path: root/tools/gen_code_vectors.py

#!/usr/bin/env python3
# Author:  cirakg & claude ai
# Summary: Generate test/data/CodeVectors.mc: zxing-cpp reference module rows for the linear barcode encoders.
"""Reference module rows for README 12.4 check 1 (all fake payloads).

For every linear symbology: fixed edge cases plus seeded random payloads,
each with the options the watch uses and zxing-cpp's module row. Where the
watch adds something zxing doesn't (a Code 39 or ITF check character, Codabar
start/stop characters), the reference is made from the completed text.

    gen_code_vectors.py [--seed 1212] [--count 25] [--out test/data/CodeVectors.mc]
"""

from __future__ import annotations

import argparse
import random
import re
import string
from pathlib import Path
from typing import Any, cast

import barcode_ref as ref
import segno

CHECK_ADD, CHECK_FIX, CHECK_OFF = 0, 1, 2
TEXT_ON = 0x10


def options(check: int) -> int:
    return TEXT_ON | (check << 2) | 1


def digits(rng: random.Random, n: int) -> str:
    return "".join(rng.choice(string.digits) for _ in range(n))


def valid_upce(rng: random.Random) -> str:
    """Six UPC-E digits that are a canonical zero suppression."""
    while True:
        d = digits(rng, 6)
        last = d[5]
        if (last == "3" and d[2] in "012") or (last == "4" and d[3] == "0") or (last in "56789" and d[4] == "0"):
            continue
        return d


def cases(rng: random.Random, count: int) -> list[tuple[int, str, int, str]]:
    """(symbology, payload, options, zxing text) tuples."""
    out: list[tuple[int, str, int, str]] = []
    fixed = [
        (ref.EAN13, "590123412345", options(CHECK_ADD), "590123412345"),
        (ref.EAN13, "5901234123457", options(CHECK_ADD), "5901234123457"),
        (ref.EAN8, "1234567", options(CHECK_ADD), "1234567"),
        (ref.UPCA, "01234567890", options(CHECK_ADD), "01234567890"),
        (ref.UPCE, "0425261", options(CHECK_ADD), "0425261"),
        (ref.UPCE, "1234565", options(CHECK_ADD), "1234565"),
        (ref.CODE128, "1234", options(CHECK_ADD), "1234"),
        (ref.CODE128, "123456789", options(CHECK_ADD), "123456789"),
        (ref.CODE128, "AB12345678", options(CHECK_ADD), "AB12345678"),
        (ref.CODE128, "A1234B12345", options(CHECK_ADD), "A1234B12345"),
        (ref.CODE128, " ~", options(CHECK_ADD), " ~"),
        (ref.CODE39, "CODE 39", options(CHECK_OFF), "CODE 39"),
        (ref.CODE39, "CODE-39", options(CHECK_ADD), "CODE-39" + ref.code39_check("CODE-39")),
        (ref.ITF, "1234", options(CHECK_OFF), "1234"),
        (ref.ITF, "123", options(CHECK_ADD), "123" + str(ref.gs1_check("123"))),
        (ref.CODABAR, "A40156B", options(CHECK_ADD), "A40156B"),
        (ref.CODABAR, "31117013206375", options(CHECK_ADD), "A31117013206375A"),
    ]
    out.extend(fixed)
    printable = string.ascii_letters + string.digits + " !#$%&()*+,-./:;<=>?@[]^_{|}~"
    for _ in range(count):
        out.append((ref.EAN13, digits(rng, 12), options(CHECK_ADD), ""))
        out.append((ref.EAN8, digits(rng, 7), options(CHECK_ADD), ""))
        out.append((ref.UPCA, digits(rng, 11), options(CHECK_ADD), ""))
        out.append((ref.UPCE, rng.choice("01") + valid_upce(rng), options(CHECK_ADD), ""))
        n = rng.randint(1, 20)
        mixed = "".join(rng.choice(string.digits) if rng.random() < 0.5 else rng.choice(printable) for _ in range(n))
        out.append((ref.CODE128, mixed, options(CHECK_ADD), mixed))
        c39 = "".join(rng.choice(ref.CODE39_ALPHABET) for _ in range(rng.randint(1, 12)))
        with_check = rng.random() < 0.5
        out.append(
            (
                ref.CODE39,
                c39,
                options(CHECK_ADD if with_check else CHECK_OFF),
                c39 + ref.code39_check(c39) if with_check else c39,
            )
        )
        itf = digits(rng, 2 * rng.randint(1, 8))
        out.append((ref.ITF, itf, options(CHECK_OFF), itf))
        inner = "".join(rng.choice("0123456789-$:/.+") for _ in range(rng.randint(1, 12)))
        guard = rng.choice("ABCD") + inner + rng.choice("ABCD")
        out.append((ref.CODABAR, guard, options(CHECK_ADD), guard))
    return out


QR_LEVELS = "LMQH"
LEVEL_CONSTS = [
    segno.consts.ERROR_LEVEL_L,
    segno.consts.ERROR_LEVEL_M,
    segno.consts.ERROR_LEVEL_Q,
    segno.consts.ERROR_LEVEL_H,
]


def qr_cases(rng: random.Random, count: int) -> list[tuple[str, int, int, int]]:
    """(payload, level 0-3, version 0 = auto, mask -1 = auto) for QR.

