binaryclock_print.py

#!/usr/bin/env python3
"""Print a binary clock on the S01 thermal printer.

Shows the current time as binary-coded decimal: six columns (HH MM SS), each a
stack of bits worth 8/4/2/1 from top to bottom. A filled dot is 1, hollow is 0.
Read each column, add the lit values, and you get that digit.

Examples:
    python binaryclock_print.py
    python binaryclock_print.py --no-print
"""
from __future__ import annotations

import argparse
from datetime import datetime
from pathlib import Path

from PIL import Image, ImageDraw

from print_common import ROOT, Card, font

BITS = [8, 4, 2, 1]


def draw_clock(h: int, m: int, s: int, w: int) -> Image.Image:
    digits = [h // 10, h % 10, m // 10, m % 10, s // 10, s % 10]
    r = 11
    gap = 8
    group_gap = 16
    left = 26
    # x position of each of the 6 columns (with extra space between HH MM SS)
    xs = []
    x = left
    for i in range(6):
        xs.append(x)
        x += 2 * r + gap + (group_gap if i % 2 == 1 else 0)
    top = 22
    img_w = xs[-1] + 2 * r + 10
    img_h = top + 4 * (2 * r + gap) + 18
    img = Image.new("L", (img_w, img_h), 255)
    d = ImageDraw.Draw(img)
    lab = font(True, 13)

    for row, bit in enumerate(BITS):
        cy = top + row * (2 * r + gap) + r
        d.text((left - 8, cy), str(bit), fill=0, font=lab, anchor="rm")  # 8/4/2/1 labels
        for col, dig in enumerate(digits):
            cx = xs[col] + r
            box = (cx - r, cy - r, cx + r, cy + r)
            if dig & bit:
                d.ellipse(box, fill=0)
            else:
                d.ellipse(box, outline=0, width=2)
    # decimal digit under each column
    by = top + 4 * (2 * r + gap) + 2
    for col, dig in enumerate(digits):
        d.text((xs[col] + r, by), str(dig), fill=0, font=lab, anchor="ma")
    return img


def main() -> int:
    parser = argparse.ArgumentParser(description="Print a binary clock on the S01 thermal printer.")
    parser.add_argument("--out", type=Path, default=ROOT / "binaryclock.png")
    parser.add_argument("--darkness", type=int, choices=range(1, 6), default=3)
    parser.add_argument("--bottom-feed", type=int, default=24)
    parser.add_argument("--no-print", action="store_true")
    args = parser.parse_args()

    now = datetime.now()
    print(f"Binary clock for {now:%H:%M:%S}")

    card = Card()
    card.title("BINARY CLOCK")
    card.line("HH  MM  SS  -  filled = 1", size=11, bold=False, center=True)
    card.gap(4).image(draw_clock(now.hour, now.minute, now.second, card.inner_w))
    card.gap(2).heading(now.strftime("%H:%M:%S"), size=22)
    card.footer("binary-coded decimal", now.strftime("%Y-%m-%d"))
    return card.finish(args.out, args.bottom_feed, args.darkness, do_print=not args.no_print)


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