/// @file
/// Test creation creation, action, and destruction for mass matrix operator
/// \test Test creation creation, action, and destruction for mass matrix operator
#include <ceed.h>
#include <stdlib.h>
#include <math.h>
#include "t310-basis.h"

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

*/

static int setup(void *ctx, CeedInt Q, const CeedScalar *const *in,
                 CeedScalar *const *out) {
  const CeedScalar *weight = in[0], *J = in[1];
  CeedScalar *rho = out[0];
  for (CeedInt i=0; i<Q; i++) {
    rho[i] = weight[i] * (J[i+Q*0]*J[i+Q*3] - J[i+Q*1]*J[i+Q*2]);
  }
  return 0;
}

static int mass(void *ctx, CeedInt Q, const CeedScalar *const *in,
                CeedScalar *const *out) {
  const CeedScalar *rho = in[0], *u = in[1];
  CeedScalar *v = out[0];
  for (CeedInt i=0; i<Q; i++) {
    v[i] = rho[i] * u[i];
  }
  return 0;
}

int main(int argc, char **argv) {
  Ceed ceed;
  CeedElemRestriction ErestrictxTet, ErestrictuTet,
                      ErestrictxiTet, ErestrictuiTet,
                      ErestrictxHex, ErestrictuHex,
                      ErestrictxiHex, ErestrictuiHex;
  CeedBasis bxTet, buTet,
            bxHex, buHex;
  CeedQFunction qf_setupTet, qf_massTet,
                qf_setupHex, qf_massHex;
  CeedOperator op_setupTet, op_massTet,
               op_setupHex, op_massHex,
               op_setup, op_mass;
  CeedVector qdataTet, qdataHex, X, U, V;
  const CeedScalar *hv;
  CeedInt nelemTet = 6, PTet = 6, QTet = 4,
          nelemHex = 6, PHex = 3, QHex = 4, dim = 2;
  CeedInt nx = 3, ny = 3,
          nxTet = 3, nyTet = 1, nxHex = 3;
  CeedInt row, col, offset;
  CeedInt ndofs = (nx*2+1)*(ny*2+1),
          nqptsTet = nelemTet*QTet,
          nqptsHex = nelemHex*QHex*QHex;
  CeedInt indxTet[nelemTet*PTet],
          indxHex[nelemHex*PHex*PHex];
  CeedScalar x[dim*ndofs];
  CeedScalar qref[dim*QTet], qweight[QTet];
  CeedScalar interp[PTet*QTet], grad[dim*PTet*QTet];
  CeedScalar sum;

  CeedInit(argv[1], &ceed);

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

  // Qdata Vectors
  CeedVectorCreate(ceed, nqptsTet, &qdataTet);
  CeedVectorCreate(ceed, nqptsHex, &qdataHex);

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

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

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

  // -- Restrictions
  CeedElemRestrictionCreate(ceed, nelemTet, PTet, ndofs, dim, CEED_MEM_HOST,
                            CEED_USE_POINTER, indxTet, &ErestrictxTet);
  CeedElemRestrictionCreateIdentity(ceed, nelemTet, PTet, nelemTet*PTet, dim,
                                    &ErestrictxiTet);

  CeedElemRestrictionCreate(ceed, nelemTet, PTet, ndofs, 1, CEED_MEM_HOST,
                            CEED_USE_POINTER, indxTet, &ErestrictuTet);
  CeedElemRestrictionCreateIdentity(ceed, nelemTet, QTet, nqptsTet, 1,
                                    &ErestrictuiTet);

  // -- Bases
  buildmats(qref, qweight, interp, grad);
  CeedBasisCreateH1(ceed, CEED_TRIANGLE, dim, PTet, QTet, interp, grad, qref,
                    qweight, &bxTet);

  buildmats(qref, qweight, interp, grad);
  CeedBasisCreateH1(ceed, CEED_TRIANGLE, 1, PTet, QTet, interp, grad, qref,
                    qweight, &buTet);

  // -- QFunctions
  CeedQFunctionCreateInterior(ceed, 1, setup, __FILE__ ":setup", &qf_setupTet);
  CeedQFunctionAddInput(qf_setupTet, "_weight", 1, CEED_EVAL_WEIGHT);
  CeedQFunctionAddInput(qf_setupTet, "dx", dim, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_setupTet, "rho", 1, CEED_EVAL_NONE);

