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

  Copyright (C) 2006 Brockmann Consult
  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:

      Timselpctl    timselpctl         Time range percentiles
*/


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


void *Timselpctl(void *argument)
{
  int timestat_date = TIMESTAT_MEAN;
  int vdate2 = 0, vtime2 = 0;
  int vdate3 = 0, vtime3 = 0;
  int nrecs = 0;
  int gridID, varID, levelID, recID;
  int tsID;
  int nsets = 0;
  int i;
  int nmiss;
  int nlevels;
  field_t **vars1 = NULL;
  field_t field;
  HISTOGRAM_SET *hset = NULL;

  cdoInitialize(argument);

  cdoOperatorAdd("timselpctl", func_pctl,  0, NULL);

  operatorInputArg("percentile number, nsets <,noffset <,nskip>>");

  int nargc = operatorArgc();
  if ( nargc < 2 ) cdoAbort("Too few arguments! Need %d found %d.", 2, nargc);

  double pn  = parameter2double(operatorArgv()[0]);
  int ndates = parameter2int(operatorArgv()[1]);
  int noffset = 0, nskip = 0;
  if ( nargc > 2 ) noffset = parameter2int(operatorArgv()[2]);
  if ( nargc > 3 ) nskip   = parameter2int(operatorArgv()[3]);

  if ( !(pn > 0 && pn < 100) )
    cdoAbort("Illegal argument: percentile number %g is not in the range 0..100!", pn);

  if ( cdoVerbose ) cdoPrint("nsets = %d, noffset = %d, nskip = %d", ndates, noffset, nskip);

  int streamID1 = streamOpenRead(cdoStreamName(0));
  int streamID2 = streamOpenRead(cdoStreamName(1));
  int streamID3 = streamOpenRead(cdoStreamName(2));

  int vlistID1 = streamInqVlist(streamID1);
  int vlistID2 = streamInqVlist(streamID2);
  int vlistID3 = streamInqVlist(streamID3);
  int vlistID4 = vlistDuplicate(vlistID1);

  vlistCompare(vlistID1, vlistID2, CMP_ALL);
  vlistCompare(vlistID1, vlistID3, CMP_ALL);

  int taxisID1 = vlistInqTaxis(vlistID1);
  int taxisID2 = vlistInqTaxis(vlistID2);
  int taxisID3 = vlistInqTaxis(vlistID3);
  /* TODO - check that time axes 2 and 3 are equal */

  int taxisID4 = taxisDuplicate(taxisID1);
  vlistDefTaxis(vlistID4, taxisID4);

  int streamID4 = streamOpenWrite(cdoStreamName(3), cdoFiletype());

  streamDefVlist(streamID4, vlistID4);

  int nvars    = vlistNvars(vlistID1);
  int nrecords = vlistNrecs(vlistID1);

  int *recVarID   = (int*) Malloc(nrecords*sizeof(int));
  int *recLevelID = (int*) Malloc(nrecords*sizeof(int));

  dtlist_type *dtlist = dtlist_new();
  dtlist_set_stat(dtlist, timestat_date);
  dtlist_set_calendar(dtlist, taxisInqCalendar(taxisID1));

  int gridsize = vlistGridsizeMax(vlistID1);

  field_init(&field);
  field.ptr = (double*) Malloc(gridsize * sizeof(double));

  vars1 = field_malloc(vlistID1, FIELD_PTR);
  hset = hsetCreate(nvars);

  for ( varID = 0; varID < nvars; varID++ )
    {
      gridID   = vlistInqVarGrid(vlistID1, varID);
      nlevels   = zaxisInqSize(vlistInqVarZaxis(vlistID1, varID));

      hsetCreateVarLevels(hset, varID, nlevels, gridID);
    }

  for ( tsID = 0; tsID < noffset; tsID++ )
    {
      nrecs = streamInqTimestep(streamID1, tsID);
      if ( nrecs == 0 ) break;

      for ( recID = 0; recID < nrecs; recID++ )
	{
	  streamInqRecord(streamID1, &varID, &levelID);

	  if ( tsID == 0 )
	    {
	      recVarID[recID]   = varID;
	      recLevelID[recID] = levelID;
	    }
	}
    }

  int otsID = 0;
  if ( tsID < noffset )
    {
      cdoWarning("noffset is larger than number of timesteps!");
      goto LABEL_END;
    }

