/* Copyright (C) 2014 InfiniDB, Inc.
   Copyright (c) 2019 MariaDB Corporation

   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.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

//  $Id: wf_lead_lag.cpp 3932 2013-06-25 16:08:10Z xlou $

//#define NDEBUG
#include <cassert>
#include <cmath>
#include <sstream>
#include <iomanip>
using namespace std;

#include <boost/shared_ptr.hpp>
using namespace boost;

#include "loggingid.h"
#include "errorcodes.h"
#include "idberrorinfo.h"
using namespace logging;

#include "rowgroup.h"
using namespace rowgroup;

#include "joblisttypes.h"
#include "calpontsystemcatalog.h"
#include "constantcolumn.h"
using namespace execplan;

#include "windowfunctionstep.h"
using namespace joblist;

#include "wf_lead_lag.h"

namespace windowfunction
{
template <typename T>
boost::shared_ptr<WindowFunctionType> WF_lead_lag<T>::makeFunction(int id, const string& name, int ct,
                                                                   WindowFunctionColumn* wc)
{
  boost::shared_ptr<WindowFunctionType> func;

  switch (ct)
  {
    case CalpontSystemCatalog::TINYINT:
    case CalpontSystemCatalog::SMALLINT:
    case CalpontSystemCatalog::MEDINT:
    case CalpontSystemCatalog::INT:
    case CalpontSystemCatalog::BIGINT:
    {
      func.reset(new WF_lead_lag<int64_t>(id, name));
      break;
    }

    case CalpontSystemCatalog::UTINYINT:
    case CalpontSystemCatalog::USMALLINT:
    case CalpontSystemCatalog::UMEDINT:
    case CalpontSystemCatalog::UINT:
    case CalpontSystemCatalog::UBIGINT:
    case CalpontSystemCatalog::DATE:
    case CalpontSystemCatalog::DATETIME:
    case CalpontSystemCatalog::TIMESTAMP:
    case CalpontSystemCatalog::TIME:
    {
      func.reset(new WF_lead_lag<uint64_t>(id, name));
      break;
    }

    case CalpontSystemCatalog::DECIMAL:
    case CalpontSystemCatalog::UDECIMAL:
    {
      decltype(datatypes::MAXDECIMALWIDTH) width = wc->functionParms()[0]->resultType().colWidth;
      if (width < datatypes::MAXDECIMALWIDTH)
      {
        if (ct == CalpontSystemCatalog::UDECIMAL)
          func.reset(new WF_lead_lag<uint64_t>(id, name));
        else
          func.reset(new WF_lead_lag<int64_t>(id, name));
      }
      else if (width == datatypes::MAXDECIMALWIDTH)
      {
        func.reset(new WF_lead_lag<int128_t>(id, name));
      }
      break;
    }
    case CalpontSystemCatalog::DOUBLE:
    case CalpontSystemCatalog::UDOUBLE:
    {
      func.reset(new WF_lead_lag<double>(id, name));
      break;
    }

    case CalpontSystemCatalog::LONGDOUBLE:
    {
      func.reset(new WF_lead_lag<long double>(id, name));
      break;
    }

    case CalpontSystemCatalog::FLOAT:
    case CalpontSystemCatalog::UFLOAT:
    {
      func.reset(new WF_lead_lag<float>(id, name));
      break;
    }

    default:
    {
      func.reset(new WF_lead_lag<string>(id, name));
      break;
    }
  }

  return func;
}

template <typename T>
WindowFunctionType* WF_lead_lag<T>::clone() const
{
  return new WF_lead_lag<T>(*this);
}

template <typename T>
void WF_lead_lag<T>::resetData()
{
  WindowFunctionType::resetData();
}

template <typename T>
void WF_lead_lag<T>::parseParms(const std::vector<execplan::SRCP>& parms)
{
  // lead | lag
  fLead = 1;
  fRespectNulls = true;
  fDefNull = false;
  //    fDefault = (T)0; // Won't work for std::string. Default should always be set below.
  fOffsetNull = false;
  fOffset = 0;

  if (fFunctionId == WF__LAG)
    fLead = -1;

  // parms[0]: value-expr
  // skip

  // parms[1]: offset
  ConstantColumn* cc = dynamic_cast<ConstantColumn*>(parms[1].get());

  if (cc != NULL)
  {
    fOffsetNull = false;
    fOffset = cc->getIntVal(fRow, fOffsetNull) * fLead;  // row not used, no need to setData.
  }

