/* Copyright (C) 2021 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. */

#include <cstdlib>
#include <string>
using namespace std;

#include "functor_str.h"
#include "funchelpers.h"
#include "functioncolumn.h"
#include "vlarray.h"
using namespace execplan;

namespace funcexp
{
void Func_decode::hash_password(ulong* result, const char* password, uint password_len)
{
  ulong nr = 1345345333L, add = 7, nr2 = 0x12345671L;
  ulong tmp;
  const char* password_end = password + password_len;
  for (; password < password_end; password++)
  {
    if (*password == ' ' || *password == '\t')
      continue;
    tmp = (ulong)(unsigned char)*password;
    nr ^= (((nr & 63) + add) * tmp) + (nr << 8);
    nr2 += (nr2 << 8) ^ nr;
    add += tmp;
  }
  result[0] = nr & (((ulong)1L << 31) - 1L);
  result[1] = nr2 & (((ulong)1L << 31) - 1L);
}

CalpontSystemCatalog::ColType Func_decode::operationType(FunctionParm& fp,
                                                         CalpontSystemCatalog::ColType& resultType)
{
  return resultType;
}

string Func_decode::getStrVal(rowgroup::Row& row, FunctionParm& parm, bool& isNull,
                              CalpontSystemCatalog::ColType&)
{
  const string& str = parm[0]->data()->getStrVal(row, isNull);
  if (isNull)
  {
    return "";
  }
  const string& password = parm[1]->data()->getStrVal(row, isNull);
  if (isNull)
  {
    return "";
  }

  int nStrLen = str.length();
  int nPassLen = password.length();
  utils::VLArray<char> res(nStrLen + 1);
  memset(res.data(), 0, nStrLen + 1);

  if (!fSeeded)
  {
    hash_password(fSeeds, password.c_str(), nPassLen);
    sql_crypt.init(fSeeds);
    fSeeded = true;
  }

  memcpy(res.data(), str.c_str(), nStrLen);
  sql_crypt.decode(res.data(), nStrLen);
  sql_crypt.reinit();

  return res.data();
}

}  // namespace funcexp
