"""生成 m3u 播放列表文件。"""

from pathlib import Path

from .parser import Channel

# 分类顺序
_GROUP_ORDER = ["央视", "卫视", "地方台", "港澳台", "其他"]

# 分类关键词
_CCTV_KEYWORDS = ("cctv", "cgtn", "央视", "中央")
_SAT_KEYWORDS = ("卫视", "satellite")
_LOCAL_KEYWORDS = (
    "北京",
    "上海",
    "天津",
    "重庆",
    "广东",
    "江苏",
    "浙江",
    "湖南",
    "湖北",
    "河南",
    "河北",
    "山东",
    "山西",
    "陕西",
    "四川",
    "云南",
    "贵州",
    "广西",
    "福建",
    "江西",
    "安徽",
    "辽宁",
    "吉林",
    "黑龙江",
    "甘肃",
    "青海",
    "宁夏",
    "新疆",
    "西藏",
    "内蒙古",
    "海南",
    "深圳",
    "广州",
    "杭州",
    "南京",
    "武汉",
    "成都",
    "西安",
)
_HMT_KEYWORDS = ("香港", "澳门", "台湾", "翡翠", "明珠", "凤凰", "tvb", "hkstv", "澳视", "莲花")


def _classify(ch: Channel) -> str:
    """根据频道名/分组归类。"""
    text = f"{ch.group} {ch.name}".lower()
    if any(k in text for k in _CCTV_KEYWORDS):
        return "央视"
    if any(k in text for k in _HMT_KEYWORDS):
        return "港澳台"
    if any(k in text for k in _SAT_KEYWORDS):
        return "卫视"
    if any(k in ch.name for k in _LOCAL_KEYWORDS):
        return "地方台"
    return "其他"


def build_m3u(channels: list[Channel]) -> str:
    """将频道列表转换为 m3u 字符串。"""
    # 分组
    grouped: dict[str, list[Channel]] = {g: [] for g in _GROUP_ORDER}
    for ch in channels:
        grouped[_classify(ch)].append(ch)

    lines: list[str] = ["#EXTM3U"]
    for group in _GROUP_ORDER:
        items = grouped.get(group, [])
        if not items:
            continue
        for ch in items:
            attrs = []
            if ch.tvg_id:
                attrs.append(f'tvg-id="{ch.tvg_id}"')
            attrs.append(f'tvg-name="{ch.name}"')
            if ch.logo:
                attrs.append(f'tvg-logo="{ch.logo}"')
            attrs.append(f'group-title="{group}"')
            attr_str = " ".join(attrs)
            lines.append(f"#EXTINF:-1 {attr_str},{ch.name}")
            lines.append(ch.url)
    return "\n".join(lines) + "\n"


def write_m3u(channels: list[Channel], out_path: str | Path) -> Path:
    """写出 m3u 文件，自动创建目录。"""
    out = Path(out_path)
    out.parent.mkdir(parents=True, exist_ok=True)
    out.write_text(build_m3u(channels), encoding="utf-8")
    return out