#include <petsc/private/drawimpl.h> /*I "petscdraw.h" I*/

/*@
   PetscDrawSetViewPort - Sets the portion of the window (page) to which draw
   routines will write.

   Collective

   Input Parameters:
+  xl - the horizontal coordinate of the lower left corner of the subwindow.
.  yl - the vertical coordinate of the lower left corner of the subwindow.
.  xr - the horizontal coordinate of the upper right corner of the subwindow.
.  yr - the vertical coordinate of the upper right corner of the subwindow.
-  draw - the drawing context

   Level: advanced

   Notes:
   These numbers must always be between 0.0 and 1.0.

   Lower left corner is (0,0).

.seealso: `PetscDrawGetViewPort(), ``PetscDraw`, `PetscDrawSplitViewPort()`, `PetscDrawViewPortsCreate()`
@*/
PetscErrorCode PetscDrawSetViewPort(PetscDraw draw, PetscReal xl, PetscReal yl, PetscReal xr, PetscReal yr)
{
  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw, PETSC_DRAW_CLASSID, 1);
  PetscCheck(xl >= 0.0 && xr <= 1.0 && yl >= 0.0 && yr <= 1.0 && xr > xl && yr > yl, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "ViewPort values must be >= 0 and <= 1: Instead %g %g %g %g", (double)xl, (double)yl, (double)xr, (double)yr);
  draw->port_xl = xl;
  draw->port_yl = yl;
  draw->port_xr = xr;
  draw->port_yr = yr;
  PetscTryTypeMethod(draw, setviewport, xl, yl, xr, yr);
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
   PetscDrawGetViewPort - Gets the portion of the window (page) to which draw
   routines will write.

   Collective

   Input Parameter:
.  draw - the drawing context

   Output Parameters:
+  xl - the horizontal coordinate of the lower left corner of the subwindow.
.  yl - the vertical coordinate of the lower left corner of the subwindow.
.  xr - the horizontal coordinate of the upper right corner of the subwindow.
-  yr - the vertical coordinate of the upper right corner of the subwindow.

   Level: advanced

   Notes:
   These numbers must always be between 0.0 and 1.0.

   Lower left corner is (0,0).

.seealso: `PetscDraw`, `PetscDrawSplitViewPort()`, `PetscDrawSetViewPort()`
@*/
PetscErrorCode PetscDrawGetViewPort(PetscDraw draw, PetscReal *xl, PetscReal *yl, PetscReal *xr, PetscReal *yr)
{
  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw, PETSC_DRAW_CLASSID, 1);
  PetscValidRealPointer(xl, 2);
  PetscValidRealPointer(yl, 3);
  PetscValidRealPointer(xr, 4);
  PetscValidRealPointer(yr, 5);
  *xl = draw->port_xl;
  *yl = draw->port_yl;
  *xr = draw->port_xr;
  *yr = draw->port_yr;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
   PetscDrawSplitViewPort - Splits a window shared by several processes into smaller
   view ports. One for each process.

   Collective

   Input Parameter:
.  draw - the drawing context

   Level: advanced

.seealso: `PetscDrawDivideViewPort()`, `PetscDrawSetViewPort()`
@*/
PetscErrorCode PetscDrawSplitViewPort(PetscDraw draw)
{
  PetscMPIInt rank, size;
  PetscInt    n;
  PetscBool   isnull;
  PetscReal   xl, xr, yl, yr, h;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw, PETSC_DRAW_CLASSID, 1);
  PetscCall(PetscDrawIsNull(draw, &isnull));
  if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
  PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)draw), &rank));
  PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)draw), &size));

  n = (PetscInt)(.1 + PetscSqrtReal((PetscReal)size));
  while (n * n < size) n++;

  h  = 1.0 / n;
  xl = (rank % n) * h;
  xr = xl + h;
  yl = (rank / n) * h;
  yr = yl + h;

  PetscDrawCollectiveBegin(draw);
  PetscCall(PetscDrawLine(draw, xl, yl, xl, yr, PETSC_DRAW_BLACK));
  PetscCall(PetscDrawLine(draw, xl, yr, xr, yr, PETSC_DRAW_BLACK));
  PetscCall(PetscDrawLine(draw, xr, yr, xr, yl, PETSC_DRAW_BLACK));
  PetscCall(PetscDrawLine(draw, xr, yl, xl, yl, PETSC_DRAW_BLACK));
  PetscDrawCollectiveEnd(draw);
  PetscCall(PetscDrawFlush(draw));

  draw->port_xl = xl + .05 * h;
  draw->port_xr = xr - .05 * h;
  draw->port_yl = yl + .05 * h;
  draw->port_yr = yr - .05 * h;

  PetscTryTypeMethod(draw, setviewport, xl, yl, xr, yr);
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
   PetscDrawViewPortsCreate - Splits a window into smaller view ports. Each processor shares all the viewports.

