#!/usr/bin/env python3
"""
小程序 iconfont 生成工具（FontAwesome 子集化 + base64 输出）

用法: python3 scripts/iconfont-build.py <woff2路径> <输出css路径> [--names name1,name2,...]
示例: python3 scripts/iconfont-build.py node_modules/@fortawesome/fontawesome-free/webfonts/fa-solid-900.woff2 src/styles/iconfont.css --names calendar,star,heart

功能:
  1. 将 woff2 转为 ttf
  2. 按 --names 指定的图标名子集化（保留最小字形，减小包体）
  3. 生成 base64 内联 @font-face CSS（font-family: 'fa-icons'）
  4. 输出 unicode 映射 JSON（供 Icon 组件使用）

图标名 -> unicode 映射（FontAwesome v6 fa-solid）：
"""
import sys
import json
import base64
import argparse
from pathlib import Path

from fontTools.ttLib import TTFont
from fontTools import subset

# FontAwesome v6 fa-solid 图标名 -> unicode 码点
ICON_NAMES = {
    'arrow-up': 0xF062,
    'arrow-down': 0xF063,
    'arrow-left': 0xF060,
    'arrow-right': 0xF061,
    'check': 0xF00C,
    'close': 0xF00D,
    'right': 0xF054,
    'checkbox-checked': 0xF14A,
    'checkbox-unchecked': 0xF0C8,
    'plus': 0xF067,
    'minus': 0xF068,
    'search': 0xF002,
    'calendar': 0xF073,
    'star': 0xF005,
    'heart': 0xF004,
    'settings': 0xF013,
    'home': 0xF015,
    'user': 0xF007,
    'info': 0xF129,
    'warning': 0xF071,
    'refresh': 0xF021,
    'download': 0xF019,
    'upload': 0xF093,
    'share': 0xF064,
    'copy': 0xF0C5,
    'delete': 0xF1F8,
    'edit': 0xF044,
    'filter': 0xF0B0,
    'sort': 0xF0DC,
    'export': 0xF14D,
    'history': 0xF1DA,
    'bookmark': 0xF02E,
    'chevron-up': 0xF077,
    'chevron-down': 0xF078,
    'chevron-left': 0xF053,
    'chevron-right': 0xF054,
}

def main():
    parser = argparse.ArgumentParser(description='FontAwesome iconfont 子集化构建')
    parser.add_argument('woff2', help='fa-solid woff2 字体路径')
    parser.add_argument('output_css', help='输出 CSS 路径')
    parser.add_argument('--names', help='逗号分隔的图标名（默认全部）')
    parser.add_argument('--font-family', default='fa-icons', help='字体族名')
    args = parser.parse_args()

    # 解析图标名
    if args.names:
        names = [n.strip() for n in args.names.split(',') if n.strip()]
    else:
        names = list(ICON_NAMES.keys())

    # 收集 unicode
    unicodes = []
    mapping = {}
    missing = []
    for n in names:
        if n not in ICON_NAMES:
            print(f'⚠️ 未知图标名: {n}'); continue
        unicodes.append(ICON_NAMES[n])
        mapping[n] = ICON_NAMES[n]

    # 加载并验证 cmap
    tmp_ttf = Path('/tmp/fa-icons-subset.ttf')
    font = TTFont(args.woff2)
    cmap = font.getBestCmap()
    for n, cp in mapping.items():
        if cp not in cmap:
            missing.append(f'{n}(U+{cp:04X})')
    if missing:
        print(f'⚠️ 缺失字形: {", ".join(missing)}')
    print(f'图标数: {len(mapping)}')

    # 子集化
    options = subset.Options()
    options.desubroutinize = True
    options.ignore_missing_glyphs = True
    options.drop_tables += ['GSUB', 'GPOS', 'GDEF', 'kern', 'cmap'] if False else []
    sub = subset.Subsetter(options=options)
    sub.populate(unicodes=unicodes)
    sub.subset(font)
    font.save(str(tmp_ttf))

    # base64
    b64 = base64.b64encode(tmp_ttf.read_bytes()).decode()
    print(f'子集 ttf: {(tmp_ttf.stat().st_size/1024):.0f}KB | base64: {(len(b64)/1024):.0f}KB')

    # 生成 CSS
    css = f"""/* 自动生成: scripts/iconfont-build.py —— FontAwesome 子集化图标字体（仅含所需字形） */
@font-face {{
  font-family: '{args.font_family}';
  src: url(data:font/ttf;charset=utf-8;base64,{b64}) format('truetype');
  font-weight: normal;
  font-style: normal;
}}
"""
    out = Path(args.output_css)
    out.parent.mkdir(parents=True, exist_ok=True)
    out.write_text(css)
    print(f'CSS 已生成: {out} ({len(css)/1024:.0f}KB)')

    # 输出映射 JSON（供 Icon 组件）
    json_path = Path(args.output_css).with_suffix('.json')
    json_path.write_text(json.dumps(mapping, ensure_ascii=False, indent=2))
    print(f'映射已生成: {json_path}')

if __name__ == '__main__':
    main()