  CeedQFunctionCreateInterior(ceed, 1, mass, __FILE__ ":mass", &qf_massTet);
  CeedQFunctionAddInput(qf_massTet, "rho", 1, CEED_EVAL_NONE);
  CeedQFunctionAddInput(qf_massTet, "u", 1, CEED_EVAL_INTERP);
  CeedQFunctionAddOutput(qf_massTet, "v", 1, CEED_EVAL_INTERP);

  // -- Operators
  // ---- Setup Tet
  CeedOperatorCreate(ceed, qf_setupTet, NULL, NULL, &op_setupTet);
  CeedOperatorSetField(op_setupTet, "_weight", ErestrictxiTet, CEED_NOTRANSPOSE,
                       bxTet, CEED_VECTOR_NONE);
  CeedOperatorSetField(op_setupTet, "dx", ErestrictxTet, CEED_NOTRANSPOSE,
                       bxTet, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_setupTet, "rho", ErestrictuiTet, CEED_NOTRANSPOSE,
                       CEED_BASIS_COLLOCATED, qdataTet);
  // ---- Mass Tet
  CeedOperatorCreate(ceed, qf_massTet, NULL, NULL, &op_massTet);
  CeedOperatorSetField(op_massTet, "rho", ErestrictuiTet, CEED_NOTRANSPOSE,
                       CEED_BASIS_COLLOCATED, qdataTet);
  CeedOperatorSetField(op_massTet, "u", ErestrictuTet, CEED_NOTRANSPOSE,
                       buTet, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_massTet, "v", ErestrictuTet, CEED_NOTRANSPOSE,
                       buTet, CEED_VECTOR_ACTIVE);

  // Hex Elements
  for (CeedInt i=0; i<nelemHex; i++) {
    col = i % nxHex;
    row = i / nxHex;
    offset = (nxTet*2+1)*(nyTet*2)*(1+row) + col*2;
    for (CeedInt j=0; j<PHex; j++)
      for (CeedInt k=0; k<PHex; k++)
        indxHex[PHex*(PHex*i+k)+j] = offset + k*(nxHex*2+1) + j;
  }

  // -- Restrictions
  CeedElemRestrictionCreate(ceed, nelemHex, PHex*PHex, ndofs, dim,
                            CEED_MEM_HOST, CEED_USE_POINTER, indxHex,
                            &ErestrictxHex);
  CeedElemRestrictionCreateIdentity(ceed, nelemHex, PHex*PHex,
                                    nelemHex*PHex*PHex, dim, &ErestrictxiHex);

  CeedElemRestrictionCreate(ceed, nelemHex, PHex*PHex, ndofs, 1,
                            CEED_MEM_HOST, CEED_USE_POINTER, indxHex,
                            &ErestrictuHex);
  CeedElemRestrictionCreateIdentity(ceed, nelemHex, QHex*QHex, nqptsHex, 1,
                                    &ErestrictuiHex);

  // -- Bases
  CeedBasisCreateTensorH1Lagrange(ceed, dim, dim, PHex, QHex, CEED_GAUSS,
                                  &bxHex);
  CeedBasisCreateTensorH1Lagrange(ceed, dim, 1, PHex, QHex, CEED_GAUSS, &buHex);

  // -- QFunctions
  CeedQFunctionCreateInterior(ceed, 1, setup, __FILE__ ":setup", &qf_setupHex);
  CeedQFunctionAddInput(qf_setupHex, "_weight", 1, CEED_EVAL_WEIGHT);
  CeedQFunctionAddInput(qf_setupHex, "dx", dim, CEED_EVAL_GRAD);
  CeedQFunctionAddOutput(qf_setupHex, "rho", 1, CEED_EVAL_NONE);

  CeedQFunctionCreateInterior(ceed, 1, mass, __FILE__ ":mass", &qf_massHex);
  CeedQFunctionAddInput(qf_massHex, "rho", 1, CEED_EVAL_NONE);
  CeedQFunctionAddInput(qf_massHex, "u", 1, CEED_EVAL_INTERP);
  CeedQFunctionAddOutput(qf_massHex, "v", 1, CEED_EVAL_INTERP);

