zint/backend/maxicode.c

/* maxicode.c - Handles MaxiCode */
/*
    libzint - the open source barcode library
    Copyright (C) 2010-2024 Robin Stuart <rstuart114@gmail.com>

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. Neither the name of the project nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.
 */
/* SPDX-License-Identifier: BSD-3-Clause */

/* Includes corrections thanks to Monica Swanson @ Source Technologies */
#include <assert.h>
#include <stdio.h>
#include "common.h"
#include "maxicode.h"
#include "reedsol.h"

/* Handles error correction of primary message */
static void maxi_do_primary_check(unsigned char maxi_codeword[144]) {
    unsigned char results[15];
    int j;
    int datalen = 10;
    int ecclen = 10;
    rs_t rs;

    rs_init_gf(&rs, 0x43);
    rs_init_code(&rs, ecclen, 1);

    rs_encode(&rs, datalen, maxi_codeword, results);

    for (j = 0; j < ecclen; j += 1)
        maxi_codeword[ datalen + j] = results[ecclen - 1 - j];
}

/* Handles error correction of odd characters in secondary */
static void maxi_do_secondary_chk_odd(unsigned char maxi_codeword[144], const int ecclen) {
    unsigned char data[100];
    unsigned char results[30];
    int j;
    int datalen = 68;
    rs_t rs;

    rs_init_gf(&rs, 0x43);
    rs_init_code(&rs, ecclen, 1);

    if (ecclen == 20)
        datalen = 84;

    for (j = 1; j < datalen; j += 2)
        data[(j - 1) / 2] = maxi_codeword[j + 20];

    rs_encode(&rs, datalen / 2, data, results);

    for (j = 0; j < (ecclen); j += 1)
        maxi_codeword[ datalen + (2 * j) + 1 + 20 ] = results[ecclen - 1 - j];
}

/* Handles error correction of even characters in secondary */
static void maxi_do_secondary_chk_even(unsigned char maxi_codeword[144], const int ecclen) {
    unsigned char data[100];
    unsigned char results[30];
    int j;
    int datalen = 68;
    rs_t rs;

    if (ecclen == 20)
        datalen = 84;

    rs_init_gf(&rs, 0x43);
    rs_init_code(&rs, ecclen, 1);

    for (j = 0; j < datalen + 1; j += 2)
        data[j / 2] = maxi_codeword[j + 20];

    rs_encode(&rs, datalen / 2, data, results);

    for (j = 0; j < (ecclen); j += 1)
        maxi_codeword[ datalen + (2 * j) + 20] = results[ecclen - 1 - j];
}

/* Moves everything up so that a shift or latch can be inserted */
static void maxi_bump(unsigned char set[], unsigned char character[], const int bump_posn, int *p_length) {

    if (bump_posn < 143) {
        memmove(set + bump_posn + 1, set + bump_posn, 143 - bump_posn);
        memmove(character + bump_posn + 1, character + bump_posn, 143 - bump_posn);
    }
    (*p_length)++; /* Increment length regardless to make sure too long always triggered */
}

/* If the value is present in  array, return the value, else return badvalue */
static int maxi_value_in_array(const unsigned char val, const unsigned char arr[], const int badvalue,
            const int arrLength) {
    int i;
    for (i = 0; i < arrLength; i++) {
        if (arr[i] == val) return val;
    }
    return badvalue;
}

/* Choose the best set from previous and next set in the range of the setval array, if no value can be found we
 * return setval[0] */
static int maxi_bestSurroundingSet(const int index, const int length, const unsigned char set[], const int sp,
            const unsigned char setval[], const int setLength) {
    int badValue = -1;
    int option1 = maxi_value_in_array(set[sp + index - 1], setval, badValue, setLength);
    if (index + 1 < length) {
        /* we have two options to check (previous & next) */
        int option2 = maxi_value_in_array(set[sp + index + 1], setval, badValue, setLength);
        if (option2 != badValue && option1 > option2) {
            return option2;
        }
    }

    if (option1 != badValue) {
        return option1;
    }
    return setval[0];
}

/* Format text according to Appendix A */
static int maxi_text_process(unsigned char set[144], unsigned char character[144], const unsigned char in_source[],
            int length, const int eci, const int scm_vv, int *p_sp, int current_set, const int debug_print) {

