/*
  This file is part of p4est.
  p4est is a C library to manage a collection (a forest) of multiple
  connected adaptive quadtrees or octrees in parallel.

  Copyright (C) 2010 The University of Texas System
  Additional copyright (C) 2011 individual authors
  Written by Carsten Burstedde, Lucas C. Wilcox, and Tobin Isaac

  p4est is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  p4est is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with p4est; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/

/********************************************************************
 *                          IMPORTANT NOTE                          *
 *                                                                  *
 * The p4est_points functionality depends on sc/src/sc_sort.        *
 * That parallel bitonic sort is still buggy (see sc/bugs).         *
 * If you want to use this code you have to fix the sort first.     *
 ********************************************************************/

#ifdef P4_TO_P8
#include <p8est_bits.h>
#include <p8est_points.h>
#include <p8est_vtk.h>
#else
#include <p4est_bits.h>
#include <p4est_points.h>
#include <p4est_vtk.h>
#endif /* !P4_TO_P8 */
#include <sc_io.h>

/*
 * Usage: p4est_points <configuration> <level> <prefix>
 *        possible configurations:
 *        o unit      Refinement on the unit square.
 *        o three     Refinement on a forest with three trees.
 *        o moebius   Refinement on a 5-tree Moebius band.
 *        o star      Refinement on a 6-tree star shaped domain.
 *        o periodic  Refinement on the unit square with periodic b.c.
 */

static p4est_quadrant_t *
read_points (const char *filename, p4est_topidx_t num_trees,
             p4est_locidx_t * num_points)
{
  int                 retval;
  int                 qshift;
  unsigned            ucount, u, ignored;
  double              x, y, z;
  double              qlen;
  double             *point_buffer;
  p4est_quadrant_t   *points, *q;
  FILE               *file;

  file = fopen (filename, "rb");
  SC_CHECK_ABORTF (file != NULL, "Open file %s", filename);

  sc_fread (&ucount, sizeof (unsigned int), 1, file, "Read point count");

  point_buffer = P4EST_ALLOC (double, 3 * ucount);
  sc_fread (point_buffer, sizeof (double), (size_t) (3 * ucount), file,
            "Read points");

  retval = fclose (file);
  SC_CHECK_ABORTF (retval == 0, "Close file %s", filename);

  q = points = P4EST_ALLOC_ZERO (p4est_quadrant_t, ucount);
  qlen = (double) (1 << P4EST_QMAXLEVEL);
  qshift = P4EST_MAXLEVEL - P4EST_QMAXLEVEL;
  for (ignored = u = 0; u < ucount; ++u) {
    x = point_buffer[3 * u + 0];
    y = point_buffer[3 * u + 1];
    z = point_buffer[3 * u + 2];
    if (x < 0. || x > 1. || y < 0. || y > 1. || z < 0. || z > 1.) {
      ++ignored;
      continue;
    }

    q->x = (p4est_qcoord_t) (x * qlen) << qshift;
    q->x = SC_MIN (q->x, P4EST_ROOT_LEN - 1);
    q->y = (p4est_qcoord_t) (y * qlen) << qshift;
    q->y = SC_MIN (q->y, P4EST_ROOT_LEN - 1);
#ifdef P4_TO_P8
    q->z = (p4est_qcoord_t) (z * qlen) << qshift;
    q->z = SC_MIN (q->z, P4EST_ROOT_LEN - 1);
#endif
    q->level = P4EST_MAXLEVEL;
    q->p.which_tree =
      (p4est_topidx_t) ((double) num_trees * rand () / (RAND_MAX + 1.0));
    P4EST_ASSERT (p4est_quadrant_is_node (q, 1));

    ++q;
  }
  P4EST_FREE (point_buffer);

  if (num_points != NULL) {
    *num_points = (p4est_locidx_t) (ucount - ignored);
  }

  return points;
}

int
main (int argc, char **argv)
{
  int                 mpiret;
  int                 num_procs, rank;
  int                 maxlevel;
  int                 wrongusage;
  char                buffer[BUFSIZ];
  p4est_locidx_t      num_points, max_points;
  p4est_connectivity_t *conn;
  p4est_quadrant_t   *points;
  p4est_t            *p4est;
  sc_MPI_Comm         mpicomm;
  const char         *usage;

