<?php

/**
 * General PHP Barcode Generator
 *
 * @author Casper Bakker - picqer.com
 * Based on TCPDF Barcode Generator
 */

// Copyright (C) 2002-2015 Nicola Asuni - Tecnick.com LTD
//
// This file is part of TCPDF software library.
//
// TCPDF is free software: you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// TCPDF 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 Lesser General Public License for more details.
//
// You should have received a copy of the License
// along with TCPDF. If not, see
// <http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT>.
//
// See LICENSE.TXT file for more information.

namespace Picqer\Barcode;

use Picqer\Barcode\Exceptions\BarcodeException;
use Picqer\Barcode\Exceptions\InvalidCharacterException;
use Picqer\Barcode\Exceptions\InvalidCheckDigitException;
use Picqer\Barcode\Exceptions\InvalidFormatException;
use Picqer\Barcode\Exceptions\InvalidLengthException;
use Picqer\Barcode\Exceptions\UnknownTypeException;

abstract class BarcodeGenerator
{
    const TYPE_CODE_39 = 'C39';
    const TYPE_CODE_39_CHECKSUM = 'C39+';
    const TYPE_CODE_39E = 'C39E';
    const TYPE_CODE_39E_CHECKSUM = 'C39E+';
    const TYPE_CODE_93 = 'C93';
    const TYPE_STANDARD_2_5 = 'S25';
    const TYPE_STANDARD_2_5_CHECKSUM = 'S25+';
    const TYPE_INTERLEAVED_2_5 = 'I25';
    const TYPE_INTERLEAVED_2_5_CHECKSUM = 'I25+';
    const TYPE_CODE_128 = 'C128';
    const TYPE_CODE_128_A = 'C128A';
    const TYPE_CODE_128_B = 'C128B';
    const TYPE_CODE_128_C = 'C128C';
    const TYPE_EAN_2 = 'EAN2';
    const TYPE_EAN_5 = 'EAN5';
    const TYPE_EAN_8 = 'EAN8';
    const TYPE_EAN_13 = 'EAN13';
    const TYPE_UPC_A = 'UPCA';
    const TYPE_UPC_E = 'UPCE';
    const TYPE_MSI = 'MSI';
    const TYPE_MSI_CHECKSUM = 'MSI+';
    const TYPE_POSTNET = 'POSTNET';
    const TYPE_PLANET = 'PLANET';
    const TYPE_RMS4CC = 'RMS4CC';
    const TYPE_KIX = 'KIX';
    const TYPE_IMB = 'IMB';
    const TYPE_CODABAR = 'CODABAR';
    const TYPE_CODE_11 = 'CODE11';
    const TYPE_PHARMA_CODE = 'PHARMA';
    const TYPE_PHARMA_CODE_TWO_TRACKS = 'PHARMA2T';

    /**
     * Get the barcode data
     *
     * @param string $code code to print
     * @param string $type type of barcode
     * @return array barcode array
     * @public
     */
    protected function getBarcodeData($code, $type)
    {
        switch (strtoupper($type)) {
            case self::TYPE_CODE_39: { // CODE 39 - ANSI MH10.8M-1983 - USD-3 - 3 of 9.
                $arrcode = $this->barcode_code39($code, false, false);
                break;
            }
            case self::TYPE_CODE_39_CHECKSUM: { // CODE 39 with checksum
                $arrcode = $this->barcode_code39($code, false, true);
                break;
            }
            case self::TYPE_CODE_39E: { // CODE 39 EXTENDED
                $arrcode = $this->barcode_code39($code, true, false);
                break;
            }
            case self::TYPE_CODE_39E_CHECKSUM: { // CODE 39 EXTENDED + CHECKSUM
                $arrcode = $this->barcode_code39($code, true, true);
                break;
            }
            case self::TYPE_CODE_93: { // CODE 93 - USS-93
                $arrcode = $this->barcode_code93($code);
                break;
            }
            case self::TYPE_STANDARD_2_5: { // Standard 2 of 5
                $arrcode = $this->barcode_s25($code, false);
                break;
            }
            case self::TYPE_STANDARD_2_5_CHECKSUM: { // Standard 2 of 5 + CHECKSUM
                $arrcode = $this->barcode_s25($code, true);
                break;
            }
            case self::TYPE_INTERLEAVED_2_5: { // Interleaved 2 of 5
                $arrcode = $this->barcode_i25($code, false);
                break;
            }
            case self::TYPE_INTERLEAVED_2_5_CHECKSUM: { // Interleaved 2 of 5 + CHECKSUM
                $arrcode = $this->barcode_i25($code, true);
                break;
            }
            case self::TYPE_CODE_128: { // CODE 128
                $arrcode = $this->barcode_c128($code, '');
                break;
            }
            case self::TYPE_CODE_128_A: { // CODE 128 A
                $arrcode = $this->barcode_c128($code, 'A');
                break;
            }
            case self::TYPE_CODE_128_B: { // CODE 128 B
                $arrcode = $this->barcode_c128($code, 'B');
                break;
            }
            case self::TYPE_CODE_128_C: { // CODE 128 C
                $arrcode = $this->barcode_c128($code, 'C');
                break;
            }
            case self::TYPE_EAN_2: { // 2-Digits UPC-Based Extention
                $arrcode = $this->barcode_eanext($code, 2);
                break;
            }
            case self::TYPE_EAN_5: { // 5-Digits UPC-Based Extention
                $arrcode = $this->barcode_eanext($code, 5);
                break;
            }
            case self::TYPE_EAN_8: { // EAN 8
                $arrcode = $this->barcode_eanupc($code, 8);
                break;
            }
            case self::TYPE_EAN_13: { // EAN 13
                $arrcode = $this->barcode_eanupc($code, 13);
                break;
            }
            case self::TYPE_UPC_A: { // UPC-A
                $arrcode = $this->barcode_eanupc($code, 12);
                break;
            }
            case self::TYPE_UPC_E: { // UPC-E
                $arrcode = $this->barcode_eanupc($code, 6);
                break;
            }
            case self::TYPE_MSI: { // MSI (Variation of Plessey code)
                $arrcode = $this->barcode_msi($code, false);
                break;
            }
            case self::TYPE_MSI_CHECKSUM: { // MSI + CHECKSUM (modulo 11)
                $arrcode = $this->barcode_msi($code, true);
                break;
            }
            case self::TYPE_POSTNET: { // POSTNET
                $arrcode = $this->barcode_postnet($code, false);
                break;
            }
            case self::TYPE_PLANET: { // PLANET
                $arrcode = $this->barcode_postnet($code, true);
                break;
            }
            case self::TYPE_RMS4CC: { // RMS4CC (Royal Mail 4-state Customer Code) - CBC (Customer Bar Code)
                $arrcode = $this->barcode_rms4cc($code, false);
                break;
            }
            case self::TYPE_KIX: { // KIX (Klant index - Customer index)
                $arrcode = $this->barcode_rms4cc($code, true);
                break;
            }
            case self::TYPE_IMB: { // IMB - Intelligent Mail Barcode - Onecode - USPS-B-3200
                $arrcode = $this->barcode_imb($code);
                break;
            }
            case self::TYPE_CODABAR: { // CODABAR
                $arrcode = $this->barcode_codabar($code);
                break;
            }
            case self::TYPE_CODE_11: { // CODE 11
                $arrcode = $this->barcode_code11($code);
                break;
            }
            case self::TYPE_PHARMA_CODE: { // PHARMACODE
                $arrcode = $this->barcode_pharmacode($code);
                break;
            }
            case self::TYPE_PHARMA_CODE_TWO_TRACKS: { // PHARMACODE TWO-TRACKS
                $arrcode = $this->barcode_pharmacode2t($code);
                break;
            }
            default: {
                throw new UnknownTypeException();
                break;
            }
        }

        if ( ! isset($arrcode['maxWidth'])) {
            $arrcode = $this->convertBarcodeArrayToNewStyle($arrcode);
        }

        return $arrcode;
    }

    /**
     * CODE 39 - ANSI MH10.8M-1983 - USD-3 - 3 of 9.
     * General-purpose code in very wide use world-wide
     *
     * @param $code (string) code to represent.
     * @param $extended (boolean) if true uses the extended mode.
     * @param $checksum (boolean) if true add a checksum to the code.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_code39($code, $extended = false, $checksum = false)
    {
        $chr = [];
        $chr['0'] = '111331311';
        $chr['1'] = '311311113';
        $chr['2'] = '113311113';
        $chr['3'] = '313311111';
        $chr['4'] = '111331113';
        $chr['5'] = '311331111';
        $chr['6'] = '113331111';
        $chr['7'] = '111311313';
        $chr['8'] = '311311311';
        $chr['9'] = '113311311';
        $chr['A'] = '311113113';
        $chr['B'] = '113113113';
        $chr['C'] = '313113111';
        $chr['D'] = '111133113';
        $chr['E'] = '311133111';
        $chr['F'] = '113133111';
        $chr['G'] = '111113313';
        $chr['H'] = '311113311';
        $chr['I'] = '113113311';
        $chr['J'] = '111133311';
        $chr['K'] = '311111133';
        $chr['L'] = '113111133';
        $chr['M'] = '313111131';
        $chr['N'] = '111131133';
        $chr['O'] = '311131131';
        $chr['P'] = '113131131';
        $chr['Q'] = '111111333';
        $chr['R'] = '311111331';
        $chr['S'] = '113111331';
        $chr['T'] = '111131331';
        $chr['U'] = '331111113';
        $chr['V'] = '133111113';
        $chr['W'] = '333111111';
        $chr['X'] = '131131113';
        $chr['Y'] = '331131111';
        $chr['Z'] = '133131111';
        $chr['-'] = '131111313';
        $chr['.'] = '331111311';
        $chr[' '] = '133111311';
        $chr['$'] = '131313111';
        $chr['/'] = '131311131';
        $chr['+'] = '131113131';
        $chr['%'] = '111313131';
        $chr['*'] = '131131311';

        $code = strtoupper($code);

        if ($extended) {
            // extended mode
            $code = $this->encode_code39_ext($code);
        }

        if ($checksum) {
            // checksum
            $code .= $this->checksum_code39($code);
        }

        // add start and stop codes
        $code = '*' . $code . '*';

