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

  Author: Uwe Schulzweida
          Ralf Quast

*/

/*
   This module contains the following operators:

      Runpctl    runpctl         Running percentiles
*/

#include <cdi.h>

#include "process_int.h"
#include "param_conversion.h"
#include "percentiles.h"
#include "datetime.h"
#include "field_functions.h"
#include "cdo_omp.h"

template <typename T>
static size_t
runpctl(double pn, int ndates, size_t gridsize, Varray<T> &v2, double mv, const FieldVector3D &vars1, int varID, int levelID,
        MemType memType)
{
  T missval = mv;
  size_t numMissVals = 0;
  Varray2D<T> array_2D(Threading::ompNumThreads, Varray<T>(ndates));

#ifdef _OPENMP
#pragma omp parallel for default(shared) schedule(dynamic)
#endif
  for (size_t i = 0; i < gridsize; ++i)
    {
      auto ompthID = cdo_omp_get_thread_num();
      auto &array = array_2D[ompthID];

      int j = 0;

      if (memType == MemType::Float)
        {
          for (int inp = 0; inp < ndates; ++inp)
            {
              auto val = vars1[inp][varID][levelID].vec_f[i];
              if (fp_is_not_equal(val, missval)) array[j++] = val;
            }
        }
      else
        {
          for (int inp = 0; inp < ndates; ++inp)
            {
              auto val = vars1[inp][varID][levelID].vec_d[i];
              if (fp_is_not_equal(val, missval)) array[j++] = val;
            }
        }
      /*
      for (int inp = 0; inp < ndates; ++inp)
        {
          auto func = [&](auto &v) {
            auto val = v[i];
            if (fp_is_not_equal(val, missval)) array[j++] = val;
          };
          field_operation(func, vars1[inp][varID][levelID]);
        }
      */
      if (j > 0) { v2[i] = percentile(array.data(), j, pn); }
      else
        {
          v2[i] = missval;
          numMissVals++;
        }
    }

  return numMissVals;
}

static void
runpctl(double pn, int ndates, Field &field1, const FieldVector3D &vars1, int varID, int levelID)
{
  auto func = [&](auto &v) {
    field1.numMissVals = runpctl(pn, ndates, field1.gridsize, v, field1.missval, vars1, varID, levelID, field1.memType);
  };
  field_operation(func, field1);
}

class Runpctl : public Process
{
public:
  using Process::Process;
  inline static CdoModule module = {
    .name = "Runpctl",
    .operators = { { "runpctl", RunpctlHelp } },
    .aliases = {},
    .mode = EXPOSED,     // Module mode: 0:intern 1:extern
    .number = CDI_REAL,  // Allowed number type
    .constraints = { 1, 1, NoRestriction },
  };
  inline static RegisterEntry<Runpctl> registration = RegisterEntry<Runpctl>(module);

  CdoStreamID streamID1;
  CdoStreamID streamID2;
  int vlistID1;
  int vlistID2;
  VarList varList1;
  int taxisID1;
  int taxisID2;
  FieldVector3D varsData1;

  DateTimeList dtlist;
  double pn;
  int ndates;
  int maxFields;
  std::vector<FieldInfo> fieldInfoList;
  int tsID;

public:
  void
  init() override
  {
    constexpr auto timestatDate{ TimeStat::MEAN };

    operator_input_arg("percentile number, number of timesteps");
    operator_check_argc(2);
    pn = parameter_to_double(cdo_operator_argv(0));
    ndates = parameter_to_int(cdo_operator_argv(1));

    streamID1 = cdo_open_read(0);

    vlistID1 = cdo_stream_inq_vlist(streamID1);
    vlistID2 = vlistDuplicate(vlistID1);

    vlist_unpack(vlistID2);

    taxisID1 = vlistInqTaxis(vlistID1);
    taxisID2 = taxisDuplicate(taxisID1);
    taxisWithBounds(taxisID2);
    vlistDefTaxis(vlistID2, taxisID2);

    streamID2 = cdo_open_write(1);
    cdo_def_vlist(streamID2, vlistID2);

    varList1 = VarList(vlistID1);

    maxFields = varList1.maxFields();
    fieldInfoList = std::vector<FieldInfo>(maxFields);

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

    varsData1 = FieldVector3D(ndates + 1);
    for (int its = 0; its < ndates; its++) field2D_init(varsData1[its], varList1);
  }

  void
  write_fields(int otsID)
  {
    dtlist.stat_taxis_def_timestep(taxisID2, ndates);
    cdo_def_timestep(streamID2, otsID);
    for (int fieldID = 0; fieldID < maxFields; ++fieldID)
      {
        auto [varID, levelID] = fieldInfoList[fieldID].get();
        if (otsID && varList1.vars[varID].isConstant) continue;

        cdo_def_field(streamID2, varID, levelID);
        auto &field1 = varsData1[0][varID][levelID];
        cdo_write_field(streamID2, field1);
      }
  }

  void
  run() override
  {
    for (tsID = 0; tsID < ndates; ++tsID)
      {
        auto numFields = cdo_stream_inq_timestep(streamID1, tsID);
        if (numFields == 0) cdo_abort("File has less than %d timesteps!", ndates);

        dtlist.taxis_inq_timestep(taxisID1, tsID);

        for (int fieldID = 0; fieldID < numFields; ++fieldID)
          {
            auto [varID, levelID] = cdo_inq_field(streamID1);

            if (tsID == 0) fieldInfoList[fieldID].set(varID, levelID);

            auto &field = varsData1[tsID][varID][levelID];
            field.init(varList1.vars[varID]);
            cdo_read_field(streamID1, field);
          }
      }
    int otsID = 0;
    while (true)
      {
        auto numVars = varList1.numVars();
        for (int varID = 0; varID < numVars; ++varID)
          {
            if (varList1.vars[varID].isConstant) continue;

            auto nlevels = varList1.vars[varID].nlevels;
            for (int levelID = 0; levelID < nlevels; ++levelID)
              {
                auto &field1 = varsData1[0][varID][levelID];
                runpctl(pn, ndates, field1, varsData1, varID, levelID);
              }
          }

        write_fields(otsID);
        otsID++;

        dtlist.shift();

        varsData1[ndates] = varsData1[0];
        for (int inp = 0; inp < ndates; ++inp) varsData1[inp] = varsData1[inp + 1];

        auto numFields = cdo_stream_inq_timestep(streamID1, tsID);
        if (numFields == 0) break;

        dtlist.taxis_inq_timestep(taxisID1, ndates - 1);

        for (int fieldID = 0; fieldID < numFields; ++fieldID)
          {
            auto [varID, levelID] = cdo_inq_field(streamID1);
            auto &fieldN = varsData1[ndates - 1][varID][levelID];
            cdo_read_field(streamID1, fieldN);
          }

        tsID++;
      }
  }

  void
  close() override
  {
    cdo_stream_close(streamID2);
    cdo_stream_close(streamID1);
  }
};
