#!/usr/bin/env python3
"""Add John's 24x55mm label stock to the generic CUPS DYMO PPD.

The macOS-supplied generic dymo.ppd (ModelName "DYMO Label Printer") ships 10 fixed
label sizes and NO CustomPageSize block -- so a "custom paper size" made in the macOS
page-setup dialog can never reach the printer, and CUPS silently falls back to
w81h252 (Address, 28.6 x 88.9 mm). That is why the label prints rotated and shrunk.

We add BOTH orientations so the correct one can be picked in the print dialog:
  pg55x25   72 x 155 pt  = 25.4 x 54.7 mm  -- roll ~25 mm wide, label runs 55 mm along the feed
  pg55x25L 155 x  72 pt  = 54.7 x 25.4 mm  -- roll ~55 mm wide, label runs 25 mm along the feed

Margins: 2 pt sides, 4 pt ends (~0.7 / 1.4 mm) -- tighter than the driver's stock
14.9 pt end margin, which would eat 10.5 mm of a 55 mm label.

Regenerate from the PRISTINE driver PPD, not from the live queue -- once you have applied
this, /etc/cups/ppd/<queue>.ppd IS the patched file and the script will refuse it:

    ppdc -d /tmp/ppdout /usr/share/cups/drv/sample.drv
    python3 patch_ppd.py dymo-24x55.ppd /tmp/ppdout/dymo.ppd

(Verified: that route reproduces the committed dymo-24x55.ppd byte-for-byte and PASSes
cupstestppd.) Source defaults to JING5's queue for a first run on a stock install.
"""
import re
import shutil
import sys

DST = sys.argv[1] if len(sys.argv) > 1 else 'dymo-24x55.ppd'
SRC = sys.argv[2] if len(sys.argv) > 2 else '/etc/cups/ppd/make_it_soso.ppd'

# name, width_pt, height_pt, human label
NEW = [
    ('pg55x25',  72, 155, '24x55mm Price Label (portrait feed)'),
    ('pg55x25L', 155, 72, '24x55mm Price Label (landscape feed)'),
]

shutil.copyfile(SRC, DST)
with open(DST, encoding='utf-8', errors='surrogateescape') as f:
    ppd = f.read()

if 'pg55x25' in ppd:
    sys.exit('already patched')


def area(w, h):
    """left bottom right top -- 2pt sides, 4pt ends"""
    return f'2 4 {w - 2} {h - 4}'


# 1. *PageSize entries -- insert after the last existing *PageSize line
def insert_after_last(text, prefix, lines):
    idx = [m.start() for m in re.finditer(rf'^\*{prefix} ', text, re.M)]
    end = text.index('\n', idx[-1]) + 1
    return text[:end] + ''.join(lines) + text[end:]


ppd = insert_after_last(ppd, 'PageSize', [
    f'*PageSize {n}/{lab}: "<</PageSize[{w} {h}]/ImagingBBox null>>setpagedevice"\n'
    for n, w, h, lab in NEW])

ppd = insert_after_last(ppd, 'PageRegion', [
    f'*PageRegion {n}/{lab}: "<</PageSize[{w} {h}]/ImagingBBox null>>setpagedevice"\n'
    for n, w, h, lab in NEW])

ppd = insert_after_last(ppd, 'ImageableArea', [
    f'*ImageableArea {n}/{lab}: "{area(w, h)}"\n'
    for n, w, h, lab in NEW])

ppd = insert_after_last(ppd, 'PaperDimension', [
    f'*PaperDimension {n}/{lab}: "{w} {h}"\n'
    for n, w, h, lab in NEW])

# 1b. per-language translation strings. The PPD declares 31 languages in *cupsLanguages
# and cupstestppd FAILs if a PageSize choice is missing any of them.
langs = re.search(r'^\*cupsLanguages:\s*"([^"]+)"', ppd, re.M).group(1).split()
for lg in langs:
    if lg == 'en':
        continue
    for opt in ('PageSize', 'PageRegion'):
        pat = rf'^\*{lg}\.{opt} \S+.*$'
        hits = [m for m in re.finditer(pat, ppd, re.M)]
        if not hits:
            continue
        end = hits[-1].end() + 1
        add = ''.join(f'*{lg}.{opt} {n}/{lab}: ""\n' for n, w, h, lab in NEW)
        ppd = ppd[:end] + add + ppd[end:]

# 2. make the portrait one the default so a plain "print" already lands right
ppd = ppd.replace('*DefaultPageSize: w81h252', '*DefaultPageSize: pg55x25')
ppd = ppd.replace('*DefaultPageRegion: w81h252', '*DefaultPageRegion: pg55x25')
ppd = ppd.replace('*DefaultImageableArea: w81h252', '*DefaultImageableArea: pg55x25')
ppd = ppd.replace('*DefaultPaperDimension: w81h252', '*DefaultPaperDimension: pg55x25')

with open(DST, 'w', encoding='utf-8', errors='surrogateescape') as f:
    f.write(ppd)

print(f'wrote {DST}')
for n, w, h, lab in NEW:
    print(f'  {n:9s} {w:3d} x {h:3d} pt = {w/72*25.4:5.1f} x {h/72*25.4:5.1f} mm   {lab}')