/*====================================================================*
 *
 *   xmlscan.c - markup scanner;
 *
 *   node.h
 *
 *   scan XML source and create a parse tree;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

#ifndef XMLSCAN_SOURCE
#define XMLSCAN_SOURCE

/*====================================================================*
 *  system header files;
 *--------------------------------------------------------------------*/

#include <string.h>
#include <ctype.h>

/*====================================================================*
 *  custom header files;
 *--------------------------------------------------------------------*/

#include "../nodes/node.h"
#include "../tools/number.h"
#include "../tools/error.h"

/*====================================================================*
 *
 *   char * advance (char * string, unsigned * line);
 *
 *   discard whitespace and count newlines up to the next meaningful
 *   character; 
 *
 *   this function is critical to the XML parsing engine because it
 *   ensures that node strings are NUL terminated and line counts
 *   are accurate;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * advance (char * string, unsigned * lineno) 

{ 
	while (isspace ((unsigned char)* string)) 
	{ 
		if (* string == '\n') 
		{ 
			(* lineno)++; 
		} 
		* string++ = (char) (0); 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   char * discard (char * string, unsigned * line);
 *
 *   discard current character; advance to next character;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * discard (char * string, unsigned * lineno) 

{ 
	* string++ = (char) (0); 
	string = advance (string, lineno); 
	return (string); 
} 

/*====================================================================*
 *
 *   char * nmtoken (char * string);
 *
 *   collect nmtoken as per w3c xml 1.0 specification;
 *   
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * nmtoken (char * string) 

{ 
	while (isalnum ((unsigned char)* string) || (* string == '-') || (* string == '_') || (* string == '.') || (* string == ':'))
	{ 
		string++; 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   char * content (char * string, char quote, unsigned * line);
 *
 *   collect literal string; discard quotes; preserve whitespace; 
 *   count newlines;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * content (char * string, char quote, unsigned * lineno) 

{ 
	if (* string == quote) 
	{ 
		* string++ = (char) (0); 
	} 
	while (* string) 
	{ 
		if (* string == quote) 
		{ 
			break; 
		} 
		if (* string++ == '\n') 
		{ 
			(* lineno)++; 
		} 
	} 
	if (* string == quote) 
	{ 
		* string++ = (char) (0); 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   char * collect (char * string);
 *
 *   collect entity; an entity consists of non-blank characters 
 *   excluding common tag punctuation;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * collect (char * string) 

{ 
	while (* string) 
	{ 
		if (* string == '<') 
		{ 
			break; 
		} 
		if (* string == '=') 
		{ 
			break; 
		} 
		if (* string == '/') 
		{ 
			break; 
		} 
		if (* string == '?') 
		{ 
			break; 
		} 
		if (* string == '>') 
		{ 
			break; 
		} 
		if (isspace ((unsigned char)* string)) 
		{ 
			break; 
		} 
		string++; 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   static char * comment (char * string, unsigned * line);
 *
 *   collect comment; 
 *   preserve delimiters;
 *   preserve whitespace; 
 *   count newlines;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * comment (char * string, unsigned * lineno) 

{ 
	string++; 
	if (* string == '-') 
	{ 
		while (* string == '-') 
		{ 
			string++; 
		} 
		while ((* string) && (* string != '-')) 
		{ 
			while ((* string) && (* string != '-')) 
			{ 
				if (* string == '\n') 
				{ 
					(* lineno)++; 
				} 
				string++; 
			} 
			string++; 
		} 
		while (* string == '-') 
		{ 
			string++; 
		} 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   char * literal (char * string, char quote, unsigned * line);
 *
 *   collect literal; 
 *   preserve delimiters; 
 *   preserve whitespace; 
 *   count newlines;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * literal (char * string, char quote, unsigned * lineno) 

{ 
	if (* string == quote) 
	{ 
		* string++ = (char) (0); 
	} 
	while (* string) 
	{ 
		if (* string == quote) 
		{ 
			break; 
		} 
		if (* string == '\n') 
		{ 
			(* lineno)++; 
		} 
		string++; 
	} 
	if (* string == quote) 
	{ 
		* string++ = (char) (0); 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   char * context (char * string, signed c, unsigned *line);
 *
 *   collect context; 
 *   preserve delimiters;
 *   preserve whitespace; 
 *   count newlines;
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

static char * context (char * string, signed c, unsigned * lineno) 

{ 
	string++; 
	while (* string) 
	{ 
		if (* string == (char) (c)) 
		{ 
			string++; 
			break; 
		} 
		if (* string == '{') 
		{ 
			string = context (string, '}', lineno); 
			continue; 
		} 
		if (* string == '(') 
		{ 
			string = context (string, ')', lineno); 
			continue; 
		} 
		if (* string == '[') 
		{ 
			string = context (string, ']', lineno); 
			continue; 
		} 
		if ((* string == '\"') || (* string == '\'')) 
		{ 
			string = literal (string, * string, lineno); 
			continue; 
		} 
		if (* string == '\n') 
		{ 
			(* lineno)++; 
		} 
		string++; 
	} 
	return (string); 
} 

