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

  Copyright (C) 2003-2018 Uwe Schulzweida, <uwe.schulzweida AT mpimet.mpg.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:

      Timstat    timmin          Time minimum
      Timstat    timmax          Time maximum
      Timstat    timsum          Time sum
      Timstat    timmean         Time mean
      Timstat    timavg          Time average
      Timstat    timvar          Time variance
      Timstat    timvar1         Time variance [Normalize by (n-1)]
      Timstat    timstd          Time standard deviation
      Timstat    timstd1         Time standard deviation [Normalize by (n-1)]
      Hourstat   hourmin         Hourly minimum
      Hourstat   hourmax         Hourly maximum
      Hourstat   hoursum         Hourly sum
      Hourstat   hourmean        Hourly mean
      Hourstat   houravg         Hourly average
      Hourstat   hourvar         Hourly variance
      Hourstat   hourvar1        Hourly variance [Normalize by (n-1)]
      Hourstat   hourstd         Hourly standard deviation
      Hourstat   hourstd1        Hourly standard deviation [Normalize by (n-1)]
      Daystat    daymin          Daily minimum
      Daystat    daymax          Daily maximum
      Daystat    daysum          Daily sum
      Daystat    daymean         Daily mean
      Daystat    dayavg          Daily average
      Daystat    dayvar          Daily variance
      Daystat    dayvar1         Daily variance [Normalize by (n-1)]
      Daystat    daystd          Daily standard deviation
      Daystat    daystd1         Daily standard deviation [Normalize by (n-1)]
      Monstat    monmin          Monthly minimum
      Monstat    monmax          Monthly maximum
      Monstat    monsum          Monthly sum
      Monstat    monmean         Monthly mean
      Monstat    monavg          Monthly average
      Monstat    monvar          Monthly variance
      Monstat    monvar1         Monthly variance [Normalize by (n-1)]
      Monstat    monstd          Monthly standard deviation
      Monstat    monstd1         Monthly standard deviation [Normalize by (n-1)]
      Yearstat   yearmin         Yearly minimum
      Yearstat   yearmax         Yearly maximum
      Yearstat   yearsum         Yearly sum
      Yearstat   yearmean        Yearly mean
      Yearstat   yearavg         Yearly average
      Yearstat   yearvar         Yearly variance
      Yearstat   yearvar1        Yearly variance [Normalize by (n-1)]
      Yearstat   yearstd         Yearly standard deviation
      Yearstat   yearstd1        Yearly standard deviation [Normalize by (n-1)]
*/


#include <cdi.h>
#include "cdo.h"
#include "cdo_int.h"
#include "cdo_task.h"
#include "pstream.h"
//#include "pstream_write.h"


typedef struct {
  int tsIDnext;
  int streamID, nrecs;
  recinfo_type *recinfo;
  field_type **vars;
}
readarg_t;

static int num_recs = 0;

static
void *cdoReadTimestep(void *rarg)
{
  int varID, levelID;
  size_t nmiss;
  readarg_t *readarg = (readarg_t *) rarg;
  field_type **input_vars = readarg->vars;
  recinfo_type *recinfo = readarg->recinfo;
  int streamID = readarg->streamID;
  int tsIDnext = readarg->tsIDnext;
  int nrecs = readarg->nrecs;

  // timer_start(timer_read);

  for ( int recID = 0; recID < nrecs; ++recID )
    {
      pstreamInqRecord(streamID, &varID, &levelID);

      if ( tsIDnext == 1 && recinfo )
        {
          recinfo[recID].varID   = varID;
          recinfo[recID].levelID = levelID;
        }

      if ( CDO_Memtype == MEMTYPE_FLOAT )
        pstreamReadRecordF(streamID, (float*)input_vars[varID][levelID].ptr2, &nmiss);
      else
        pstreamReadRecord(streamID, (double*)input_vars[varID][levelID].ptr2, &nmiss);
      
      input_vars[varID][levelID].nmiss2 = nmiss;
    }

  // timer_stop(timer_read);

  num_recs = pstreamInqTimestep(streamID, tsIDnext);

  return ((void *) &num_recs);
}

static
void cdoUpdateVars(int nvars, int vlistID, field_type **vars)
{
  void *tmp = NULL;