    int sp = *p_sp;
    int i, count;
#ifndef NDEBUG
    int ns_count1 = 0, ns_count2 = 0;
#endif

    static const unsigned char set15[2] = { 1, 5 };
    static const unsigned char set12[2] = { 1, 2 };
    static const unsigned char set12345[5] = { 1, 2, 3, 4, 5 };

    const unsigned char *source = in_source;
    unsigned char *source_buf = (unsigned char *) z_alloca(length + 9); /* For prefixing 9-character SCM sequence */

    if (sp + length > 144) {
        return 0;
    }

    /* Insert ECI at the beginning of message if needed */
    /* Encode ECI assignment numbers according to table 3 */
    if (eci != 0) {
        if (sp + 1 + length > 144) return 0;
        character[sp++] = 27; /* ECI */
        if (eci <= 31) {
            if (sp + 1 + length > 144) return 0;
            character[sp++] = eci;
        } else if (eci <= 1023) {
            if (sp + 2 + length > 144) return 0;
            character[sp++] = 0x20 | ((eci >> 6) & 0x0F);
            character[sp++] = eci & 0x3F;
        } else if (eci <= 32767) {
            if (sp + 3 + length > 144) return 0;
            character[sp++] = 0x30 | ((eci >> 12) & 0x07);
            character[sp++] = (eci >> 6) & 0x3F;
            character[sp++] = eci & 0x3F;
        } else {
            if (sp + 4 + length > 144) return 0;
            character[sp++] = 0x38 | ((eci >> 18) & 0x03);
            character[sp++] = (eci >> 12) & 0x3F;
            character[sp++] = (eci >> 6) & 0x3F;
            character[sp++] = eci & 0x3F;
        }
    }

    if (scm_vv != -1) { /* Add SCM prefix */
        if (sp + length > 135) {
            return 0;
        }
        sprintf((char *) source_buf, "[)>\03601\035%02d", scm_vv); /* [)>\R01\Gvv */
        memcpy(source_buf + 9, in_source, length);
        source = source_buf;
        length += 9;
    }

    for (i = 0; i < length; i++) {
        /* Look up characters in table from Appendix A - this gives
         value and code set for most characters */
        set[sp + i] = maxiCodeSet[source[i]];
        character[sp + i] = maxiSymbolChar[source[i]];
    }

    /* If a character can be represented in more than one code set,
    pick which version to use */
    if (set[sp + 0] == 0) {
        if (character[sp + 0] == 13) {
            character[sp + 0] = 0;
        }
        set[sp + 0] = 1;
    }

    for (i = 1; i < length; i++) {
        if (set[sp + i] == 0) {
            /* Special character */
            if (character[sp + i] == 13) {
                /* Carriage Return */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set15, 2);
                if (set[sp + i] == 5) {
                    character[sp + i] = 13;
                } else {
                    character[sp + i] = 0;
                }

            } else if (character[sp + i] == 28) {
                /* FS */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12345, 5);
                if (set[sp + i] == 5) {
                    character[sp + i] = 32;
                }

            } else if (character[sp + i] == 29) {
                /* GS */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12345, 5);
                if (set[sp + i] == 5) {
                    character[sp + i] = 33;
                }

            } else if (character[sp + i] == 30) {
                /* RS */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12345, 5);
                if (set[sp + i] == 5) {
                    character[sp + i] = 34;
                }

            } else if (character[sp + i] == 32) {
                /* Space */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12345, 5);
                if (set[sp + i] == 1) {
                    character[sp + i] = 32;
                } else if (set[sp + i] == 2) {
                    character[sp + i] = 47;
                } else {
                    character[sp + i] = 59;
                }

            } else if (character[sp + i] == 44) {
                /* Comma */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12, 2);
                if (set[sp + i] == 2) {
                    character[sp + i] = 48;
                }

            } else if (character[sp + i] == 46) {
                /* Full Stop */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12, 2);
                if (set[sp + i] == 2) {
                    character[sp + i] = 49;
                }

            } else if (character[sp + i] == 47) {
                /* Slash */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12, 2);
                if (set[sp + i] == 2) {
                    character[sp + i] = 50;
                }

            } else if (character[sp + i] == 58) {
                /* Colon */
                set[sp + i] = maxi_bestSurroundingSet(i, length, set, sp, set12, 2);
                if (set[sp + i] == 2) {
                    character[sp + i] = 51;
                }
            }
        }
    }

    /* Find candidates for number compression */
    /* Note the prohibition on number compression in the primary message in ISO/IEC 16023:2000 B.1 (1)
       applies to modes 2 & 3 only */
    count = 0;
    for (i = 0; sp + i < 144 && sp + i < length; i++) {
        if ((set[sp + i] == 1) && ((character[sp + i] >= 48) && (character[sp + i] <= 57))) {
            /* Character is a number */
            count++;
            if (count == 9) {
                /* Nine digits in a row can be compressed */
                memset(set + sp + i - 8, 6, 9); /* Set set of nine digits to 6 */
                count = 0;
#ifndef NDEBUG
                ns_count1++;
#endif
            }
        } else {
            count = 0;
        }
    }

    /* Add shift and latch characters */
    for (i = 0; sp + i < 144 && set[sp + i] != 255; i++) {

        if ((set[sp + i] != current_set) && (set[sp + i] != 6)) {
            switch (set[sp + i]) {
                case 1:
                    if (current_set == 2) { /* Set B */
                        if (sp + i + 1 < 144 && set[sp + i + 1] == 1) {
                            if (sp + i + 2 < 144 && set[sp + i + 2] == 1) {
                                if (sp + i + 3 < 144 && set[sp + i + 3] == 1) {
                                    /* Latch A */
                                    maxi_bump(set, character, sp + i, &length);
                                    character[sp + i] = 63; /* Set B Latch A */
                                    current_set = 1;
                                    i += 3; /* Next 3 Set A so skip over */
                                    if (debug_print) fputs("LCHA ", stdout);
                                } else {
                                    /* 3 Shift A */
                                    maxi_bump(set, character, sp + i, &length);
                                    character[sp + i] = 57; /* Set B triple shift A */
                                    i += 2; /* Next 2 Set A so skip over */
                                    if (debug_print) fputs("3SHA ", stdout);
                                }
                            } else {
                                /* 2 Shift A */
                                maxi_bump(set, character, sp + i, &length);
                                character[sp + i] = 56; /* Set B double shift A */
                                i++; /* Next Set A so skip over */
                                if (debug_print) fputs("2SHA ", stdout);
                            }
                        } else {
                            /* Shift A */
                            maxi_bump(set, character, sp + i, &length);
                            character[sp + i] = 59; /* Set A Shift B */
                            if (debug_print) fputs("SHA ", stdout);
                        }
                    } else { /* All sets other than B only have latch */
                        /* Latch A */
                        maxi_bump(set, character, sp + i, &length);
                        character[sp + i] = 58; /* Sets C,D,E Latch A */
                        current_set = 1;
                        if (debug_print) fputs("LCHA ", stdout);
                    }
                    break;
                case 2: /* Set B */
                    /* If not Set A or next Set B */
                    if (current_set != 1 || (sp + i + 1 < 144 && set[sp + i + 1] == 2)) {
                        /* Latch B */
                        maxi_bump(set, character, sp + i, &length);
                        character[sp + i] = 63; /* Sets A,C,D,E Latch B */
                        current_set = 2;
                        if (debug_print) fputs("LCHB ", stdout);
                    } else { /* Only available from Set A */
                        /* Shift B */
                        maxi_bump(set, character, sp + i, &length);
                        character[sp + i] = 59; /* Set B Shift A */
                        if (debug_print) fputs("SHB ", stdout);
                    }
                    break;
                case 3: /* Set C */
                case 4: /* Set D */
                case 5: /* Set E */
                    /* If first and next 3 same set, or not first and previous and next 2 same set */
                    if ((sp + i == 0 && sp + i + 3 < 144 && set[sp + i + 1] == set[sp + i]
                                && set[sp + i + 2] == set[sp + i] && set[sp + i + 3] == set[sp + i])
                            || (sp + i > 0 && set[sp + i - 1] == set[sp + i] && sp + i + 2 < 144
                                && set[sp + i + 1] == set[sp + i] && set[sp + i + 2] == set[sp + i])) {
                        /* Lock in C/D/E */
                        if (sp + i == 0) {
                            maxi_bump(set, character, sp + i, &length);
                            character[sp + i] = 60 + set[sp + i] - 3;
                            i++; /* Extra bump */
                            maxi_bump(set, character, sp + i, &length);
                            character[sp + i] = 60 + set[sp + i] - 3;
                            i += 3; /* Next 3 same set so skip over */
                        } else {
                            /* Add single Shift to previous Shift */
                            maxi_bump(set, character, sp + i - 1, &length);
                            character[sp + i - 1] = 60 + set[sp + i] - 3;
                            i += 2; /* Next 2 same set so skip over */
                        }
                        current_set = set[sp + i];
                        if (debug_print) printf("LCK%c ", 'C' + set[sp + i] - 3);
                    } else {
                        /* Shift C/D/E */
                        maxi_bump(set, character, sp + i, &length);
                        character[sp + i] = 60 + set[sp + i] - 3;
                        if (debug_print) printf("SH%c ", 'C' + set[sp + i] - 3);
                    }
                    break;
            }
            i++; /* Allow for bump */
        }
    }

    /* Number compression has not been forgotten! - It's handled below */
    for (i = 0; sp + i < 144 && sp + i <= length - 9; i++) {
        if (set[sp + i] == 6) {
            /* Number compression */
            int value = to_int(character + sp + i, 9);

            character[sp + i] = 31; /* NS */
            character[sp + i + 1] = (value & 0x3f000000) >> 24;
            character[sp + i + 2] = (value & 0xfc0000) >> 18;
            character[sp + i + 3] = (value & 0x3f000) >> 12;
            character[sp + i + 4] = (value & 0xfc0) >> 6;
            character[sp + i + 5] = (value & 0x3f);

            memmove(set + sp + i + 6, set + sp + i + 9, 144 - (sp + i + 9));
            memmove(character + sp + i + 6, character + sp + i + 9, 144 - (sp + i + 9));
            i += 5;
            length -= 3;
#ifndef NDEBUG
            ns_count2++;
#endif
        }
    }
    assert(ns_count1 == ns_count2);

    *p_sp = sp + length;

    return current_set;
}

/* Call `maxi_text_process()` for each segment, dealing with Structured Append beforehand and populating
   `maxi_codeword` afterwards */
static int maxi_text_process_segs(unsigned char maxi_codeword[144], const int mode, const struct zint_seg segs[],
            const int seg_count, const int structapp_cw, int scm_vv, const int debug_print) {
    unsigned char set[144], character[144] = {0};
    int i;
    int sp = 0;
    int current_set = 1; /* Initial Code Set A */
    int padding_set = 0, padding_char = 0; /* Suppress clang-tidy-20 warnings */
    const int max_length = mode == 5 ? 77 : mode <= 3 ? 84 : 93;

    memset(set, 255, 144);

    /* Insert Structured Append at beginning if needed */
    if (structapp_cw) {
        character[sp++] = 33; /* PAD */
        character[sp++] = structapp_cw;
    }

    for (i = 0; i < seg_count; i++) {
        current_set = maxi_text_process(set, character, segs[i].source, segs[i].length, segs[i].eci, scm_vv, &sp,
                        current_set, debug_print);
        if (current_set == 0) {
            return ZINT_ERROR_TOO_LONG;
        }
        scm_vv = -1;
    }

