/// @file
/// Test creation, evaluation, and destruction for qfunction
/// \test Test creation, evaluation, and destruction for qfunction
#include <ceed.h>
#include <math.h>

static int setup(void *ctx, CeedInt Q, const CeedScalar *const *in,
                 CeedScalar *const *out) {
  const CeedScalar *w = in[0];
  CeedScalar *qdata = out[0];
  for (CeedInt i=0; i<Q; i++) {
    qdata[i] = w[i];
  }
  return 0;
}

static int mass(void *ctx, CeedInt Q, const CeedScalar *const *in,
                CeedScalar *const *out) {
  CeedScalar *scale = (CeedScalar *)ctx;
  const CeedScalar *qdata = in[0], *u = in[1];
  CeedScalar *v = out[0];
  for (CeedInt i=0; i<Q; i++) {
    v[i] = scale[4] * qdata[i] * u[i];
  }
  return 0;
}

int main(int argc, char **argv) {
  Ceed ceed;
  CeedVector in[16], out[16];
  CeedVector Qdata, W, U, V;
  CeedQFunction qf_setup, qf_mass;
  CeedInt Q = 8;
  const CeedScalar *vv;
  CeedScalar w[Q], u[Q], v[Q], ctx[5] = {1, 2, 3, 4, 5};


  CeedInit(argv[1], &ceed);

  CeedQFunctionCreateInterior(ceed, 1, setup, __FILE__ ":setup", &qf_setup);
  CeedQFunctionAddInput(qf_setup, "w", 1, CEED_EVAL_INTERP);
  CeedQFunctionAddOutput(qf_setup, "qdata", 1, CEED_EVAL_INTERP);

  CeedQFunctionCreateInterior(ceed, 1, mass, __FILE__ ":mass", &qf_mass);
  CeedQFunctionAddInput(qf_mass, "qdata", 1, CEED_EVAL_INTERP);
  CeedQFunctionAddInput(qf_mass, "u", 1, CEED_EVAL_INTERP);
  CeedQFunctionAddOutput(qf_mass, "v", 1, CEED_EVAL_INTERP);

  CeedQFunctionSetContext(qf_mass, &ctx, sizeof(ctx));

  for (CeedInt i=0; i<Q; i++) {
    CeedScalar x = 2.*i/(Q-1) - 1;
    w[i] = 1 - x*x;
    u[i] = 2 + 3*x + 5*x*x;
    v[i] = w[i] * u[i];
  }

  CeedVectorCreate(ceed, Q, &W);
  CeedVectorSetArray(W, CEED_MEM_HOST, CEED_USE_POINTER, (CeedScalar *)&w);
  CeedVectorCreate(ceed, Q, &U);
  CeedVectorSetArray(U, CEED_MEM_HOST, CEED_USE_POINTER, (CeedScalar *)&u);
  CeedVectorCreate(ceed, Q, &V);
  CeedVectorSetValue(V, 0);
  CeedVectorCreate(ceed, Q, &Qdata);
  CeedVectorSetValue(Qdata, 0);

  {
    in[0] = W;
    out[0] = Qdata;
    CeedQFunctionApply(qf_setup, Q, in, out);
  }
  {
    in[0] = W;
    in[1] = U;
    out[0] = V;
    CeedQFunctionApply(qf_mass, Q, in, out);
  }

  CeedVectorGetArrayRead(V, CEED_MEM_HOST, &vv);
  for (CeedInt i=0; i<Q; i++)
    if (fabs(ctx[4] * v[i] - vv[i]) > 1.e-14)
      // LCOV_EXCL_START
      printf("[%d] v %f != vv %f\n",i, v[i], vv[i]);
      // LCOV_EXCL_STOP
  CeedVectorRestoreArrayRead(V, &vv);

  CeedVectorDestroy(&W);
  CeedVectorDestroy(&U);
  CeedVectorDestroy(&V);
  CeedVectorDestroy(&Qdata);
  CeedQFunctionDestroy(&qf_setup);
  CeedQFunctionDestroy(&qf_mass);
  CeedDestroy(&ceed);
  return 0;
}