lamp-testbench/crates/lamp-label/tools/golden.py

"""Generate golden data for the Rust lamp-label crate.

Writes into ``crates/lamp-label/tests/golden/``:

* ``qr_matrices.txt``: for each ID, the QR code Python ``qrcode`` 8.2 builds
  for ``render_label`` (ERROR_CORRECT_M, fit=True, automatic mask): a header
  line ``<id> version=<v> mask=<m> size=<n>`` followed by ``n`` rows of
  ``0``/``1`` (1 = dark), quiet zone not included.
* ``label_<id>.png``: the complete 202x202 label from Python ``render_label``.
* ``text_info.txt``: per ID the font, chosen size, PIL text bbox and the draw
  origin used by ``render_label``.

Run with: C:/dev/HPCS/.venv/Scripts/python.exe -W ignore crates/lamp-label/tools/golden.py
"""

import argparse
import importlib.util
import os
import re
from pathlib import Path

import qrcode
from PIL import Image, ImageDraw, ImageFont

OUT = Path(__file__).resolve().parent.parent / "tests" / "golden"
DOTS = (202, 202)
TEXT_HEIGHT = 52

QR_IDS = [f"L{i:04d}" for i in range(1, 21)] + [
    "L0999",
    "L1000",
    "L12345",
    "L123456",
    # mode / version coverage
    "12345678",                                  # numeric mode
    "LAMP-7 X",                                  # alphanumeric with space
    "lamp_7",                                    # upper-cased, '_' -> byte mode
    "https://example.com/lamp/L0006?x=1",        # alnum chunk + byte chunk
    "L" + "0123456789" * 13,                     # byte 'L' + numeric chunk, version 4
    "L" + "ABCDEFGHIJ" * 20,                     # alphanumeric, version 8 (version info)
]
TEXT_IDS = ["L0001", "L0006", "L0123", "L12345", "L9", "L123456", "L0123456789012", "LAVA-7", "WWWWWWWWWW", "lamp_7"]

# ---- verbatim copy of label_printer.py (HPCS) -------------------------------
def _font(size):
    for name in ("arialbd.ttf", "arial.ttf", "DejaVuSans-Bold.ttf"):
        try:
            return ImageFont.truetype(name, size)
        except OSError:
            continue
    return ImageFont.load_default(size)


def render_label(lamp_id: str) -> Image.Image:
    image = Image.new("1", DOTS, 1)
    qr = qrcode.QRCode(
        error_correction=qrcode.constants.ERROR_CORRECT_M,
        box_size=1,
        border=2,
    )
    qr.add_data(lamp_id.upper())
    qr.make(fit=True)
    modules = len(qr.get_matrix())
    qr_size = DOTS[1] - TEXT_HEIGHT
    qr.box_size = max(1, qr_size // modules)
    qr_img = qr.make_image().get_image().convert("1")
    image.paste(qr_img, ((DOTS[0] - qr_img.width) // 2, (qr_size - qr_img.height) // 2))

    draw = ImageDraw.Draw(image)
    size = 44
    while size > 10:
        font = _font(size)
        box = draw.textbbox((0, 0), lamp_id, font=font)
        if box[2] - box[0] <= DOTS[0] - 8:
            break
        size -= 2
    draw.text(
        ((DOTS[0] - (box[2] - box[0])) // 2 - box[0], DOTS[1] - TEXT_HEIGHT + (TEXT_HEIGHT - (box[3] - box[1])) // 2 - box[1]),
        lamp_id,
        font=font,
        fill=0,
    )
    return image
# -----------------------------------------------------------------------------


def text_layout(lamp_id):
    """Same loop as render_label, returning what it decided."""
    draw = ImageDraw.Draw(Image.new("1", DOTS, 1))
    size = 44
    while size > 10:
        font = _font(size)
        box = draw.textbbox((0, 0), lamp_id, font=font)
        if box[2] - box[0] <= DOTS[0] - 8:
            break
        size -= 2
    origin = (
        (DOTS[0] - (box[2] - box[0])) // 2 - box[0],
        DOTS[1] - TEXT_HEIGHT + (TEXT_HEIGHT - (box[3] - box[1])) // 2 - box[1],
    )
    return font, size, box, origin


def file_safe(lamp_id):
    return re.sub(r"[^A-Za-z0-9_-]", "_", lamp_id)[:40]


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--reference", default=os.environ.get("LABEL_PRINTER_PY"))
    args = ap.parse_args()
    reference = None
    if args.reference and Path(args.reference).exists():
        spec = importlib.util.spec_from_file_location("label_printer_ref", args.reference)
        reference = importlib.util.module_from_spec(spec)
        spec.loader.exec_module(reference)

    OUT.mkdir(parents=True, exist_ok=True)
    for f in OUT.iterdir():
        if f.suffix in (".png", ".txt"):
            f.unlink()

    lines = []
    for lamp_id in QR_IDS:
        qr = qrcode.QRCode(error_correction=qrcode.constants.ERROR_CORRECT_M, box_size=1, border=2)
        qr.add_data(lamp_id.upper())
        qr.make(fit=True)
        mask = qr.best_mask_pattern()  # deterministic; same choice make() used
        qr.make(fit=True)
        n = qr.modules_count
        lines.append(f"{lamp_id} version={qr.version} mask={mask} size={n}")
        for row in qr.modules:
            lines.append("".join("1" if m else "0" for m in row))
    (OUT / "qr_matrices.txt").write_bytes(("\n".join(lines) + "\n").encode("utf-8"))

    names = []
    for lamp_id in dict.fromkeys(QR_IDS + TEXT_IDS):
        im = render_label(lamp_id)
        if reference is not None:
            assert reference.render_label(lamp_id).tobytes() == im.tobytes(), lamp_id
        name = f"label_{file_safe(lamp_id)}.png"
        im.save(OUT / name)
        names.append(f"{lamp_id}\t{name}")
    (OUT / "labels.txt").write_bytes(("\n".join(names) + "\n").encode("utf-8"))

    info = []
    for lamp_id in TEXT_IDS:
        font, size, box, origin = text_layout(lamp_id)
        path = Path(getattr(font, "path", "builtin")).name
        info.append(
            f"{lamp_id}\tfont={path}\tsize={size}\tbbox={box[0]},{box[1]},{box[2]},{box[3]}\torigin={origin[0]},{origin[1]}"
        )
    (OUT / "text_info.txt").write_bytes(("\n".join(info) + "\n").encode("utf-8"))
    print(f"{len(QR_IDS)} QR matrices, {len(names)} labels, {len(info)} text layouts -> {OUT}")
    print("reference render_label checked" if reference else "reference render_label NOT checked")
    for line in info:
        print(line)


if __name__ == "__main__":
    main()