/*@@
   @file      CheckpointRecovery.c
   @date      Jun 04 1999
   @author    Thomas Radke
   @desc 
   Utility routines for checkpointing/recovery and the filereader
   The actual work is done by the IO thorns.
 @@*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "cctk.h"
#include "cctk_parameters.h"
#include "ioGH.h"
#include "StoreHandledData.h"

/* Local data holding info on Recover Functions*/
static cHandledData *RecoverFunctions = NULL;
static int num_functions = 0;

/************************************************************************
 *
 *  Registration functions for Restoring from IO Files
 *
 ************************************************************************/

 /*@@
   @routine    IOUtil_RegisterRecover
   @date       Monday 21 June 1999
   @author     Gabrielle Allen
   @desc 
               Registers a new recovery method
   @enddesc 
   @calls      Util_GetHandle
               Util_NewHandle
   @history 
   @endhistory
 
   @var        name
   @vdesc      The name of the function for recovery
   @vtype      const char *
   @vio        in
   @vcomment 
   @endvar 

   @returntype int
   @returndesc
               -2  = memory allocation failed
               -1  = method with this name already registered
               i>0 = handle for function
   @endreturndesc

   @version    $Header$
@@*/

int IOUtil_RegisterRecover(const char *name, int (*func)(cGH *, const char *, int))
{

  int handle;

  /* Check that the method hasn't already been registered */
  handle = Util_GetHandle(RecoverFunctions, name, NULL);

  if(handle < 0)
  {
    /* New function */

    /* Get a handle for it. */
    handle = Util_NewHandle(&RecoverFunctions, name, func);

    /* Remember how many methods there are */
    num_functions++;
  }
  else
  {
    /* function already exists. */
    handle = -1;
  }
    
  return handle;
}

 /*@@
   @routine    IOUtil_PrepareFilename
   @date       Fri Aug 21 14:54:38 1998
   @author     Gerd Lanfermann
   @desc 
     This routine prepares the filenames for the checkpoint/recovery
     and filereader files, paying attention to the different types:
     * it returns the full filename (directory+filename)

     * it prepends "Ln_" level indicators to the filename
       and "low_"/"med_" for convergence levels > 1

     * for checkpoint files it prepends the iteration number as "it_%d"

     * for chunked files it prepends the file number as "file_%d"

   @enddesc 
   @calls     
   @calledby   FlexIO_DumpGH HDF5IO_DumpGH
   @var        GH
   @vdesc      Pointer to CCTK grid hierarchy
   @vtype      cGH
   @vio        in
   @endvar
   @var        basename
   @vdesc      basename of the file(s) to recover from
   @vtype      const char *
   @vio        in
   @endvar
   @var        fname
   @vdesc      the resulting filename
   @vtype      char *
   @vio        out
   @endvar
   @var        called_from
   @vdesc      indicates the caller function:
                 * either Filereader (FILEREADER_DATA) 
                 * or IOUtil_RecoverGH() (CP_RECOVER_DATA)
   @vtype      int
   @vio        in
   @endvar
   @var        file_ioproc
   @vdesc      the IO processor number (for chunked files)
   @vtype      int
   @vio        in
   @endvar
   @var        file_unchunked
   @vdesc      flag to indicate whether file mode is unchunked or not
   @vtype      int
   @vio        in
   @endvar
   @history 
   @hdate Nov 4 1998 @hauthor Gabrielle Allen
   @hdesc A file_* in the name indicates it needs recombining 
   @hdate Apr 14 1999 @hauthor Thomas Radke
   @hdesc Removed code for expanding "basedir" and "nameofparfile"
   @hdate May 06 1999 @hauthor Thomas Radke
   @hdesc Added parameter unchunked to be independent of current chunking mode
          for recovery
   @endhistory 

@@*/
 
void IOUtil_PrepareFilename (cGH *GH, const char *basename, char *fname,
                           int called_from, int file_ioproc, int file_unchunked)
{
  DECLARE_CCTK_PARAMETERS

  /* get the right parameters */
  switch (called_from) {
    case CP_INITIAL_DATA: 
      sprintf (fname, "%s/%s", checkpoint_dir, checkpoint_ID_file); break;
    case CP_EVOLUTION_DATA:
      sprintf (fname, "%s/%s", checkpoint_dir, checkpoint_file); break;
    case CP_RECOVER_DATA:
      sprintf (fname, "%s/%s", recovery_dir, recover_file); break;
    case FILEREADER_DATA:
      strcpy (fname, basename); break;

    default:
      CCTK_WARN (2, "Unknown calling mode in IO_PrepareFilename().");
      break;
  }

  /* add refinement factor and convergence level (med/low) inbetween: */
  /* FIXME Gab ... asymmetric levfac */
  if (GH->cctk_levfac[0] > 1)
    sprintf (fname, "%sL%d_", fname, GH->cctk_levfac[0]);
  if (GH->cctk_convlevel > 1)
    strcat (fname, GH->cctk_convlevel == 2 ? "med_" : "low_");

  /* If checkpoint filename, merge in the iteration number
     and for chunked files also the file number */
  if (called_from == CP_INITIAL_DATA || called_from == CP_EVOLUTION_DATA)
    sprintf (fname, "%s.it_%d", fname, (int) GH->cctk_iteration);

  /* If not one unchunked file give a file number */
  if (! file_unchunked)
    sprintf (fname, "%s.file_%d", fname, file_ioproc);

}


 /*@@
   @routine    IOUtil_RecoverFromFile
   @date       Jun 14 1999
   @author     Thomas Radke
   @desc 
     Recover from a given file.
     This routine loops through all XXX_RecoverGH routines
     registered by IO thorns.
   @enddesc 
   @var        GH
   @vdesc      Pointer to CCTK grid hierarchy
   @vtype      cGH
   @vio        in
   @endvar
   @var        basename
   @vdesc      basename of the file(s) to recover from
   @vtype      const char *
   @vio        in
   @endvar
   @var        called_from
   @vdesc      indicates the caller function:
                 * either Filereader (FILEREADER_DATA) 
                 * or IOUtil_RecoverGH() (CP_RECOVER_DATA)
   @vtype      int
   @vio        in
   @endvar

   @history 
   @endhistory 
 @@*/
int IOUtil_RecoverFromFile (cGH *GH, const char *basename, int called_from)
{
  int handle;
  int retval;
  int (*fnRecoverGH)(cGH *GH, const char *basename, int called_from);

  retval = -1;

  for (handle = 0;handle<num_functions;handle++)
  {

    fnRecoverGH = (int (*)(cGH *, const char *, int))((Util_GetHandledData(RecoverFunctions, handle)));
    if (fnRecoverGH)
    {
      if (fnRecoverGH(GH,basename,called_from) >=0)
      {
	retval = handle;
	break;
      }
    }
    else
    {
      CCTK_WARN (1, "Could not recover");
      break;
    }
  }

  return retval;

}


 /*@@
   @routine    IOUtil_RecoverGH
   @date       Jun 14 1999
   @author     Thomas Radke
   @desc 
     The rfr-registered recovery routine.
     Just calls IOUtil_RecoverFromFile() with called_from == CP_RECOVER_DATA.
   @enddesc 
   @var        GH
   @vdesc      Pointer to CCTK grid hierarchy
   @vtype      cGH
   @vio        in
   @endvar
   @history 
   @endhistory 
 @@*/
void IOUtil_RecoverGH (cGH *GH)
{
  IOUtil_RecoverFromFile (GH, NULL, CP_RECOVER_DATA);
}