  while ( TRUE )
    {
      nrecs = streamInqTimestep(streamID2, otsID);
      if ( nrecs != streamInqTimestep(streamID3, otsID) )
        cdoAbort("Number of records at time step %d of %s and %s differ!", otsID+1, cdoStreamName(1)->args, cdoStreamName(2)->args);

      vdate2 = taxisInqVdate(taxisID2);
      vtime2 = taxisInqVtime(taxisID2);
      vdate3 = taxisInqVdate(taxisID3);
      vtime3 = taxisInqVtime(taxisID3);
      if ( vdate2 != vdate3 || vtime2 != vtime3 )
        cdoAbort("Verification dates at time step %d of %s and %s differ!", otsID+1, cdoStreamName(1)->args, cdoStreamName(2)->args);
      
      for ( recID = 0; recID < nrecs; recID++ )
        {
          streamInqRecord(streamID2, &varID, &levelID);
          streamReadRecord(streamID2, vars1[varID][levelID].ptr, &nmiss);
          vars1[varID][levelID].nmiss = nmiss;
        }

      for ( recID = 0; recID < nrecs; recID++ )
        {
          streamInqRecord(streamID3, &varID, &levelID);
          streamReadRecord(streamID3, field.ptr, &nmiss);
          field.nmiss   = nmiss;
          field.grid    = vars1[varID][levelID].grid;
          field.missval = vars1[varID][levelID].missval;
          
          hsetDefVarLevelBounds(hset, varID, levelID, &vars1[varID][levelID], &field);
        }

      nsets = 0;
      if ( nrecs )
	for ( nsets = 0; nsets < ndates; nsets++ )
	  {
	    nrecs = streamInqTimestep(streamID1, tsID);
	    if ( nrecs == 0 ) break;

	    dtlist_taxisInqTimestep(dtlist, taxisID1, nsets);

	    for ( recID = 0; recID < nrecs; recID++ )
	      {
		streamInqRecord(streamID1, &varID, &levelID);

		if ( tsID == 0 )
		  {
		    recVarID[recID]   = varID;
		    recLevelID[recID] = levelID;
		  }

		streamReadRecord(streamID1, vars1[varID][levelID].ptr, &nmiss);
		vars1[varID][levelID].nmiss = nmiss;
                  
		hsetAddVarLevelValues(hset, varID, levelID, &vars1[varID][levelID]);
	      }

	    tsID++;
	  }

      if ( nrecs == 0 && nsets == 0 ) break;

      for ( varID = 0; varID < nvars; varID++ )
        {
          if ( vlistInqVarTsteptype(vlistID1, varID) == TSTEP_CONSTANT ) continue;
          nlevels = zaxisInqSize(vlistInqVarZaxis(vlistID1, varID));
          
          for ( levelID = 0; levelID < nlevels; levelID++ )
            hsetGetVarLevelPercentiles(&vars1[varID][levelID], hset, varID, levelID, pn);
        }

      dtlist_stat_taxisDefTimestep(dtlist, taxisID4, nsets);
      streamDefTimestep(streamID4, otsID);

      for ( recID = 0; recID < nrecords; recID++ )
	{
	  varID   = recVarID[recID];
	  levelID = recLevelID[recID];

	  if ( otsID && vlistInqVarTsteptype(vlistID1, varID) == TSTEP_CONSTANT ) continue;

	  streamDefRecord(streamID4, varID, levelID);
	  streamWriteRecord(streamID4, vars1[varID][levelID].ptr,  vars1[varID][levelID].nmiss);
	}

      if ( nrecs == 0 ) break;
      otsID++;

      for ( i = 0; i < nskip; i++ )
	{
	  nrecs = streamInqTimestep(streamID1, tsID);
	  if ( nrecs == 0 ) break;
	  tsID++;
	}

      if ( nrecs == 0 ) break;
    }

 LABEL_END:

  field_free(vars1, vlistID1);
  hsetDestroy(hset);

  dtlist_delete(dtlist);

  if ( field.ptr ) Free(field.ptr);

  if ( recVarID   ) Free(recVarID);
  if ( recLevelID ) Free(recLevelID);

  streamClose(streamID4);
  streamClose(streamID3);
  streamClose(streamID2);
  streamClose(streamID1);

  cdoFinish();

  return 0;
}