  for ( int varID = 0; varID < nvars; varID++ )
    {
      int nlevels = zaxisInqSize(vlistInqVarZaxis(vlistID, varID));
      for ( int levelID = 0; levelID < nlevels; levelID++ )
        {
          if ( CDO_Memtype == MEMTYPE_FLOAT )
            {
              tmp = vars[varID][levelID].ptrf;
              vars[varID][levelID].ptrf = (float*) vars[varID][levelID].ptr2;
            }
          else
            {
              tmp = vars[varID][levelID].ptr;
              vars[varID][levelID].ptr = (double*) vars[varID][levelID].ptr2;
            }
          vars[varID][levelID].ptr2  = tmp;
          vars[varID][levelID].nmiss = vars[varID][levelID].nmiss2;
        }
    }
}


void *XTimstat(void *argument)
{
  enum {HOUR_LEN=4, DAY_LEN=6, MON_LEN=8, YEAR_LEN=10};
  int timestat_date = TIMESTAT_MEAN;
  int vdate = 0, vtime = 0;
  int vdate0 = 0, vtime0 = 0;
  int varID;
  int streamID3 = -1;
  int vlistID3, taxisID3 = -1;
  size_t nmiss;
  bool lvfrac = false;
  int nwpv; // number of words per value; real:1  complex:2
  char indate1[DATE_LEN+1], indate2[DATE_LEN+1];
  double vfrac = 1;

  cdoInitialize(argument);

  // clang-format off
  cdoOperatorAdd("xtimmin",    func_min,   DATE_LEN, NULL);
  cdoOperatorAdd("xtimmax",    func_max,   DATE_LEN, NULL);
  cdoOperatorAdd("xtimsum",    func_sum,   DATE_LEN, NULL);
  cdoOperatorAdd("xtimmean",   func_mean,  DATE_LEN, NULL);
  cdoOperatorAdd("xtimavg",    func_avg,   DATE_LEN, NULL);
  cdoOperatorAdd("xtimvar",    func_var,   DATE_LEN, NULL);
  cdoOperatorAdd("xtimvar1",   func_var1,  DATE_LEN, NULL);
  cdoOperatorAdd("xtimstd",    func_std,   DATE_LEN, NULL);
  cdoOperatorAdd("xtimstd1",   func_std1,  DATE_LEN, NULL);
  cdoOperatorAdd("xyearmin",   func_min,   YEAR_LEN, NULL);
  cdoOperatorAdd("xyearmax",   func_max,   YEAR_LEN, NULL);
  cdoOperatorAdd("xyearsum",   func_sum,   YEAR_LEN, NULL);
  cdoOperatorAdd("xyearmean",  func_mean,  YEAR_LEN, NULL);
  cdoOperatorAdd("xyearavg",   func_avg,   YEAR_LEN, NULL);
  cdoOperatorAdd("xyearvar",   func_var,   YEAR_LEN, NULL);
  cdoOperatorAdd("xyearvar1",  func_var1,  YEAR_LEN, NULL);
  cdoOperatorAdd("xyearstd",   func_std,   YEAR_LEN, NULL);
  cdoOperatorAdd("xyearstd1",  func_std1,  YEAR_LEN, NULL);
  cdoOperatorAdd("xmonmin",    func_min,   MON_LEN, NULL);
  cdoOperatorAdd("xmonmax",    func_max,   MON_LEN, NULL);
  cdoOperatorAdd("xmonsum",    func_sum,   MON_LEN, NULL);
  cdoOperatorAdd("xmonmean",   func_mean,  MON_LEN, NULL);
  cdoOperatorAdd("xmonavg",    func_avg,   MON_LEN, NULL);
  cdoOperatorAdd("xmonvar",    func_var,   MON_LEN, NULL);
  cdoOperatorAdd("xmonvar1",   func_var1,  MON_LEN, NULL);
  cdoOperatorAdd("xmonstd",    func_std,   MON_LEN, NULL);
  cdoOperatorAdd("xmonstd1",   func_std1,  MON_LEN, NULL);

  int operatorID = cdoOperatorID();
  int operfunc   = cdoOperatorF1(operatorID);
  int comparelen = cdoOperatorF2(operatorID);

  bool lmean   = operfunc == func_mean || operfunc == func_avg;
  bool lstd    = operfunc == func_std || operfunc == func_std1;
  bool lvarstd = operfunc == func_std || operfunc == func_var || operfunc == func_std1 || operfunc == func_var1;
  int divisor  = operfunc == func_std1 || operfunc == func_var1;
  // clang-format on

  if ( operfunc == func_mean )
    {
      int oargc = operatorArgc();
      char **oargv = operatorArgv();

      if ( oargc == 1 )
	{
	  lvfrac = true;
	  vfrac = atof(oargv[0]);
	  if ( cdoVerbose ) cdoPrint("Set vfrac to %g", vfrac);
	  if ( vfrac < 0 || vfrac > 1 ) cdoAbort("vfrac out of range!");
	}
      else if ( oargc > 1 )
	cdoAbort("Too many arguments!");
    }

