/*
   Plots vectors obtained with DMDACreate1d()
*/

#include <petsc/private/dmdaimpl.h> /*I  "petscdmda.h"   I*/

/*@
  DMDASetUniformCoordinates - Sets a `DMDA` coordinates to be a uniform grid

  Collective

  Input Parameters:
+ da   - the distributed array object
. xmin - min extreme in the x direction
. xmax - max extreme in the x direction
. ymin - min extreme in the y direction (value ignored for 1 dimensional problems)
. ymax - max extreme in the y direction (value ignored for 1 dimensional problems)
. zmin - min extreme in the z direction (value ignored for 1 or 2 dimensional problems)
- zmax - max extreme in the z direction (value ignored for 1 or 2 dimensional problems)

  Level: beginner

.seealso: [](sec_struct), `DM`, `DMDA`, `DMSetCoordinates()`, `DMGetCoordinates()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMStagSetUniformCoordinates()`
@*/
PetscErrorCode DMDASetUniformCoordinates(DM da, PetscReal xmin, PetscReal xmax, PetscReal ymin, PetscReal ymax, PetscReal zmin, PetscReal zmax)
{
  MPI_Comm       comm;
  DM             cda;
  DM_DA         *dd = (DM_DA *)da->data;
  DMBoundaryType bx, by, bz;
  Vec            xcoor;
  PetscScalar   *coors;
  PetscReal      hx, hy, hz_;
  PetscInt       i, j, k, M, N, P, istart, isize, jstart, jsize, kstart, ksize, dim, cnt;

  PetscFunctionBegin;
  PetscValidHeaderSpecificType(da, DM_CLASSID, 1, DMDA);
  PetscCheck(dd->gtol, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_WRONGSTATE, "Cannot set coordinates until after DMDA has been setup");
  PetscCall(DMDAGetInfo(da, &dim, &M, &N, &P, NULL, NULL, NULL, NULL, NULL, &bx, &by, &bz, NULL));
  PetscCheck(xmax >= xmin, PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_INCOMP, "xmax must be larger than xmin %g %g", (double)xmin, (double)xmax);
  PetscCheck(!(dim > 1) || !(ymax < ymin), PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_INCOMP, "ymax must be larger than ymin %g %g", (double)ymin, (double)ymax);
  PetscCheck(!(dim > 2) || !(zmax < zmin), PetscObjectComm((PetscObject)da), PETSC_ERR_ARG_INCOMP, "zmax must be larger than zmin %g %g", (double)zmin, (double)zmax);
  PetscCall(PetscObjectGetComm((PetscObject)da, &comm));
  PetscCall(DMDAGetCorners(da, &istart, &jstart, &kstart, &isize, &jsize, &ksize));
  PetscCall(DMGetCoordinateDM(da, &cda));
  PetscCall(DMCreateGlobalVector(cda, &xcoor));
  if (dim == 1) {
    if (bx == DM_BOUNDARY_PERIODIC) hx = (xmax - xmin) / M;
    else hx = (xmax - xmin) / (M - 1);
    PetscCall(VecGetArray(xcoor, &coors));
    for (i = 0; i < isize; i++) coors[i] = xmin + hx * (i + istart);
    PetscCall(VecRestoreArray(xcoor, &coors));
  } else if (dim == 2) {
    if (bx == DM_BOUNDARY_PERIODIC) hx = (xmax - xmin) / (M);
    else hx = (xmax - xmin) / (M - 1);
    if (by == DM_BOUNDARY_PERIODIC) hy = (ymax - ymin) / (N);
    else hy = (ymax - ymin) / (N - 1);
    PetscCall(VecGetArray(xcoor, &coors));
    cnt = 0;
    for (j = 0; j < jsize; j++) {
      for (i = 0; i < isize; i++) {
        coors[cnt++] = xmin + hx * (i + istart);
        coors[cnt++] = ymin + hy * (j + jstart);
      }
    }
    PetscCall(VecRestoreArray(xcoor, &coors));
  } else if (dim == 3) {
    if (bx == DM_BOUNDARY_PERIODIC) hx = (xmax - xmin) / (M);
    else hx = (xmax - xmin) / (M - 1);
    if (by == DM_BOUNDARY_PERIODIC) hy = (ymax - ymin) / (N);
    else hy = (ymax - ymin) / (N - 1);
    if (bz == DM_BOUNDARY_PERIODIC) hz_ = (zmax - zmin) / (P);
    else hz_ = (zmax - zmin) / (P - 1);
    PetscCall(VecGetArray(xcoor, &coors));
    cnt = 0;
    for (k = 0; k < ksize; k++) {
      for (j = 0; j < jsize; j++) {
        for (i = 0; i < isize; i++) {
          coors[cnt++] = xmin + hx * (i + istart);
          coors[cnt++] = ymin + hy * (j + jstart);
          coors[cnt++] = zmin + hz_ * (k + kstart);
        }
      }
    }
    PetscCall(VecRestoreArray(xcoor, &coors));
  } else SETERRQ(PetscObjectComm((PetscObject)da), PETSC_ERR_SUP, "Cannot create uniform coordinates for this dimension %" PetscInt_FMT, dim);
  PetscCall(DMSetCoordinates(da, xcoor));
  PetscCall(VecDestroy(&xcoor));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*
    Allows a user to select a subset of the fields to be drawn by VecView() when the vector comes from a DMDA
*/
PetscErrorCode DMDASelectFields(DM da, PetscInt *outfields, PetscInt **fields)
{
  PetscInt  step, ndisplayfields, *displayfields, k, j;
  PetscBool flg;

