#!/usr/bin/env python3
"""Rebuild local fonts from the specified v7.9 ZIP: python3 scripts/prepare-maple-font.py /path/to/MapleMonoNormalNL-NF-CN.zip.
Use --css-only to regenerate declarations from checked-in chunks.
Only font regeneration requires fonttools[woff]; application builds use the checked-in WOFF2 files.
Source: https://github.com/subframe7536/maple-font/releases/tag/v7.9
"""
import io
from pathlib import Path
import sys
import zipfile

root = Path(__file__).resolve().parents[1] / 'web/src/common/appearance'
output = root / 'fonts/maple'
output.mkdir(exist_ok=True)
family = 'Maple Mono Normal NL NF CN'
if sys.argv[1:] != ['--css-only']:
    from fontTools import subset
    from fontTools.ttLib import TTFont
    with zipfile.ZipFile(sys.argv[1]) as archive:
        (output / 'LICENSE.txt').write_bytes(archive.read('LICENSE.txt'))
        for variant, weight, style in [('Regular', 400, 'normal'), ('Bold', 700, 'normal'), ('Italic', 400, 'italic'), ('BoldItalic', 700, 'italic')]:
            data = archive.read('MapleMonoNormalNL-NF-CN-' + variant + '.ttf')
            source = TTFont(io.BytesIO(data))
            points = sorted(source.getBestCmap())
            # Split by Unicode range so Chinese and Nerd Font glyphs need not download alongside Latin text.
            for block in sorted({cp // 4096 for cp in points}):
                unicodes = [cp for cp in points if cp // 4096 == block]
                font = TTFont(io.BytesIO(data), recalcTimestamp=False)
                options = subset.Options()
                options.flavor = 'woff2'
                subsetter = subset.Subsetter(options=options)
                subsetter.populate(unicodes=unicodes)
                subsetter.subset(font)
                font.flavor = 'woff2'
                name = f'{variant.lower()}-{block:02x}.woff2'
                font.save(output / name)
css = ['/* Maple Mono v7.9; generated by scripts/prepare-maple-font.py. See fonts/maple/LICENSE.txt for licensing. */']
for variant, weight, style in [('regular', 400, 'normal'), ('bold', 700, 'normal'), ('italic', 400, 'italic'), ('bolditalic', 700, 'italic')]:
    files = sorted(output.glob(f'{variant}-*.woff2'))
    if not files:
        raise ValueError(f'Missing checked-in font chunks: {variant}')
    for file in files:
        block = int(file.stem.split('-')[1], 16)
        css.append(f"@font-face {{ font-family: '{family}'; font-style: {style}; font-weight: {weight}; font-display: swap; src: url('./fonts/maple/{file.name}') format('woff2'); unicode-range: U+{block * 4096:X}-{(block + 1) * 4096 - 1:X}; }}")
(root / 'maple-font.css').write_text('\n'.join(css) + '\n')