/* Copyright (C) 2003 MySQL AB

   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; either version 2 of the License, or
   (at your option) any later version.

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include <NdbSqlUtil.hpp>

int
NdbSqlUtil::char_compare(const char* s1, unsigned n1,
                         const char* s2, unsigned n2, bool padded)
{
  int c1 = 0;
  int c2 = 0;
  unsigned i = 0;
  while (i < n1 || i < n2) {
    c1 = i < n1 ? s1[i] : padded ? 0x20 : 0;
    c2 = i < n2 ? s2[i] : padded ? 0x20 : 0;
    if (c1 != c2)
      break;
    i++;
  }
  return c1 - c2;
}

bool
NdbSqlUtil::char_like(const char* s1, unsigned n1,
                      const char* s2, unsigned n2, bool padded)
{
  int c1 = 0;
  int c2 = 0;
  unsigned i1 = 0;
  unsigned i2 = 0;
  while (i1 < n1 || i2 < n2) {
    c1 = i1 < n1 ? s1[i1] : padded ? 0x20 : 0;
    c2 = i2 < n2 ? s2[i2] : padded ? 0x20 : 0;
    if (c2 == '%') {
      while (i2 + 1 < n2 && s2[i2 + 1] == '%') {
        i2++;
      }
      unsigned m = 0;
      while (m <= n1 - i1) {
        if (char_like(s1 + i1 + m, n1 -i1 - m,
                      s2 + i2 + 1, n2 - i2 - 1, padded))
        return true;
        m++;
      }
      return false;
    }
    if (c2 == '_') {
      if (c1 == 0)
        return false;
    } else {
      if (c1 != c2)
        return false;
    }
    i1++;
    i2++;
  }
  return i1 == n2 && i2 == n2;
}

/*
 * Data types.
 */

const NdbSqlUtil::Type
NdbSqlUtil::m_typeList[] = {
  {
    Type::Undefined,
    NULL
  },
  {
    Type::Tinyint,
    cmpTinyint
  },
  {
    Type::Tinyunsigned,
    cmpTinyunsigned
  },
  {
    Type::Smallint,
    cmpSmallint
  },
  {
    Type::Smallunsigned,
    cmpSmallunsigned
  },
  {
    Type::Mediumint,
    cmpMediumint
  },
  {
    Type::Mediumunsigned,
    cmpMediumunsigned
  },
  {
    Type::Int,
    cmpInt
  },
  {
    Type::Unsigned,
    cmpUnsigned
  },
  {
    Type::Bigint,
    cmpBigint
  },
  {
    Type::Bigunsigned,
    cmpBigunsigned
  },
  {
    Type::Float,
    cmpFloat
  },
  {
    Type::Double,
    cmpDouble
  },
  {
    Type::Decimal,
    NULL  // cmpDecimal
  },
  {
    Type::Char,
    cmpChar
  },
  {
    Type::Varchar,
    NULL  // cmpVarchar
  },
  {
    Type::Binary,
    cmpBinary
  },
  {
    Type::Varbinary,
    NULL  // cmpVarbinary
  },
  {
    Type::Datetime,
    cmpDatetime
  },
  {
    Type::Timespec,
    NULL  // cmpTimespec
  },
  {
    Type::Blob,
    NULL  // cmpBlob
  },
  {
    Type::Text,
    NULL  // cmpText
  }
};

const NdbSqlUtil::Type&
NdbSqlUtil::getType(Uint32 typeId)
{
  if (typeId < sizeof(m_typeList) / sizeof(m_typeList[0]) &&
      m_typeList[typeId].m_typeId != Type::Undefined) {
    return m_typeList[typeId];
  }
  return m_typeList[Type::Undefined];
}

const NdbSqlUtil::Type&
NdbSqlUtil::getTypeBinary(Uint32 typeId)
{
  switch (typeId) {
  case Type::Char:
    typeId = Type::Binary;
    break;
  case Type::Varchar:
    typeId = Type::Varbinary; 
    break;
  case Type::Text:
    typeId = Type::Blob;
    break;
  default:
    break;
  }
  return getType(typeId);
}