  PetscFunctionBegin;
  PetscCall(DMDAGetInfo(da, NULL, NULL, NULL, NULL, NULL, NULL, NULL, &step, NULL, NULL, NULL, NULL, NULL));
  PetscCall(PetscMalloc1(step, &displayfields));
  for (k = 0; k < step; k++) displayfields[k] = k;
  ndisplayfields = step;
  PetscCall(PetscOptionsGetIntArray(NULL, NULL, "-draw_fields", displayfields, &ndisplayfields, &flg));
  if (!ndisplayfields) ndisplayfields = step;
  if (!flg) {
    char      **fields;
    const char *fieldname;
    PetscInt    nfields = step;
    PetscCall(PetscMalloc1(step, &fields));
    PetscCall(PetscOptionsGetStringArray(NULL, NULL, "-draw_fields_by_name", fields, &nfields, &flg));
    if (flg) {
      ndisplayfields = 0;
      for (k = 0; k < nfields; k++) {
        for (j = 0; j < step; j++) {
          PetscCall(DMDAGetFieldName(da, j, &fieldname));
          PetscCall(PetscStrcmp(fieldname, fields[k], &flg));
          if (flg) goto found;
        }
        SETERRQ(PetscObjectComm((PetscObject)da), PETSC_ERR_USER, "Unknown fieldname %s", fields[k]);
      found:
        displayfields[ndisplayfields++] = j;
      }
    }
    for (k = 0; k < nfields; k++) PetscCall(PetscFree(fields[k]));
    PetscCall(PetscFree(fields));
  }
  *fields    = displayfields;
  *outfields = ndisplayfields;
  PetscFunctionReturn(PETSC_SUCCESS);
}

#include <petscdraw.h>

PetscErrorCode VecView_MPI_Draw_DA1d(Vec xin, PetscViewer v)
{
  DM                  da;
  PetscMPIInt         rank, size, tag;
  PetscInt            i, n, N, dof, istart, isize, j, nbounds;
  MPI_Status          status;
  PetscReal           min, max, xmin = 0.0, xmax = 0.0, tmp = 0.0, xgtmp = 0.0;
  const PetscScalar  *array, *xg;
  PetscDraw           draw;
  PetscBool           isnull, useports = PETSC_FALSE, showmarkers = PETSC_FALSE;
  MPI_Comm            comm;
  PetscDrawAxis       axis;
  Vec                 xcoor;
  DMBoundaryType      bx;
  const char         *tlabel = NULL, *xlabel = NULL;
  const PetscReal    *bounds;
  PetscInt           *displayfields;
  PetscInt            k, ndisplayfields;
  PetscBool           hold;
  PetscDrawViewPorts *ports = NULL;
  PetscViewerFormat   format;

  PetscFunctionBegin;
  PetscCall(PetscViewerDrawGetDraw(v, 0, &draw));
  PetscCall(PetscDrawIsNull(draw, &isnull));
  if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
  PetscCall(PetscViewerDrawGetBounds(v, &nbounds, &bounds));

  PetscCall(VecGetDM(xin, &da));
  PetscCheck(da, PetscObjectComm((PetscObject)xin), PETSC_ERR_ARG_WRONG, "Vector not generated from a DMDA");
  PetscCall(PetscObjectGetComm((PetscObject)xin, &comm));
  PetscCallMPI(MPI_Comm_size(comm, &size));
  PetscCallMPI(MPI_Comm_rank(comm, &rank));

  PetscCall(PetscOptionsGetBool(NULL, NULL, "-draw_vec_use_markers", &showmarkers, NULL));

  PetscCall(DMDAGetInfo(da, NULL, &N, NULL, NULL, NULL, NULL, NULL, &dof, NULL, &bx, NULL, NULL, NULL));
  PetscCall(DMDAGetCorners(da, &istart, NULL, NULL, &isize, NULL, NULL));
  PetscCall(VecGetArrayRead(xin, &array));
  PetscCall(VecGetLocalSize(xin, &n));
  n = n / dof;

  /* Get coordinates of nodes */
  PetscCall(DMGetCoordinates(da, &xcoor));
  if (!xcoor) {
    PetscCall(DMDASetUniformCoordinates(da, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0));
    PetscCall(DMGetCoordinates(da, &xcoor));
  }
  PetscCall(VecGetArrayRead(xcoor, &xg));
  PetscCall(DMDAGetCoordinateName(da, 0, &xlabel));

  /* Determine the min and max coordinate in plot */
  if (rank == 0) xmin = PetscRealPart(xg[0]);
  if (rank == size - 1) xmax = PetscRealPart(xg[n - 1]);
  PetscCallMPI(MPI_Bcast(&xmin, 1, MPIU_REAL, 0, comm));
  PetscCallMPI(MPI_Bcast(&xmax, 1, MPIU_REAL, size - 1, comm));

