/* Copyright (c) 2003, 2012, 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 Street, Fifth Floor, Boston, MA 02110-1301, USA */

#include "my_global.h"
#include "m_string.h"
#include "my_xml.h"


#define MY_XML_UNKNOWN 'U'
#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 '!'
#define MY_XML_CDATA 'D'

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


/*
 XML ctype:
*/
#define	MY_XML_ID0 0x01 /* Identifier initial character */
#define	MY_XML_ID1 0x02 /* Identifier medial character */
#define	MY_XML_SPC 0x08 /* Spacing character */


/*
 http://www.w3.org/TR/REC-xml/ 
 [4] NameChar ::= Letter | Digit | '.' | '-' | '_' | ':' |
 CombiningChar | Extender
 [5] Name ::= (Letter | '_' | ':') (NameChar)*
*/

static char my_xml_ctype[256]=
{
/*00*/ 0,0,0,0,0,0,0,0,0,8,8,0,0,8,0,0,
/*10*/ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
/*20*/ 8,0,0,0,0,0,0,0,0,0,0,0,0,2,2,0, /* !"#$%&'()*+,-./ */
/*30*/ 2,2,2,2,2,2,2,2,2,2,3,0,0,0,0,0, /* 0123456789:;<=>? */
/*40*/ 0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, /* @ABCDEFGHIJKLMNO */
/*50*/ 3,3,3,3,3,3,3,3,3,3,3,0,0,0,0,3, /* PQRSTUVWXYZ[\]^_ */
/*60*/ 0,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, /* `abcdefghijklmno */
/*70*/ 3,3,3,3,3,3,3,3,3,3,3,0,0,0,0,0, /* pqrstuvwxyz{|}~ */
/*80*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*90*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*A0*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*B0*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*C0*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*D0*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*E0*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,
/*F0*/ 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3
};

#define my_xml_is_space(c) (my_xml_ctype[(uchar) (c)] & MY_XML_SPC)
#define my_xml_is_id0(c) (my_xml_ctype[(uchar) (c)] & MY_XML_ID0)
#define my_xml_is_id1(c) (my_xml_ctype[(uchar) (c)] & MY_XML_ID1)


static const char *lex2str(int lex)
{
 switch(lex)
 {
 case MY_XML_EOF: return "END-OF-INPUT";
 case MY_XML_STRING: return "STRING";
 case MY_XML_IDENT: return "IDENT";
 case MY_XML_CDATA: return "CDATA";
 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 token";
}

static void my_xml_norm_text(MY_XML_ATTR *a)
{
 for ( ; (a->beg < a->end) && my_xml_is_space(a->beg[0]) ; a->beg++ );
 for ( ; (a->beg < a->end) && my_xml_is_space(a->end[-1]) ; a->end-- );
}


static inline my_bool
my_xml_parser_prefix_cmp(MY_XML_PARSER *p, const char *s, size_t slen)
{
 return (p->cur + slen > p->end) || memcmp(p->cur, s, slen);
}


static int my_xml_scan(MY_XML_PARSER *p,MY_XML_ATTR *a)
{
 int lex;
 
