- Restrictions
  CeedElemRestrictionCreate(ceed, num_elem_hex, P_hex*P_hex, dim, num_dofs,
                            dim*num_dofs,
                            CEED_MEM_HOST, CEED_USE_POINTER, ind_x_hex,
                            &elem_restr_x_hex);

  CeedElemRestrictionCreate(ceed, num_elem_hex, P_hex*P_hex, 1, 1, num_dofs,
                            CEED_MEM_HOST, CEED_USE_POINTER, ind_x_hex,
                            &elem_restr_u_hex);
  CeedInt strides_qd_hex[3] = {1, Q_hex*Q_hex, Q_hex *Q_hex *dim *(dim+1)/2};
  CeedElemRestrictionCreateStrided(ceed, num_elem_hex, Q_hex*Q_hex, dim*(dim+1)/2,
                                   dim*(dim+1)/2*num_qpts_hex, strides_qd_hex,
                                   &elem_restr_qd_i_hex);

  // -- Bases
  CeedBasisCreateTensorH1Lagrange(ceed, dim, dim, P_hex, Q_hex, CEED_GAUSS,
                                  &basis_x_hex);
  CeedBasisCreateTensorH1Lagrange(ceed, dim, 1, P_hex, Q_hex, CEED_GAUSS,
                                  &basis_u_hex);

  // -- QFunctions
  CeedQFunctionCreateInterior(ceed, 1, setup, setup_loc, &qf_setup_hex);
  CeedQFunctionAddInput(qf_setup_hex, "_weight", 1, CEED_EVAL_WEIGHT);
  CeedQFunctionAddInput(qf_setup_hex, "dx", dim*dim, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_setup_hex, "rho", dim*(dim+1)/2, CEED_EVAL_NONE);

  CeedQFunctionCreateInterior(ceed, 1, diff, diff_loc, &qf_diff_hex);
  CeedQFunctionAddInput(qf_diff_hex, "rho", dim*(dim+1)/2, CEED_EVAL_NONE);
  CeedQFunctionAddInput(qf_diff_hex, "u", dim, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_diff_hex, "v", dim, CEED_EVAL_GRAD);

  // -- Operators
  CeedOperatorCreate(ceed, qf_setup_hex, CEED_QFUNCTION_NONE,
                     CEED_QFUNCTION_NONE, &op_setup_hex);
  CeedOperatorSetField(op_setup_hex, "_weight", CEED_ELEMRESTRICTION_NONE,
                       basis_x_hex,
                       CEED_VECTOR_NONE);
  CeedOperatorSetField(op_setup_hex, "dx", elem_restr_x_hex, basis_x_hex,
                       CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_setup_hex, "rho", elem_restr_qd_i_hex,
                       CEED_BASIS_COLLOCATED, q_data_hex);

  CeedOperatorCreate(ceed, qf_diff_hex, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE,
                     &op_diff_hex);
  CeedOperatorSetField(op_diff_hex, "rho", elem_restr_qd_i_hex,
                       CEED_BASIS_COLLOCATED, q_data_hex);
  CeedOperatorSetField(op_diff_hex, "u", elem_restr_u_hex, basis_u_hex,
                       CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_diff_hex, "v", elem_restr_u_hex, basis_u_hex,
                       CEED_VECTOR_ACTIVE);

  // Composite Operators
  CeedCompositeOperatorCreate(ceed, &op_setup);
  CeedCompositeOperatorAddSub(op_setup, op_setup_tet);
  CeedCompositeOperatorAddSub(op_setup, op_setup_hex);

  CeedCompositeOperatorCreate(ceed, &op_diff);
  CeedCompositeOperatorAddSub(op_diff, op_diff_tet);
  CeedCompositeOperatorAddSub(op_diff, op_diff_hex);

  // Apply Setup Operator
  CeedOperatorApply(op_setup, X, CEED_VECTOR_NONE, CEED_REQUEST_IMMEDIATE);

  // Apply diff Operator
  CeedVectorCreate(ceed, num_dofs, &U);
  CeedVectorSetValue(U, 1.0);
  CeedVectorCreate(ceed, num_dofs, &V);

  CeedOperatorApply(op_diff, U, V, CEED_REQUEST_IMMEDIATE);

  // Check output
  CeedVectorGetArrayRead(V, CEED_MEM_HOST, &hv);
  for (CeedInt i=0; i<num_dofs; i++)
    if (fabs(hv[i])>100.*CEED_EPSILON) printf("Computed: %f != True: 0.0\n", hv[i]);
  CeedVectorRestoreArrayRead(V, &hv);

  // Cleanup
  CeedQFunctionDestroy(&qf_setup_tet);
  CeedQFunctionDestroy(&qf_diff_tet);
  CeedOperatorDestroy(&op_setup_tet);
  CeedOperatorDestroy(&op_diff_tet);
  CeedQFunctionDestroy(&qf_setup_hex);
  CeedQFunctionDestroy(&qf_diff_hex);
  CeedOperatorDestroy(&op_setup_hex);
  CeedOperatorDestroy(&op_diff_hex);
  CeedOperatorDestroy(&op_setup);
  CeedOperatorDestroy(&op_diff);
  CeedElemRestrictionDestroy(&elem_restr_u_tet);
  CeedElemRestrictionDestroy(&elem_restr_x_tet);
  CeedElemRestrictionDestroy(&elem_restr_qd_i_tet);
  CeedElemRestrictionDestroy(&elem_restr_u_hex);
  CeedElemRestrictionDestroy(&elem_restr_x_hex);
  CeedElemRestrictionDestroy(&elem_restr_qd_i_hex);
  CeedBasisDestroy(&basis_u_tet);
  CeedBasisDestroy(&basis_x_tet);
  CeedBasisDestroy(&basis_u_hex);
  CeedBasisDestroy(&basis_x_hex);
  CeedVectorDestroy(&X);
  CeedVectorDestroy(&U);
  CeedVectorDestroy(&V);
  CeedVectorDestroy(&q_data_tet);
  CeedVectorDestroy(&q_data_hex);
  CeedDestroy(&ceed);
  return 0;
}