# -*- coding: utf-8 -*-
"""封面中文 PIL / ffmpeg 字体解析（避免 load_default 导致乱码）"""

from __future__ import annotations

import os
import platform
import sys
from pathlib import Path
from typing import List, Optional

try:
    from PIL import ImageFont
except ImportError:
    ImageFont = None  # type: ignore

_FAMILY_ALIASES = {
    "microsoft yahei": "Microsoft YaHei",
    "微软雅黑": "Microsoft YaHei",
    "simhei": "SimHei",
    "黑体": "SimHei",
    "simsun": "SimSun",
    "宋体": "SimSun",
    "arial": "Arial",
    "times new roman": "Times New Roman",
}

_WIN_FAMILY_FILES = {
    "SimHei": ["simhei.ttf"],
    "Microsoft YaHei": ["msyh.ttc", "msyh.ttf", "msyhbd.ttc"],
    "SimSun": ["simsun.ttc", "simsunb.ttf"],
    "Arial": ["arial.ttf", "arialbd.ttf"],
    "Times New Roman": ["times.ttf", "timesbd.ttf"],
}


def _scripts_dir() -> Optional[Path]:
    env = os.environ.get("AICLIENT_COVER_SCRIPTS_DIR", "").strip()
    if env:
        p = Path(env)
        if p.is_dir():
            return p
    # advanced_cover_generator.py 位于 scripts/cover/
    here = Path(__file__).resolve().parent.parent
    if (here / "advanced_cover_generator.py").is_file():
        return here
    return None


def _windows_fonts_dir() -> Path:
    windir = os.environ.get("WINDIR", "C:\\Windows")
    return Path(windir) / "Fonts"


def _normalize_family(font_family: Optional[str]) -> str:
    raw = (font_family or "Microsoft YaHei").strip()
    key = raw.lower()
    return _FAMILY_ALIASES.get(key, raw)


def _candidate_filenames(family: str, weight: int = 400) -> List[str]:
    names = list(_WIN_FAMILY_FILES.get(family, []))
    if weight >= 700 and family == "Microsoft YaHei":
        names = ["msyhbd.ttc", "msyhl.ttc"] + names
    # 通用回退：.ttf 优先于 .ttc（PIL 对 ttf 更稳）
    fallback = ["simhei.ttf", "msyh.ttc", "simsun.ttc", "msyh.ttf"]
    out: List[str] = []
    for n in names + fallback:
        if n not in out:
            out.append(n)
    return out


def resolve_cjk_font_path(
    font_family: Optional[str] = None,
    weight: int = 400,
) -> str:
    """
    解析可用于 PIL / ffmpeg 的中文字体文件路径。
    """
    family = _normalize_family(font_family)
    candidates = _candidate_filenames(family, weight)

    scripts = _scripts_dir()
    if scripts:
        fonts_dir = scripts / "fonts"
        if fonts_dir.is_dir():
            for name in candidates:
                p = fonts_dir / name
                if p.is_file():
                    return str(p.resolve())

    if platform.system() == "Windows":
        win_fonts = _windows_fonts_dir()
        for name in candidates:
            p = win_fonts / name
            if p.is_file():
                return str(p.resolve())

    if platform.system() == "Darwin":
        mac_candidates = [
            "/System/Library/Fonts/PingFang.ttc",
            "/System/Library/Fonts/STHeiti Light.ttc",
            "/Library/Fonts/Arial Unicode.ttf",
        ]
        for p in mac_candidates:
            if os.path.isfile(p):
                return p

    # Linux
    linux_candidates = [
        "/usr/share/fonts/truetype/noto/NotoSansCJK-Regular.ttc",
        "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
        "/usr/share/fonts/truetype/wqy/wqy-microhei.ttc",
        "/usr/share/fonts/truetype/droid/DroidSansFallbackFull.ttf",
    ]
    for p in linux_candidates:
        if os.path.isfile(p):
            return p

    # 最后尝试：Windows 黑体
    if platform.system() == "Windows":
        simhei = _windows_fonts_dir() / "simhei.ttf"
        if simhei.is_file():
            return str(simhei.resolve())

    raise FileNotFoundError(
        f"未找到中文字体（family={family}），请在 cover/fonts 放置 simhei.ttf 或安装系统字体"
    )


def load_cjk_font(
    font_family: Optional[str],
    size: int,
    weight: int = 400,
) -> "ImageFont.FreeTypeFont":
    """加载支持中文的 PIL 字体，禁止回退到 load_default。"""
    if ImageFont is None:
        raise RuntimeError("PIL ImageFont 不可用")

    path = resolve_cjk_font_path(font_family, weight)
    ext = os.path.splitext(path)[1].lower()

    if ext == ".ttc":
        last_err: Optional[Exception] = None
        for index in range(8):
            try:
                font = ImageFont.truetype(path, size, index=index)
                print(
                    f"[chinese_font] Loaded TTC index={index}: {path} size={size}",
                    file=sys.stderr,
                )
                return font
            except OSError as e:
                last_err = e
                continue
        raise OSError(f"无法加载字体集合 {path}: {last_err}")

    font = ImageFont.truetype(path, size)
    print(f"[chinese_font] Loaded: {path} size={size}", file=sys.stderr)
    return font