  int cmplen = DATE_LEN - comparelen;

  int streamID1 = pstreamOpenRead(cdoStreamName(0));
  //int streamID1 = pstreamOpenRead(cdoStreamName(0)->args);

  int vlistID1 = pstreamInqVlist(streamID1);
  int vlistID2 = vlistDuplicate(vlistID1);

  if ( cmplen == 0 ) vlistDefNtsteps(vlistID2, 1);

  int taxisID1 = vlistInqTaxis(vlistID1);
  int taxisID2 = taxisDuplicate(taxisID1);
  taxisWithBounds(taxisID2);
  if ( taxisInqType(taxisID2) == TAXIS_FORECAST ) taxisDefType(taxisID2, TAXIS_RELATIVE);
  vlistDefTaxis(vlistID2, taxisID2);

  int nvars = vlistNvars(vlistID1);

  const char *freq = NULL;
  if      ( comparelen == DAY_LEN )  freq = "day";
  else if ( comparelen == MON_LEN )  freq = "mon";
  else if ( comparelen == YEAR_LEN ) freq = "year";
  if ( freq ) cdiDefAttTxt(vlistID2, CDI_GLOBAL, "frequency", (int)strlen(freq), freq);

  int streamID2 = pstreamOpenWrite(cdoStreamName(1), cdoFiletype());
  pstreamDefVlist(streamID2, vlistID2);

  if ( cdoDiag )
    {
      char filename[8192];
      strcpy(filename, cdoOperatorName(operatorID));
      strcat(filename, "_");
      strcat(filename, cdoStreamName(1)->args);
      argument_t *fileargument = file_argument_new(filename);
      streamID3 = pstreamOpenWrite(fileargument, cdoFiletype());
      file_argument_free(fileargument);

      vlistID3 = vlistDuplicate(vlistID1);

      for ( varID = 0; varID < nvars; ++varID )
	{
	  vlistDefVarDatatype(vlistID3, varID, CDI_DATATYPE_INT32);
	  vlistDefVarMissval(vlistID3, varID, -1);
	  vlistDefVarUnits(vlistID3, varID, "");
	  vlistDefVarAddoffset(vlistID3, varID, 0);
	  vlistDefVarScalefactor(vlistID3, varID, 1);
	}

      taxisID3 = taxisDuplicate(taxisID1);
      taxisWithBounds(taxisID3);
      vlistDefTaxis(vlistID3, taxisID3);

      pstreamDefVlist(streamID3, vlistID3);
    }

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

  int gridsizemax = vlistGridsizeMax(vlistID1);
  if ( vlistNumber(vlistID1) != CDI_REAL ) gridsizemax *= 2;

  int FIELD_MEMTYPE = 0;
  if ( CDO_Memtype == MEMTYPE_FLOAT ) FIELD_MEMTYPE = FIELD_FLT;
  field_type **input_vars = field_malloc(vlistID1, FIELD_PTR | FIELD_PTR2 | FIELD_MEMTYPE);
  field_type **vars1 = field_malloc(vlistID1, FIELD_PTR);
  field_type **samp1 = field_malloc(vlistID1, FIELD_NONE);
  field_type **vars2 = NULL;
  if ( lvarstd ) vars2 = field_malloc(vlistID1, FIELD_PTR);

  readarg_t readarg;
  readarg.streamID = streamID1;
  readarg.vars = input_vars;

  bool lparallelread = CDO_Parallel_Read > 0;
  bool ltsfirst = true;
  void *read_task = NULL;
  void *readresult = NULL;

  if ( lparallelread )
    {
      read_task = cdo_task_new();
      if ( read_task == NULL )
        {
          lparallelread = false;
          cdoWarning("CDO tasks not available!");
        }
    }

  int tsID  = 0;
  int otsID = 0;
  int nrecs = pstreamInqTimestep(streamID1, tsID);
  int maxrecs = nrecs;
  recinfo_type *recinfo = (recinfo_type *) Malloc(maxrecs*sizeof(recinfo_type));
  
  tsID++;
  while ( TRUE )
    {
      int nsets = 0;
      while ( nrecs > 0 )
	{
	  dtlist_taxisInqTimestep(dtlist, taxisID1, nsets);
	  vdate = dtlist_get_vdate(dtlist, nsets);
	  vtime = dtlist_get_vtime(dtlist, nsets);