 for (; ( p->cur < p->end) && my_xml_is_space(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 (!my_xml_parser_prefix_cmp(p, C_STRING_WITH_LEN("<!--")))
 {
 for (; p->cur < p->end; p->cur++)
 {
 if (!my_xml_parser_prefix_cmp(p, C_STRING_WITH_LEN("-->")))
 {
 p->cur+= 3;
 break;
 }
 }
 a->end=p->cur;
 lex=MY_XML_COMMENT;
 }
 else if (!my_xml_parser_prefix_cmp(p, C_STRING_WITH_LEN("<![CDATA[")))
 {
 p->cur+= 9;
 for (; p->cur < p->end - 2 ; p->cur++)
 {
 if (p->cur[0] == ']' && p->cur[1] == ']' && p->cur[2] == '>')
 {
 p->cur+= 3;
 a->end= p->cur;
 break;
 }
 }
 lex= MY_XML_CDATA;
 }
 else if (strchr("?=/<>!",p->cur[0]))
 {
 p->cur++;
 a->end=p->cur;
 lex=a->beg[0];
 }
 else if ( (p->cur[0] == '"') || (p->cur[0] == '\'') )
 {
 /*
 "string" or 'string' found.
 Scan until the closing quote/doublequote, or until the END-OF-INPUT.
 */
 p->cur++;
 for (; ( p->cur < p->end ) && (p->cur[0] != a->beg[0]); p->cur++)
 {}
 a->end=p->cur;
 if (p->cur < p->end) /* Closing quote or doublequote has been found */
 p->cur++;
 a->beg++;
 if (!(p->flags & MY_XML_FLAG_SKIP_TEXT_NORMALIZATION))
 my_xml_norm_text(a);
 lex=MY_XML_STRING;
 }
 else if (my_xml_is_id0(p->cur[0]))
 {
 p->cur++;
 while (p->cur < p->end && my_xml_is_id1(p->cur[0]))
 p->cur++;
 a->end=p->cur;
 my_xml_norm_text(a);
 lex=MY_XML_IDENT;
 }
 else
 lex= MY_XML_UNKNOWN;

#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, size_t len)
{
 return (st->value) ? (st->value)(st,str,len) : MY_XML_OK;
}


/**
 Ensure the attr buffer is wide enough to hold the new value

 Expand and/or allocate dynamic buffer as needed to hold the concatenated
 path and the terminating zero.

 @attr st the parser instance
 @attr len the length of the attribute to be added
 @return state
 @retval 1 failed
 @retval 0 success
*/
static int my_xml_attr_ensure_space(MY_XML_PARSER *st, size_t len)
{
 size_t ofs= st->attr.end - st->attr.start;
 len++; // Add terminating zero.
 if (ofs + len > st->attr.buffer_size)
 {
 st->attr.buffer_size= (SIZE_T_MAX - len) / 2 > st->attr.buffer_size ?
 st->attr.buffer_size * 2 + len : SIZE_T_MAX;

 if (!st->attr.buffer)
 {
 st->attr.buffer= (char *) my_str_malloc(st->attr.buffer_size);
 if (st->attr.buffer)
 memcpy(st->attr.buffer, st->attr.static_buffer, ofs + 1 /*term. zero */);
 }
 else
 st->attr.buffer= (char *) my_str_realloc(st->attr.buffer,
 st->attr.buffer_size);
 st->attr.start= st->attr.buffer;
 st->attr.end= st->attr.start + ofs;
 
 return st->attr.buffer ? MY_XML_OK : MY_XML_ERROR;
 }
 return MY_XML_OK;
}


/** rewind the attr buffer to initial state */
static void my_xml_attr_rewind(MY_XML_PARSER *p)
{
 /* keep the buffer already allocated */
 p->attr.end= p->attr.start;
}


static int my_xml_enter(MY_XML_PARSER *st, const char *str, size_t len)
{
 if (my_xml_attr_ensure_space(st, len + 1 /* the separator char */))
 return MY_XML_ERROR;

 if (st->attr.end > st->attr.start)
 {
 st->attr.end[0]= '/';
 st->attr.end++;
 }
 memcpy(st->attr.end, str, len);
 st->attr.end+= len;
 st->attr.end[0]= '0円';
 if (st->flags & MY_XML_FLAG_RELATIVE_NAMES)
 return st->enter ? st->enter(st, str, len) : MY_XML_OK;
 else
 return st->enter ?
 st->enter(st, st->attr.start, st->attr.end - st->attr.start) : MY_XML_OK;
}


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


static int my_xml_leave(MY_XML_PARSER *p, const char *str, size_t slen)
{
 char *e;
 size_t glen;
 char s[32];
 char g[32];
 int rc;

