/***************************************************************************
                       code39.cpp  -  description
                           -------------------
  begin                : Mie Jun 18 2003
  copyright            : (C) 2003 by InfoSiAL, S.L.
  email                : mail@infosial.com
***************************************************************************/ 
/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

/*
 * code39.c -- encoding for code39
 *
 * Copyright (c) 1999 Alessandro Rubini (rubini@gnu.org)
 * Copyright (c) 1999 Prosa Srl. (prosa@prosa.it)
 *
 *   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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "barcode.h"


/* this is ordered in decades to simplify encoding */
static char alphabet[] =
    "1234567890" "ABCDEFGHIJ" "KLMNOPQRST" "UVWXYZ-. *" "$/+%";

/* the checksum alphabet has a different order */
static char checkbet[] =
    "0123456789" "ABCDEFGHIJ" "KLMNOPQRST" "UVWXYZ-. $" "/+%";

/* The first 40 symbols repeat this bar pattern */
static char *bars[] = {
                          "31113", "13113", "33111", "11313", "31311",
                          "13311", "11133", "31131", "13131", "11331"
                      };

/* The first 4 decades use these space patterns */
static char *spaces[] = { "1311", "1131", "1113", "3111" };

/* the last four symbols are special */
static char *specialbars[] = {
                                 "11111", "11111", "11111", "11111"
                             };

static char *specialspaces[] = {
                                   "3331", "3313", "3133", "1333"
                               };

static char *fillers[] = {
                             "0a3a1c1c1a",
                             "1a3a1c1c1a"
                         };


/*
 * Check that the text can be encoded. Returns 0 or -1.
 * If it's all lowecase convert to uppercase and accept it
 */
int Barcode_39_verify( char *text ) {
	int i, lower = 0, upper = 0;

	if ( text[ 0 ] == '\0' )
		return -1;
	for ( i = 0; text[ i ]; i++ ) {
		if ( isupper( text[ i ] ) )
			upper++;
		if ( islower( text[ i ] ) )
			lower++;
		if ( !strchr( alphabet, toupper( text[ i ] ) ) )
			return -1;
	}
	if ( lower && upper )
		return -1;
	return 0;
}

static int add_one( char *ptr, int code ) {
	char * b, *s;

	if ( code < 40 ) {
		b = bars[ code % 10 ];
		s = spaces[ code / 10 ];
	} else {
		b = specialbars[ code - 40 ];
		s = specialspaces[ code - 40 ];
	}
	sprintf( ptr, "1%c%c%c%c%c%c%c%c%c",  	/* separator */
	         b[ 0 ], s[ 0 ], b[ 1 ], s[ 1 ], b[ 2 ], s[ 2 ], b[ 3 ], s[ 3 ], b[ 4 ] );
	return 0;
}

/*
 * The encoding functions fills the "partial" and "textinfo" fields.
 * Lowercase chars are converted to uppercase
 */
int Barcode_39_encode( struct Barcode_Item *bc ) {
	static char *text;
	static char *partial;				/* dynamic */
	static char *textinfo;			/* dynamic */
	char *c, *ptr, *textptr;
	int i, code, textpos, checksum = 0;

	if ( bc->partial )
		free( bc->partial );
	if ( bc->textinfo )
		free( bc->textinfo );
	bc->partial = bc->textinfo = NULL;	/* safe */

	if ( !bc->encoding )
		bc->encoding = strdup( "code 39" );

	text = bc->ascii;
	if ( !text ) {
		bc->error = EINVAL;
		return -1;
	}
	/* the partial code is 10* (head + text + check + tail) + margin + term. */
	partial = ( char * ) malloc( ( strlen( text ) + 3 ) * 10 + 2 );
	if ( !partial ) {
		bc->error = errno;
		return -1;
	}

	/* the text information is at most "nnn:fff:c " * strlen +term */
	textinfo = ( char * ) malloc( 10 * strlen( text ) + 2 );
	if ( !textinfo ) {
		bc->error = errno;
		free( partial );
		return -1;
	}

	strcpy( partial, fillers[ 0 ] );
	ptr = partial + strlen( partial );
	textptr = textinfo;
	textpos = 22;

	for ( i = 0; text[ i ]; i++ ) {
		c = strchr( alphabet, toupper( text[ i ] ) );
		if ( !c ) {
			bc->error = EINVAL;	/* impossible if text is verified */
			free( partial );
			free( textinfo );
			return -1;
		}
		code = c - alphabet;
		add_one( ptr, code );
		c = strchr( checkbet, *c );
		if ( c )  									/* the '*' is not there */
			checksum += ( c - checkbet );
		sprintf( textptr, "%i:12:%c ", textpos, toupper( text[ i ] ) );

		textpos += 16;					/* width of each code */
		textptr += strlen( textptr );
		ptr += strlen( ptr );
	}
	/* Add the checksum */
	if ( ( bc->flags & BARCODE_NO_CHECKSUM ) == 0 ) {
		code = ( strchr( alphabet, checkbet[ checksum % 43 ] ) - alphabet );
		add_one( ptr, code );
	}
	strcat( ptr, fillers[ 1 ] );		/* end */
	bc->partial = partial;
	bc->textinfo = textinfo;

	return 0;
}