	  if ( nsets == 0 ) SET_DATE(indate2, vdate, vtime);
	  SET_DATE(indate1, vdate, vtime);

	  if ( DATE_IS_NEQ(indate1, indate2, cmplen) ) break;

          readarg.tsIDnext = tsID;
          readarg.nrecs    = nrecs;
          readarg.recinfo  = recinfo;

          if ( ltsfirst || lparallelread == false )
            {
              ltsfirst = false;
              readresult = cdoReadTimestep(&readarg);
            }
          else
            {
              readresult = cdo_task_wait(read_task);
            }
          
          nrecs = *(int *)readresult;

          cdoUpdateVars(nvars, vlistID1, input_vars);

          if ( nrecs && lparallelread )
            {
              readarg.tsIDnext = tsID+1;
              cdo_task_start(read_task, cdoReadTimestep, &readarg);
            }

          if ( nsets == 0 )
            {
#ifdef  _OPENMP
#pragma omp parallel for default(none) shared(maxrecs, recinfo, input_vars, vars1, samp1) if(maxrecs>1)
#endif
              for ( int recID = 0; recID < maxrecs; recID++ )
                {
                  int varID    = recinfo[recID].varID;
                  int levelID  = recinfo[recID].levelID;

                  field_type *pvars1 = &vars1[varID][levelID];
                  field_type *pinput_var = &input_vars[varID][levelID];

                  int nwpv     = pvars1->nwpv;
                  int gridsize = pvars1->size;
                  size_t nmiss    = pinput_var->nmiss;

                  farcpy(pvars1, *pinput_var);
                  pvars1->nmiss = nmiss;
                  if ( nmiss > 0 || samp1[varID][levelID].ptr )
                    {
                      if ( samp1[varID][levelID].ptr == NULL )
                        samp1[varID][levelID].ptr = (double*) malloc(nwpv*gridsize*sizeof(double));
                      
                      for ( int i = 0; i < nwpv*gridsize; i++ )
                        samp1[varID][levelID].ptr[i] = !DBL_IS_EQUAL(pvars1->ptr[i], pvars1->missval);
                    }
                }
            }
          else
            {
#ifdef  _OPENMP
#pragma omp parallel for default(none) shared(lvarstd, nsets, maxrecs, recinfo, input_vars, vars1, samp1, vars2, operfunc) if(maxrecs>1)
#endif
              for ( int recID = 0; recID < maxrecs; recID++ )
                {
                  int varID    = recinfo[recID].varID;
                  int levelID  = recinfo[recID].levelID;
                  
                  field_type *pvars1 = &vars1[varID][levelID];
                  field_type *pinput_var = &input_vars[varID][levelID];

                  int nwpv     = pvars1->nwpv;
                  int gridsize = pvars1->size;
                  size_t nmiss    = pinput_var->nmiss;

                  if ( nmiss > 0 || samp1[varID][levelID].ptr )
                    {
                      if ( samp1[varID][levelID].ptr == NULL )
                        {
                          samp1[varID][levelID].ptr = (double*) malloc(nwpv*gridsize*sizeof(double));
                          for ( int i = 0; i < nwpv*gridsize; i++ )
                            samp1[varID][levelID].ptr[i] = nsets;
                        }
                          
                      for ( int i = 0; i < nwpv*gridsize; i++ )
                        if ( !DBL_IS_EQUAL(pinput_var->ptr[i], pvars1->missval) )
                          samp1[varID][levelID].ptr[i]++;
                    }
                  
		  if ( lvarstd )
		    {
                      field_type *pvars2 = &vars2[varID][levelID];
		      farsumq(pvars2, *pinput_var);
		      farsum(pvars1, *pinput_var);
		    }
		  else
		    {
		      farfun(pvars1, *pinput_var, operfunc);
		    }
                }
            }

	  if ( nsets == 0 && lvarstd )
            for ( int recID = 0; recID < maxrecs; recID++ )
              {
                int varID   = recinfo[recID].varID;
                int levelID = recinfo[recID].levelID;
                field_type *pvars1 = &vars1[varID][levelID];
                field_type *pvars2 = &vars2[varID][levelID];

		if ( vlistInqVarTimetype(vlistID1, varID) == TIME_CONSTANT ) continue;

                farmoq(pvars2, *pvars1);
	      }

	  vdate0 = vdate;
	  vtime0 = vtime;
	  nsets++;
	  tsID++;
	}

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

      if ( lmean )
        {
#ifdef  _OPENMP
#pragma omp parallel for default(none) shared(vlistID1, nsets, maxrecs, recinfo, vars1, samp1) if(maxrecs>1)
#endif
          for ( int recID = 0; recID < maxrecs; recID++ )
            {
              int varID   = recinfo[recID].varID;
              int levelID = recinfo[recID].levelID;
              field_type *pvars1 = &vars1[varID][levelID];