        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        $k = 0;
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            $char = $code[$i];
            if ( ! isset($chr[$char])) {
                throw new InvalidCharacterException('Char ' . $char . ' is unsupported');
            }
            for ($j = 0; $j < 9; ++$j) {
                if (($j % 2) == 0) {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $w = $chr[$char][$j];
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
            }
            // intercharacter gap
            $bararray['bcode'][$k] = array('t' => false, 'w' => 1, 'h' => 1, 'p' => 0);
            $bararray['maxw'] += 1;
            ++$k;
        }

        return $bararray;
    }

    /**
     * Encode a string to be used for CODE 39 Extended mode.
     *
     * @param string $code code to represent.
     * @return bool|string encoded string.
     * @protected
     */
    protected function encode_code39_ext($code)
    {
        $encode = array(
            chr(0)   => '%U',
            chr(1)   => '$A',
            chr(2)   => '$B',
            chr(3)   => '$C',
            chr(4)   => '$D',
            chr(5)   => '$E',
            chr(6)   => '$F',
            chr(7)   => '$G',
            chr(8)   => '$H',
            chr(9)   => '$I',
            chr(10)  => '$J',
            chr(11)  => '£K',
            chr(12)  => '$L',
            chr(13)  => '$M',
            chr(14)  => '$N',
            chr(15)  => '$O',
            chr(16)  => '$P',
            chr(17)  => '$Q',
            chr(18)  => '$R',
            chr(19)  => '$S',
            chr(20)  => '$T',
            chr(21)  => '$U',
            chr(22)  => '$V',
            chr(23)  => '$W',
            chr(24)  => '$X',
            chr(25)  => '$Y',
            chr(26)  => '$Z',
            chr(27)  => '%A',
            chr(28)  => '%B',
            chr(29)  => '%C',
            chr(30)  => '%D',
            chr(31)  => '%E',
            chr(32)  => ' ',
            chr(33)  => '/A',
            chr(34)  => '/B',
            chr(35)  => '/C',
            chr(36)  => '/D',
            chr(37)  => '/E',
            chr(38)  => '/F',
            chr(39)  => '/G',
            chr(40)  => '/H',
            chr(41)  => '/I',
            chr(42)  => '/J',
            chr(43)  => '/K',
            chr(44)  => '/L',
            chr(45)  => '-',
            chr(46)  => '.',
            chr(47)  => '/O',
            chr(48)  => '0',
            chr(49)  => '1',
            chr(50)  => '2',
            chr(51)  => '3',
            chr(52)  => '4',
            chr(53)  => '5',
            chr(54)  => '6',
            chr(55)  => '7',
            chr(56)  => '8',
            chr(57)  => '9',
            chr(58)  => '/Z',
            chr(59)  => '%F',
            chr(60)  => '%G',
            chr(61)  => '%H',
            chr(62)  => '%I',
            chr(63)  => '%J',
            chr(64)  => '%V',
            chr(65)  => 'A',
            chr(66)  => 'B',
            chr(67)  => 'C',
            chr(68)  => 'D',
            chr(69)  => 'E',
            chr(70)  => 'F',
            chr(71)  => 'G',
            chr(72)  => 'H',
            chr(73)  => 'I',
            chr(74)  => 'J',
            chr(75)  => 'K',
            chr(76)  => 'L',
            chr(77)  => 'M',
            chr(78)  => 'N',
            chr(79)  => 'O',
            chr(80)  => 'P',
            chr(81)  => 'Q',
            chr(82)  => 'R',
            chr(83)  => 'S',
            chr(84)  => 'T',
            chr(85)  => 'U',
            chr(86)  => 'V',
            chr(87)  => 'W',
            chr(88)  => 'X',
            chr(89)  => 'Y',
            chr(90)  => 'Z',
            chr(91)  => '%K',
            chr(92)  => '%L',
            chr(93)  => '%M',
            chr(94)  => '%N',
            chr(95)  => '%O',
            chr(96)  => '%W',
            chr(97)  => '+A',
            chr(98)  => '+B',
            chr(99)  => '+C',
            chr(100) => '+D',
            chr(101) => '+E',
            chr(102) => '+F',
            chr(103) => '+G',
            chr(104) => '+H',
            chr(105) => '+I',
            chr(106) => '+J',
            chr(107) => '+K',
            chr(108) => '+L',
            chr(109) => '+M',
            chr(110) => '+N',
            chr(111) => '+O',
            chr(112) => '+P',
            chr(113) => '+Q',
            chr(114) => '+R',
            chr(115) => '+S',
            chr(116) => '+T',
            chr(117) => '+U',
            chr(118) => '+V',
            chr(119) => '+W',
            chr(120) => '+X',
            chr(121) => '+Y',
            chr(122) => '+Z',
            chr(123) => '%P',
            chr(124) => '%Q',
            chr(125) => '%R',
            chr(126) => '%S',
            chr(127) => '%T'
        );
        $code_ext = '';
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            if (ord($code[$i]) > 127) {
                throw new InvalidCharacterException('Only supports till char 127');
            }
            $code_ext .= $encode[$code[$i]];
        }

        return $code_ext;
    }

    /**
     * Calculate CODE 39 checksum (modulo 43).
     *
     * @param string $code code to represent.
     * @return string char checksum.
     * @protected
     */
    protected function checksum_code39($code)
    {
        $chars = array(
            '0',
            '1',
            '2',
            '3',
            '4',
            '5',
            '6',
            '7',
            '8',
            '9',
            'A',
            'B',
            'C',
            'D',
            'E',
            'F',
            'G',
            'H',
            'I',
            'J',
            'K',
            'L',
            'M',
            'N',
            'O',
            'P',
            'Q',
            'R',
            'S',
            'T',
            'U',
            'V',
            'W',
            'X',
            'Y',
            'Z',
            '-',
            '.',
            ' ',
            '$',
            '/',
            '+',
            '%'
        );
        $sum = 0;
        $codelength = strlen($code);
        for ($i = 0; $i < $codelength; ++$i) {
            $k = array_keys($chars, $code[$i]);
            $sum += $k[0];
        }
        $j = ($sum % 43);

        return $chars[$j];
    }

    /**
     * CODE 93 - USS-93
     * Compact code similar to Code 39
     *
     * @param $code (string) code to represent.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_code93($code)
    {
        $chr = [];
        $chr[48] = '131112'; // 0
        $chr[49] = '111213'; // 1
        $chr[50] = '111312'; // 2
        $chr[51] = '111411'; // 3
        $chr[52] = '121113'; // 4
        $chr[53] = '121212'; // 5
        $chr[54] = '121311'; // 6
        $chr[55] = '111114'; // 7
        $chr[56] = '131211'; // 8
        $chr[57] = '141111'; // 9
        $chr[65] = '211113'; // A
        $chr[66] = '211212'; // B
        $chr[67] = '211311'; // C
        $chr[68] = '221112'; // D
        $chr[69] = '221211'; // E
        $chr[70] = '231111'; // F
        $chr[71] = '112113'; // G
        $chr[72] = '112212'; // H
        $chr[73] = '112311'; // I
        $chr[74] = '122112'; // J
        $chr[75] = '132111'; // K
        $chr[76] = '111123'; // L
        $chr[77] = '111222'; // M
        $chr[78] = '111321'; // N
        $chr[79] = '121122'; // O
        $chr[80] = '131121'; // P
        $chr[81] = '212112'; // Q
        $chr[82] = '212211'; // R
        $chr[83] = '211122'; // S
        $chr[84] = '211221'; // T
        $chr[85] = '221121'; // U
        $chr[86] = '222111'; // V
        $chr[87] = '112122'; // W
        $chr[88] = '112221'; // X
        $chr[89] = '122121'; // Y
        $chr[90] = '123111'; // Z
        $chr[45] = '121131'; // -
        $chr[46] = '311112'; // .
        $chr[32] = '311211'; //
        $chr[36] = '321111'; // $
        $chr[47] = '112131'; // /
        $chr[43] = '113121'; // +
        $chr[37] = '211131'; // %
        $chr[128] = '121221'; // ($)
        $chr[129] = '311121'; // (/)
        $chr[130] = '122211'; // (+)
        $chr[131] = '312111'; // (%)
        $chr[42] = '111141'; // start-stop
        $code = strtoupper($code);
        $encode = array(
            chr(0)   => chr(131) . 'U',
            chr(1)   => chr(128) . 'A',
            chr(2)   => chr(128) . 'B',
            chr(3)   => chr(128) . 'C',
            chr(4)   => chr(128) . 'D',
            chr(5)   => chr(128) . 'E',
            chr(6)   => chr(128) . 'F',
            chr(7)   => chr(128) . 'G',
            chr(8)   => chr(128) . 'H',
            chr(9)   => chr(128) . 'I',
            chr(10)  => chr(128) . 'J',
            chr(11)  => '£K',
            chr(12)  => chr(128) . 'L',
            chr(13)  => chr(128) . 'M',
            chr(14)  => chr(128) . 'N',
            chr(15)  => chr(128) . 'O',
            chr(16)  => chr(128) . 'P',
            chr(17)  => chr(128) . 'Q',
            chr(18)  => chr(128) . 'R',
            chr(19)  => chr(128) . 'S',
            chr(20)  => chr(128) . 'T',
            chr(21)  => chr(128) . 'U',
            chr(22)  => chr(128) . 'V',
            chr(23)  => chr(128) . 'W',
            chr(24)  => chr(128) . 'X',
            chr(25)  => chr(128) . 'Y',
            chr(26)  => chr(128) . 'Z',
            chr(27)  => chr(131) . 'A',
            chr(28)  => chr(131) . 'B',
            chr(29)  => chr(131) . 'C',
            chr(30)  => chr(131) . 'D',
            chr(31)  => chr(131) . 'E',
            chr(32)  => ' ',
            chr(33)  => chr(129) . 'A',
            chr(34)  => chr(129) . 'B',
            chr(35)  => chr(129) . 'C',
            chr(36)  => chr(129) . 'D',
            chr(37)  => chr(129) . 'E',
            chr(38)  => chr(129) . 'F',
            chr(39)  => chr(129) . 'G',
            chr(40)  => chr(129) . 'H',
            chr(41)  => chr(129) . 'I',
            chr(42)  => chr(129) . 'J',
            chr(43)  => chr(129) . 'K',
            chr(44)  => chr(129) . 'L',
            chr(45)  => '-',
            chr(46)  => '.',
            chr(47)  => chr(129) . 'O',
            chr(48)  => '0',
            chr(49)  => '1',
            chr(50)  => '2',
            chr(51)  => '3',
            chr(52)  => '4',
            chr(53)  => '5',
            chr(54)  => '6',
            chr(55)  => '7',
            chr(56)  => '8',
            chr(57)  => '9',
            chr(58)  => chr(129) . 'Z',
            chr(59)  => chr(131) . 'F',
            chr(60)  => chr(131) . 'G',
            chr(61)  => chr(131) . 'H',
            chr(62)  => chr(131) . 'I',
            chr(63)  => chr(131) . 'J',
            chr(64)  => chr(131) . 'V',
            chr(65)  => 'A',
            chr(66)  => 'B',
            chr(67)  => 'C',
            chr(68)  => 'D',
            chr(69)  => 'E',
            chr(70)  => 'F',
            chr(71)  => 'G',
            chr(72)  => 'H',
            chr(73)  => 'I',
            chr(74)  => 'J',
            chr(75)  => 'K',
            chr(76)  => 'L',
            chr(77)  => 'M',
            chr(78)  => 'N',
            chr(79)  => 'O',
            chr(80)  => 'P',
            chr(81)  => 'Q',
            chr(82)  => 'R',
            chr(83)  => 'S',
            chr(84)  => 'T',
            chr(85)  => 'U',
            chr(86)  => 'V',
            chr(87)  => 'W',
            chr(88)  => 'X',
            chr(89)  => 'Y',
            chr(90)  => 'Z',
            chr(91)  => chr(131) . 'K',
            chr(92)  => chr(131) . 'L',
            chr(93)  => chr(131) . 'M',
            chr(94)  => chr(131) . 'N',
            chr(95)  => chr(131) . 'O',
            chr(96)  => chr(131) . 'W',
            chr(97)  => chr(130) . 'A',
            chr(98)  => chr(130) . 'B',
            chr(99)  => chr(130) . 'C',
            chr(100) => chr(130) . 'D',
            chr(101) => chr(130) . 'E',
            chr(102) => chr(130) . 'F',
            chr(103) => chr(130) . 'G',
            chr(104) => chr(130) . 'H',
            chr(105) => chr(130) . 'I',
            chr(106) => chr(130) . 'J',
            chr(107) => chr(130) . 'K',
            chr(108) => chr(130) . 'L',
            chr(109) => chr(130) . 'M',
            chr(110) => chr(130) . 'N',
            chr(111) => chr(130) . 'O',
            chr(112) => chr(130) . 'P',
            chr(113) => chr(130) . 'Q',
            chr(114) => chr(130) . 'R',
            chr(115) => chr(130) . 'S',
            chr(116) => chr(130) . 'T',
            chr(117) => chr(130) . 'U',
            chr(118) => chr(130) . 'V',
            chr(119) => chr(130) . 'W',
            chr(120) => chr(130) . 'X',
            chr(121) => chr(130) . 'Y',
            chr(122) => chr(130) . 'Z',
            chr(123) => chr(131) . 'P',
            chr(124) => chr(131) . 'Q',
            chr(125) => chr(131) . 'R',
            chr(126) => chr(131) . 'S',
            chr(127) => chr(131) . 'T'
        );
        $code_ext = '';
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            if (ord($code[$i]) > 127) {
                throw new InvalidCharacterException('Only supports till char 127');
            }
            $code_ext .= $encode[$code[$i]];
        }
        // checksum
        $code_ext .= $this->checksum_code93($code_ext);
        // add start and stop codes
        $code = '*' . $code_ext . '*';
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        $k = 0;
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            $char = ord($code[$i]);
            if ( ! isset($chr[$char])) {
                throw new InvalidCharacterException('Char ' . $char . ' is unsupported');
            }
            for ($j = 0; $j < 6; ++$j) {
                if (($j % 2) == 0) {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $w = $chr[$char][$j];
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
            }
        }
        $bararray['bcode'][$k] = array('t' => true, 'w' => 1, 'h' => 1, 'p' => 0);
        $bararray['maxw'] += 1;

        return $bararray;
    }

    /**
     * Calculate CODE 93 checksum (modulo 47).
     *
     * @param $code (string) code to represent.
     * @return string checksum code.
     * @protected
     */
    protected function checksum_code93($code)
    {
        $chars = array(
            '0',
            '1',
            '2',
            '3',
            '4',
            '5',
            '6',
            '7',
            '8',
            '9',
            'A',
            'B',
            'C',
            'D',
            'E',
            'F',
            'G',
            'H',
            'I',
            'J',
            'K',
            'L',
            'M',
            'N',
            'O',
            'P',
            'Q',
            'R',
            'S',
            'T',
            'U',
            'V',
            'W',
            'X',
            'Y',
            'Z',
            '-',
            '.',
            ' ',
            '$',
            '/',
            '+',
            '%',
            '<',
            '=',
            '>',
            '?'
        );
        // translate special characters
        $code = strtr($code, chr(128) . chr(131) . chr(129) . chr(130), '<=>?');
        $len = strlen($code);
        // calculate check digit C
        $p = 1;
        $check = 0;
        for ($i = ($len - 1); $i >= 0; --$i) {
            $k = array_keys($chars, $code[$i]);
            $check += ($k[0] * $p);
            ++$p;
            if ($p > 20) {
                $p = 1;
            }
        }
        $check %= 47;
        $c = $chars[$check];
        $code .= $c;
        // calculate check digit K
        $p = 1;
        $check = 0;
        for ($i = $len; $i >= 0; --$i) {
            $k = array_keys($chars, $code[$i]);
            $check += ($k[0] * $p);
            ++$p;
            if ($p > 15) {
                $p = 1;
            }
        }
        $check %= 47;
        $k = $chars[$check];
        $checksum = $c . $k;
        // resto respecial characters
        $checksum = strtr($checksum, '<=>?', chr(128) . chr(131) . chr(129) . chr(130));

        return $checksum;
    }

    /**
     * Checksum for standard 2 of 5 barcodes.
     *
     * @param $code (string) code to process.
     * @return int checksum.
     * @protected
     */
    protected function checksum_s25($code)
    {
        $len = strlen($code);
        $sum = 0;
        for ($i = 0; $i < $len; $i += 2) {
            $sum += $code[$i];
        }
        $sum *= 3;
        for ($i = 1; $i < $len; $i += 2) {
            $sum += ($code[$i]);
        }
        $r = $sum % 10;
        if ($r > 0) {
            $r = (10 - $r);
        }

        return $r;
    }

    /**
     * MSI.
     * Variation of Plessey code, with similar applications
     * Contains digits (0 to 9) and encodes the data only in the width of bars.
     *
     * @param $code (string) code to represent.
     * @param $checksum (boolean) if true add a checksum to the code (modulo 11)
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_msi($code, $checksum = false)
    {
        $chr['0'] = '100100100100';
        $chr['1'] = '100100100110';
        $chr['2'] = '100100110100';
        $chr['3'] = '100100110110';
        $chr['4'] = '100110100100';
        $chr['5'] = '100110100110';
        $chr['6'] = '100110110100';
        $chr['7'] = '100110110110';
        $chr['8'] = '110100100100';
        $chr['9'] = '110100100110';
        $chr['A'] = '110100110100';
        $chr['B'] = '110100110110';
        $chr['C'] = '110110100100';
        $chr['D'] = '110110100110';
        $chr['E'] = '110110110100';
        $chr['F'] = '110110110110';
        if ($checksum) {
            // add checksum
            $clen = strlen($code);
            $p = 2;
            $check = 0;
            for ($i = ($clen - 1); $i >= 0; --$i) {
                $check += (hexdec($code[$i]) * $p);
                ++$p;
                if ($p > 7) {
                    $p = 2;
                }
            }
            $check %= 11;
            if ($check > 0) {
                $check = 11 - $check;
            }
            $code .= $check;
        }
        $seq = '110'; // left guard
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            $digit = $code[$i];
            if ( ! isset($chr[$digit])) {
                throw new InvalidCharacterException('Char ' . $digit . ' is unsupported');
            }
            $seq .= $chr[$digit];
        }
        $seq .= '1001'; // right guard
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());

        return $this->binseq_to_array($seq, $bararray);
    }

    /**
     * Standard 2 of 5 barcodes.
     * Used in airline ticket marking, photofinishing
     * Contains digits (0 to 9) and encodes the data only in the width of bars.
     *
     * @param $code (string) code to represent.
     * @param $checksum (boolean) if true add a checksum to the code
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_s25($code, $checksum = false)
    {
        $chr['0'] = '10101110111010';
        $chr['1'] = '11101010101110';
        $chr['2'] = '10111010101110';
        $chr['3'] = '11101110101010';
        $chr['4'] = '10101110101110';
        $chr['5'] = '11101011101010';
        $chr['6'] = '10111011101010';
        $chr['7'] = '10101011101110';
        $chr['8'] = '10101110111010';
        $chr['9'] = '10111010111010';
        if ($checksum) {
            // add checksum
            $code .= $this->checksum_s25($code);
        }
        if ((strlen($code) % 2) != 0) {
            // add leading zero if code-length is odd
            $code = '0' . $code;
        }
        $seq = '11011010';
        $clen = strlen($code);
        for ($i = 0; $i < $clen; ++$i) {
            $digit = $code[$i];
            if ( ! isset($chr[$digit])) {
                throw new InvalidCharacterException('Char ' . $digit . ' is unsupported');
            }
            $seq .= $chr[$digit];
        }
        $seq .= '1101011';
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());

        return $this->binseq_to_array($seq, $bararray);
    }

    /**
     * Convert binary barcode sequence to TCPDF barcode array.
     *
     * @param $seq (string) barcode as binary sequence.
     * @param $bararray (array) barcode array.
     * òparam array $bararray TCPDF barcode array to fill up
     * @return array barcode representation.
     * @protected
     */
    protected function binseq_to_array($seq, $bararray)
    {
        $len = strlen($seq);
        $w = 0;
        $k = 0;
        for ($i = 0; $i < $len; ++$i) {
            $w += 1;
            if (($i == ($len - 1)) OR (($i < ($len - 1)) AND ($seq[$i] != $seq[($i + 1)]))) {
                if ($seq[$i] == '1') {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
                $w = 0;
            }
        }

        return $bararray;
    }

    /**
     * Interleaved 2 of 5 barcodes.
     * Compact numeric code, widely used in industry, air cargo
     * Contains digits (0 to 9) and encodes the data in the width of both bars and spaces.
     *
     * @param $code (string) code to represent.
     * @param $checksum (boolean) if true add a checksum to the code
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_i25($code, $checksum = false)
    {
        $chr['0'] = '11221';
        $chr['1'] = '21112';
        $chr['2'] = '12112';
        $chr['3'] = '22111';
        $chr['4'] = '11212';
        $chr['5'] = '21211';
        $chr['6'] = '12211';
        $chr['7'] = '11122';
        $chr['8'] = '21121';
        $chr['9'] = '12121';
        $chr['A'] = '11';
        $chr['Z'] = '21';
        if ($checksum) {
            // add checksum
            $code .= $this->checksum_s25($code);
        }
        if ((strlen($code) % 2) != 0) {
            // add leading zero if code-length is odd
            $code = '0' . $code;
        }
        // add start and stop codes
        $code = 'AA' . strtolower($code) . 'ZA';

        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        $k = 0;
        $clen = strlen($code);
        for ($i = 0; $i < $clen; $i = ($i + 2)) {
            $char_bar = $code[$i];
            $char_space = $code[$i + 1];
            if ( ! isset($chr[$char_bar]) || ! isset($chr[$char_space])) {
                throw new InvalidCharacterException();
            }
            // create a bar-space sequence
            $seq = '';
            $chrlen = strlen($chr[$char_bar]);
            for ($s = 0; $s < $chrlen; $s++) {
                $seq .= $chr[$char_bar][$s] . $chr[$char_space][$s];
            }
            $seqlen = strlen($seq);
            for ($j = 0; $j < $seqlen; ++$j) {
                if (($j % 2) == 0) {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $w = $seq[$j];
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
            }
        }

        return $bararray;
    }

    /**
     * C128 barcodes.
     * Very capable code, excellent density, high reliability; in very wide use world-wide
     *
     * @param $code (string) code to represent.
     * @param $type (string) barcode type: A, B, C or empty for automatic switch (AUTO mode)
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_c128($code, $type = '')
    {
        $chr = array(
            '212222', /* 00 */
            '222122', /* 01 */
            '222221', /* 02 */
            '121223', /* 03 */
            '121322', /* 04 */
            '131222', /* 05 */
            '122213', /* 06 */
            '122312', /* 07 */
            '132212', /* 08 */
            '221213', /* 09 */
            '221312', /* 10 */
            '231212', /* 11 */
            '112232', /* 12 */
            '122132', /* 13 */
            '122231', /* 14 */
            '113222', /* 15 */
            '123122', /* 16 */
            '123221', /* 17 */
            '223211', /* 18 */
            '221132', /* 19 */
            '221231', /* 20 */
            '213212', /* 21 */
            '223112', /* 22 */
            '312131', /* 23 */
            '311222', /* 24 */
            '321122', /* 25 */
            '321221', /* 26 */
            '312212', /* 27 */
            '322112', /* 28 */
            '322211', /* 29 */
            '212123', /* 30 */
            '212321', /* 31 */
            '232121', /* 32 */
            '111323', /* 33 */
            '131123', /* 34 */
            '131321', /* 35 */
            '112313', /* 36 */
            '132113', /* 37 */
            '132311', /* 38 */
            '211313', /* 39 */
            '231113', /* 40 */
            '231311', /* 41 */
            '112133', /* 42 */
            '112331', /* 43 */
            '132131', /* 44 */
            '113123', /* 45 */
            '113321', /* 46 */
            '133121', /* 47 */
            '313121', /* 48 */
            '211331', /* 49 */
            '231131', /* 50 */
            '213113', /* 51 */
            '213311', /* 52 */
            '213131', /* 53 */
            '311123', /* 54 */
            '311321', /* 55 */
            '331121', /* 56 */
            '312113', /* 57 */
            '312311', /* 58 */
            '332111', /* 59 */
            '314111', /* 60 */
            '221411', /* 61 */
            '431111', /* 62 */
            '111224', /* 63 */
            '111422', /* 64 */
            '121124', /* 65 */
            '121421', /* 66 */
            '141122', /* 67 */
            '141221', /* 68 */
            '112214', /* 69 */
            '112412', /* 70 */
            '122114', /* 71 */
            '122411', /* 72 */
            '142112', /* 73 */
            '142211', /* 74 */
            '241211', /* 75 */
            '221114', /* 76 */
            '413111', /* 77 */
            '241112', /* 78 */
            '134111', /* 79 */
            '111242', /* 80 */
            '121142', /* 81 */
            '121241', /* 82 */
            '114212', /* 83 */
            '124112', /* 84 */
            '124211', /* 85 */
            '411212', /* 86 */
            '421112', /* 87 */
            '421211', /* 88 */
            '212141', /* 89 */
            '214121', /* 90 */
            '412121', /* 91 */
            '111143', /* 92 */
            '111341', /* 93 */
            '131141', /* 94 */
            '114113', /* 95 */
            '114311', /* 96 */
            '411113', /* 97 */
            '411311', /* 98 */
            '113141', /* 99 */
            '114131', /* 100 */
            '311141', /* 101 */
            '411131', /* 102 */
            '211412', /* 103 START A */
            '211214', /* 104 START B */
            '211232', /* 105 START C */
            '233111', /* STOP */
            '200000'  /* END */
        );
        // ASCII characters for code A (ASCII 00 - 95)
        $keys_a = ' !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_';
        $keys_a .= chr(0) . chr(1) . chr(2) . chr(3) . chr(4) . chr(5) . chr(6) . chr(7) . chr(8) . chr(9);
        $keys_a .= chr(10) . chr(11) . chr(12) . chr(13) . chr(14) . chr(15) . chr(16) . chr(17) . chr(18) . chr(19);
        $keys_a .= chr(20) . chr(21) . chr(22) . chr(23) . chr(24) . chr(25) . chr(26) . chr(27) . chr(28) . chr(29);
        $keys_a .= chr(30) . chr(31);
        // ASCII characters for code B (ASCII 32 - 127)
        $keys_b = ' !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~' . chr(127);
        // special codes
        $fnc_a = array(241 => 102, 242 => 97, 243 => 96, 244 => 101);
        $fnc_b = array(241 => 102, 242 => 97, 243 => 96, 244 => 100);
        // array of symbols
        $code_data = array();
        // length of the code
        $len = strlen($code);
        switch (strtoupper($type)) {
            case 'A': { // MODE A
                $startid = 103;
                for ($i = 0; $i < $len; ++$i) {
                    $char = $code[$i];
                    $char_id = ord($char);
                    if (($char_id >= 241) AND ($char_id <= 244)) {
                        $code_data[] = $fnc_a[$char_id];
                    } elseif (($char_id >= 0) AND ($char_id <= 95)) {
                        $code_data[] = strpos($keys_a, $char);
                    } else {
                        throw new InvalidCharacterException('Char ' . $char . ' is unsupported');
                    }
                }
                break;
            }
            case 'B': { // MODE B
                $startid = 104;
                for ($i = 0; $i < $len; ++$i) {
                    $char = $code[$i];
                    $char_id = ord($char);
                    if (($char_id >= 241) AND ($char_id <= 244)) {
                        $code_data[] = $fnc_b[$char_id];
                    } elseif (($char_id >= 32) AND ($char_id <= 127)) {
                        $code_data[] = strpos($keys_b, $char);
                    } else {
                        throw new InvalidCharacterException('Char ' . $char . ' is unsupported');
                    }
                }
                break;
            }
            case 'C': { // MODE C
                $startid = 105;
                if (ord($code[0]) == 241) {
                    $code_data[] = 102;
                    $code = substr($code, 1);
                    --$len;
                }
                if (($len % 2) != 0) {
                    throw new InvalidLengthException('Length must be even');
                }
                for ($i = 0; $i < $len; $i += 2) {
                    $chrnum = $code[$i] . $code[$i + 1];
                    if (preg_match('/([0-9]{2})/', $chrnum) > 0) {
                        $code_data[] = intval($chrnum);
                    } else {
                        throw new InvalidCharacterException();
                    }
                }
                break;
            }
            default: { // MODE AUTO
                // split code into sequences
                $sequence = array();
                // get numeric sequences (if any)
                $numseq = array();
                preg_match_all('/([0-9]{4,})/', $code, $numseq, PREG_OFFSET_CAPTURE);
                if (isset($numseq[1]) AND ! empty($numseq[1])) {
                    $end_offset = 0;
                    foreach ($numseq[1] as $val) {
                        $offset = $val[1];
                        
                        // numeric sequence
                        $slen = strlen($val[0]);
                        if (($slen % 2) != 0) {
                            // the length must be even
                            ++$offset;
                            $val[0] = substr($val[0],1);
                        }
                        
                        if ($offset > $end_offset) {
                            // non numeric sequence
                            $sequence = array_merge($sequence,
                                $this->get128ABsequence(substr($code, $end_offset, ($offset - $end_offset))));
                        }
                        // numeric sequence fallback
                        $slen = strlen($val[0]);
                        if (($slen % 2) != 0) {
                            // the length must be even
                            --$slen;
                        }
                        $sequence[] = array('C', substr($code, $offset, $slen), $slen);
                        $end_offset = $offset + $slen;
                    }
                    if ($end_offset < $len) {
                        $sequence = array_merge($sequence, $this->get128ABsequence(substr($code, $end_offset)));
                    }
                } else {
                    // text code (non C mode)
                    $sequence = array_merge($sequence, $this->get128ABsequence($code));
                }
                // process the sequence
                foreach ($sequence as $key => $seq) {
                    switch ($seq[0]) {
                        case 'A': {
                            if ($key == 0) {
                                $startid = 103;
                            } elseif ($sequence[($key - 1)][0] != 'A') {
                                if (($seq[2] == 1) AND ($key > 0) AND ($sequence[($key - 1)][0] == 'B') AND ( ! isset($sequence[($key - 1)][3]))) {
                                    // single character shift
                                    $code_data[] = 98;
                                    // mark shift
                                    $sequence[$key][3] = true;
                                } elseif ( ! isset($sequence[($key - 1)][3])) {
                                    $code_data[] = 101;
                                }
                            }
                            for ($i = 0; $i < $seq[2]; ++$i) {
                                $char = $seq[1][$i];
                                $char_id = ord($char);
                                if (($char_id >= 241) AND ($char_id <= 244)) {
                                    $code_data[] = $fnc_a[$char_id];
                                } else {
                                    $code_data[] = strpos($keys_a, $char);
                                }
                            }
                            break;
                        }
                        case 'B': {
                            if ($key == 0) {
                                $tmpchr = ord($seq[1][0]);
                                if (($seq[2] == 1) AND ($tmpchr >= 241) AND ($tmpchr <= 244) AND isset($sequence[($key + 1)]) AND ($sequence[($key + 1)][0] != 'B')) {
                                    switch ($sequence[($key + 1)][0]) {
                                        case 'A': {
                                            $startid = 103;
                                            $sequence[$key][0] = 'A';
                                            $code_data[] = $fnc_a[$tmpchr];
                                            break;
                                        }
                                        case 'C': {
                                            $startid = 105;
                                            $sequence[$key][0] = 'C';
                                            $code_data[] = $fnc_a[$tmpchr];
                                            break;
                                        }
                                    }
                                    break;
                                } else {
                                    $startid = 104;
                                }
                            } elseif ($sequence[($key - 1)][0] != 'B') {
                                if (($seq[2] == 1) AND ($key > 0) AND ($sequence[($key - 1)][0] == 'A') AND ( ! isset($sequence[($key - 1)][3]))) {
                                    // single character shift
                                    $code_data[] = 98;
                                    // mark shift
                                    $sequence[$key][3] = true;
                                } elseif ( ! isset($sequence[($key - 1)][3])) {
                                    $code_data[] = 100;
                                }
                            }
                            for ($i = 0; $i < $seq[2]; ++$i) {
                                $char = $seq[1][$i];
                                $char_id = ord($char);
                                if (($char_id >= 241) AND ($char_id <= 244)) {
                                    $code_data[] = $fnc_b[$char_id];
                                } else {
                                    $code_data[] = strpos($keys_b, $char);
                                }
                            }
                            break;
                        }
                        case 'C': {
                            if ($key == 0) {
                                $startid = 105;
                            } elseif ($sequence[($key - 1)][0] != 'C') {
                                $code_data[] = 99;
                            }
                            for ($i = 0; $i < $seq[2]; $i += 2) {
                                $chrnum = $seq[1][$i] . $seq[1][$i + 1];
                                $code_data[] = intval($chrnum);
                            }
                            break;
                        }
                    }
                }
            }
        }
        // calculate check character
        $sum = $startid;
        foreach ($code_data as $key => $val) {
            $sum += ($val * ($key + 1));
        }
        // add check character
        $code_data[] = ($sum % 103);
        // add stop sequence
        $code_data[] = 106;
        $code_data[] = 107;
        // add start code at the beginning
        array_unshift($code_data, $startid);
        // build barcode array
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        foreach ($code_data as $val) {
            $seq = $chr[$val];
            for ($j = 0; $j < 6; ++$j) {
                if (($j % 2) == 0) {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $w = $seq[$j];
                $bararray['bcode'][] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
            }
        }

        return $bararray;
    }

    /**
     * Split text code in A/B sequence for 128 code
     *
     * @param $code (string) code to split.
     * @return array sequence
     * @protected
     */
    protected function get128ABsequence($code)
    {
        $len = strlen($code);
        $sequence = array();
        // get A sequences (if any)
        $numseq = array();
        preg_match_all('/([\x00-\x1f])/', $code, $numseq, PREG_OFFSET_CAPTURE);
        if (isset($numseq[1]) AND ! empty($numseq[1])) {
            $end_offset = 0;
            foreach ($numseq[1] as $val) {
                $offset = $val[1];
                if ($offset > $end_offset) {
                    // B sequence
                    $sequence[] = array(
                        'B',
                        substr($code, $end_offset, ($offset - $end_offset)),
                        ($offset - $end_offset)
                    );
                }
                // A sequence
                $slen = strlen($val[0]);
                $sequence[] = array('A', substr($code, $offset, $slen), $slen);
                $end_offset = $offset + $slen;
            }
            if ($end_offset < $len) {
                $sequence[] = array('B', substr($code, $end_offset), ($len - $end_offset));
            }
        } else {
            // only B sequence
            $sequence[] = array('B', $code, $len);
        }

        return $sequence;
    }

    /**
     * EAN13 and UPC-A barcodes.
     * EAN13: European Article Numbering international retail product code
     * UPC-A: Universal product code seen on almost all retail products in the USA and Canada
     * UPC-E: Short version of UPC symbol
     *
     * @param $code (string) code to represent.
     * @param $len (string) barcode type: 6 = UPC-E, 8 = EAN8, 13 = EAN13, 12 = UPC-A
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_eanupc($code, $len = 13)
    {
        $upce = false;
        if ($len == 6) {
            $len = 12; // UPC-A
            $upce = true; // UPC-E mode
        }
        $data_len = $len - 1;
        //Padding
        $code = str_pad($code, $data_len, '0', STR_PAD_LEFT);
        $code_len = strlen($code);
        // calculate check digit
        $sum_a = 0;
        for ($i = 1; $i < $data_len; $i += 2) {
            $sum_a += $code[$i];
        }
        if ($len > 12) {
            $sum_a *= 3;
        }
        $sum_b = 0;
        for ($i = 0; $i < $data_len; $i += 2) {
            $sum_b += intval(($code[$i]));
        }
        if ($len < 13) {
            $sum_b *= 3;
        }
        $r = ($sum_a + $sum_b) % 10;
        if ($r > 0) {
            $r = (10 - $r);
        }
        if ($code_len == $data_len) {
            // add check digit
            $code .= $r;
        } elseif ($r !== intval($code[$data_len])) {
            throw new InvalidCheckDigitException();
        }
        if ($len == 12) {
            // UPC-A
            $code = '0' . $code;
            ++$len;
        }
        if ($upce) {
            // convert UPC-A to UPC-E
            $tmp = substr($code, 4, 3);
            if (($tmp == '000') OR ($tmp == '100') OR ($tmp == '200')) {
                // manufacturer code ends in 000, 100, or 200
                $upce_code = substr($code, 2, 2) . substr($code, 9, 3) . substr($code, 4, 1);
            } else {
                $tmp = substr($code, 5, 2);
                if ($tmp == '00') {
                    // manufacturer code ends in 00
                    $upce_code = substr($code, 2, 3) . substr($code, 10, 2) . '3';
                } else {
                    $tmp = substr($code, 6, 1);
                    if ($tmp == '0') {
                        // manufacturer code ends in 0
                        $upce_code = substr($code, 2, 4) . substr($code, 11, 1) . '4';
                    } else {
                        // manufacturer code does not end in zero
                        $upce_code = substr($code, 2, 5) . substr($code, 11, 1);
                    }
                }
            }
        }
        //Convert digits to bars
        $codes = array(
            'A' => array( // left odd parity
                '0' => '0001101',
                '1' => '0011001',
                '2' => '0010011',
                '3' => '0111101',
                '4' => '0100011',
                '5' => '0110001',
                '6' => '0101111',
                '7' => '0111011',
                '8' => '0110111',
                '9' => '0001011'
            ),
            'B' => array( // left even parity
                '0' => '0100111',
                '1' => '0110011',
                '2' => '0011011',
                '3' => '0100001',
                '4' => '0011101',
                '5' => '0111001',
                '6' => '0000101',
                '7' => '0010001',
                '8' => '0001001',
                '9' => '0010111'
            ),
            'C' => array( // right
                '0' => '1110010',
                '1' => '1100110',
                '2' => '1101100',
                '3' => '1000010',
                '4' => '1011100',
                '5' => '1001110',
                '6' => '1010000',
                '7' => '1000100',
                '8' => '1001000',
                '9' => '1110100'
            )
        );
        $parities = array(
            '0' => array('A', 'A', 'A', 'A', 'A', 'A'),
            '1' => array('A', 'A', 'B', 'A', 'B', 'B'),
            '2' => array('A', 'A', 'B', 'B', 'A', 'B'),
            '3' => array('A', 'A', 'B', 'B', 'B', 'A'),
            '4' => array('A', 'B', 'A', 'A', 'B', 'B'),
            '5' => array('A', 'B', 'B', 'A', 'A', 'B'),
            '6' => array('A', 'B', 'B', 'B', 'A', 'A'),
            '7' => array('A', 'B', 'A', 'B', 'A', 'B'),
            '8' => array('A', 'B', 'A', 'B', 'B', 'A'),
            '9' => array('A', 'B', 'B', 'A', 'B', 'A')
        );
        $upce_parities = array();
        $upce_parities[0] = array(
            '0' => array('B', 'B', 'B', 'A', 'A', 'A'),
            '1' => array('B', 'B', 'A', 'B', 'A', 'A'),
            '2' => array('B', 'B', 'A', 'A', 'B', 'A'),
            '3' => array('B', 'B', 'A', 'A', 'A', 'B'),
            '4' => array('B', 'A', 'B', 'B', 'A', 'A'),
            '5' => array('B', 'A', 'A', 'B', 'B', 'A'),
            '6' => array('B', 'A', 'A', 'A', 'B', 'B'),
            '7' => array('B', 'A', 'B', 'A', 'B', 'A'),
            '8' => array('B', 'A', 'B', 'A', 'A', 'B'),
            '9' => array('B', 'A', 'A', 'B', 'A', 'B')
        );
        $upce_parities[1] = array(
            '0' => array('A', 'A', 'A', 'B', 'B', 'B'),
            '1' => array('A', 'A', 'B', 'A', 'B', 'B'),
            '2' => array('A', 'A', 'B', 'B', 'A', 'B'),
            '3' => array('A', 'A', 'B', 'B', 'B', 'A'),
            '4' => array('A', 'B', 'A', 'A', 'B', 'B'),
            '5' => array('A', 'B', 'B', 'A', 'A', 'B'),
            '6' => array('A', 'B', 'B', 'B', 'A', 'A'),
            '7' => array('A', 'B', 'A', 'B', 'A', 'B'),
            '8' => array('A', 'B', 'A', 'B', 'B', 'A'),
            '9' => array('A', 'B', 'B', 'A', 'B', 'A')
        );
        $k = 0;
        $seq = '101'; // left guard bar
        if ($upce) {
            $bararray = array('code' => $upce_code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
            $p = $upce_parities[$code[1]][$r];
            for ($i = 0; $i < 6; ++$i) {
                $seq .= $codes[$p[$i]][$upce_code[$i]];
            }
            $seq .= '010101'; // right guard bar
        } else {
            $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
            $half_len = intval(ceil($len / 2));
            if ($len == 8) {
                for ($i = 0; $i < $half_len; ++$i) {
                    $seq .= $codes['A'][$code[$i]];
                }
            } else {
                $p = $parities[$code[0]];
                for ($i = 1; $i < $half_len; ++$i) {
                    $seq .= $codes[$p[$i - 1]][$code[$i]];
                }
            }
            $seq .= '01010'; // center guard bar
            for ($i = $half_len; $i < $len; ++$i) {
                if ( ! isset($codes['C'][$code[$i]])) {
                    throw new InvalidCharacterException('Char ' . $code[$i] . ' not allowed');
                }
                $seq .= $codes['C'][$code[$i]];
            }
            $seq .= '101'; // right guard bar
        }
        $clen = strlen($seq);
        $w = 0;
        for ($i = 0; $i < $clen; ++$i) {
            $w += 1;
            if (($i == ($clen - 1)) OR (($i < ($clen - 1)) AND ($seq[$i] != $seq[($i + 1)]))) {
                if ($seq[$i] == '1') {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
                $w = 0;
            }
        }

        return $bararray;
    }

    /**
     * UPC-Based Extensions
     * 2-Digit Ext.: Used to indicate magazines and newspaper issue numbers
     * 5-Digit Ext.: Used to mark suggested retail price of books
     *
     * @param $code (string) code to represent.
     * @param $len (string) barcode type: 2 = 2-Digit, 5 = 5-Digit
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_eanext($code, $len = 5)
    {
        //Padding
        $code = str_pad($code, $len, '0', STR_PAD_LEFT);
        // calculate check digit
        if ($len == 2) {
            $r = $code % 4;
        } elseif ($len == 5) {
            $r = (3 * ($code[0] + $code[2] + $code[4])) + (9 * ($code[1] + $code[3]));
            $r %= 10;
        } else {
            throw new InvalidCheckDigitException();
        }
        //Convert digits to bars
        $codes = array(
            'A' => array( // left odd parity
                '0' => '0001101',
                '1' => '0011001',
                '2' => '0010011',
                '3' => '0111101',
                '4' => '0100011',
                '5' => '0110001',
                '6' => '0101111',
                '7' => '0111011',
                '8' => '0110111',
                '9' => '0001011'
            ),
            'B' => array( // left even parity
                '0' => '0100111',
                '1' => '0110011',
                '2' => '0011011',
                '3' => '0100001',
                '4' => '0011101',
                '5' => '0111001',
                '6' => '0000101',
                '7' => '0010001',
                '8' => '0001001',
                '9' => '0010111'
            )
        );
        $parities = array();
        $parities[2] = array(
            '0' => array('A', 'A'),
            '1' => array('A', 'B'),
            '2' => array('B', 'A'),
            '3' => array('B', 'B')
        );
        $parities[5] = array(
            '0' => array('B', 'B', 'A', 'A', 'A'),
            '1' => array('B', 'A', 'B', 'A', 'A'),
            '2' => array('B', 'A', 'A', 'B', 'A'),
            '3' => array('B', 'A', 'A', 'A', 'B'),
            '4' => array('A', 'B', 'B', 'A', 'A'),
            '5' => array('A', 'A', 'B', 'B', 'A'),
            '6' => array('A', 'A', 'A', 'B', 'B'),
            '7' => array('A', 'B', 'A', 'B', 'A'),
            '8' => array('A', 'B', 'A', 'A', 'B'),
            '9' => array('A', 'A', 'B', 'A', 'B')
        );
        $p = $parities[$len][$r];
        $seq = '1011'; // left guard bar
        $seq .= $codes[$p[0]][$code[0]];
        for ($i = 1; $i < $len; ++$i) {
            $seq .= '01'; // separator
            $seq .= $codes[$p[$i]][$code[$i]];
        }
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());

        return $this->binseq_to_array($seq, $bararray);
    }

    /**
     * POSTNET and PLANET barcodes.
     * Used by U.S. Postal Service for automated mail sorting
     *
     * @param $code (string) zip code to represent. Must be a string containing a zip code of the form DDDDD or
     *     DDDDD-DDDD.
     * @param $planet (boolean) if true print the PLANET barcode, otherwise print POSTNET
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_postnet($code, $planet = false)
    {
        // bar length
        if ($planet) {
            $barlen = Array(
                0 => Array(1, 1, 2, 2, 2),
                1 => Array(2, 2, 2, 1, 1),
                2 => Array(2, 2, 1, 2, 1),
                3 => Array(2, 2, 1, 1, 2),
                4 => Array(2, 1, 2, 2, 1),
                5 => Array(2, 1, 2, 1, 2),
                6 => Array(2, 1, 1, 2, 2),
                7 => Array(1, 2, 2, 2, 1),
                8 => Array(1, 2, 2, 1, 2),
                9 => Array(1, 2, 1, 2, 2)
            );
        } else {
            $barlen = Array(
                0 => Array(2, 2, 1, 1, 1),
                1 => Array(1, 1, 1, 2, 2),
                2 => Array(1, 1, 2, 1, 2),
                3 => Array(1, 1, 2, 2, 1),
                4 => Array(1, 2, 1, 1, 2),
                5 => Array(1, 2, 1, 2, 1),
                6 => Array(1, 2, 2, 1, 1),
                7 => Array(2, 1, 1, 1, 2),
                8 => Array(2, 1, 1, 2, 1),
                9 => Array(2, 1, 2, 1, 1)
            );
        }
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 2, 'bcode' => array());
        $k = 0;
        $code = str_replace('-', '', $code);
        $code = str_replace(' ', '', $code);
        $len = strlen($code);
        // calculate checksum
        $sum = 0;
        for ($i = 0; $i < $len; ++$i) {
            $sum += intval($code[$i]);
        }
        $chkd = ($sum % 10);
        if ($chkd > 0) {
            $chkd = (10 - $chkd);
        }
        $code .= $chkd;
        $len = strlen($code);
        // start bar
        $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => 2, 'p' => 0);
        $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
        $bararray['maxw'] += 2;
        for ($i = 0; $i < $len; ++$i) {
            for ($j = 0; $j < 5; ++$j) {
                $h = $barlen[$code[$i]][$j];
                $p = floor(1 / $h);
                $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => $h, 'p' => $p);
                $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
                $bararray['maxw'] += 2;
            }
        }
        // end bar
        $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => 2, 'p' => 0);
        $bararray['maxw'] += 1;

        return $bararray;
    }

    /**
     * RMS4CC - CBC - KIX
     * RMS4CC (Royal Mail 4-state Customer Code) - CBC (Customer Bar Code) - KIX (Klant index - Customer index)
     * RM4SCC is the name of the barcode symbology used by the Royal Mail for its Cleanmail service.
     *
     * @param $code (string) code to print
     * @param $kix (boolean) if true prints the KIX variation (doesn't use the start and end symbols, and the checksum)
     *     - in this case the house number must be sufficed with an X and placed at the end of the code.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_rms4cc($code, $kix = false)
    {
        $notkix = ! $kix;
        // bar mode
        // 1 = pos 1, length 2
        // 2 = pos 1, length 3
        // 3 = pos 2, length 1
        // 4 = pos 2, length 2
        $barmode = array(
            '0' => array(3, 3, 2, 2),
            '1' => array(3, 4, 1, 2),
            '2' => array(3, 4, 2, 1),
            '3' => array(4, 3, 1, 2),
            '4' => array(4, 3, 2, 1),
            '5' => array(4, 4, 1, 1),
            '6' => array(3, 1, 4, 2),
            '7' => array(3, 2, 3, 2),
            '8' => array(3, 2, 4, 1),
            '9' => array(4, 1, 3, 2),
            'A' => array(4, 1, 4, 1),
            'B' => array(4, 2, 3, 1),
            'C' => array(3, 1, 2, 4),
            'D' => array(3, 2, 1, 4),
            'E' => array(3, 2, 2, 3),
            'F' => array(4, 1, 1, 4),
            'G' => array(4, 1, 2, 3),
            'H' => array(4, 2, 1, 3),
            'I' => array(1, 3, 4, 2),
            'J' => array(1, 4, 3, 2),
            'K' => array(1, 4, 4, 1),
            'L' => array(2, 3, 3, 2),
            'M' => array(2, 3, 4, 1),
            'N' => array(2, 4, 3, 1),
            'O' => array(1, 3, 2, 4),
            'P' => array(1, 4, 1, 4),
            'Q' => array(1, 4, 2, 3),
            'R' => array(2, 3, 1, 4),
            'S' => array(2, 3, 2, 3),
            'T' => array(2, 4, 1, 3),
            'U' => array(1, 1, 4, 4),
            'V' => array(1, 2, 3, 4),
            'W' => array(1, 2, 4, 3),
            'X' => array(2, 1, 3, 4),
            'Y' => array(2, 1, 4, 3),
            'Z' => array(2, 2, 3, 3)
        );
        $code = strtoupper($code);
        $len = strlen($code);
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 3, 'bcode' => array());
        if ($notkix) {
            // table for checksum calculation (row,col)
            $checktable = array(
                '0' => array(1, 1),
                '1' => array(1, 2),
                '2' => array(1, 3),
                '3' => array(1, 4),
                '4' => array(1, 5),
                '5' => array(1, 0),
                '6' => array(2, 1),
                '7' => array(2, 2),
                '8' => array(2, 3),
                '9' => array(2, 4),
                'A' => array(2, 5),
                'B' => array(2, 0),
                'C' => array(3, 1),
                'D' => array(3, 2),
                'E' => array(3, 3),
                'F' => array(3, 4),
                'G' => array(3, 5),
                'H' => array(3, 0),
                'I' => array(4, 1),
                'J' => array(4, 2),
                'K' => array(4, 3),
                'L' => array(4, 4),
                'M' => array(4, 5),
                'N' => array(4, 0),
                'O' => array(5, 1),
                'P' => array(5, 2),
                'Q' => array(5, 3),
                'R' => array(5, 4),
                'S' => array(5, 5),
                'T' => array(5, 0),
                'U' => array(0, 1),
                'V' => array(0, 2),
                'W' => array(0, 3),
                'X' => array(0, 4),
                'Y' => array(0, 5),
                'Z' => array(0, 0)
            );
            $row = 0;
            $col = 0;
            for ($i = 0; $i < $len; ++$i) {
                $row += $checktable[$code[$i]][0];
                $col += $checktable[$code[$i]][1];
            }
            $row %= 6;
            $col %= 6;
            $chk = array_keys($checktable, array($row, $col));
            $code .= $chk[0];
            ++$len;
        }
        $k = 0;
        if ($notkix) {
            // start bar
            $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => 2, 'p' => 0);
            $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
            $bararray['maxw'] += 2;
        }
        for ($i = 0; $i < $len; ++$i) {
            for ($j = 0; $j < 4; ++$j) {
                switch ($barmode[$code[$i]][$j]) {
                    case 1: {
                        $p = 0;
                        $h = 2;
                        break;
                    }
                    case 2: {
                        $p = 0;
                        $h = 3;
                        break;
                    }
                    case 3: {
                        $p = 1;
                        $h = 1;
                        break;
                    }
                    case 4: {
                        $p = 1;
                        $h = 2;
                        break;
                    }
                }
                $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => $h, 'p' => $p);
                $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
                $bararray['maxw'] += 2;
            }
        }
        if ($notkix) {
            // stop bar
            $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => 3, 'p' => 0);
            $bararray['maxw'] += 1;
        }

        return $bararray;
    }

    /**
     * CODABAR barcodes.
     * Older code often used in library systems, sometimes in blood banks
     *
     * @param $code (string) code to represent.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_codabar($code)
    {
        $chr = array(
            '0' => '11111221',
            '1' => '11112211',
            '2' => '11121121',
            '3' => '22111111',
            '4' => '11211211',
            '5' => '21111211',
            '6' => '12111121',
            '7' => '12112111',
            '8' => '12211111',
            '9' => '21121111',
            '-' => '11122111',
            '$' => '11221111',
            ':' => '21112121',
            '/' => '21211121',
            '.' => '21212111',
            '+' => '11222221',
            'A' => '11221211',
            'B' => '12121121',
            'C' => '11121221',
            'D' => '11122211'
        );
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        $k = 0;
        $w = 0;
        $seq = '';
        $code = 'A' . strtoupper($code) . 'A';
        $len = strlen($code);
        for ($i = 0; $i < $len; ++$i) {
            if ( ! isset($chr[$code[$i]])) {
                throw new InvalidCharacterException('Char ' . $code[$i] . ' is unsupported');
            }
            $seq = $chr[$code[$i]];
            for ($j = 0; $j < 8; ++$j) {
                if (($j % 2) == 0) {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $w = $seq[$i];
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
            }
        }

        return $bararray;
    }

    /**
     * CODE11 barcodes.
     * Used primarily for labeling telecommunications equipment
     *
     * @param $code (string) code to represent.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_code11($code)
    {
        $chr = array(
            '0' => '111121',
            '1' => '211121',
            '2' => '121121',
            '3' => '221111',
            '4' => '112121',
            '5' => '212111',
            '6' => '122111',
            '7' => '111221',
            '8' => '211211',
            '9' => '211111',
            '-' => '112111',
            'S' => '112211'
        );
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());
        $k = 0;
        $w = 0;
        $seq = '';
        $len = strlen($code);
        // calculate check digit C
        $p = 1;
        $check = 0;
        for ($i = ($len - 1); $i >= 0; --$i) {
            $digit = $code[$i];
            if ($digit == '-') {
                $dval = 10;
            } else {
                $dval = intval($digit);
            }
            $check += ($dval * $p);
            ++$p;
            if ($p > 10) {
                $p = 1;
            }
        }
        $check %= 11;
        if ($check == 10) {
            $check = '-';
        }
        $code .= $check;
        if ($len > 10) {
            // calculate check digit K
            $p = 1;
            $check = 0;
            for ($i = $len; $i >= 0; --$i) {
                $digit = $code[$i];
                if ($digit == '-') {
                    $dval = 10;
                } else {
                    $dval = intval($digit);
                }
                $check += ($dval * $p);
                ++$p;
                if ($p > 9) {
                    $p = 1;
                }
            }
            $check %= 11;
            $code .= $check;
            ++$len;
        }
        $code = 'S' . $code . 'S';
        $len += 3;
        for ($i = 0; $i < $len; ++$i) {
            if ( ! isset($chr[$code[$i]])) {
                throw new InvalidCharacterException('Char ' . $code[$i] . ' is unsupported');
            }
            $seq = $chr[$code[$i]];
            for ($j = 0; $j < 6; ++$j) {
                if (($j % 2) == 0) {
                    $t = true; // bar
                } else {
                    $t = false; // space
                }
                $w = $seq[$j];
                $bararray['bcode'][$k] = array('t' => $t, 'w' => $w, 'h' => 1, 'p' => 0);
                $bararray['maxw'] += $w;
                ++$k;
            }
        }

        return $bararray;
    }

    /**
     * Pharmacode
     * Contains digits (0 to 9)
     *
     * @param $code (string) code to represent.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_pharmacode($code)
    {
        $seq = '';
        $code = intval($code);
        while ($code > 0) {
            if (($code % 2) == 0) {
                $seq .= '11100';
                $code -= 2;
            } else {
                $seq .= '100';
                $code -= 1;
            }
            $code /= 2;
        }
        $seq = substr($seq, 0, -2);
        $seq = strrev($seq);
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 1, 'bcode' => array());

        return $this->binseq_to_array($seq, $bararray);
    }

    /**
     * Pharmacode two-track
     * Contains digits (0 to 9)
     *
     * @param $code (string) code to represent.
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_pharmacode2t($code)
    {
        $seq = '';
        $code = intval($code);
        do {
            switch ($code % 3) {
                case 0: {
                    $seq .= '3';
                    $code = ($code - 3) / 3;
                    break;
                }
                case 1: {
                    $seq .= '1';
                    $code = ($code - 1) / 3;
                    break;
                }
                case 2: {
                    $seq .= '2';
                    $code = ($code - 2) / 3;
                    break;
                }
            }
        } while ($code != 0);
        $seq = strrev($seq);
        $k = 0;
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 2, 'bcode' => array());
        $len = strlen($seq);
        for ($i = 0; $i < $len; ++$i) {
            switch ($seq[$i]) {
                case '1': {
                    $p = 1;
                    $h = 1;
                    break;
                }
                case '2': {
                    $p = 0;
                    $h = 1;
                    break;
                }
                case '3': {
                    $p = 0;
                    $h = 2;
                    break;
                }
            }
            $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => $h, 'p' => $p);
            $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
            $bararray['maxw'] += 2;
        }
        unset($bararray['bcode'][($k - 1)]);
        --$bararray['maxw'];

        return $bararray;
    }

    /**
     * IMB - Intelligent Mail Barcode - Onecode - USPS-B-3200
     * (requires PHP bcmath extension)
     * Intelligent Mail barcode is a 65-bar code for use on mail in the United States.
     * The fields are described as follows:<ul><li>The Barcode Identifier shall be assigned by USPS to encode the
     * presort identification that is currently printed in human readable form on the optional endorsement line (OEL)
     * as well as for future USPS use. This shall be two digits, with the second digit in the range of 0–4. The
     * allowable encoding ranges shall be 00–04, 10–14, 20–24, 30–34, 40–44, 50–54, 60–64, 70–74, 80–84, and
     * 90–94.</li><li>The Service Type Identifier shall be assigned by USPS for any combination of services requested
     * on the mailpiece. The allowable encoding range shall be 000http://it2.php.net/manual/en/function.dechex.php–999.
     * Each 3-digit value shall correspond to a particular mail class with a particular combination of service(s). Each
     * service program, such as OneCode Confirm and OneCode ACS, shall provide the list of Service Type Identifier
     * values.</li><li>The Mailer or Customer Identifier shall be assigned by USPS as a unique, 6 or 9 digit number
     * that identifies a business entity. The allowable encoding range for the 6 digit Mailer ID shall be 000000-
     * 899999, while the allowable encoding range for the 9 digit Mailer ID shall be 900000000-999999999.</li><li>The
     * Serial or Sequence Number shall be assigned by the mailer for uniquely identifying and tracking mailpieces. The
     * allowable encoding range shall be 000000000–999999999 when used with a 6 digit Mailer ID and 000000-999999 when
     * used with a 9 digit Mailer ID. e. The Delivery Point ZIP Code shall be assigned by the mailer for routing the
     * mailpiece. This shall replace POSTNET for routing the mailpiece to its final delivery point. The length may be
     * 0, 5, 9, or 11 digits. The allowable encoding ranges shall be no ZIP Code, 00000–99999,  000000000–999999999,
     * and 00000000000–99999999999.</li></ul>
     *
     * @param $code (string) code to print, separate the ZIP (routing code) from the rest using a minus char '-'
     *     (BarcodeID_ServiceTypeID_MailerID_SerialNumber-RoutingCode)
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_imb($code)
    {
        $asc_chr = array(
            4,
            0,
            2,
            6,
            3,
            5,
            1,
            9,
            8,
            7,
            1,
            2,
            0,
            6,
            4,
            8,
            2,
            9,
            5,
            3,
            0,
            1,
            3,
            7,
            4,
            6,
            8,
            9,
            2,
            0,
            5,
            1,
            9,
            4,
            3,
            8,
            6,
            7,
            1,
            2,
            4,
            3,
            9,
            5,
            7,
            8,
            3,
            0,
            2,
            1,
            4,
            0,
            9,
            1,
            7,
            0,
            2,
            4,
            6,
            3,
            7,
            1,
            9,
            5,
            8
        );
        $dsc_chr = array(
            7,
            1,
            9,
            5,
            8,
            0,
            2,
            4,
            6,
            3,
            5,
            8,
            9,
            7,
            3,
            0,
            6,
            1,
            7,
            4,
            6,
            8,
            9,
            2,
            5,
            1,
            7,
            5,
            4,
            3,
            8,
            7,
            6,
            0,
            2,
            5,
            4,
            9,
            3,
            0,
            1,
            6,
            8,
            2,
            0,
            4,
            5,
            9,
            6,
            7,
            5,
            2,
            6,
            3,
            8,
            5,
            1,
            9,
            8,
            7,
            4,
            0,
            2,
            6,
            3
        );
        $asc_pos = array(
            3,
            0,
            8,
            11,
            1,
            12,
            8,
            11,
            10,
            6,
            4,
            12,
            2,
            7,
            9,
            6,
            7,
            9,
            2,
            8,
            4,
            0,
            12,
            7,
            10,
            9,
            0,
            7,
            10,
            5,
            7,
            9,
            6,
            8,
            2,
            12,
            1,
            4,
            2,
            0,
            1,
            5,
            4,
            6,
            12,
            1,
            0,
            9,
            4,
            7,
            5,
            10,
            2,
            6,
            9,
            11,
            2,
            12,
            6,
            7,
            5,
            11,
            0,
            3,
            2
        );
        $dsc_pos = array(
            2,
            10,
            12,
            5,
            9,
            1,
            5,
            4,
            3,
            9,
            11,
            5,
            10,
            1,
            6,
            3,
            4,
            1,
            10,
            0,
            2,
            11,
            8,
            6,
            1,
            12,
            3,
            8,
            6,
            4,
            4,
            11,
            0,
            6,
            1,
            9,
            11,
            5,
            3,
            7,
            3,
            10,
            7,
            11,
            8,
            2,
            10,
            3,
            5,
            8,
            0,
            3,
            12,
            11,
            8,
            4,
            5,
            1,
            3,
            0,
            7,
            12,
            9,
            8,
            10
        );
        $code_arr = explode('-', $code);
        $tracking_number = $code_arr[0];
        if (isset($code_arr[1])) {
            $routing_code = $code_arr[1];
        } else {
            $routing_code = '';
        }
        // Conversion of Routing Code
        switch (strlen($routing_code)) {
            case 0: {
                $binary_code = 0;
                break;
            }
            case 5: {
                $binary_code = bcadd($routing_code, '1');
                break;
            }
            case 9: {
                $binary_code = bcadd($routing_code, '100001');
                break;
            }
            case 11: {
                $binary_code = bcadd($routing_code, '1000100001');
                break;
            }
            default: {
                throw new BarcodeException('Routing code unknown');
                break;
            }
        }
        $binary_code = bcmul($binary_code, 10);
        $binary_code = bcadd($binary_code, $tracking_number[0]);
        $binary_code = bcmul($binary_code, 5);
        $binary_code = bcadd($binary_code, $tracking_number[1]);
        $binary_code .= substr($tracking_number, 2, 18);
        // convert to hexadecimal
        $binary_code = $this->dec_to_hex($binary_code);
        // pad to get 13 bytes
        $binary_code = str_pad($binary_code, 26, '0', STR_PAD_LEFT);
        // convert string to array of bytes
        $binary_code_arr = chunk_split($binary_code, 2, "\r");
        $binary_code_arr = substr($binary_code_arr, 0, -1);
        $binary_code_arr = explode("\r", $binary_code_arr);
        // calculate frame check sequence
        $fcs = $this->imb_crc11fcs($binary_code_arr);
        // exclude first 2 bits from first byte
        $first_byte = sprintf('%2s', dechex((hexdec($binary_code_arr[0]) << 2) >> 2));
        $binary_code_102bit = $first_byte . substr($binary_code, 2);
        // convert binary data to codewords
        $codewords = array();
        $data = $this->hex_to_dec($binary_code_102bit);
        $codewords[0] = bcmod($data, 636) * 2;
        $data = bcdiv($data, 636);
        for ($i = 1; $i < 9; ++$i) {
            $codewords[$i] = bcmod($data, 1365);
            $data = bcdiv($data, 1365);
        }
        $codewords[9] = $data;
        if (($fcs >> 10) == 1) {
            $codewords[9] += 659;
        }
        // generate lookup tables
        $table2of13 = $this->imb_tables(2, 78);
        $table5of13 = $this->imb_tables(5, 1287);
        // convert codewords to characters
        $characters = array();
        $bitmask = 512;
        foreach ($codewords as $k => $val) {
            if ($val <= 1286) {
                $chrcode = $table5of13[$val];
            } else {
                $chrcode = $table2of13[($val - 1287)];
            }
            if (($fcs & $bitmask) > 0) {
                // bitwise invert
                $chrcode = ((~$chrcode) & 8191);
            }
            $characters[] = $chrcode;
            $bitmask /= 2;
        }
        $characters = array_reverse($characters);
        // build bars
        $k = 0;
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 3, 'bcode' => array());
        for ($i = 0; $i < 65; ++$i) {
            $asc = (($characters[$asc_chr[$i]] & pow(2, $asc_pos[$i])) > 0);
            $dsc = (($characters[$dsc_chr[$i]] & pow(2, $dsc_pos[$i])) > 0);
            if ($asc AND $dsc) {
                // full bar (F)
                $p = 0;
                $h = 3;
            } elseif ($asc) {
                // ascender (A)
                $p = 0;
                $h = 2;
            } elseif ($dsc) {
                // descender (D)
                $p = 1;
                $h = 2;
            } else {
                // tracker (T)
                $p = 1;
                $h = 1;
            }
            $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => $h, 'p' => $p);
            $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
            $bararray['maxw'] += 2;
        }
        unset($bararray['bcode'][($k - 1)]);
        --$bararray['maxw'];

        return $bararray;
    }

    /**
     * IMB - Intelligent Mail Barcode - Onecode - USPS-B-3200
     *
     * @param $code (string) pre-formatted IMB barcode (65 chars "FADT")
     * @return array barcode representation.
     * @protected
     */
    protected function barcode_imb_pre($code)
    {
        if ( ! preg_match('/^[fadtFADT]{65}$/', $code) == 1) {
            throw new InvalidFormatException();
        }
        $characters = str_split(strtolower($code), 1);
        // build bars
        $k = 0;
        $bararray = array('code' => $code, 'maxw' => 0, 'maxh' => 3, 'bcode' => array());
        for ($i = 0; $i < 65; ++$i) {
            switch ($characters[$i]) {
                case 'f': {
                    // full bar
                    $p = 0;
                    $h = 3;
                    break;
                }
                case 'a': {
                    // ascender
                    $p = 0;
                    $h = 2;
                    break;
                }
                case 'd': {
                    // descender
                    $p = 1;
                    $h = 2;
                    break;
                }
                case 't': {
                    // tracker (short)
                    $p = 1;
                    $h = 1;
                    break;
                }
            }
            $bararray['bcode'][$k++] = array('t' => 1, 'w' => 1, 'h' => $h, 'p' => $p);
            $bararray['bcode'][$k++] = array('t' => 0, 'w' => 1, 'h' => 2, 'p' => 0);
            $bararray['maxw'] += 2;
        }
        unset($bararray['bcode'][($k - 1)]);
        --$bararray['maxw'];

        return $bararray;
    }

    /**
     * Convert large integer number to hexadecimal representation.
     * (requires PHP bcmath extension)
     *
     * @param $number (string) number to convert specified as a string
     * @return string hexadecimal representation
     */
    protected function dec_to_hex($number)
    {
        if ($number == 0) {
            return '00';
        }

        $hex = [];

        while ($number > 0) {
            array_push($hex, strtoupper(dechex(bcmod($number, '16'))));
            $number = bcdiv($number, '16', 0);
        }
        $hex = array_reverse($hex);

        return implode($hex);
    }

    /**
     * Convert large hexadecimal number to decimal representation (string).
     * (requires PHP bcmath extension)
     *
     * @param $hex (string) hexadecimal number to convert specified as a string
     * @return string hexadecimal representation
     */
    protected function hex_to_dec($hex)
    {
        $dec = 0;
        $bitval = 1;
        $len = strlen($hex);
        for ($pos = ($len - 1); $pos >= 0; --$pos) {
            $dec = bcadd($dec, bcmul(hexdec($hex[$pos]), $bitval));
            $bitval = bcmul($bitval, 16);
        }

        return $dec;
    }

    /**
     * Intelligent Mail Barcode calculation of Frame Check Sequence
     *
     * @param $code_arr (string) array of hexadecimal values (13 bytes holding 102 bits right justified).
     * @return int 11 bit Frame Check Sequence as integer (decimal base)
     * @protected
     */
    protected function imb_crc11fcs($code_arr)
    {
        $genpoly = 0x0F35; // generator polynomial
        $fcs = 0x07FF; // Frame Check Sequence
        // do most significant byte skipping the 2 most significant bits
        $data = hexdec($code_arr[0]) << 5;
        for ($bit = 2; $bit < 8; ++$bit) {
            if (($fcs ^ $data) & 0x400) {
                $fcs = ($fcs << 1) ^ $genpoly;
            } else {
                $fcs = ($fcs << 1);
            }
            $fcs &= 0x7FF;
            $data <<= 1;
        }
        // do rest of bytes
        for ($byte = 1; $byte < 13; ++$byte) {
            $data = hexdec($code_arr[$byte]) << 3;
            for ($bit = 0; $bit < 8; ++$bit) {
                if (($fcs ^ $data) & 0x400) {
                    $fcs = ($fcs << 1) ^ $genpoly;
                } else {
                    $fcs = ($fcs << 1);
                }
                $fcs &= 0x7FF;
                $data <<= 1;
            }
        }

        return $fcs;
    }

    /**
     * Reverse unsigned short value
     *
     * @param $num (int) value to reversr
     * @return int reversed value
     * @protected
     */
    protected function imb_reverse_us($num)
    {
        $rev = 0;
        for ($i = 0; $i < 16; ++$i) {
            $rev <<= 1;
            $rev |= ($num & 1);
            $num >>= 1;
        }

        return $rev;
    }

    /**
     * generate Nof13 tables used for Intelligent Mail Barcode
     *
     * @param $n (int) is the type of table: 2 for 2of13 table, 5 for 5of13table
     * @param $size (int) size of table (78 for n=2 and 1287 for n=5)
     * @return array requested table
     * @protected
     */
    protected function imb_tables($n, $size)
    {
        $table = array();
        $lli = 0; // LUT lower index
        $lui = $size - 1; // LUT upper index
        for ($count = 0; $count < 8192; ++$count) {
            $bit_count = 0;
            for ($bit_index = 0; $bit_index < 13; ++$bit_index) {
                $bit_count += intval(($count & (1 << $bit_index)) != 0);
            }
            // if we don't have the right number of bits on, go on to the next value
            if ($bit_count == $n) {
                $reverse = ($this->imb_reverse_us($count) >> 3);
                // if the reverse is less than count, we have already visited this pair before
                if ($reverse >= $count) {
                    // If count is symmetric, place it at the first free slot from the end of the list.
                    // Otherwise, place it at the first free slot from the beginning of the list AND place $reverse ath the next free slot from the beginning of the list
                    if ($reverse == $count) {
                        $table[$lui] = $count;
                        --$lui;
                    } else {
                        $table[$lli] = $count;
                        ++$lli;
                        $table[$lli] = $reverse;
                        ++$lli;
                    }
                }
            }
        }

        return $table;
    }

    protected function convertBarcodeArrayToNewStyle($oldBarcodeArray)
    {
        $newBarcodeArray = [];
        $newBarcodeArray['code'] = $oldBarcodeArray['code'];
        $newBarcodeArray['maxWidth'] = $oldBarcodeArray['maxw'];
        $newBarcodeArray['maxHeight'] = $oldBarcodeArray['maxh'];
        $newBarcodeArray['bars'] = [];
        foreach ($oldBarcodeArray['bcode'] as $oldbar) {
            $newBar = [];
            $newBar['width'] = $oldbar['w'];
            $newBar['height'] = $oldbar['h'];
            $newBar['positionVertical'] = $oldbar['p'];
            $newBar['drawBar'] = $oldbar['t'];
            $newBar['drawSpacing'] = ! $oldbar['t'];

            $newBarcodeArray['bars'][] = $newBar;
        }

        return $newBarcodeArray;
    }
}