/*****************************************************************/
/* Substitution maps to replace some unicode characters with     */
/* multicharacter sequences                                      */
/*                                                               */
/* This file is part of catdoc project                           */
/* (c) Victor Wagner 1998-2003, (c) Alex Ott 2003	             */
/*****************************************************************/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include "catdoc.h"
SUBSTMAP spec_chars, replacements;
char *map_path=CHARSETPATH;
void map_insert(SUBSTMAP map, int uc, const char *s) ;
int longest_sequence=6;/* six is longest character sequence which can be
						  generated by catdoc internally*/

/******************************************************************/
/* checks for terminator of character sequence. If stop is something
 * like quote - check for same char. If it is \n, check for any space
 ********************************************************************/ 
int isstop(char  c, char stop) {
	if (stop=='\n') {
		return isspace(c);
	} else {
		return c==stop;
	}
}
/************************************************************************/
/* Reads substitution map file.                                         */
/************************************************************************/
SUBSTMAP read_substmap(char* filename) {
	FILE *f;
	SUBSTMAP map=calloc(sizeof(char **),256);
	char *path, line[1024], *p, *q;
	char s[256];
	char stopchar;
	int escaped, lineno=0, i;
	unsigned int uc;
	path=find_file(filename,add_exe_path(map_path));
	if (!path) {
		free(map);
		return(NULL);
	}   
	if (!map) {
		fprintf(stderr,"Insufficient memory\n");
		exit(1);
	}
	f=fopen(path,"rb");
	if (!f) {
		perror("catdoc");
		return NULL;
	}
	if (input_buffer)
		setvbuf(f,input_buffer,_IOFBF,FILE_BUFFER);

	while (!feof(f)) {
		if (!fgets(line,1024,f)) continue;
		lineno++;
		/* parse line */

		/* skip leading space */
		for(p=line;*p && isspace(*p);p++);
		/* if #, it is comment */
		if (!*p ||
#ifdef  __MSDOS__
				*p==0x1A || /* DOS have strange habit of using ^Z as eof */
#endif
				*p=='#') continue;
		/* read hexadecimal code */
		uc = strtol(p,&p,16);
		if (!isspace(*p)|| uc<0 || uc>0xfffd) {
			fprintf(stderr,"Error parsing %s(%d)\n",path,lineno);
			continue;
		}
		/* skip space between  code and sequence */
		for(;*p && isspace(*p);p++);
		if (!p) continue;
		switch (*p) {
			case '\'':
			case '"':
				stopchar=*p;
				break;
			case '(':
				stopchar=')';
				break;
			case '[':
				stopchar=']';
				break;
			case '{':
				stopchar='}';
				break;
			default:
				p--;
				stopchar='\n';
		}
		p++;
		q=p;
		escaped=0;
		while (*q && (!isstop(*q,stopchar) || escaped)) {
			if (escaped) {
				escaped=0;
			} else {
				escaped= (*q=='\\');
			}
			q++;
		}
		if (*q!=stopchar && !(isspace(*q) && stopchar=='\n')) {
			fprintf(stderr,"Error parsing %s(%d): unterminated sequence\n",
					path,lineno);
			continue;
		}
		/* HERE SHOULD BE BACKSLASH ESCAPE PROCESSING !!!*/
		*q=0;
		for (q=s,i=0;*p && i<256;q++,i++) {
			if (*p!='\\') {
				*q=*p++;
			} else {
				switch (*(++p)) {
					case 'n': *q='\n'; break;
					case 'r': *q='\r'; break;
					case 't': *q='\t'; break;
					case 'b': *q='\b'; break;
							  case '\"': *q='\"'; break;
					case '\'': *q='\''; break;
					case '0': *q=strtol(p,&p,8); p--; break;
					case '\\':
					default:
							  *q=*p;
				}
				p++;
			}
		}
		*q=0;
		if (i>longest_sequence)
			longest_sequence=i;
		map_insert(map,uc,s);
	}
	fclose(f);
	free(path);
	return map;
}

/*************************************************************************/
/* searches for string in the substituton map. Returns NULL if not found */
/*************************************************************************/
char * map_subst ( SUBSTMAP map, int uc) {
	char **p=map[(unsigned)uc >>8];
	if (!p) return NULL;
	return p[uc & 0xff];
}

/*************************************************************************/
/*  inserts string + unicode code into map                               */
/*************************************************************************/
void map_insert(SUBSTMAP map, int uc, const char *s) {
	SUBSTMAP p=map+((unsigned)uc>>8);

	if (!*p) {
		*p= calloc(sizeof(char*),256);
		if (!*p) { 
			fprintf(stderr,"Insufficient memory\n");
			exit(1);
		}
	}
	(*p)[uc & 0xff] = strdup(s);
}