/*
 * Copyright (c) 2005 Sandia Corporation. Under the terms of Contract
 * DE-AC04-94AL85000 with Sandia Corporation, the U.S. Governement
 * 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 Sandia Corporation 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.
 * 
 */
/*****************************************************************************
*
* exopen - ex_open
*
* entry conditions - 
*   input parameters:
*       char*   path                    exodus filename path
*       int     mode                    access mode w/r
*
* exit conditions - 
*       int     exoid                   exodus file id
*       int*    comp_ws                 computer word size
*       int*    io_ws                   storage word size
*       float*  version                 EXODUSII interface version number
*
* revision history - 
*
*
*****************************************************************************/

#include <stdio.h>
#include "exodusII.h"
#include "exodusII_int.h"

/*!  

The function ex_open() opens an existing exodus file and returns
an ID that can subsequently be used to refer to the file, the word
size of the floating point values stored in the file, and the version
of the exodus database (returned as a ``float'', regardless of the
compute or I/O word size). Multiple files may be ``open'' simultaneously.

\return In case of an error, ex_open() returns a negative
number. Possible causes of errors include:
  -  The specified file does not exist.
  -  The mode specified is something other than the predefined constant \fparam{EX_READ} or \fparam{EX_WRITE}.
  -  Database version is earlier than 2.0.

\param path The file name of the exodus file. This can be given as either an
            absolute path name (from the root of the file system) or a relative
            path name (from the current directory).

\param mode Access mode. Use one of the following predefined constants:
        -  \fparam{EX_READ} To open the file just for reading.
        -  \fparam{EX_WRITE} To open the file for writing and reading.

\param[in,out] comp_ws The word size in bytes (0, 4 or 8) of the floating point variables
               used in the application program. If 0 (zero) is passed, the default
               size of floating point values for the machine will be used and
               returned in this variable. WARNING: all exodus functions requiring
               reals must be passed reals declared with this passed in or returned
               compute word size (4 or 8).


\param[in,out] io_ws The word size in bytes (0, 4 or 8) of the floating 
                    point data as they are stored in the exodus file. If the word 
                    size does not match the word size of data stored in the file, 
                    a fatal error is returned. If this argument is 0, the word size 
                    of the floating point data already stored in the file is returned.

\param[out] version  Returned exodus database version number.

The following opens an exodus file named \file{test.exo} for read
only, using default settings for compute and I/O word sizes:

\code
#include "exodusII.h"
int CPU_word_size,IO_word_size, exoid;
float version;

CPU_word_size = sizeof(float);   \co{float or double}
IO_word_size = 0;                \co{use what is stored in file}

\comment{open exodus files}
exoid = ex_open ("test.exo",     \co{filename path}
                 EX_READ,        \co{access mode = READ}
     &CPU_word_size, \co{CPU word size}
     &IO_word_size,  \co{IO word size}
           &version);      \co{ExodusII library version}
\endcode
 */

int ex_open_int (const char  *path,
     int    mode,
     int   *comp_ws,
     int   *io_ws,
     float *version,
     int    run_version)
{
   int exoid;
   int status, stat_att, stat_dim;
   nc_type att_type = NC_NAT;
   size_t att_len = 0;
   int old_fill;
   int file_wordsize;
   int dim_str_name;
   char errmsg[MAX_ERR_LENGTH];

  exerrval = 0; /* clear error code */
 
/* set error handling mode to no messages, non-fatal errors */
  ex_opts(exoptval);    /* call required to set ncopts first time through */

  if (run_version != EX_API_VERS_NODOT) {
    int run_version_major = run_version / 100;
    int run_version_minor = run_version % 100;
    int lib_version_major = EX_API_VERS_NODOT / 100;
    int lib_version_minor = EX_API_VERS_NODOT % 100;
    fprintf(stderr, "EXODUSII: Warning: This code was compiled with exodusII version %d.%02d,\n          but was linked with exodusII library version %d.%02d\n          This is probably an error in the build process of this code.\n",
      run_version_major, run_version_minor, lib_version_major, lib_version_minor);
  }
  
  if (mode == EX_READ) { /* READ ONLY */
#if defined(__LIBCATAMOUNT__)
    if ((status = nc_open (path, NC_NOWRITE, &exoid)) != NC_NOERR)
#else
    if ((status = nc_open (path, NC_NOWRITE|NC_SHARE, &exoid)) != NC_NOERR)
#endif
    {
      /* NOTE: netCDF returns an id of -1 on an error - but no error code! */
      if (status == 0)
        exerrval = EX_FATAL;
      else
        exerrval = status;
      sprintf(errmsg,"Error: failed to open %s read only",path);
      ex_err("ex_open",errmsg,exerrval); 
      return(EX_FATAL);
    } 
  }