  // parms[2]: default value
  cc = dynamic_cast<ConstantColumn*>(parms[2].get());

  if (cc != NULL)
  {
    fDefNull = false;
    getConstValue(cc, fDefault, fDefNull);
  }

  // parms[3]: respect null | ignore null
  cc = dynamic_cast<ConstantColumn*>(parms[3].get());
  if (cc != NULL)
  {
    bool isNull = false;  // dummy. Return not used
    fRespectNulls = (cc->getIntVal(fRow, isNull) > 0);
  }
}

template <typename T>
void WF_lead_lag<T>::operator()(int64_t b, int64_t e, int64_t c)
{
  uint64_t colIn = fFieldIndex[1];
  bool isNull = true;

  for (int64_t c = b; c <= e; c++)
  {
    if (c % 1000 == 0 && fStep->cancelled())
      break;

    fRow.setData(getPointer(fRowData->at(c)));
    // get offset if not constant
    int64_t idx = fFieldIndex[2];

    if (idx != -1)
    {
      double tmp = 0.0;  // use double to cover all column types
      fOffsetNull = fRow.isNullValue(idx);

      if (!fOffsetNull)
      {
        implicit2T(idx, tmp, 0);
        fOffset = round(tmp);
        fOffset *= fLead;
      }
    }

    // get default if not constant
    idx = fFieldIndex[3];

    if (idx != -1)
    {
      fDefNull = fRow.isNullValue(idx);

      if (!fDefNull)
        implicit2T(idx, fDefault, (int)fRow.getScale(idx));
    }

    int64_t o = c + fOffset;

    if (o < b || o > e || fOffsetNull)  // out of bound
    {
      T* v = (fDefNull) ? NULL : &fDefault;
      setValue(fRow.getColType(fFieldIndex[0]), b, e, c, v);
      continue;
    }

    if (fRespectNulls == false && fRow.isNullValue(colIn) == true)
    {
      if (fOffset > 0)
      {
        while (++o < e)
        {
          fRow.setData(getPointer(fRowData->at(o)));

          if (fRow.isNullValue(colIn) == false)
            break;
        }

        if (o <= e)
        {
          fRow.setData(getPointer(fRowData->at(o)));
          getValue(colIn, fValue);
          isNull = fRow.isNullValue(colIn);
        }
      }
      else if (fOffset < 0)
      {
        while (--o > b)
        {
          fRow.setData(getPointer(fRowData->at(o)));

          if (fRow.isNullValue(colIn) == false)
            break;
        }

        if (o >= b)
        {
          fRow.setData(getPointer(fRowData->at(o)));
          getValue(colIn, fValue);
          isNull = fRow.isNullValue(colIn);
        }
      }

      T* v = NULL;

      if (!isNull)
        v = &fValue;
      else if (!fDefNull)
        v = &fDefault;

      setValue(fRow.getColType(fFieldIndex[0]), b, e, c, v);
    }
    else
    {
      fRow.setData(getPointer(fRowData->at(o)));
      getValue(colIn, fValue);
      isNull = fRow.isNullValue(colIn);

      T* v = NULL;

      if (!isNull)
        v = &fValue;
      else if (!fDefNull)
        v = &fDefault;

      setValue(fRow.getColType(fFieldIndex[0]), b, e, c, v);
    }
  }
}

template boost::shared_ptr<WindowFunctionType> WF_lead_lag<int64_t>::makeFunction(int, const string&, int,
                                                                                  WindowFunctionColumn*);

template void WF_lead_lag<int64_t>::parseParms(const std::vector<execplan::SRCP>&);
template void WF_lead_lag<uint64_t>::parseParms(const std::vector<execplan::SRCP>&);
template void WF_lead_lag<int128_t>::parseParms(const std::vector<execplan::SRCP>&);
template void WF_lead_lag<float>::parseParms(const std::vector<execplan::SRCP>&);
template void WF_lead_lag<double>::parseParms(const std::vector<execplan::SRCP>&);
template void WF_lead_lag<string>::parseParms(const std::vector<execplan::SRCP>&);

}  // namespace windowfunction
// vim:ts=4 sw=4:
