/***************************************************************************
                       plessey.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.                                   *
 *                                                                         *
 ***************************************************************************/

/*
 * plessey.c -- encoding for Plessey
 *
 * Copyright (c) 2000 Leonid A. Broukhis (leob@mailcom.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.
 *
 *   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"

static char *patterns[] = { "13", "31" };

/* this is ordered in decades to simplify encoding */
static char alphabet[] = "0123456789" "ABCDEF";

/* stop sequence may be 231311313 (barcodemill.com) */
static char *fillers[] = { "031311331", "331311313" };

static int width = 16, startpos = 16;

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

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

static int add_one( char *ptr, int code ) {
	sprintf( ptr, "%s%s%s%s",
	         patterns[ code & 1 ],
	         patterns[ ( code >> 1 ) & 1 ],
	         patterns[ ( code >> 2 ) & 1 ], patterns[ ( code >> 3 ) & 1 ]
	       );
	return 0;
}

/*
 * The encoding functions fills the "partial" and "textinfo" fields.
 * Lowercase chars are converted to uppercase
 */
int Barcode_pls_encode( struct Barcode_Item *bc ) {
	static char *text;
	static char *partial;				/* dynamic */
	static char *textinfo;			/* dynamic */
	char *c, *ptr, *textptr;
	char *checkptr;
	int i, code, textpos;
	static char check[ 9 ] = { 1, 1, 1, 1, 0, 1, 0, 0, 1 };
	if ( bc->partial )
		free( bc->partial );
	if ( bc->textinfo )
		free( bc->textinfo );
	bc->partial = bc->textinfo = NULL;	/* safe */

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

	text = bc->ascii;
	if ( !text ) {
		bc->error = EINVAL;
		return -1;
	}
	/* the partial code is 8 * (head + text + check + tail) + margin + term. */
	partial = ( char * ) malloc( ( strlen( text ) + 4 ) * 8 + 3 );
	checkptr = ( char * ) calloc( 1, strlen( text ) * 4 + 8 );

	if ( !partial || !checkptr ) {
		if ( partial )
			free( partial );
		if ( checkptr )
			free( checkptr );
		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 = startpos;

	for ( i = 0; i < strlen( text ); 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 );
		sprintf( textptr, "%i:12:%c ", textpos, toupper( text[ i ] ) );

		textpos += width;				/* width of each code */
		textptr += strlen( textptr );
		ptr += strlen( ptr );
		checkptr[ 4 * i ] = code & 1;
		checkptr[ 4 * i + 1 ] = ( code >> 1 ) & 1;
		checkptr[ 4 * i + 2 ] = ( code >> 2 ) & 1;
		checkptr[ 4 * i + 3 ] = ( code >> 3 ) & 1;
	}
	/* The CRC checksum is required */
	for ( i = 0; i < 4 * strlen( text ); i++ ) {
		int j;
		if ( checkptr[ i ] )
			for ( j = 0; j < 9; j++ )
				checkptr[ i + j ] ^= check[ j ];
	}
	for ( i = 0; i < 8; i++ ) {
		sprintf( ptr, patterns[ checkptr[ strlen( text ) * 4 + i ] ] );
		ptr += 2;
	}
	fprintf( stderr, "CRC: " );
	for ( i = 0; i < 8; i++ ) {
		fputc( '0' + checkptr[ strlen( text ) * 4 + i ], stderr );
	}
	fputc( '\n', stderr );
	strcpy( ptr, fillers[ 1 ] );
	bc->partial = partial;
	bc->textinfo = textinfo;

	return 0;
}