    /* If end in Code Set C or D, switch to A for padding */
    if (sp < max_length && (current_set == 3 || current_set == 4)) {
        set[sp] = 1;
        character[sp] = 58; /* Sets C,D Latch A */
        sp++;
        current_set = 1;
        if (debug_print) fputs("LCHA ", stdout);
    }

    if (debug_print) {
        if (sp < max_length) {
            printf("\nPads (%d)\n", max_length - sp);
        } else {
            fputs("\nNo Pads\n", stdout);
        }
    }

    if (sp < max_length) {
        padding_set = current_set == 5 ? 5 : current_set == 2 ? 2 : 1;
        padding_char = current_set == 5 ? 28 : 33;
        for (; sp < max_length; sp++) {
            /* Add the padding */
            set[sp] = padding_set;
            character[sp] = padding_char;
        }
    }

    if (debug_print) printf("Length: %d\n", sp);

    if (sp > max_length) {
        return ZINT_ERROR_TOO_LONG;
    }

    /* Copy the encoded text into the codeword array */
    if ((mode == 2) || (mode == 3)) {
        for (i = 0; i < 84; i++) { /* secondary only */
            maxi_codeword[i + 20] = character[i];
        }

    } else if ((mode == 4) || (mode == 6)) {
        for (i = 0; i < 9; i++) { /* primary */
            maxi_codeword[i + 1] = character[i];
        }
        for (i = 0; i < 84; i++) { /* secondary */
            maxi_codeword[i + 20] = character[i + 9];
        }

    } else { /* Mode 5 */
        for (i = 0; i < 9; i++) { /* primary */
            maxi_codeword[i + 1] = character[i];
        }
        for (i = 0; i < 68; i++) { /* secondary */
            maxi_codeword[i + 20] = character[i + 9];
        }
    }

    return 0;
}

/* Format structured primary for Mode 2 */
static void maxi_do_primary_2(unsigned char maxi_codeword[144], const unsigned char postcode[],
            const int postcode_length, const int country, const int service) {
    int postcode_num;

    postcode_num = to_int(postcode, postcode_length);

    maxi_codeword[0] = ((postcode_num & 0x03) << 4) | 2;
    maxi_codeword[1] = ((postcode_num & 0xfc) >> 2);
    maxi_codeword[2] = ((postcode_num & 0x3f00) >> 8);
    maxi_codeword[3] = ((postcode_num & 0xfc000) >> 14);
    maxi_codeword[4] = ((postcode_num & 0x3f00000) >> 20);
    maxi_codeword[5] = ((postcode_num & 0x3c000000) >> 26) | ((postcode_length & 0x3) << 4);
    maxi_codeword[6] = ((postcode_length & 0x3c) >> 2) | ((country & 0x3) << 4);
    maxi_codeword[7] = (country & 0xfc) >> 2;
    maxi_codeword[8] = ((country & 0x300) >> 8) | ((service & 0xf) << 2);
    maxi_codeword[9] = ((service & 0x3f0) >> 4);
}

/* Format structured primary for Mode 3 */
static void maxi_do_primary_3(unsigned char maxi_codeword[144], unsigned char postcode[], const int country,
            const int service) {
    int i;

    /* Convert to Code Set A */
    for (i = 0; i < 6; i++) {
        postcode[i] = maxiSymbolChar[postcode[i]];
    }

    maxi_codeword[0] = ((postcode[5] & 0x03) << 4) | 3;
    maxi_codeword[1] = ((postcode[4] & 0x03) << 4) | ((postcode[5] & 0x3c) >> 2);
    maxi_codeword[2] = ((postcode[3] & 0x03) << 4) | ((postcode[4] & 0x3c) >> 2);
    maxi_codeword[3] = ((postcode[2] & 0x03) << 4) | ((postcode[3] & 0x3c) >> 2);
    maxi_codeword[4] = ((postcode[1] & 0x03) << 4) | ((postcode[2] & 0x3c) >> 2);
    maxi_codeword[5] = ((postcode[0] & 0x03) << 4) | ((postcode[1] & 0x3c) >> 2);
    maxi_codeword[6] = ((postcode[0] & 0x3c) >> 2) | ((country & 0x3) << 4);
    maxi_codeword[7] = (country & 0xfc) >> 2;
    maxi_codeword[8] = ((country & 0x300) >> 8) | ((service & 0xf) << 2);
    maxi_codeword[9] = ((service & 0x3f0) >> 4);
}

INTERNAL int maxicode(struct zint_symbol *symbol, struct zint_seg segs[], const int seg_count) {
    int i, j, block, shift, mode, lp = 0;
    int error_number, eclen;
    unsigned char maxi_codeword[144] = {0};
    int scm_vv = -1;
    int structapp_cw = 0;
    const int debug_print = symbol->debug & ZINT_DEBUG_PRINT;

    mode = symbol->option_1;

    if (mode <= 0) { /* If mode is unspecified (-1) or to be auto-determined (0) between 2 and 3 */
        lp = (int) strlen(symbol->primary);
        if (lp == 0) {
            if (mode == 0) { /* Require primary message to auto-determine between 2 and 3 */
                return errtxt(ZINT_ERROR_INVALID_DATA, symbol, 554, "Primary Message empty");
            }
            mode = 4;
        } else {
            mode = 2;
            for (i = 0; i < lp - 6; i++) {
                if (!z_isdigit(symbol->primary[i]) && (symbol->primary[i] != ' ')) {
                    mode = 3;
                    break;
                }
            }
        }
    }

    if ((mode < 2) || (mode > 6)) { /* Only codes 2 to 6 supported */
        return errtxtf(ZINT_ERROR_INVALID_OPTION, symbol, 550, "Mode '%d' out of range (2 to 6)", mode);
    }

    if ((mode == 2) || (mode == 3)) { /* Modes 2 and 3 need data in symbol->primary */
        unsigned char postcode[10];
        int countrycode;
        int service;
        int postcode_len;
        if (lp == 0) { /* Mode set manually means lp doesn't get set */
            lp = (int) strlen(symbol->primary);
        }
        if (lp < 7 || lp > 15) { /* 1 to 9 character postcode + 3 digit country code + 3 digit service class */
            if (lp == 0) {
                return errtxt(ZINT_ERROR_INVALID_DATA, symbol, 548, "Primary Message empty");
            }
            return errtxtf(ZINT_ERROR_INVALID_DATA, symbol, 551, "Primary Message length %d wrong (7 to 15 only)",
                            lp);
        }
        postcode_len = lp - 6;

        countrycode = to_int((const unsigned char *) (symbol->primary + postcode_len), 3);
        service = to_int((const unsigned char *) (symbol->primary + postcode_len + 3), 3);

        if (countrycode == -1 || service == -1) { /* check that country code and service are numeric */
            return errtxt(ZINT_ERROR_INVALID_DATA, symbol, 552,
                            "Non-numeric country code or service class in Primary Message");
        }

        memcpy(postcode, symbol->primary, postcode_len);
        postcode[postcode_len] = '\0';

        if (mode == 2) {
            for (i = 0; i < postcode_len; i++) {
                if (postcode[i] == ' ') {
                    postcode[i] = '\0';
                    postcode_len = i;
                    break;
                } else if (!z_isdigit(postcode[i])) {
                    return errtxt(ZINT_ERROR_INVALID_DATA, symbol, 555, "Non-numeric postcode in Primary Message");
                }
            }
            if (countrycode == 840 && postcode_len == 5) {
                /* Annex B, section B.1, paragraph 4.a, "In the case of country code 840, if the "+4" is unknown,
                   then fill with zeroes" (adapted from OkaiBarcode, stricter interpretation, props Daniel Gredler) */
                memcpy(postcode + 5, "0000", 5); /* Include NUL char */
                postcode_len = 9;
            }
            maxi_do_primary_2(maxi_codeword, postcode, postcode_len, countrycode, service);
        } else {
            /* Just truncate and space-pad */
            postcode[6] = '\0';
            for (i = postcode_len; i < 6; i++) {
                postcode[i] = ' ';
            }
            /* Upper-case and check for Code Set A characters only */
            to_upper(postcode, postcode_len);
            for (i = 0; i < 6; i++) {
                /* Don't allow Code Set A control characters CR, RS, GS and RS */
                if (postcode[i] < ' ' || maxiCodeSet[postcode[i]] > 1) {
                    return errtxt(ZINT_ERROR_INVALID_DATA, symbol, 556,
                                    "Invalid character in postcode in Primary Message");
                }
            }
            maxi_do_primary_3(maxi_codeword, postcode, countrycode, service);
        }