  else if (mode == EX_WRITE) /* READ/WRITE */
  {
#if defined(__LIBCATAMOUNT__)
    if ((status = nc_open (path, NC_WRITE, &exoid)) != NC_NOERR)
#else
    if ((status = nc_open (path, NC_WRITE|NC_SHARE, &exoid)) != NC_NOERR)
#endif
    {
      /* NOTE: netCDF returns an id of -1 on an error - but no error code! */
      if (status == 0)
        exerrval = EX_FATAL;
      else
        exerrval = status;
      sprintf(errmsg,"Error: failed to open %s write only",path);
      ex_err("ex_open",errmsg,exerrval); 
      return(EX_FATAL);
    } 

    /* turn off automatic filling of netCDF variables */
    if ((status = nc_set_fill (exoid, NC_NOFILL, &old_fill)) != NC_NOERR) {
      exerrval = status;
      sprintf(errmsg,
             "Error: failed to set nofill mode in file id %d",
              exoid);
      ex_err("ex_open", errmsg, exerrval);
      return (EX_FATAL);
    }

    stat_att = nc_inq_att(exoid, NC_GLOBAL, ATT_MAX_NAME_LENGTH, &att_type, &att_len);
    stat_dim = nc_inq_dimid(exoid, DIM_STR_NAME, &dim_str_name);
    if(stat_att != NC_NOERR || stat_dim != NC_NOERR) {
      nc_redef(exoid);
      if (stat_att != NC_NOERR) {
  int max_so_far = 32;
  status=nc_put_att_int(exoid, NC_GLOBAL, ATT_MAX_NAME_LENGTH, NC_INT, 1, &max_so_far);
      }

      /* If the DIM_STR_NAME variable does not exist on the database, we need to add it now. */
      if(stat_dim != NC_NOERR) {
  /* Not found; set to default value of 32+1. */
  int max_name = ex_max_name_length < 32 ? 32 : ex_max_name_length;
  status = nc_def_dim(exoid, DIM_STR_NAME, max_name+1, &dim_str_name);
      }
      nc_enddef (exoid);
    }
  }
  else 
  {
    exerrval = EX_BADFILEMODE;
    sprintf(errmsg,"Error: invalid file open mode: %d",mode);
    ex_err("ex_open",errmsg,exerrval); 
    return (EX_FATAL);
  }

/* determine version of EXODUS II file, and the word size of
 * floating point values stored in the file
 */

  if ((status = nc_get_att_float(exoid, NC_GLOBAL, ATT_VERSION, version)) != NC_NOERR) {
     exerrval  = status;
     sprintf(errmsg,"Error: failed to get database version for file id: %d",
             exoid);
     ex_err("ex_open",errmsg,exerrval);
     return(EX_FATAL);
   }
   
/* check ExodusII file version - old version 1.x files are not supported */
   if (*version < 2.0) {
     exerrval  = EX_FATAL;
     sprintf(errmsg,"Error: Unsupported file version %.2f in file id: %d",
             *version, exoid);
     ex_err("ex_open",errmsg,exerrval);
     return(EX_FATAL);
   }
   
   if (nc_get_att_int (exoid, NC_GLOBAL, ATT_FLT_WORDSIZE, &file_wordsize) != NC_NOERR)
   {  /* try old (prior to db version 2.02) attribute name */
     if (nc_get_att_int (exoid,NC_GLOBAL,ATT_FLT_WORDSIZE_BLANK,&file_wordsize) != NC_NOERR)
     {
       exerrval  = EX_FATAL;
       sprintf(errmsg,"Error: failed to get file wordsize from file id: %d",
             exoid);
       ex_err("ex_open",errmsg,exerrval);
       return(exerrval);
     }
   }

/* initialize floating point size conversion.
 */

   if (ex_conv_ini( exoid, comp_ws, io_ws, file_wordsize ) != EX_NOERR ) {
     exerrval = EX_FATAL;
     sprintf(errmsg,
           "Error: failed to init conversion routines in file id %d",
            exoid);
     ex_err("ex_open", errmsg, exerrval);
     return (EX_FATAL);
   }

   return (exoid);
}