/*
   Copyright (C) 2020-2022 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. */
#pragma once

#if defined(PREFER_MY_CONFIG_H)

#if !defined(MY_CONFIG_H)
#error my_config.h was not included (but PREFER_MY_CONFIG_H was set)
#endif

#include "mcsconfig_conflicting_defs_remember.h"
#include "mcsconfig_conflicting_defs_undef.h"

#else
#if defined(MY_CONFIG_H)
#error my_config.h was included before mcsconfig.h (and PREFER_MY_CONFIG_H was not set)
#endif
#endif  // PREFER_MY_CONFIG_H

#include "mcsconfig.h"

#include "exceptclasses.h"
#include "conststring.h"

/*
  Redefine definitions used by MariaDB m_ctype.h.
  This is needed to avoid including <mariadb.h> and <my_sys.h>,
  which conflict with many MCS and boost headers.
*/

#ifndef FALSE
#define FALSE (0)
#endif

#ifndef TRUE
#define TRUE (1)
#endif

#ifndef DBUG_ASSERT
#define DBUG_ASSERT(x) idbassert(x)
#define DBUG_ASSERT_TEMPORARILY_DEFINED
#endif

#ifndef MYSQL_PLUGIN_IMPORT
#if (defined(_WIN32) && defined(MYSQL_DYNAMIC_PLUGIN))
#define MYSQL_PLUGIN_IMPORT __declspec(dllimport)
#else
#define MYSQL_PLUGIN_IMPORT
#endif
#endif

typedef long long int longlong;
typedef unsigned long long int ulonglong;
typedef uint32_t uint32;
typedef uint16_t uint16;
typedef char my_bool;
typedef unsigned char uchar;

#if defined(__GNUC__) && !defined(_lint)
typedef char pchar;   /* Mixed prototypes can take char */
typedef char puchar;  /* Mixed prototypes can take char */
typedef char pbool;   /* Mixed prototypes can take char */
typedef short pshort; /* Mixed prototypes can take short int */
typedef float pfloat; /* Mixed prototypes can take float */
#else
typedef int pchar;     /* Mixed prototypes can't take char */
typedef uint puchar;   /* Mixed prototypes can't take char */
typedef int pbool;     /* Mixed prototypes can't take char */
typedef int pshort;    /* Mixed prototypes can't take short int */
typedef double pfloat; /* Mixed prototypes can't take float */
#endif

typedef const struct charset_info_st CHARSET_INFO;
extern "C" MYSQL_PLUGIN_IMPORT CHARSET_INFO* default_charset_info;

#define HAVE_PSI_INTERFACE

#include "m_ctype.h"

#undef FALSE
#undef TRUE

#ifdef DBUG_ASSERT_TEMPORARILY_DEFINED
#undef DBUG_ASSERT
#endif

#if defined(PREFER_MY_CONFIG_H)
#include "mcsconfig_conflicting_defs_restore.h"
#endif

namespace datatypes
{
class MariaDBHasher
{
#ifdef MY_HASH_ADD_MARIADB
  /*
    Server 12.3+ (MDEV-9826): hash state is accumulated in a my_hasher_st
    object passed to hash_sort().
  */
  my_hasher_st mHasher;
#else
  ulong mPart1;
  ulong mPart2;
#endif

 public:
#ifdef MY_HASH_ADD_MARIADB
  MariaDBHasher() : mHasher(my_hasher_mysql5x())
  {
  }
#else
  MariaDBHasher() : mPart1(1), mPart2(4)
  {
  }
#endif
  MariaDBHasher& add(CHARSET_INFO* cs, const char* str, size_t length)
  {
    // Hashing an empty string is a no-op in every MariaDB collation
    // (skip_trailing_space/my_hash_sort_* return immediately when len==0).
    // Avoid calling hash_sort() with a NULL pointer: MariaDB computes
    // `ptr + len` before checking, which is UB ("applying zero offset to
    // null pointer"), and MDEV-35620 hardened skip_trailing_space() with
    // DBUG_ASSERT(ptr), which then fires in debug builds.  Columnstore's
    // utils::ConstString explicitly documents that its internal pointer
    // can be NULL (e.g. for NULL string columns in a rowgroup::Row), so
    // just short-circuit here.
    if (length == 0)
      return *this;
#ifdef MY_HASH_ADD_MARIADB
    cs->hash_sort(&mHasher, (const uchar*)str, length);
#else
    cs->hash_sort((const uchar*)str, length, &mPart1, &mPart2);
#endif
    return *this;
  }
  MariaDBHasher& add(CHARSET_INFO* cs, const utils::ConstString& str)
  {
    return add(cs, str.str(), str.length());
  }
  uint32_t finalize() const
  {
#ifdef MY_HASH_ADD_MARIADB
    return (uint32_t)mHasher.m_nr1;
#else
    return (uint32_t)mPart1;
#endif
  }
};

// A reference to MariaDB CHARSET_INFO.