        if (symbol->option_2) { /* Check for option_2 = vv + 1, where vv is version of SCM prefix "[)>\R01\Gvv" */
            if (symbol->option_2 < 0 || symbol->option_2 > 100) {
                return errtxtf(ZINT_ERROR_INVALID_OPTION, symbol, 557,
                                "SCM prefix version '%d' out of range (1 to 100)", symbol->option_2);
            }
            scm_vv = symbol->option_2 - 1;
        }

        if (debug_print) {
            printf("Postcode: %s, Country Code: %d, Service Class: %d\n", postcode, countrycode, service);
        }
    } else {
        maxi_codeword[0] = mode;
    }

    if (debug_print) {
        printf("Mode: %d\n", mode);
    }

    if (symbol->structapp.count) {
        if (symbol->structapp.count < 2 || symbol->structapp.count > 8) {
            return errtxtf(ZINT_ERROR_INVALID_OPTION, symbol, 558,
                            "Structured Append count '%d' out of range (2 to 8)", symbol->structapp.count);
        }
        if (symbol->structapp.index < 1 || symbol->structapp.index > symbol->structapp.count) {
            return errtxtf(ZINT_ERROR_INVALID_OPTION, symbol, 559,
                            "Structured Append index '%1$d' out of range (1 to count %2$d)",
                            symbol->structapp.index, symbol->structapp.count);
        }
        if (symbol->structapp.id[0]) {
            return errtxt(ZINT_ERROR_INVALID_OPTION, symbol, 549, "Structured Append ID not available for MaxiCode");
        }
        structapp_cw = (symbol->structapp.count - 1) | ((symbol->structapp.index - 1) << 3);
    }

    error_number = maxi_text_process_segs(maxi_codeword, mode, segs, seg_count, structapp_cw, scm_vv, debug_print);
    if (error_number == ZINT_ERROR_TOO_LONG) {
        return errtxt(error_number, symbol, 553, "Input too long, requires too many codewords (maximum 144)");
    }

    /* All the data is sorted - now do error correction */
    maxi_do_primary_check(maxi_codeword); /* always EEC */

    if (mode == 5)
        eclen = 56; /* 68 data codewords , 56 error corrections */
    else
        eclen = 40; /* 84 data codewords,  40 error corrections */

    maxi_do_secondary_chk_even(maxi_codeword, eclen / 2); /* do error correction of even */
    maxi_do_secondary_chk_odd(maxi_codeword, eclen / 2); /* do error correction of odd */

    if (debug_print) {
        fputs("Codewords:", stdout);
        for (i = 0; i < 144; i++) printf(" %d", maxi_codeword[i]);
        fputc('\n', stdout);
    }
#ifdef ZINT_TEST
    if (symbol->debug & ZINT_DEBUG_TEST) {
        debug_test_codeword_dump(symbol, maxi_codeword, 144);
    }
#endif

    /* Copy data into symbol grid */
    for (i = 0; i < 33; i++) {
        for (j = 0; j < 30; j++) {
            block = (MaxiGrid[(i * 30) + j] + 5) / 6;

            if (block != 0) {
                shift = 5 - ((MaxiGrid[(i * 30) + j] + 5) % 6);

                if ((maxi_codeword[block - 1] >> shift) & 0x1) {
                    set_module(symbol, i, j);
                }
            }
        }
    }

    /* Add orientation markings */
    set_module(symbol, 0, 28); /* Top right filler */
    set_module(symbol, 0, 29);
    set_module(symbol, 9, 10); /* Top left marker */
    set_module(symbol, 9, 11);
    set_module(symbol, 10, 11);
    set_module(symbol, 15, 7); /* Left hand marker */
    set_module(symbol, 16, 8);
    set_module(symbol, 16, 20); /* Right hand marker */
    set_module(symbol, 17, 20);
    set_module(symbol, 22, 10); /* Bottom left marker */
    set_module(symbol, 23, 10);
    set_module(symbol, 22, 17); /* Bottom right marker */
    set_module(symbol, 23, 17);

    symbol->width = 30;
    symbol->rows = 33;

    /* Note MaxiCode fixed size so symbol height ignored but set anyway */
    (void) set_height(symbol, 5.0f, 0.0f, 0.0f, 1 /*no_errtxt*/);

    return error_number;
}

/* vim: set ts=4 sw=4 et : */