  /* initialize MPI and p4est internals */
  mpiret = sc_MPI_Init (&argc, &argv);
  SC_CHECK_MPI (mpiret);
  mpicomm = sc_MPI_COMM_WORLD;
  mpiret = sc_MPI_Comm_size (mpicomm, &num_procs);
  SC_CHECK_MPI (mpiret);
  mpiret = sc_MPI_Comm_rank (mpicomm, &rank);
  SC_CHECK_MPI (mpiret);

  sc_init (mpicomm, 1, 1, NULL, SC_LP_DEFAULT);
  p4est_init (NULL, SC_LP_DEFAULT);

  /* process command line arguments */
  usage =
    "Arguments: <configuration> <level> <maxpoints> <prefix>\n"
    "   Configuration can be any of\n"
#ifndef P4_TO_P8
    "      unit|three|moebius|star|periodic\n"
#else
    "      unit|periodic|rotwrap|twocubes|rotcubes\n"
#endif
    "   Level controls the maximum depth of refinement\n"
    "   Maxpoints is the maximum number of points per quadrant\n"
    "      which applies to all quadrants above maxlevel\n"
    "      A value of 0 refines recursively to maxlevel\n"
    "      A value of -1 does no refinement at all\n"
    "   Prefix is for loading a point data file\n";
  wrongusage = 0;
  if (!wrongusage && argc != 5) {
    wrongusage = 1;
  }
  conn = NULL;
  if (!wrongusage) {
#ifndef P4_TO_P8
    if (!strcmp (argv[1], "unit")) {
      conn = p4est_connectivity_new_unitsquare ();
    }
    else if (!strcmp (argv[1], "three")) {
      conn = p4est_connectivity_new_corner ();
    }
    else if (!strcmp (argv[1], "moebius")) {
      conn = p4est_connectivity_new_moebius ();
    }
    else if (!strcmp (argv[1], "star")) {
      conn = p4est_connectivity_new_star ();
    }
    else if (!strcmp (argv[1], "periodic")) {
      conn = p4est_connectivity_new_periodic ();
    }
#else
    if (!strcmp (argv[1], "unit")) {
      conn = p8est_connectivity_new_unitcube ();
    }
    else if (!strcmp (argv[1], "periodic")) {
      conn = p8est_connectivity_new_periodic ();
    }
    else if (!strcmp (argv[1], "rotwrap")) {
      conn = p8est_connectivity_new_rotwrap ();
    }
    else if (!strcmp (argv[1], "twocubes")) {
      conn = p8est_connectivity_new_twocubes ();
    }
    else if (!strcmp (argv[1], "rotcubes")) {
      conn = p8est_connectivity_new_rotcubes ();
    }
#endif
    else {
      wrongusage = 1;
    }
  }
  if (!wrongusage) {
    maxlevel = atoi (argv[2]);
    if (maxlevel < 0 || maxlevel > P4EST_QMAXLEVEL) {
      wrongusage = 1;
    }
  }
  if (!wrongusage) {
    max_points = (p4est_locidx_t) atoi (argv[3]);
    if (max_points < -1) {
      wrongusage = 1;
    }
  }
  if (wrongusage) {
    P4EST_GLOBAL_LERROR (usage);
    sc_abort_collective ("Usage error");
  }

  snprintf (buffer, BUFSIZ, "%s%d_%d.pts", argv[4], rank, num_procs);
  points = read_points (buffer, conn->num_trees, &num_points);
  SC_LDEBUGF ("Read %lld points\n", (long long) num_points);

  p4est = p4est_new_points (mpicomm, conn, maxlevel, points,
                            num_points, max_points, 5, NULL, NULL);
  P4EST_FREE (points);
  p4est_vtk_write_file (p4est, NULL, P4EST_STRING "_points_created");

  p4est_partition (p4est, 0, NULL);
  p4est_vtk_write_file (p4est, NULL, P4EST_STRING "_points_partition");

  p4est_balance (p4est, P4EST_CONNECT_FULL, NULL);
  p4est_vtk_write_file (p4est, NULL, P4EST_STRING "_points_balance");

  p4est_destroy (p4est);
  p4est_connectivity_destroy (conn);

  /* clean up and exit */
  sc_finalize ();

  mpiret = sc_MPI_Finalize ();
  SC_CHECK_MPI (mpiret);

  return 0;
}