    Single-mode payloads only (numeric, alphanumeric or bytes), so segno's
    one-segment encoding and the watch's optimal segmentation agree: a digit
    run inside other text would be a cheaper numeric segment on the watch.
    Mixed content is covered by the decoding check instead.
    """
    fixed = [
        ("01234567", 1, 1, 2),
        ("HELLO WORLD", 2, 1, 6),
        ("hello, world", 0, 2, 0),
        ("Zürich ✓ fake", 1, 5, 3),
        ("https://example.com/member/abc", 1, 0, -1),
        ("314159265358979323846264338327950288419716939937510", 3, 0, -1),
        ("THE QUICK BROWN FOX 0123456789 $%*+-./:", 2, 7, 4),
        ("v" * 120, 1, 10, 5),
        ("Z" * 300, 0, 0, -1),
        ("9" * 700, 1, 0, -1),
        ("byte data " * 40, 3, 0, -1),
    ]
    out = list(fixed)
    for _ in range(count):
        kind = rng.randrange(3)
        n = rng.randint(1, 60)
        if kind == 0:
            payload = digits(rng, n)
        elif kind == 1:
            payload = "".join(rng.choice("ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 $%*+-./:") for _ in range(n))
            if payload.isdigit():
                payload += "A"
        else:
            payload = "".join(rng.choice(string.ascii_lowercase + "!?,;") for _ in range(n))
        if not payload.isdigit() and re.search(r"\d{4,}", payload):
            continue
        out.append((payload, rng.randrange(4), 0, -1))
    return out


def single_mode_bits(payload: str, version: int) -> int:
    """Bits of payload as one numeric, alphanumeric or byte segment."""
    c = 0 if version <= 9 else (1 if version <= 26 else 2)
    if payload.isdigit():
        n = len(payload)
        return 4 + (10, 12, 14)[c] + 10 * (n // 3) + (0, 4, 7)[n % 3]
    if all(ch in "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:" for ch in payload):
        n = len(payload)
        return 4 + (9, 11, 13)[c] + 11 * (n // 2) + 6 * (n % 2)
    return 4 + (8, 16, 16)[c] + 8 * len(payload.encode())


def segno_pads_extra_byte(payload: str, level: int, version: int) -> bool:
    """True when segno would insert an extra zero byte: after the terminator
    its write_padding_bits adds 8 - (length % 8) bits even when the stream
    already ends on a codeword boundary (ISO/IEC 18004 7.4.10 adds none).
    The watch follows the standard, so such payloads make no exact reference."""
    groups = cast(dict[int, dict[int, tuple[Any, ...]]], segno.consts.ECC)[version][LEVEL_CONSTS[level]]
    capacity = 8 * sum(g.num_blocks * g.num_data for g in groups)
    bits = single_mode_bits(payload, version)
    terminated = bits + min(4, capacity - bits)
    return bool(terminated < capacity and terminated % 8 == 0)


def qr_reference(payload: str, level: int, version: int, mask: int) -> tuple[int, int, str]:
    """segno's (version, mask, matrix as hex of row-major bits) for the case."""
    qr = segno.make_qr(
        payload,
        error=QR_LEVELS[level],
        version=version or None,
        mask=None if mask < 0 else mask,
        boost_error=False,
        encoding="utf-8",
    )
    bits = "".join(str(b) for row in qr.matrix for b in row)
    bits += "0" * (-len(bits) % 8)
    packed = bytes(int(bits[i : i + 8], 2) for i in range(0, len(bits), 8))
    return int(qr.designator.split("-")[0]), qr.mask, packed.hex()


def render(rows: list[tuple[int, str, int, str]], seed: int) -> str:
    lines = []
    for symbology, payload, opts, text in rows:
        modules = ref.reference_modules(symbology, text or payload)
        escaped = payload.replace("\\", "\\\\").replace('"', '\\"')
        lines.append(f'        [{symbology}, "{escaped}", {opts}, "{modules}"]')
    body = ",\n".join(lines)
    qr_lines = []
    for case in qr_cases(random.Random(seed + 1), 20):
        payload, level, version, mask = case
        ref_version, ref_mask, hexbits = qr_reference(payload, level, version, mask)
        while segno_pads_extra_byte(payload, level, ref_version):
            # Lengthen by one character of the same kind until segno's padding
            # quirk doesn't apply.
            payload += payload[-1]
            ref_version, ref_mask, hexbits = qr_reference(payload, level, version, mask)
        escaped = payload.replace("\\", "\\\\").replace('"', '\\"')
        qr_lines.append(f'        ["{escaped}", {level}, {version}, {mask}, {ref_version}, {ref_mask}, "{hexbits}"]')
    qr_body = ",\n".join(qr_lines)
    return (
        "// Author:  cirakg & claude ai\n"
        "// Summary: zxing-cpp reference module rows for the linear barcode encoders (generated; do not edit).\n"
        f"//\n// Generated by tools/gen_code_vectors.py, seed {seed}. Rows: [symbology, payload, options,\n"
        "// expected modules without quiet zones]. Fake payloads only.\n\n"
        "import Toybox.Lang;\n\n(:test)\nmodule CodeVectors {\n    const LINEAR = [\n"
        + body
        + "\n    ];\n\n    // [payload, level, version (0 auto), mask (-1 auto), segno version, segno mask,\n"
        + "    //  segno matrix as hex of row-major bits]\n    const QR = [\n"
        + qr_body
        + "\n    ];\n}\n"
    )


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
    parser.add_argument("--seed", type=int, default=1212)
    parser.add_argument("--count", type=int, default=25)
    parser.add_argument("--out", type=Path, default=Path("test/data/CodeVectors.mc"))
    args = parser.parse_args(argv)
    rows = cases(random.Random(args.seed), args.count)
    args.out.write_text(render(rows, args.seed), encoding="utf-8")
    print(f"wrote {len(rows)} reference rows to {args.out}")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())