/*
 * Copyright (c) 2005-2017 National Technology & Engineering Solutions
 * of Sandia, LLC (NTESS).  Under the terms of Contract DE-NA0003525 with
 * NTESS, the U.S. Government retains certain rights in this software.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *
 *     * Neither the name of NTESS nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "exodusII.h"     // for ex_err, etc
#include "exodusII_int.h" // for EX_FATAL, ex_comp_ws, etc
#include "vtk_netcdf.h"       // for NC_NOERR, etc
#include <stddef.h>       // for size_t
#include <stdio.h>

/*!

The function ex_get_time() reads the time value for a specified time
step.

Because time values are floating point values, the application code
must declare the array passed to be the appropriate type (float or
double) to match the compute word size passed in ex_create() or
ex_open().

\return In case of an error, ex_get_time() returns a negative number; a
warning will return a positive number. Possible causes of errors
include:
  -  data file not properly opened with call to ex_create() or ex_open()
  -  no time steps have been stored in the file.


\param[in]  exoid       exodus file ID returned from a previous call to
ex_create() or ex_open().
\param[in]  time_step   The time step number. This is essentially an index (in
the time
                        dimension) into the global, nodal, and element variables
arrays stored
                        in the database. The first time step is 1.
\param[out] time_value  Returned time at the specified time step.

As an example, the following coding will read the time value stored in
the data file for time step n:

~~~{.c}
int n, error, exoid;
float time_value;

\comment{read time value at time step 3}
n = 3;
error = ex_get_time (exoid, n, &time_value);
~~~

*/

int ex_get_time(int exoid, int time_step, void *time_value)
{
  int                  status;
  int                  varid;
  size_t               start[1];
  char                 errmsg[MAX_ERR_LENGTH];
  struct ex_file_item *file = NULL;

  EX_FUNC_ENTER();
  ex_check_valid_file_id(exoid, __func__);

  file  = ex_find_file_item(exoid);
  varid = file->time_varid;
  if (varid < 0) {
    /* inquire previously defined variable */
    if ((status = nc_inq_varid(exoid, VAR_WHOLE_TIME, &varid)) != NC_NOERR) {
      snprintf(errmsg, MAX_ERR_LENGTH, "ERROR: failed to locate time variable in file id %d",
               exoid);
      ex_err(__func__, errmsg, status);
      EX_FUNC_LEAVE(EX_FATAL);
    }
    file->time_varid = varid;
  }

  /* read time value */
  start[0] = --time_step;

  if (ex_comp_ws(exoid) == 4) {
    status = nc_get_var1_float(exoid, varid, start, time_value);
  }
  else {
    status = nc_get_var1_double(exoid, varid, start, time_value);
  }

  if (status != NC_NOERR) {
    snprintf(errmsg, MAX_ERR_LENGTH, "ERROR: failed to get time value in file id %d", exoid);
    ex_err(__func__, errmsg, status);
    EX_FUNC_LEAVE(EX_FATAL);
  }
  EX_FUNC_LEAVE(EX_NOERR);
}
