/* Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

   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 St, Fifth Floor, Boston, MA 02110-1301  USA */

#include <my_global.h>
#include <m_ctype.h>
#include <my_xml.h>
#ifndef SCO
#include <m_string.h>
#endif


/*

  This files implements routines which parse XML based
  character set and collation description files.
  
  Unicode collations are encoded according to
  
    Unicode Technical Standard #35
    Locale Data Markup Language (LDML)
    http://www.unicode.org/reports/tr35/
  
  and converted into ICU string according to
  
    Collation Customization
    http://oss.software.ibm.com/icu/userguide/Collate_Customization.html
  
*/

int (*my_string_stack_guard)(int)= NULL;

static char *mstr(char *str,const char *src,size_t l1,size_t l2)
{
  l1= l1<l2 ? l1 : l2;
  memcpy(str,src,l1);
  str[l1]='\0';
  return str;
}

struct my_cs_file_section_st
{
  int        state;
  const char *str;
};

#define _CS_MISC	1
#define _CS_ID		2
#define _CS_CSNAME	3
#define _CS_FAMILY	4
#define _CS_ORDER	5
#define _CS_COLNAME	6
#define _CS_FLAG	7
#define _CS_CHARSET	8
#define _CS_COLLATION	9
#define _CS_UPPERMAP	10
#define _CS_LOWERMAP	11
#define _CS_UNIMAP	12
#define _CS_COLLMAP	13
#define _CS_CTYPEMAP	14
#define _CS_PRIMARY_ID	15
#define _CS_BINARY_ID	16
#define _CS_CSDESCRIPT	17
#define _CS_RESET	18
#define	_CS_DIFF1	19
#define	_CS_DIFF2	20
#define	_CS_DIFF3	21
#define	_CS_IDENTICAL	22


static struct my_cs_file_section_st sec[] =
{
  {_CS_MISC,		"xml"},
  {_CS_MISC,		"xml/version"},
  {_CS_MISC,		"xml/encoding"},
  {_CS_MISC,		"charsets"},
  {_CS_MISC,		"charsets/max-id"},
  {_CS_CHARSET,		"charsets/charset"},
  {_CS_PRIMARY_ID,	"charsets/charset/primary-id"},
  {_CS_BINARY_ID,	"charsets/charset/binary-id"},
  {_CS_CSNAME,		"charsets/charset/name"},
  {_CS_FAMILY,		"charsets/charset/family"},
  {_CS_CSDESCRIPT,	"charsets/charset/description"},
  {_CS_MISC,		"charsets/charset/alias"},
  {_CS_MISC,		"charsets/charset/ctype"},
  {_CS_CTYPEMAP,	"charsets/charset/ctype/map"},
  {_CS_MISC,		"charsets/charset/upper"},
  {_CS_UPPERMAP,	"charsets/charset/upper/map"},
  {_CS_MISC,		"charsets/charset/lower"},
  {_CS_LOWERMAP,	"charsets/charset/lower/map"},
  {_CS_MISC,		"charsets/charset/unicode"},
  {_CS_UNIMAP,		"charsets/charset/unicode/map"},
  {_CS_COLLATION,	"charsets/charset/collation"},
  {_CS_COLNAME,		"charsets/charset/collation/name"},
  {_CS_ID,		"charsets/charset/collation/id"},
  {_CS_ORDER,		"charsets/charset/collation/order"},
  {_CS_FLAG,		"charsets/charset/collation/flag"},
  {_CS_COLLMAP,		"charsets/charset/collation/map"},
  {_CS_RESET,		"charsets/charset/collation/rules/reset"},
  {_CS_DIFF1,		"charsets/charset/collation/rules/p"},
  {_CS_DIFF2,		"charsets/charset/collation/rules/s"},
  {_CS_DIFF3,		"charsets/charset/collation/rules/t"},
  {_CS_IDENTICAL,	"charsets/charset/collation/rules/i"},
  {0,	NULL}
};

static struct my_cs_file_section_st * cs_file_sec(const char *attr, size_t len)
{
  struct my_cs_file_section_st *s;
  for (s=sec; s->str; s++)
  {
    if (!strncmp(attr,s->str,len))
      return s;
  }
  return NULL;
}