   Collective

   Input Parameters:
+  draw - the drawing context
-  nports - the number of ports

   Output Parameter:
.  ports - a `PetscDrawViewPorts` context (C structure)

   Options Database Key:
.  -draw_ports - display multiple fields in the same window with PetscDrawPorts() instead of in separate windows

   Level: advanced

.seealso: `PetscDrawSplitViewPort()`, `PetscDrawSetViewPort()`, `PetscDrawViewPortsSet()`, `PetscDrawViewPortsDestroy()`
@*/
PetscErrorCode PetscDrawViewPortsCreate(PetscDraw draw, PetscInt nports, PetscDrawViewPorts **newports)
{
  PetscDrawViewPorts *ports;
  PetscInt            i, n;
  PetscBool           isnull;
  PetscMPIInt         rank;
  PetscReal          *xl, *xr, *yl, *yr, h;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw, PETSC_DRAW_CLASSID, 1);
  PetscCheck(nports >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of divisions must be positive: %" PetscInt_FMT, nports);
  PetscValidPointer(newports, 3);
  PetscCall(PetscDrawIsNull(draw, &isnull));
  if (isnull) {
    *newports = NULL;
    PetscFunctionReturn(PETSC_SUCCESS);
  }
  PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)draw), &rank));

  PetscCall(PetscNew(&ports));
  *newports     = ports;
  ports->draw   = draw;
  ports->nports = nports;
  PetscCall(PetscObjectReference((PetscObject)draw));
  /* save previous drawport of window */
  PetscCall(PetscDrawGetViewPort(draw, &ports->port_xl, &ports->port_yl, &ports->port_xr, &ports->port_yr));

  n = (PetscInt)(.1 + PetscSqrtReal((PetscReal)nports));
  while (n * n < nports) n++;
  h = 1.0 / n;

  PetscCall(PetscMalloc4(n * n, &xl, n * n, &xr, n * n, &yl, n * n, &yr));
  ports->xl = xl;
  ports->xr = xr;
  ports->yl = yl;
  ports->yr = yr;

  PetscCall(PetscDrawSetCoordinates(draw, 0.0, 0.0, 1.0, 1.0));
  PetscDrawCollectiveBegin(draw);
  for (i = 0; i < n * n; i++) {
    xl[i] = (i % n) * h;
    xr[i] = xl[i] + h;
    yl[i] = (i / n) * h;
    yr[i] = yl[i] + h;

    if (rank == 0) {
      PetscCall(PetscDrawLine(draw, xl[i], yl[i], xl[i], yr[i], PETSC_DRAW_BLACK));
      PetscCall(PetscDrawLine(draw, xl[i], yr[i], xr[i], yr[i], PETSC_DRAW_BLACK));
      PetscCall(PetscDrawLine(draw, xr[i], yr[i], xr[i], yl[i], PETSC_DRAW_BLACK));
      PetscCall(PetscDrawLine(draw, xr[i], yl[i], xl[i], yl[i], PETSC_DRAW_BLACK));
    }

    xl[i] += .05 * h;
    xr[i] -= .05 * h;
    yl[i] += .05 * h;
    yr[i] -= .05 * h;
  }
  PetscDrawCollectiveEnd(draw);
  PetscCall(PetscDrawFlush(draw));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
   PetscDrawViewPortsCreateRect - Splits a window into smaller
       view ports. Each processor shares all the viewports. The number
       of views in the x- and y-directions is specified.

   Collective

   Input Parameters:
+  draw - the drawing context
.  nx - the number of x divisions
-  ny - the number of y divisions

   Output Parameter:
.  ports - a `PetscDrawViewPorts` context (C structure)

   Level: advanced

.seealso: `PetscDrawSplitViewPort()`, `PetscDrawSetViewPort()`, `PetscDrawViewPortsSet()`, `PetscDrawViewPortsDestroy()`, `PetscDrawViewPorts`
@*/
PetscErrorCode PetscDrawViewPortsCreateRect(PetscDraw draw, PetscInt nx, PetscInt ny, PetscDrawViewPorts **newports)
{
  PetscDrawViewPorts *ports;
  PetscReal          *xl, *xr, *yl, *yr, hx, hy;
  PetscInt            i, j, k, n;
  PetscBool           isnull;
  PetscMPIInt         rank;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(draw, PETSC_DRAW_CLASSID, 1);
  PetscCheck(nx >= 1 && ny >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of divisions must be positive: %" PetscInt_FMT " x %" PetscInt_FMT, nx, ny);
  PetscValidPointer(newports, 4);
  PetscCall(PetscDrawIsNull(draw, &isnull));
  if (isnull) {
    *newports = NULL;
    PetscFunctionReturn(PETSC_SUCCESS);
  }
  PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)draw), &rank));