              if ( vlistInqVarTimetype(vlistID1, varID) == TIME_CONSTANT ) continue;

              if ( samp1[varID][levelID].ptr == NULL )
                farcdiv(pvars1, (double)nsets);
              else
                fardiv(pvars1, samp1[varID][levelID]);
            }
        }
      else if ( lvarstd )
        {
          for ( int recID = 0; recID < maxrecs; recID++ )
            {
              int varID   = recinfo[recID].varID;
              int levelID = recinfo[recID].levelID;
              field_type *pvars1 = &vars1[varID][levelID];
              field_type *pvars2 = &vars2[varID][levelID];

              if ( vlistInqVarTimetype(vlistID1, varID) == TIME_CONSTANT ) continue;

              if ( samp1[varID][levelID].ptr == NULL )
                {
                  if ( lstd ) farcstd(pvars1, *pvars2, nsets, divisor);
                  else        farcvar(pvars1, *pvars2, nsets, divisor);
                }
              else
                {
                  if ( lstd ) farstd(pvars1, *pvars2, samp1[varID][levelID], divisor);
                  else        farvar(pvars1, *pvars2, samp1[varID][levelID], divisor);
                }
            }
        }

      if ( cdoVerbose )
	{
	  char vdatestr[32], vtimestr[32];
	  date2str(vdate0, vdatestr, sizeof(vdatestr));
	  time2str(vtime0, vtimestr, sizeof(vtimestr));
	  cdoPrint("%s %s  vfrac = %g, nsets = %d", vdatestr, vtimestr, vfrac, nsets);
	}

      if ( lvfrac && operfunc == func_mean )
        for ( int recID = 0; recID < maxrecs; recID++ )
          {
            int varID   = recinfo[recID].varID;
            int levelID = recinfo[recID].levelID;
            field_type *pvars1 = &vars1[varID][levelID];

	    if ( vlistInqVarTimetype(vlistID1, varID) == TIME_CONSTANT ) continue;

            nwpv     = pvars1->nwpv;
            int gridsize = pvars1->size;
            double missval = pvars1->missval;
            if ( samp1[varID][levelID].ptr )
              {
                int irun = 0;
                for ( int i = 0; i < nwpv*gridsize; ++i )
                  {
                    if ( (samp1[varID][levelID].ptr[i] / nsets) < vfrac )
                      {
                        pvars1->ptr[i] = missval;
                        irun++;
                      }
                  }

                if ( irun )
                  {
                    nmiss = 0;
                    for ( int i = 0; i < nwpv*gridsize; ++i )
                      if ( DBL_IS_EQUAL(pvars1->ptr[i], missval) ) nmiss++;
                    pvars1->nmiss = nmiss;
                  }
	      }
	  }

      dtlist_stat_taxisDefTimestep(dtlist, taxisID2, nsets);
      pstreamDefTimestep(streamID2, otsID);

      if ( cdoDiag )
	{
	  dtlist_stat_taxisDefTimestep(dtlist, taxisID3, nsets);
	  pstreamDefTimestep(streamID3, otsID);
	}

      for ( int recID = 0; recID < maxrecs; recID++ )
	{
          int varID   = recinfo[recID].varID;
          int levelID = recinfo[recID].levelID;
          field_type *pvars1 = &vars1[varID][levelID];

	  if ( otsID && vlistInqVarTimetype(vlistID1, varID) == TIME_CONSTANT ) continue;

          pstreamDefRecord(streamID2, varID, levelID);
	  pstreamWriteRecord(streamID2, pvars1->ptr,  pvars1->nmiss);
              
          if ( cdoDiag )
            {
              if ( samp1[varID][levelID].ptr )
                {
                  pstreamDefRecord(streamID3, varID, levelID);
                  pstreamWriteRecord(streamID3, samp1[varID][levelID].ptr, 0);
                }
            }
	}

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


  field_free(input_vars, vlistID1);
  field_free(vars1, vlistID1);
  field_free(samp1, vlistID1);
  if ( lvarstd ) field_free(vars2, vlistID1);

  dtlist_delete(dtlist);
  Free(recinfo);

  if ( cdoDiag ) pstreamClose(streamID3);
  pstreamClose(streamID2);
  pstreamClose(streamID1);

  cdoFinish();

  return 0;
}