#define MY_CS_CSDESCR_SIZE	64
#define MY_CS_TAILORING_SIZE	1024

typedef struct my_cs_file_info
{
  char   csname[MY_CS_NAME_SIZE];
  char   name[MY_CS_NAME_SIZE];
  uchar  ctype[MY_CS_CTYPE_TABLE_SIZE];
  uchar  to_lower[MY_CS_TO_LOWER_TABLE_SIZE];
  uchar  to_upper[MY_CS_TO_UPPER_TABLE_SIZE];
  uchar  sort_order[MY_CS_SORT_ORDER_TABLE_SIZE];
  uint16 tab_to_uni[MY_CS_TO_UNI_TABLE_SIZE];
  char   comment[MY_CS_CSDESCR_SIZE];
  char   tailoring[MY_CS_TAILORING_SIZE];
  size_t tailoring_length;
  CHARSET_INFO cs;
  int (*add_collation)(CHARSET_INFO *cs);
} MY_CHARSET_LOADER;



static int fill_uchar(uchar *a,uint size,const char *str, size_t len)
{
  uint i= 0;
  const char *s, *b, *e=str+len;
  
  for (s=str ; s < e ; i++)
  { 
    for ( ; (s < e) && strchr(" \t\r\n",s[0]); s++) ;
    b=s;
    for ( ; (s < e) && !strchr(" \t\r\n",s[0]); s++) ;
    if (s == b || i > size)
      break;
    a[i]= (uchar) strtoul(b,NULL,16);
  }
  return 0;
}

static int fill_uint16(uint16 *a,uint size,const char *str, size_t len)
{
  uint i= 0;
  
  const char *s, *b, *e=str+len;
  for (s=str ; s < e ; i++)
  { 
    for ( ; (s < e) && strchr(" \t\r\n",s[0]); s++) ;
    b=s;
    for ( ; (s < e) && !strchr(" \t\r\n",s[0]); s++) ;
    if (s == b || i > size)
      break;
    a[i]= (uint16) strtol(b,NULL,16);
  }
  return 0;
}


static int cs_enter(MY_XML_PARSER *st,const char *attr, size_t len)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *)st->user_data;
  struct my_cs_file_section_st *s= cs_file_sec(attr,len);
  
  if ( s && (s->state == _CS_CHARSET))
    bzero(&i->cs,sizeof(i->cs));
  
  if (s && (s->state == _CS_COLLATION))
    i->tailoring_length= 0;

  return MY_XML_OK;
}


static int cs_leave(MY_XML_PARSER *st,const char *attr, size_t len)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *)st->user_data;
  struct my_cs_file_section_st *s= cs_file_sec(attr,len);
  int    state= s ? s->state : 0;
  int    rc;
  
  switch(state){
  case _CS_COLLATION:
    rc= i->add_collation ? i->add_collation(&i->cs) : MY_XML_OK;
    break;
  default:
    rc=MY_XML_OK;
  }
  return rc;
}


static int cs_value(MY_XML_PARSER *st,const char *attr, size_t len)
{
  struct my_cs_file_info *i= (struct my_cs_file_info *)st->user_data;
  struct my_cs_file_section_st *s;
  int    state= (int)((s=cs_file_sec(st->attr, strlen(st->attr))) ? s->state :
                      0);
  
  switch (state) {
  case _CS_ID:
    i->cs.number= strtol(attr,(char**)NULL,10);
    break;
  case _CS_BINARY_ID:
    i->cs.binary_number= strtol(attr,(char**)NULL,10);
    break;
  case _CS_PRIMARY_ID:
    i->cs.primary_number= strtol(attr,(char**)NULL,10);
    break;
  case _CS_COLNAME:
    i->cs.name=mstr(i->name,attr,len,MY_CS_NAME_SIZE-1);
    break;
  case _CS_CSNAME:
    i->cs.csname=mstr(i->csname,attr,len,MY_CS_NAME_SIZE-1);
    break;
  case _CS_CSDESCRIPT:
    i->cs.comment=mstr(i->comment,attr,len,MY_CS_CSDESCR_SIZE-1);
    break;
  case _CS_FLAG:
    if (!strncmp("primary",attr,len))
      i->cs.state|= MY_CS_PRIMARY;
    else if (!strncmp("binary",attr,len))
      i->cs.state|= MY_CS_BINSORT;
    else if (!strncmp("compiled",attr,len))
      i->cs.state|= MY_CS_COMPILED;
    break;
  case _CS_UPPERMAP:
    fill_uchar(i->to_upper,MY_CS_TO_UPPER_TABLE_SIZE,attr,len);
    i->cs.to_upper=i->to_upper;
    break;
  case _CS_LOWERMAP:
    fill_uchar(i->to_lower,MY_CS_TO_LOWER_TABLE_SIZE,attr,len);
    i->cs.to_lower=i->to_lower;
    break;
  case _CS_UNIMAP:
    fill_uint16(i->tab_to_uni,MY_CS_TO_UNI_TABLE_SIZE,attr,len);
    i->cs.tab_to_uni=i->tab_to_uni;
    break;
  case _CS_COLLMAP:
    fill_uchar(i->sort_order,MY_CS_SORT_ORDER_TABLE_SIZE,attr,len);
    i->cs.sort_order=i->sort_order;
    break;
  case _CS_CTYPEMAP:
    fill_uchar(i->ctype,MY_CS_CTYPE_TABLE_SIZE,attr,len);
    i->cs.ctype=i->ctype;
    break;
  case _CS_RESET:
  case _CS_DIFF1:
  case _CS_DIFF2:
  case _CS_DIFF3:
  case _CS_IDENTICAL:
    {
      /*
        Convert collation description from
        Locale Data Markup Language (LDML)
        into ICU Collation Customization expression.
      */
      char arg[16];
      const char *cmd[]= {"&","<","<<","<<<","="};
      i->cs.tailoring= i->tailoring;
      mstr(arg,attr,len,sizeof(arg)-1);
      if (i->tailoring_length + 20 < sizeof(i->tailoring))
      {
        char *dst= i->tailoring_length + i->tailoring;
        i->tailoring_length+= sprintf(dst," %s %s",cmd[state-_CS_RESET],arg);
      }
    }
  }
  return MY_XML_OK;
}