/*====================================================================*
 *
 *   void xmlscan (NODE * node);
 *
 *   node.h
 *
 *   Motley Tools by Charles Maier <cmaier@cmassoc.net>;
 *   Copyright (c) 2001-2006 by Charles Maier Associates;
 *   Licensed under the Internet Software Consortium License;
 *
 *--------------------------------------------------------------------*/

signed xmlscan (NODE * node) 

{ 
	NODE * section = node; 
	NODE * element; 
	NODE * attribute; 
	NODE * value; 
	char prefix = (char) (0); 
	char suffix = (char) (0); 
	char * string = node->text; 
	unsigned lineno = 1; 
	if (! section) 
	{ 
		error (1, EFAULT, "section is null"); 
	} 
	if (! string) 
	{ 
		error (1, EFAULT, "string is null"); 
	} 
	while (* string) 
	{ 
		if (* string == '<') 
		{ 
			prefix = '<'; 
			suffix = '>'; 
			string = discard (string, & lineno); 
			if ((* string == '/') || (* string == '?') || (* string == '!')) 
			{ 
				prefix = * string; 
				string = discard (string, & lineno); 
			} 
			element = xmlnode (section); 
			element->line = lineno; 
			element->type = NODE_ELEM; 
			element->text = string; 
			if (isalpha ((unsigned char)* string))  
			{ 
				string = nmtoken (string); 
			} 
			else if (* string == '-') 
			{ 
				string = comment (string, & lineno); 
			} 
			else if (* string == '[') 
			{ 
				string = context (string, ']', & lineno); 
			} 
			else 
			{ 
				string = collect (string); 
			} 
			string = advance (string, & lineno); 
			while ((* string) && (* string != '<') && (* string != '/') && (* string != '?') && (* string != '>')) 
			{ 
				attribute = xmlnode (element); 
				attribute->line = lineno; 
				attribute->type = NODE_ATTR; 
				attribute->text = string; 
				if (isalpha (* string)) 
				{ 
					string = nmtoken (string); 
				} 
				else if (* string == '-') 
				{ 
					string = comment (string, & lineno); 
				} 
				else if (* string == '[') 
				{ 
					string = context (string, ']', & lineno); 
				} 
				else if ((* string == '\"') || (* string == '\'')) 
				{ 
					string = content (string, * string, & lineno); 
					attribute->text++; 
				} 
				else 
				{ 
					string = collect (string); 
				} 
				string = advance (string, & lineno); 
				if (* string == '=') 
				{ 
					string = discard (string, & lineno); 
					value = xmlnode (attribute); 
					value->line = lineno; 
					value->type = NODE_VALU; 
					value->text = string; 
					if ((* string == '\"') || (* string == '\'')) 
					{ 
						string = content (string, * string, & lineno); 
						value->text++; 
					} 
					else 
					{ 
						string = collect (string); 
					} 
					string = advance (string, & lineno); 
				} 
			} 
			if ((* string == '/') || (* string == '?')) 
			{ 
				suffix = * string; 
				string = discard (string, & lineno); 
			} 
		} 
		else if (* string == '>') 
		{ 
			string = discard (string, & lineno); 
			if (prefix == '!') 
			{ 
				element->type = NODE_SGML; 
			} 
			else if (prefix == '?') 
			{ 
				element->type = NODE_INST; 
			} 
			else if (suffix == '?') 
			{ 
			} 
			else if (prefix == '/') 
			{ 
				element->type = NODE_ETAG; 
				if (element->below) 
				{ 
					error (1, 0, "Element </%s> on line %d has attributes or content.", element->text, element->line); 
				} 
				if (strcmp (section->text, element->text)) 
				{ 
					error (1, 0, "Element <%s> on line %d teminated by </%s> on line %d", section->text, section->line, element->text, element->line); 
				} 
				if (section->above) 
				{ 
					section = section->above; 
				} 
			} 
			else if (suffix == '/') 
			{ 
			} 
			else 
			{ 
				section = element; 
			} 
		} 
		else 
		{ 
			signed space = 0; 
			char * output = string; 
			NODE * segment = xmlnode (section); 
			segment->line = lineno; 
			segment->type = NODE_DATA; 
			segment->text = string; 
			while (* string) 
			{ 
				if (* string == '<') 
				{ 
					break; 
				} 
				if (isspace ((unsigned char)* string)) 
				{ 
					string = advance (string, & lineno); 
					space++; 
					continue; 
				} 
				if (space) 
				{ 
					* output++ = ' '; 
					space--; 
				} 
				* output++ = * string++; 
			} 
			if (output < string) 
			{ 
				* output = (char) (0); 
			} 
		} 
	} 
	return (0); 
} 

#endif