/*
 * Comparison functions.
 */

int
NdbSqlUtil::cmpTinyint(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Int8)) {
    Int8 v1, v2;
    memcpy(&v1, p1, sizeof(Int8));
    memcpy(&v2, p2, sizeof(Int8));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpTinyunsigned(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Uint8)) {
    Uint8 v1, v2;
    memcpy(&v1, p1, sizeof(Uint8));
    memcpy(&v2, p2, sizeof(Uint8));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpSmallint(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Int16)) {
    Int16 v1, v2;
    memcpy(&v1, p1, sizeof(Int16));
    memcpy(&v2, p2, sizeof(Int16));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpSmallunsigned(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Uint16)) {
    Uint16 v1, v2;
    memcpy(&v1, p1, sizeof(Uint16));
    memcpy(&v2, p2, sizeof(Uint16));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpMediumint(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= 3) {
    Int32 v1, v2;
    v1 = sint3korr((const uchar*)p1);
    v2 = sint3korr((const uchar*)p2);
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpMediumunsigned(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= 3) {
    Uint32 v1, v2;
    v1 = uint3korr((const uchar*)p1);
    v2 = uint3korr((const uchar*)p2);
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpInt(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Int32)) {
    Int32 v1, v2;
    memcpy(&v1, p1, sizeof(Int32));
    memcpy(&v2, p2, sizeof(Int32));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpUnsigned(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Uint32)) {
    Uint32 v1, v2;
    memcpy(&v1, p1, sizeof(Uint32));
    memcpy(&v2, p2, sizeof(Uint32));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpBigint(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Int64)) {
    Int64 v1, v2;
    memcpy(&v1, p1, sizeof(Int64));
    memcpy(&v2, p2, sizeof(Int64));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpBigunsigned(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(Uint64)) {
    Uint64 v1, v2;
    memcpy(&v1, p1, sizeof(Uint64));
    memcpy(&v2, p2, sizeof(Uint64));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpFloat(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(float)) {
    float v1, v2;
    memcpy(&v1, p1, sizeof(float));
    memcpy(&v2, p2, sizeof(float));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

int
NdbSqlUtil::cmpDouble(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  if (n2 >= sizeof(double)) {
    double v1, v2;
    memcpy(&v1, p1, sizeof(double));
    memcpy(&v2, p2, sizeof(double));
    if (v1 < v2)
      return -1;
    if (v1 > v2)
      return +1;
    return 0;
  }
  assert(! full);
  return CmpUnknown;
}

// not used by MySQL or NDB
int
NdbSqlUtil::cmpDecimal(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  assert(false);
  return 0;
}

int
NdbSqlUtil::cmpChar(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  // collation does not work on prefix for some charsets
  assert(full);
  const uchar* v1 = (const uchar*)p1;
  const uchar* v2 = (const uchar*)p2;
  // not const in MySQL
  CHARSET_INFO* cs = (CHARSET_INFO*)(info);
  // compare with space padding
  int k = (*cs->coll->strnncollsp)(cs, v1, n1, v2, n2, false);
  return k < 0 ? -1 : k > 0 ? +1 : 0;
}

// waiting for MySQL and new NDB implementation
int
NdbSqlUtil::cmpVarchar(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  assert(false);
  return 0;
}

int
NdbSqlUtil::cmpBinary(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  const uchar* v1 = (const uchar*)p1;
  const uchar* v2 = (const uchar*)p2;
  // compare as binary strings
  unsigned n = (n1 <= n2 ? n1 : n2);
  int k = memcmp(v1, v2, n);
  if (k == 0) {
    if (full)
      k = (int)n1 - (int)n2;
    else
      k = (int)n - (int)n2;
  }
  return k < 0 ? -1 : k > 0 ? +1 : full ? 0 : CmpUnknown;
}

// waiting for MySQL and new NDB implementation
int
NdbSqlUtil::cmpVarbinary(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  assert(false);
  return 0;
}

// allowed but ordering is wrong before wl-1442 done
int
NdbSqlUtil::cmpDatetime(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  return cmpBinary(info, p1, n1, p2, n2, full);
}

// not used by MySQL or NDB
int
NdbSqlUtil::cmpTimespec(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  assert(false);
  return 0;
}

// not supported
int
NdbSqlUtil::cmpBlob(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  assert(false);
  return 0;
}

// not supported
int
NdbSqlUtil::cmpText(const void* info, const void* p1, unsigned n1, const void* p2, unsigned n2, bool full)
{
  assert(false);
  return 0;
}

// check charset

bool
NdbSqlUtil::usable_in_pk(Uint32 typeId, const void* info)
{
  const Type& type = getType(typeId);
  switch (type.m_typeId) {
  case Type::Char:
    {
      const CHARSET_INFO *cs = (const CHARSET_INFO*)info;
      return
        cs != 0 &&
        cs->cset != 0 &&
        cs->coll != 0 &&
        cs->coll->strnxfrm != 0 &&
        cs->strxfrm_multiply <= MAX_XFRM_MULTIPLY;
    }
    break;
  case Type::Undefined:
  case Type::Varchar:
  case Type::Varbinary:
  case Type::Blob:
  case Type::Text:
    break;
  default:
    return true;
  }
  return false;
}

bool
NdbSqlUtil::usable_in_hash_index(Uint32 typeId, const void* info)
{
  return usable_in_pk(typeId, info);
}

bool
NdbSqlUtil::usable_in_ordered_index(Uint32 typeId, const void* info)
{
  const Type& type = getType(typeId);
  if (type.m_cmp == NULL)
    return false;
  switch (type.m_typeId) {
  case Type::Char:
    {
      const CHARSET_INFO *cs = (const CHARSET_INFO*)info;
      return
        cs != 0 &&
        cs->cset != 0 &&
        cs->coll != 0 &&
        cs->coll->strnxfrm != 0 &&
        cs->coll->strnncollsp != 0 &&
        cs->strxfrm_multiply <= MAX_XFRM_MULTIPLY;
    }
    break;
  case Type::Undefined:
  case Type::Varchar:
  case Type::Varbinary:
  case Type::Blob:
  case Type::Text:
    break;
  default:
    return true;
  }
  return false;
}