  n  = nx * ny;
  hx = 1.0 / nx;
  hy = 1.0 / ny;
  PetscCall(PetscNew(&ports));
  *newports     = ports;
  ports->draw   = draw;
  ports->nports = n;
  PetscCall(PetscObjectReference((PetscObject)draw));
  /* save previous drawport of window */
  PetscCall(PetscDrawGetViewPort(draw, &ports->port_xl, &ports->port_yl, &ports->port_xr, &ports->port_yr));

  PetscCall(PetscMalloc4(n, &xl, n, &xr, n, &yl, n, &yr));
  ports->xr = xr;
  ports->xl = xl;
  ports->yl = yl;
  ports->yr = yr;

  PetscCall(PetscDrawSetCoordinates(draw, 0.0, 0.0, 1.0, 1.0));
  PetscDrawCollectiveBegin(draw);
  for (i = 0; i < nx; i++) {
    for (j = 0; j < ny; j++) {
      k = j * nx + i;

      xl[k] = i * hx;
      xr[k] = xl[k] + hx;
      yl[k] = j * hy;
      yr[k] = yl[k] + hy;

      if (rank == 0) {
        PetscCall(PetscDrawLine(draw, xl[k], yl[k], xl[k], yr[k], PETSC_DRAW_BLACK));
        PetscCall(PetscDrawLine(draw, xl[k], yr[k], xr[k], yr[k], PETSC_DRAW_BLACK));
        PetscCall(PetscDrawLine(draw, xr[k], yr[k], xr[k], yl[k], PETSC_DRAW_BLACK));
        PetscCall(PetscDrawLine(draw, xr[k], yl[k], xl[k], yl[k], PETSC_DRAW_BLACK));
      }

      xl[k] += .05 * hx;
      xr[k] -= .05 * hx;
      yl[k] += .05 * hy;
      yr[k] -= .05 * hy;
    }
  }
  PetscDrawCollectiveEnd(draw);
  PetscCall(PetscDrawFlush(draw));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
   PetscDrawViewPortsDestroy - frees a `PetscDrawViewPorts` object

   Collective on the PetscDraw inside ports

   Input Parameter:
.  ports - the `PetscDrawViewPorts` object

   Level: advanced

.seealso: `PetscDrawViewPorts`, `PetscDrawSplitViewPort()`, `PetscDrawSetViewPort()`, `PetscDrawViewPortsSet()`, `PetscDrawViewPortsCreate()`
@*/
PetscErrorCode PetscDrawViewPortsDestroy(PetscDrawViewPorts *ports)
{
  PetscFunctionBegin;
  if (!ports) PetscFunctionReturn(PETSC_SUCCESS);
  PetscValidPointer(ports, 1);
  /* reset Drawport of Window back to previous value */
  PetscCall(PetscDrawSetViewPort(ports->draw, ports->port_xl, ports->port_yl, ports->port_xr, ports->port_yr));
  PetscCall(PetscDrawDestroy(&ports->draw));
  PetscCall(PetscFree4(ports->xl, ports->xr, ports->yl, ports->yr));
  PetscCall(PetscFree(ports));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
   PetscDrawViewPortsSet - sets a draw object to use a particular subport

   Logically Collective on the `PetscDraw` inside ports

   Input Parameters:
+  ports - the `PetscDrawViewPorts` object
-  port - the port number, from 0 to nports-1

   Level: advanced

.seealso: `PetscDrawViewPorts`, `PetscDrawSplitViewPort()`, `PetscDrawSetViewPort()`, `PetscDrawViewPortsDestroy()`, `PetscDrawViewPortsCreate()`
@*/
PetscErrorCode PetscDrawViewPortsSet(PetscDrawViewPorts *ports, PetscInt port)
{
  PetscFunctionBegin;
  if (!ports) PetscFunctionReturn(PETSC_SUCCESS);
  PetscValidPointer(ports, 1);
  PetscCheck(port >= 0 && (port <= ports->nports - 1), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Port is out of range requested %" PetscInt_FMT " from 0 to %" PetscInt_FMT, port, ports->nports - 1);
  PetscCall(PetscDrawSetViewPort(ports->draw, ports->xl[port], ports->yl[port], ports->xr[port], ports->yr[port]));
  PetscFunctionReturn(PETSC_SUCCESS);
}