 /* Find previous '/' or beginning */
 for (e= p->attr.end; (e > p->attr.start) && (e[0] != '/') ; e--);
 glen= (size_t) ((e[0] == '/') ? (p->attr.end - e - 1) : p->attr.end - e);
 
 if (str && (slen != glen))
 {
 mstr(s,str,sizeof(s)-1,slen);
 if (glen)
 {
 mstr(g,e+1,sizeof(g)-1,glen),
 sprintf(p->errstr,"'</%s>' unexpected ('</%s>' wanted)",s,g);
 }
 else
 sprintf(p->errstr,"'</%s>' unexpected (END-OF-INPUT wanted)", s);
 return MY_XML_ERROR;
 }
 
 if (p->flags & MY_XML_FLAG_RELATIVE_NAMES)
 rc= p->leave_xml ? p->leave_xml(p, str, slen) : MY_XML_OK;
 else
 rc= (p->leave_xml ? 
 p->leave_xml(p, p->attr.start, p->attr.end - p->attr.start) :
 MY_XML_OK);
 
 *e='0円';
 p->attr.end= e;
 
 return rc;
}


int my_xml_parse(MY_XML_PARSER *p,const char *str, size_t len)
{

 my_xml_attr_rewind(p);

 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;
 
 if (lex == MY_XML_CDATA)
 {
 a.beg+= 9;
 a.end-= 3;
 my_xml_value(p, a.beg, (size_t) (a.end-a.beg));
 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,"%s unexpected (ident wanted)",lex2str(lex));
 return MY_XML_ERROR;
 }
 if (MY_XML_OK != my_xml_leave(p,a.beg,(size_t) (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)
 {
 p->current_node_type= MY_XML_NODE_TAG;
 if (MY_XML_OK != my_xml_enter(p,a.beg,(size_t) (a.end-a.beg)))
 return MY_XML_ERROR;
 }
 else
 {
 sprintf(p->errstr,"%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 && exclam)))
 {
 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) )
 {
 p->current_node_type= MY_XML_NODE_ATTR;
 if ((MY_XML_OK != my_xml_enter(p,a.beg,(size_t) (a.end-a.beg))) ||
 (MY_XML_OK != my_xml_value(p,b.beg,(size_t) (b.end-b.beg))) ||
 (MY_XML_OK != my_xml_leave(p,a.beg,(size_t) (a.end-a.beg))))
 return MY_XML_ERROR;
 }
 else
 {
 sprintf(p->errstr,"%s unexpected (ident or string wanted)",
		 lex2str(lex));
 return MY_XML_ERROR;
 }
 }
 else if (MY_XML_IDENT == lex)
 {
 p->current_node_type= MY_XML_NODE_ATTR;
 if ((MY_XML_OK != my_xml_enter(p,a.beg,(size_t) (a.end-a.beg))) ||
 (MY_XML_OK != my_xml_leave(p,a.beg,(size_t) (a.end-a.beg))))
 return MY_XML_ERROR;
 }
 else if ((MY_XML_STRING == lex) && exclam)
 {
 /*
 We are in <!DOCTYPE>, e.g.
 <!DOCTYPE name SYSTEM "SystemLiteral">
 <!DOCTYPE name PUBLIC "PublidLiteral" "SystemLiteral">
 Just skip "SystemLiteral" and "PublicidLiteral"
 */
 }
 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,"%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,"%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;
 
 if (!(p->flags & MY_XML_FLAG_SKIP_TEXT_NORMALIZATION))
 my_xml_norm_text(&a);
 if (a.beg != a.end)
 {
 my_xml_value(p,a.beg,(size_t) (a.end-a.beg));
 }
 }
 }

 if (p->attr.start[0])
 {
 sprintf(p->errstr,"unexpected END-OF-INPUT");
 return MY_XML_ERROR;
 }
 return MY_XML_OK;
}


void my_xml_parser_create(MY_XML_PARSER *p)
{
 memset(p, 0, sizeof(p[0]));
 /*
 Use static buffer while it's sufficient.
 */
 p->attr.start= p->attr.end= p->attr.static_buffer;
 p->attr.buffer_size= sizeof(p->attr.static_buffer);
}


void my_xml_parser_free(MY_XML_PARSER *p)
{
 if (p->attr.buffer)
 {
 my_str_free(p->attr.buffer);
 p->attr.buffer= NULL;
 }
}


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

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


void my_xml_set_leave_handler(MY_XML_PARSER *p,
			 int (*action)(MY_XML_PARSER *p, const char *s,
					 size_t 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;
}


size_t 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 (size_t) (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;
}