/* Copyright (C) 2000 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 "my_global.h"
#include "m_string.h"
#include "my_xml.h"


#define MY_XML_EOF	'E'
#define MY_XML_STRING	'S'
#define MY_XML_IDENT	'I'
#define MY_XML_EQ	'='
#define MY_XML_LT	'<'
#define MY_XML_GT	'>'
#define MY_XML_SLASH	'/'
#define MY_XML_COMMENT	'C'
#define MY_XML_TEXT	'T'
#define MY_XML_QUESTION	'?'
#define MY_XML_EXCLAM   '!'

typedef struct xml_attr_st
{
  const char *beg;
  const char *end;
} MY_XML_ATTR;


static const char *lex2str(int lex)
{
  switch(lex)
  {
    case MY_XML_EOF:      return "EOF";
    case MY_XML_STRING:   return "STRING";
    case MY_XML_IDENT:    return "IDENT";
    case MY_XML_EQ:       return "'='";
    case MY_XML_LT:       return "'<'";
    case MY_XML_GT:       return "'>'";
    case MY_XML_SLASH:    return "'/'";
    case MY_XML_COMMENT:  return "COMMENT";
    case MY_XML_TEXT:     return "TEXT";
    case MY_XML_QUESTION: return "'?'";
    case MY_XML_EXCLAM:   return "'!'";
  }
  return "UNKNOWN";
}

static void my_xml_norm_text(MY_XML_ATTR *a)
{
  for ( ; (a->beg < a->end) && strchr(" \t\r\n",a->beg[0]) ; a->beg++ );
  for ( ; (a->beg < a->end) && strchr(" \t\r\n",a->end[-1]) ; a->end-- );
}


static int my_xml_scan(MY_XML_PARSER *p,MY_XML_ATTR *a)
{
  int lex;
  
  for(  ; ( p->cur < p->end) && strchr(" \t\r\n",p->cur[0]) ;  p->cur++);
  
  if (p->cur >= p->end)
  {
    a->beg=p->end;
    a->end=p->end;
    lex=MY_XML_EOF;
    goto ret;
  }
  
  a->beg=p->cur;
  a->end=p->cur;
  
  if ((p->end - p->cur > 3) && !bcmp(p->cur,"<!--",4))
  {
    for( ; (p->cur < p->end) && bcmp(p->cur, "-->", 3); p->cur++)
    {}
    if (!bcmp(p->cur, "-->", 3))
      p->cur+=3;
    a->end=p->cur;
    lex=MY_XML_COMMENT;
  }
  else if (strchr("?=/<>!",p->cur[0]))
  {
    p->cur++;
    a->end=p->cur;
    lex=a->beg[0];
  }
  else if ( (p->cur[0]=='"') || (p->cur[0]=='\'') )
  {
    p->cur++;
    for(  ; ( p->cur < p->end ) && (p->cur[0] != a->beg[0]); p->cur++)
    {}
    a->end=p->cur;
    if (a->beg[0]==p->cur[0])p->cur++;
    a->beg++;
    my_xml_norm_text(a);
    lex=MY_XML_STRING;
  }
  else
  {
    for(;
	(p->cur < p->end) && !strchr("?'\"=/<> \t\r\n", p->cur[0]);
	p->cur++)
    {}
    a->end=p->cur;
    my_xml_norm_text(a);
    lex=MY_XML_IDENT;
  }

#if 0
  printf("LEX=%s[%d]\n",lex2str(lex),a->end-a->beg);
#endif

ret:
  return lex;
}


static int my_xml_value(MY_XML_PARSER *st, const char *str, uint len)
{
  return (st->value) ? (st->value)(st,str,len) : MY_XML_OK;
}


static int my_xml_enter(MY_XML_PARSER *st, const char *str, uint len)
{
  if ( (st->attrend-st->attr+len+1)>sizeof(st->attr))
  {
    sprintf(st->errstr,"To deep XML");
    return MY_XML_ERROR;
  }
  if (st->attrend > st->attr)
  {
    st->attrend[0]='.';
    st->attrend++;
  }
  memcpy(st->attrend,str,len);
  st->attrend+=len;
  st->attrend[0]='\0';
  return st->enter ? st->enter(st,st->attr,st->attrend-st->attr) : MY_XML_OK;
}


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


static int my_xml_leave(MY_XML_PARSER *p, const char *str, uint slen)
{
  char *e;
  uint glen;
  char s[32];
  char g[32];
  int  rc;
  
  /* Find previous '.' or beginning */
  for( e=p->attrend; (e>p->attr) && (e[0]!='.') ; e--);
  glen = (e[0]=='.') ? (p->attrend-e-1) : p->attrend-e;
  
  if (str && (slen != glen))
  {
    mstr(s,str,sizeof(s)-1,slen);
    mstr(g,e+1,sizeof(g)-1,glen),
    sprintf(p->errstr,"'</%s>' unexpected ('</%s>' wanted)",s,g);
    return MY_XML_ERROR;
  }
  
  rc = p->leave_xml ? p->leave_xml(p,p->attr,p->attrend-p->attr) : MY_XML_OK;
  