class Charset
{
 protected:
  const struct charset_info_st* mCharset;

 private:
  static constexpr const uint flags_ = MY_STRXFRM_PAD_WITH_SPACE | MY_STRXFRM_PAD_TO_MAXLEN;

 public:
  Charset(CHARSET_INFO& cs) : mCharset(&cs)
  {
  }
  Charset(CHARSET_INFO* cs = nullptr) : mCharset(cs ? cs : &my_charset_bin)
  {
  }

  bool operator==(const Charset& rhs) const
  {
    return rhs.getCharset().cs_name.str == getCharset().cs_name.str;
  }

  bool operator!=(const Charset& rhs) const
  {
    return !(*this == rhs);
  }

  std::string convert(const std::string& from, const datatypes::Charset& fromCs) const
  {
    std::string result;
    uint dummy_errors;
    result.resize(from.size() * getCharset().mbmaxlen);
    size_t resultingSize = my_convert(const_cast<char*>(result.c_str()), result.size(), &getCharset(),
                                      from.c_str(), from.size(), &fromCs.getCharset(), &dummy_errors);
    result.resize(resultingSize);
    return result;
  }

  Charset(uint32_t charsetNumber);
  void setCharset(uint32_t charsetNumber);
  CHARSET_INFO& getCharset() const
  {
    return *mCharset;
  }
  uint32_t hash(const char* data, uint64_t len) const
  {
    return MariaDBHasher().add(mCharset, data, len).finalize();
  }
  bool eq(const std::string& str1, const std::string& str2) const
  {
    return mCharset->strnncollsp(str1.data(), str1.length(), str2.data(), str2.length()) == 0;
  }
  int strnncollsp(const std::string& str1, const std::string& str2) const
  {
    return mCharset->strnncollsp(str1.data(), str1.length(), str2.data(), str2.length());
  }
  int strnncollsp(const utils::ConstString& str1, const utils::ConstString& str2) const
  {
    // nullptr handling below should return values as if nulls are substituted with empty string.
    // please note that ConstString has an assertion so that nullptr data has zero length.
    const char* s1 = str1.str();
    const char* s2 = str2.str();
    return mCharset->strnncollsp(s1 ? s1 : "", str1.length(), s2 ? s2 : "", str2.length());
  }
  int strnncollsp(const char* str1, size_t length1, const char* str2, size_t length2) const
  {
    return mCharset->strnncollsp(str1, length1, str2, length2);
  }
  int strnncollsp(const unsigned char* str1, size_t length1, const unsigned char* str2, size_t length2) const
  {
    return mCharset->strnncollsp((const char*)str1, length1, (const char*)str2, length2);
  }
  bool test_if_important_data(const char* str, const char* end) const
  {
    if (mCharset->state & MY_CS_NOPAD)
      return str < end;
    return str + mCharset->scan(str, end, MY_SEQ_SPACES) < end;
  }
  bool like(bool neg, const utils::ConstString& subject, const utils::ConstString& pattern) const
  {
    bool res = !mCharset->wildcmp(subject.str(), subject.end(), pattern.str(), pattern.end(), '\\', '_', '%');
    return neg ? !res : res;
  }
  size_t strnxfrm(uchar* dst, size_t dstlen, uint nweights, const uchar* src, size_t srclen, uint flags)
  {
    assert(mCharset->coll);
    return mCharset->coll->strnxfrm(mCharset, dst, dstlen, nweights, src, srclen, flags);
  }
  // The magic check that tells that bytes are mapped to weights as 1:1
  bool strnxfrmIsValid() const
  {
    return (mCharset->state & MY_CS_NON1TO1) == 0;
  }
  template <typename T>
  T strnxfrm(const char* src) const
  {
    T ret = 0;
    size_t len __attribute__((unused)) =
        mCharset->strnxfrm((char*)&ret, sizeof(T), sizeof(T), src, sizeof(T), flags_);
    assert(len <= sizeof(T));
    return ret;
  }
  template <typename T>
  T strnxfrm(const utils::ConstString& src) const
  {
    T ret = 0;
    size_t len __attribute__((unused)) =
        mCharset->strnxfrm((char*)&ret, sizeof(T), sizeof(T), (char*)src.str(), src.length(), flags_);
    assert(len <= sizeof(T));
    return ret;
  }
  static uint getDefaultFlags()
  {
    return flags_;
  }
};

class CollationAwareHasher : public Charset
{
 public:
  CollationAwareHasher(const Charset& cs) : Charset(cs)
  {
  }
  inline uint32_t operator()(const std::string& s) const
  {
    return operator()(s.data(), s.length());
  }
  inline uint32_t operator()(const char* data, uint64_t len) const
  {
    return Charset::hash(data, len);
  }
};

class CollationAwareComparator : public Charset
{
 public:
  CollationAwareComparator(const Charset& cs) : Charset(cs)
  {
  }
  bool operator()(const std::string& str1, const std::string& str2) const
  {
    return Charset::eq(str1, str2);
  }
};

}  // end of namespace datatypes