  PetscCall(DMDASelectFields(da, &ndisplayfields, &displayfields));
  PetscCall(PetscViewerGetFormat(v, &format));
  PetscCall(PetscOptionsGetBool(NULL, NULL, "-draw_ports", &useports, NULL));
  if (format == PETSC_VIEWER_DRAW_PORTS) useports = PETSC_TRUE;
  if (useports) {
    PetscCall(PetscViewerDrawGetDraw(v, 0, &draw));
    PetscCall(PetscViewerDrawGetDrawAxis(v, 0, &axis));
    PetscCall(PetscDrawCheckResizedWindow(draw));
    PetscCall(PetscDrawClear(draw));
    PetscCall(PetscDrawViewPortsCreate(draw, ndisplayfields, &ports));
  }

  /* Loop over each field; drawing each in a different window */
  for (k = 0; k < ndisplayfields; k++) {
    j = displayfields[k];

    /* determine the min and max value in plot */
    PetscCall(VecStrideMin(xin, j, NULL, &min));
    PetscCall(VecStrideMax(xin, j, NULL, &max));
    if (j < nbounds) {
      min = PetscMin(min, bounds[2 * j]);
      max = PetscMax(max, bounds[2 * j + 1]);
    }
    if (min == max) {
      min -= 1.e-5;
      max += 1.e-5;
    }

    if (useports) {
      PetscCall(PetscDrawViewPortsSet(ports, k));
      PetscCall(DMDAGetFieldName(da, j, &tlabel));
    } else {
      const char *title;
      PetscCall(PetscViewerDrawGetHold(v, &hold));
      PetscCall(PetscViewerDrawGetDraw(v, k, &draw));
      PetscCall(PetscViewerDrawGetDrawAxis(v, k, &axis));
      PetscCall(DMDAGetFieldName(da, j, &title));
      if (title) PetscCall(PetscDrawSetTitle(draw, title));
      PetscCall(PetscDrawCheckResizedWindow(draw));
      if (!hold) PetscCall(PetscDrawClear(draw));
    }
    PetscCall(PetscDrawAxisSetLabels(axis, tlabel, xlabel, NULL));
    PetscCall(PetscDrawAxisSetLimits(axis, xmin, xmax, min, max));
    PetscCall(PetscDrawAxisDraw(axis));

    /* draw local part of vector */
    PetscCall(PetscObjectGetNewTag((PetscObject)xin, &tag));
    if (rank < size - 1) { /*send value to right */
      PetscCallMPI(MPI_Send((void *)&xg[n - 1], 1, MPIU_REAL, rank + 1, tag, comm));
      PetscCallMPI(MPI_Send((void *)&array[j + (n - 1) * dof], 1, MPIU_REAL, rank + 1, tag, comm));
    }
    if (rank) { /* receive value from left */
      PetscCallMPI(MPI_Recv(&xgtmp, 1, MPIU_REAL, rank - 1, tag, comm, &status));
      PetscCallMPI(MPI_Recv(&tmp, 1, MPIU_REAL, rank - 1, tag, comm, &status));
    }
    PetscDrawCollectiveBegin(draw);
    if (rank) {
      PetscCall(PetscDrawLine(draw, xgtmp, tmp, PetscRealPart(xg[0]), PetscRealPart(array[j]), PETSC_DRAW_RED));
      if (showmarkers) PetscCall(PetscDrawPoint(draw, xgtmp, tmp, PETSC_DRAW_BLACK));
    }
    for (i = 1; i < n; i++) {
      PetscCall(PetscDrawLine(draw, PetscRealPart(xg[i - 1]), PetscRealPart(array[j + dof * (i - 1)]), PetscRealPart(xg[i]), PetscRealPart(array[j + dof * i]), PETSC_DRAW_RED));
      if (showmarkers) PetscCall(PetscDrawMarker(draw, PetscRealPart(xg[i - 1]), PetscRealPart(array[j + dof * (i - 1)]), PETSC_DRAW_BLACK));
    }
    if (rank == size - 1) {
      if (showmarkers) PetscCall(PetscDrawMarker(draw, PetscRealPart(xg[n - 1]), PetscRealPart(array[j + dof * (n - 1)]), PETSC_DRAW_BLACK));
    }
    PetscDrawCollectiveEnd(draw);
    PetscCall(PetscDrawFlush(draw));
    PetscCall(PetscDrawPause(draw));
    if (!useports) PetscCall(PetscDrawSave(draw));
  }
  if (useports) {
    PetscCall(PetscViewerDrawGetDraw(v, 0, &draw));
    PetscCall(PetscDrawSave(draw));
  }

  PetscCall(PetscDrawViewPortsDestroy(ports));
  PetscCall(PetscFree(displayfields));
  PetscCall(VecRestoreArrayRead(xcoor, &xg));
  PetscCall(VecRestoreArrayRead(xin, &array));
  PetscFunctionReturn(PETSC_SUCCESS);
}
