/*
  This file is part of CDO. CDO is a collection of Operators to
  manipulate and analyse Climate model Data.

  Copyright (C) 2003-2013 Uwe Schulzweida, Uwe.Schulzweida@zmaw.de
  See COPYING file for copying and redistribution conditions.

  This program 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; version 2 of the License.

  This program 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.
*/

/*
   This module contains the following operators:

      Ninfo      npar            Number of parameters
      Ninfo      nlevel          Number of levels
      Ninfo      nyear           Number of years
      Ninfo      nmon            Number of months
      Ninfo      ndate           Number of dates
      Ninfo      ntime           Number of timesteps
*/


#include <cdi.h>
#include "cdo.h"
#include "cdo_int.h"
#include "pstream.h"


void *Ninfo(void *argument)
{
  enum {NYEAR, NMON, NDATE, NTIME, NPAR, NLEVEL};
  int operatorID;
  int operfunc;
  int varID, zaxisID;
  int vdate;
  int nrecs, nvars, ntsteps;
  int levelsize;
  int tsID, ndate, date0 = 0;
  int day, mon0 = 0, mon, nmon, year0 = 0, year, nyear;
  int taxisID;
  int streamID;
  int vlistID;

  cdoInitialize(argument);

  cdoOperatorAdd("nyear",  NYEAR,  0, NULL);
  cdoOperatorAdd("nmon",   NMON,   0, NULL);
  cdoOperatorAdd("ndate",  NDATE,  0, NULL);
  cdoOperatorAdd("ntime",  NTIME,  0, NULL);
  cdoOperatorAdd("npar",   NPAR,   0, NULL);
  cdoOperatorAdd("nlevel", NLEVEL, 0, NULL);

  operatorID = cdoOperatorID();
  operfunc   = cdoOperatorF1(operatorID);

  streamID = streamOpenRead(cdoStreamName(0));

  vlistID = streamInqVlist(streamID);

  nvars   = vlistNvars(vlistID);
  taxisID = vlistInqTaxis(vlistID);
  ntsteps = vlistNtsteps(vlistID);

  switch ( operfunc )
    {
    case NYEAR:
      nyear = 0;
      tsID = 0;
      if ( ntsteps != 0 )
	while ( (nrecs = streamInqTimestep(streamID, tsID)) )
	  {
	    vdate = taxisInqVdate(taxisID);

	    cdiDecodeDate(vdate, &year, &mon, &day);
	 
	    if ( tsID == 0 || year0 != year )
	      {
		year0 = year;
		nyear++;
	      }

	    tsID++;
	  }
      fprintf(stdout, "%d\n", nyear);
      break;
    case NMON:
      nmon = 0;
      tsID = 0;
      if ( ntsteps != 0 )
	while ( (nrecs = streamInqTimestep(streamID, tsID)) )
	  {
	    vdate = taxisInqVdate(taxisID);
	    
	    cdiDecodeDate(vdate, &year, &mon, &day);
	 
	    if ( tsID == 0 || mon0 != mon )
	      {
		mon0 = mon;
		nmon++;
	      }

	    tsID++;
	  }
      fprintf(stdout, "%d\n", nmon);
      break;
    case NDATE:
      ndate = 0;
      tsID = 0;
      if ( ntsteps != 0 )
	while ( (nrecs = streamInqTimestep(streamID, tsID)) )
	  {
	    vdate = taxisInqVdate(taxisID);
	    
	    if ( tsID == 0 || date0 != vdate )
	      {
		date0 = vdate;
		ndate++;
	      }

	    tsID++;
	  }
      fprintf(stdout, "%d\n", ndate);
      break;
    case NTIME:
      tsID = 0;
      if ( ntsteps != 0 )
	while ( (nrecs = streamInqTimestep(streamID, tsID)) ) tsID++;
      fprintf(stdout, "%d\n", tsID);
      break;
    case NPAR:
      fprintf(stdout, "%d\n", nvars);
      break;
    case NLEVEL:
      for ( varID = 0; varID < nvars; varID++ )
	{
	  zaxisID = vlistInqVarZaxis(vlistID, varID);
	  levelsize = zaxisInqSize(zaxisID);
	  fprintf(stdout, "%d\n", levelsize);
	}
      break;
    default:
      cdoAbort("operator not implemented!");
      break;
    }

  streamClose(streamID);

  cdoFinish();

  return (0);
}