  *e='\0';
  p->attrend=e;
  
  return rc;
}


int my_xml_parse(MY_XML_PARSER *p,const char *str, uint len)
{
  p->attrend=p->attr;
  p->beg=str;
  p->cur=str;
  p->end=str+len;
  
  while ( p->cur < p->end )
  {
    MY_XML_ATTR a;
    if(p->cur[0]=='<')
    {
      int lex;
      int question=0;
      int exclam=0;
      
      lex=my_xml_scan(p,&a);
      
      if (MY_XML_COMMENT==lex)
      {
        continue;
      }
      
      lex=my_xml_scan(p,&a);
      
      if (MY_XML_SLASH==lex)
      {
        if(MY_XML_IDENT!=(lex=my_xml_scan(p,&a)))
        {
          sprintf(p->errstr,"1: %s unexpected (ident wanted)",lex2str(lex));
          return MY_XML_ERROR;
        }
        if(MY_XML_OK!=my_xml_leave(p,a.beg,a.end-a.beg))
          return MY_XML_ERROR;
        lex=my_xml_scan(p,&a);
        goto gt;
      }
      
      if (MY_XML_EXCLAM==lex)
      {
        lex=my_xml_scan(p,&a);
        exclam=1;
      }
      else if (MY_XML_QUESTION==lex)
      {
        lex=my_xml_scan(p,&a);
        question=1;
      }
      
      if (MY_XML_IDENT==lex)
      {
        if(MY_XML_OK!=my_xml_enter(p,a.beg,a.end-a.beg))
          return MY_XML_ERROR;
      }
      else
      {
        sprintf(p->errstr,"3: %s unexpected (ident or '/' wanted)",
		lex2str(lex));
        return MY_XML_ERROR;
      }
      
      while ((MY_XML_IDENT==(lex=my_xml_scan(p,&a))) || (MY_XML_STRING==lex))
      {
        MY_XML_ATTR b;
        if(MY_XML_EQ==(lex=my_xml_scan(p,&b)))
        {
          lex=my_xml_scan(p,&b);
          if ( (lex==MY_XML_IDENT) || (lex==MY_XML_STRING) )
          {
            if((MY_XML_OK!=my_xml_enter(p,a.beg,a.end-a.beg))  ||
               (MY_XML_OK!=my_xml_value(p,b.beg,b.end-b.beg))  ||
               (MY_XML_OK!=my_xml_leave(p,a.beg,a.end-a.beg)))
              return MY_XML_ERROR;
          }
          else
          {
            sprintf(p->errstr,"4: %s unexpected (ident or string wanted)",
		    lex2str(lex));
            return MY_XML_ERROR;
          }
        }
        else if ( (MY_XML_STRING==lex) || (MY_XML_IDENT==lex) )
        {
          if((MY_XML_OK!=my_xml_enter(p,a.beg,a.end-a.beg)) ||
             (MY_XML_OK!=my_xml_leave(p,a.beg,a.end-a.beg)))
           return MY_XML_ERROR;
        }
        else
          break;
      }
      
      if (lex==MY_XML_SLASH)
      {
        if(MY_XML_OK!=my_xml_leave(p,NULL,0))
          return MY_XML_ERROR;
        lex=my_xml_scan(p,&a);
      }
      
gt:
      if (question)
      {
        if (lex!=MY_XML_QUESTION)
        {
          sprintf(p->errstr,"6: %s unexpected ('?' wanted)",lex2str(lex));
          return MY_XML_ERROR;
        }
        if(MY_XML_OK!=my_xml_leave(p,NULL,0))
          return MY_XML_ERROR;
        lex=my_xml_scan(p,&a);
      }
      
      if (exclam)
      {
        if(MY_XML_OK!=my_xml_leave(p,NULL,0))
          return MY_XML_ERROR;
      }
      
      if (lex!=MY_XML_GT)
      {
        sprintf(p->errstr,"5: %s unexpected ('>' wanted)",lex2str(lex));
        return MY_XML_ERROR;
      }
    }
    else
    {
      a.beg=p->cur;
      for ( ; (p->cur < p->end) && (p->cur[0]!='<')  ; p->cur++);
      a.end=p->cur;
      
      my_xml_norm_text(&a);
      if (a.beg!=a.end)
      {
        my_xml_value(p,a.beg,a.end-a.beg);
      }
    }
  }
  return MY_XML_OK;
}


void my_xml_parser_create(MY_XML_PARSER *p)
{
  bzero((void*)p,sizeof(p[0]));
}


void my_xml_parser_free(MY_XML_PARSER *p  __attribute__((unused)))
{
}


void my_xml_set_value_handler(MY_XML_PARSER *p,
			      int (*action)(MY_XML_PARSER *p, const char *s,
					    uint l))
{
  p->value=action;
}

void my_xml_set_enter_handler(MY_XML_PARSER *p,
			      int (*action)(MY_XML_PARSER *p, const char *s,
					    uint l))
{
  p->enter=action;
}


void my_xml_set_leave_handler(MY_XML_PARSER *p,
			      int (*action)(MY_XML_PARSER *p, const char *s,
					    uint l))
{
  p->leave_xml=action;
}


void my_xml_set_user_data(MY_XML_PARSER *p, void *user_data)
{
  p->user_data=user_data;
}


const char *my_xml_error_string(MY_XML_PARSER *p)
{
  return p->errstr;
}


uint my_xml_error_pos(MY_XML_PARSER *p)
{
  const char *beg=p->beg;
  const char *s;
  for ( s=p->beg ; s<p->cur; s++)
  {
    if (s[0]=='\n')
      beg=s;
  }
  return p->cur-beg;
}

uint my_xml_error_lineno(MY_XML_PARSER *p)
{
  uint res=0;
  const char *s;
  for ( s=p->beg ; s<p->cur; s++)
  {
    if (s[0]=='\n')
      res++;
  }
  return res;
}