#!/usr/bin/env python3
"""把子集字体内部的 name 表 / OS2 字重统一成 CSS 期望的规范值。

为什么需要：思源黑体的老版本 OTF 把每个字重写成独立族名
（`Source Han Sans CN Regular` / `Source Han Sans CN Bold`），
MiSans 的 usWeightClass 是 330/630 这类非标准值。
@font-face 的 `font-family` 描述符虽然能屏蔽内部族名，但保持一致更省心，
也避免字体被单独安装/引用时族名对不上。

用法（由 subset-fonts.sh 调用）：
    python3 vendor/fonts/tools/normalize-names.py
"""
from __future__ import annotations

import sys
from pathlib import Path

from fontTools.ttLib import TTFont

HERE = Path(__file__).resolve().parent
OUT_DIR = HERE.parent
CONF = HERE / "fonts.conf"

WEIGHTS = (("regular", "Regular", 400), ("bold", "Bold", 700))
STALE_NAME_IDS = (1, 2, 3, 4, 6, 16, 17, 21, 22)
PLATFORMS = ((3, 1, 0x409), (1, 0, 0))  # Windows / Mac，英文


def set_name(name, name_id: int, value: str) -> None:
    for platform_id, plat_enc_id, lang_id in PLATFORMS:
        name.setName(value, name_id, platform_id, plat_enc_id, lang_id)


def normalize(path: Path, family: str, style: str, weight: int) -> None:
    font = TTFont(path)
    name = font["name"]
    for record in list(name.names):
        if record.nameID in STALE_NAME_IDS:
            name.removeNames(record.nameID, record.platformID, record.platEncID, record.langID)

    full_name = family if style == "Regular" else f"{family} {style}"
    set_name(name, 1, family)  # family
    set_name(name, 2, style)  # subfamily
    set_name(name, 3, f"{full_name}:subset")  # unique id
    set_name(name, 4, full_name)  # full name
    set_name(name, 6, full_name.replace(" ", ""))  # postscript name
    set_name(name, 16, family)  # typographic family
    set_name(name, 17, style)  # typographic subfamily

    os2 = font["OS/2"]
    os2.usWeightClass = weight
    if weight >= 700:
        os2.fsSelection = (os2.fsSelection & ~0x40) | 0x20  # BOLD
        font["head"].macStyle |= 0x01
    else:
        os2.fsSelection = (os2.fsSelection & ~0x20) | 0x40  # REGULAR
        font["head"].macStyle &= ~0x01

    font.flavor = "woff2"
    font.save(path)
    font.close()


def main() -> int:
    for line in CONF.read_text(encoding="utf-8").splitlines():
        line = line.strip()
        if not line or line.startswith("#"):
            continue
        fid, _, family = [p.strip() for p in line.split("|")][:3]
        for weight_name, style, weight_class in WEIGHTS:
            path = OUT_DIR / f"{fid}-{weight_name}.woff2"
            if not path.is_file():
                print(f"缺少产物: {path}", file=sys.stderr)
                return 1
            normalize(path, family, style, weight_class)
            print(f"  {path.name:32s} -> {family} / {style} ({weight_class})")
    return 0


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