my_bool my_parse_charset_xml(const char *buf, size_t len,
                             int (*add_collation)(CHARSET_INFO *cs))
{
  MY_XML_PARSER p;
  struct my_cs_file_info i;
  my_bool rc;
  
  my_xml_parser_create(&p);
  my_xml_set_enter_handler(&p,cs_enter);
  my_xml_set_value_handler(&p,cs_value);
  my_xml_set_leave_handler(&p,cs_leave);
  i.add_collation= add_collation;
  my_xml_set_user_data(&p,(void*)&i);
  rc= (my_xml_parse(&p,buf,len) == MY_XML_OK) ? FALSE : TRUE;
  my_xml_parser_free(&p);
  return rc;
}


/*
  Check repertoire: detect pure ascii strings
*/
uint
my_string_repertoire(CHARSET_INFO *cs, const char *str, ulong length)
{
  const char *strend= str + length;
  if (cs->mbminlen == 1)
  {
    for ( ; str < strend; str++)
    {
      if (((uchar) *str) > 0x7F)
        return MY_REPERTOIRE_UNICODE30;
    }
  }
  else
  {
    my_wc_t wc;
    int chlen;
    for (;
         (chlen= cs->cset->mb_wc(cs, &wc, (uchar*) str, (uchar*) strend)) > 0;
         str+= chlen)
    {
      if (wc > 0x7F)
        return MY_REPERTOIRE_UNICODE30;
    }
  }
  return MY_REPERTOIRE_ASCII;
}


/*
  Returns repertoire for charset
*/
uint my_charset_repertoire(CHARSET_INFO *cs)
{
  return cs->state & MY_CS_PUREASCII ?
    MY_REPERTOIRE_ASCII : MY_REPERTOIRE_UNICODE30;
}


/*
  Detect whether a character set is ASCII compatible.

  Returns TRUE for:
  
  - all 8bit character sets whose Unicode mapping of 0x7B is '{'
    (ignores swe7 which maps 0x7B to "LATIN LETTER A WITH DIAERESIS")
  
  - all multi-byte character sets having mbminlen == 1
    (ignores ucs2 whose mbminlen is 2)
  
  TODO:
  
  When merging to 5.2, this function should be changed
  to check a new flag MY_CS_NONASCII, 
  
     return (cs->flag & MY_CS_NONASCII) ? 0 : 1;
  
  This flag was previously added into 5.2 under terms
  of WL#3759 "Optimize identifier conversion in client-server protocol"
  especially to mark character sets not compatible with ASCII.
  
  We won't backport this flag to 5.0 or 5.1.
  This function is Ok for 5.0 and 5.1, because we're not going
  to introduce new tricky character sets between 5.0 and 5.2.
*/
my_bool
my_charset_is_ascii_based(CHARSET_INFO *cs)
{
  return 
    (cs->mbmaxlen == 1 && cs->tab_to_uni && cs->tab_to_uni['{'] == '{') ||
    (cs->mbminlen == 1 && cs->mbmaxlen > 1);
}


/*
  Detect if a character set is 8bit,
  and it is pure ascii, i.e. doesn't have
  characters outside U+0000..U+007F
  This functions is shared between "conf_to_src"
  and dynamic charsets loader in "mysqld".
*/
my_bool
my_charset_is_8bit_pure_ascii(CHARSET_INFO *cs)
{
  size_t code;
  if (!cs->tab_to_uni)
    return 0;
  for (code= 0; code < 256; code++)
  {
    if (cs->tab_to_uni[code] > 0x7F)
      return 0;
  }
  return 1;
}


/*
  Shared function between conf_to_src and mysys.
  Check if a 8bit character set is compatible with
  ascii on the range 0x00..0x7F.
*/
my_bool
my_charset_is_ascii_compatible(CHARSET_INFO *cs)
{
  uint i;
  if (!cs->tab_to_uni)
    return 1;
  for (i= 0; i < 128; i++)
  {
    if (cs->tab_to_uni[i] != i)
      return 0;
  }
  return 1;
}