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

  Copyright (C) 2006 Brockmann Consult

  Author: Ralf Quast
          Uwe Schulzweida

*/

/*
   This module contains the following operators:

      Seaspctl   seaspctl        Seasonal percentiles
*/

#include <cdi.h>

#include "process_int.h"
#include "cdo_vlist.h"
#include "param_conversion.h"
#include "percentiles_hist.h"
#include "datetime.h"
#include "cdo_season.h"
#include "field_functions.h"

class ModuleSeaspctl
{
  TimeStat timestatDate{ TimeStat::MEAN };
  int seas0 = 0;
  int oldmon = 0;

  CdoStreamID streamID1;
  CdoStreamID streamID2;
  CdoStreamID streamID3;
  CdoStreamID streamID4;

  int taxisID1;
  int taxisID2;
  int taxisID3;
  int taxisID4;

  Field field1, field2;
  DateTimeList dtlist;
  VarList varList1;
  int maxrecs;
  double pn;

  std::vector<RecordInfo> recList;
  HistogramSet hset;
  FieldVector constFields;
  SeasonStart seasonStart;

public:
  void
  init(void *process)
  {
    cdo_initialize(process);

    cdo_operator_add("seaspctl", FieldFunc_Pctl, 0, nullptr);

    operator_input_arg("percentile number");
    pn = parameter_to_double(cdo_operator_argv(0));

    seasonStart = get_season_start();

    streamID1 = cdo_open_read(0);
    streamID2 = cdo_open_read(1);
    streamID3 = cdo_open_read(2);

    auto vlistID1 = cdo_stream_inq_vlist(streamID1);
    auto vlistID2 = cdo_stream_inq_vlist(streamID2);
    auto vlistID3 = cdo_stream_inq_vlist(streamID3);
    auto vlistID4 = vlistDuplicate(vlistID1);

    vlist_unpack(vlistID4);

    vlist_compare(vlistID1, vlistID2, CmpVlist::All);
    vlist_compare(vlistID1, vlistID3, CmpVlist::All);

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

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

    streamID4 = cdo_open_write(3);
    cdo_def_vlist(streamID4, vlistID4);

    auto ntsteps = vlistNtsteps(vlistID1);
    auto nvars = vlistNvars(vlistID1);

    maxrecs = vlistNrecs(vlistID1);
    recList = std::vector<RecordInfo>(maxrecs);
    constFields = FieldVector(maxrecs);

    dtlist.set_stat(timestatDate);
    dtlist.set_calendar(taxisInqCalendar(taxisID1));

    varList_init(varList1, vlistID1);

    hset = HistogramSet(nvars, ntsteps);

    for (int varID = 0; varID < nvars; ++varID)
      {
        const auto &var = varList1[varID];
        hset.createVarLevels(varID, var.nlevels, var.gridsize);
      }
  }

  void
  run()
  {
    int tsID = 0;
    int otsID = 0;
    while (true)
      {
        auto nrecs = cdo_stream_inq_timestep(streamID2, otsID);
        if (nrecs != cdo_stream_inq_timestep(streamID3, otsID))
          cdo_abort("Number of records at time step %d of %s and %s differ!", otsID + 1, cdo_get_stream_name(1),
                    cdo_get_stream_name(2));

        auto vDateTime2 = taxisInqVdatetime(taxisID2);
        auto vDateTime3 = taxisInqVdatetime(taxisID3);
        if (cdiDateTime_isNE(vDateTime2, vDateTime3))
          cdo_abort("Verification dates at time step %d of %s and %s differ!", otsID + 1, cdo_get_stream_name(1),
                    cdo_get_stream_name(2));

        for (int recID = 0; recID < nrecs; ++recID)
          {
            int varID, levelID;
            cdo_inq_record(streamID2, &varID, &levelID);
            const auto &var = varList1[varID];
            field1.init(var);
            cdo_read_record(streamID2, field1);

            cdo_inq_record(streamID3, &varID, &levelID);
            field2.init(var);
            cdo_read_record(streamID3, field2);

            hset.defVarLevelBounds(varID, levelID, field1, field2);
          }

        int numSets = 0;
        auto newseas = false;
        while (nrecs && (nrecs = cdo_stream_inq_timestep(streamID1, tsID)))
          {
            dtlist.taxis_inq_timestep(taxisID1, numSets);
            auto vDateTime1 = dtlist.get_vDateTime(numSets);

            auto month = decode_month(vDateTime1.date);
            auto newmon = month;
            if (seasonStart == SeasonStart::DEC && newmon == 12) newmon = 0;

            auto seas = month_to_season(month);

            if (numSets == 0)
              {
                seas0 = seas;
                oldmon = newmon;
              }

            if (newmon < oldmon) newseas = true;

            if ((seas != seas0) || newseas)
              {
                cdo_add_steps(-1);
                break;
              }

            oldmon = newmon;

            for (int recID = 0; recID < nrecs; ++recID)
              {
                int varID, levelID;
                cdo_inq_record(streamID1, &varID, &levelID);
                const auto &var = varList1[varID];

                if (tsID == 0) recList[recID].set(varID, levelID);

                if (tsID == 0 && var.isConstant)
                  {
                    constFields[recID].init(var);
                    cdo_read_record(streamID1, constFields[recID]);
                  }
                else
                  {
                    field1.init(var);
                    cdo_read_record(streamID1, field1);

                    hset.addVarLevelValues(varID, levelID, field1);
                  }
              }

            numSets++;
            tsID++;
          }

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

        dtlist.stat_taxis_def_timestep(taxisID4, numSets);
        cdo_def_timestep(streamID4, otsID);

        for (int recID = 0; recID < maxrecs; ++recID)
          {
            auto [varID, levelID] = recList[recID].get();
            if (otsID && varList1[varID].isConstant) continue;

            cdo_def_record(streamID4, varID, levelID);

            if (varList1[varID].isConstant) { cdo_write_record(streamID4, constFields[recID]); }
            else
              {
                const auto &var = varList1[varID];
                field1.init(var);
                hset.getVarLevelPercentiles(field1, varID, levelID, pn);
                cdo_write_record(streamID4, field1);
              }
          }

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

  void
  close()
  {

    cdo_stream_close(streamID4);
    cdo_stream_close(streamID3);
    cdo_stream_close(streamID2);
    cdo_stream_close(streamID1);

    cdo_finish();
  }
};

void *
Seaspctl(void *process)
{
  ModuleSeaspctl seaspctl;
  seaspctl.init(process);
  seaspctl.run();
  seaspctl.close();

  return nullptr;
}