  // -- Operators
  CeedOperatorCreate(ceed, qf_setupHex, NULL, NULL, &op_setupHex);
  CeedOperatorSetField(op_setupHex, "_weight", ErestrictxiHex, CEED_NOTRANSPOSE,
                       bxHex, CEED_VECTOR_NONE);
  CeedOperatorSetField(op_setupHex, "dx", ErestrictxHex, CEED_NOTRANSPOSE,
                       bxHex, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_setupHex, "rho", ErestrictuiHex, CEED_NOTRANSPOSE,
                       CEED_BASIS_COLLOCATED, qdataHex);

  CeedOperatorCreate(ceed, qf_massHex, NULL, NULL, &op_massHex);
  CeedOperatorSetField(op_massHex, "rho", ErestrictuiHex, CEED_NOTRANSPOSE,
                       CEED_BASIS_COLLOCATED, qdataHex);
  CeedOperatorSetField(op_massHex, "u", ErestrictuHex, CEED_NOTRANSPOSE,
                       buHex, CEED_VECTOR_ACTIVE);
  CeedOperatorSetField(op_massHex, "v", ErestrictuHex, CEED_NOTRANSPOSE,
                       buHex, CEED_VECTOR_ACTIVE);

  // Composite Operators
  CeedCompositeOperatorCreate(ceed, &op_setup);
  CeedCompositeOperatorAddSub(op_setup, op_setupTet);
  CeedCompositeOperatorAddSub(op_setup, op_setupHex);

  CeedCompositeOperatorCreate(ceed, &op_mass);
  CeedCompositeOperatorAddSub(op_mass, op_massTet);
  CeedCompositeOperatorAddSub(op_mass, op_massHex);

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

  // Apply Mass Operator
  CeedVectorCreate(ceed, ndofs, &U);
  CeedVectorSetValue(U, 1.0);
  CeedVectorCreate(ceed, ndofs, &V);

  CeedOperatorApply(op_mass, U, V, CEED_REQUEST_IMMEDIATE);

  // Check output
  CeedVectorGetArrayRead(V, CEED_MEM_HOST, &hv);
  sum = 0.;
  for (CeedInt i=0; i<ndofs; i++)
    sum += hv[i];
  if (fabs(sum-1.)>1e-10) printf("Computed Area: %f != True Area: 1.0\n", sum);
  CeedVectorRestoreArrayRead(V, &hv);

  // Cleanup
  CeedQFunctionDestroy(&qf_setupTet);
  CeedQFunctionDestroy(&qf_massTet);
  CeedOperatorDestroy(&op_setupTet);
  CeedOperatorDestroy(&op_massTet);
  CeedQFunctionDestroy(&qf_setupHex);
  CeedQFunctionDestroy(&qf_massHex);
  CeedOperatorDestroy(&op_setupHex);
  CeedOperatorDestroy(&op_massHex);
  CeedOperatorDestroy(&op_setup);
  CeedOperatorDestroy(&op_mass);
  CeedElemRestrictionDestroy(&ErestrictuTet);
  CeedElemRestrictionDestroy(&ErestrictxTet);
  CeedElemRestrictionDestroy(&ErestrictuiTet);
  CeedElemRestrictionDestroy(&ErestrictxiTet);
  CeedElemRestrictionDestroy(&ErestrictuHex);
  CeedElemRestrictionDestroy(&ErestrictxHex);
  CeedElemRestrictionDestroy(&ErestrictuiHex);
  CeedElemRestrictionDestroy(&ErestrictxiHex);
  CeedBasisDestroy(&buTet);
  CeedBasisDestroy(&bxTet);
  CeedBasisDestroy(&buHex);
  CeedBasisDestroy(&bxHex);
  CeedVectorDestroy(&X);
  CeedVectorDestroy(&U);
  CeedVectorDestroy(&V);
  CeedVectorDestroy(&qdataTet);
  CeedVectorDestroy(&qdataHex);
  CeedDestroy(&ceed);
  return 0;
}