/*
  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:

      Ydayarith  ydayadd         Add multi-year daily time series
      Ydayarith  ydaysub         Subtract multi-year daily time series
      Ydayarith  ydaymul         Multiply multi-year daily time series
      Ydayarith  ydaydiv         Divide multi-year daily time series
*/

#include <cdi.h>

#include "cdo_int.h"
#include "pstream_int.h"

#define MAX_DOY 373

void *
Ydayarith(void *process)
{
  int nrecs;
  int varID, levelID;
  size_t nmiss;
  int year, month, day;

  cdoInitialize(process);

  cdoOperatorAdd("ydayadd", func_add, 0, NULL);
  cdoOperatorAdd("ydaysub", func_sub, 0, NULL);
  cdoOperatorAdd("ydaymul", func_mul, 0, NULL);
  cdoOperatorAdd("ydaydiv", func_div, 0, NULL);

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

  int streamID1 = cdoStreamOpenRead(cdoStreamName(0));
  int streamID2 = cdoStreamOpenRead(cdoStreamName(1));

  int vlistID1 = cdoStreamInqVlist(streamID1);
  int vlistID2 = cdoStreamInqVlist(streamID2);
  int vlistID3 = vlistDuplicate(vlistID1);

  vlistCompare(vlistID1, vlistID2, CMP_ALL);

  size_t gridsize = vlistGridsizeMax(vlistID1);

  Field field1, field2;
  field_init(&field1);
  field_init(&field2);
  field1.ptr = (double *) Malloc(gridsize * sizeof(double));
  field2.ptr = (double *) Malloc(gridsize * sizeof(double));

  int taxisID1 = vlistInqTaxis(vlistID1);
  int taxisID2 = vlistInqTaxis(vlistID2);
  int taxisID3 = taxisDuplicate(taxisID1);
  vlistDefTaxis(vlistID3, taxisID3);

  int streamID3 = cdoStreamOpenWrite(cdoStreamName(2), cdoFiletype());
  pstreamDefVlist(streamID3, vlistID3);

  int nvars = vlistNvars(vlistID2);

  std::vector<std::vector<std::vector<double>>> vardata2(MAX_DOY);
  std::vector<std::vector<std::vector<size_t>>> varnmiss2(MAX_DOY);

  int tsID = 0;
  while ((nrecs = cdoStreamInqTimestep(streamID2, tsID)))
    {
      int64_t vdate = taxisInqVdate(taxisID2);

      cdiDecodeDate(vdate, &year, &month, &day);

      int dayoy = 0;
      if (month >= 1 && month <= 12) dayoy = (month - 1) * 31 + day;

      if (dayoy < 0 || dayoy >= MAX_DOY) cdoAbort("Day of year %d out of range (date=%d)!", dayoy, vdate);

      if (vardata2[dayoy].size() > 0) cdoAbort("Day of year %d already allocatd (date=%d)!", dayoy, vdate);

      vardata2[dayoy].resize(nvars);
      varnmiss2[dayoy].resize(nvars);

      for (varID = 0; varID < nvars; varID++)
        {
          size_t gridsize = gridInqSize(vlistInqVarGrid(vlistID2, varID));
          size_t nlev = zaxisInqSize(vlistInqVarZaxis(vlistID2, varID));
          vardata2[dayoy][varID].resize(nlev * gridsize);
          varnmiss2[dayoy][varID].resize(nlev);
        }

      for (int recID = 0; recID < nrecs; recID++)
        {
          pstreamInqRecord(streamID2, &varID, &levelID);
          size_t gridsize = gridInqSize(vlistInqVarGrid(vlistID2, varID));
          size_t offset = gridsize * levelID;
          pstreamReadRecord(streamID2, &vardata2[dayoy][varID][offset], &nmiss);
          varnmiss2[dayoy][varID][levelID] = nmiss;
        }

      tsID++;
    }

  tsID = 0;
  while ((nrecs = cdoStreamInqTimestep(streamID1, tsID)))
    {
      int64_t vdate = taxisInqVdate(taxisID1);

      cdiDecodeDate(vdate, &year, &month, &day);

      int dayoy = 0;
      if (month >= 1 && month <= 12) dayoy = (month - 1) * 31 + day;

      if (dayoy < 0 || dayoy >= MAX_DOY) cdoAbort("Day of year %d out of range (date=%d)!", dayoy, vdate);

      taxisCopyTimestep(taxisID3, taxisID1);
      pstreamDefTimestep(streamID3, tsID);

      for (int recID = 0; recID < nrecs; recID++)
        {
          pstreamInqRecord(streamID1, &varID, &levelID);
          pstreamReadRecord(streamID1, field1.ptr, &nmiss);
          field1.nmiss = nmiss;

          size_t gridsize = gridInqSize(vlistInqVarGrid(vlistID2, varID));
          size_t offset = gridsize * levelID;
          if (vardata2[dayoy].size() == 0) cdoAbort("Day of year %d not found (date=%d)!", dayoy, vdate);
          arrayCopy(gridsize, &vardata2[dayoy][varID][offset], field2.ptr);
          field2.nmiss = varnmiss2[dayoy][varID][levelID];

          field1.grid = vlistInqVarGrid(vlistID1, varID);
          field1.missval = vlistInqVarMissval(vlistID1, varID);

          field2.grid = vlistInqVarGrid(vlistID2, varID);
          field2.missval = vlistInqVarMissval(vlistID2, varID);

          farfun(&field1, field2, operfunc);

          nmiss = field1.nmiss;
          pstreamDefRecord(streamID3, varID, levelID);
          pstreamWriteRecord(streamID3, field1.ptr, nmiss);
        }
      tsID++;
    }

  pstreamClose(streamID3);
  pstreamClose(streamID2);
  pstreamClose(streamID1);

  if (field1.ptr) Free(field1.ptr);
  if (field2.ptr) Free(field2.ptr);

  cdoFinish();

  return 0;
}
