"""解析 m3u / txt 格式的直播源文本，提取频道条目。"""

import re
from dataclasses import dataclass, field


@dataclass
class Channel:
    """单个频道条目。"""
    name: str
    url: str
    logo: str = ""
    group: str = ""
    tvg_id: str = ""
    extra: dict = field(default_factory=dict)


_ATTR_RE = re.compile(r'([\w-]+)="([^"]*)"')


def _parse_extinf(line: str) -> dict:
    """解析 #EXTINF 行中的属性。"""
    attrs = {}
    for key, value in _ATTR_RE.findall(line):
        attrs[key.lower()] = value
    # 逗号后面的名称
    if "," in line:
        attrs["name"] = line.rsplit(",", 1)[1].strip()
    return attrs


def parse_m3u(text: str) -> list[Channel]:
    """解析 m3u 文本。"""
    channels: list[Channel] = []
    lines = [ln.strip() for ln in text.splitlines()]
    i = 0
    while i < len(lines):
        line = lines[i]
        if line.startswith("#EXTINF"):
            attrs = _parse_extinf(line)
            # 下一行非注释的即为 URL
            j = i + 1
            while j < len(lines) and (not lines[j] or lines[j].startswith("#")):
                j += 1
            if j < len(lines):
                url = lines[j]
                name = attrs.get("name") or attrs.get("tvg-name") or ""
                if name and url:
                    channels.append(
                        Channel(
                            name=name,
                            url=url,
                            logo=attrs.get("tvg-logo", ""),
                            group=attrs.get("group-title", ""),
                            tvg_id=attrs.get("tvg-id", ""),
                        )
                    )
                i = j + 1
                continue
        i += 1
    return channels


def parse_txt(text: str) -> list[Channel]:
    """解析常见 txt 格式：频道名,URL 或 频道名 URL。"""
    channels: list[Channel] = []
    for raw in text.splitlines():
        line = raw.strip()
        if not line or line.startswith("#"):
            continue
        # 支持 , 或空格分隔
        if "," in line:
            name, url = line.split(",", 1)
        elif " " in line:
            name, url = line.split(" ", 1)
        else:
            continue
        name, url = name.strip(), url.strip()
        if name and url.startswith(("http://", "https://", "rtmp://", "rtsp://")):
            channels.append(Channel(name=name, url=url))
    return channels


def parse(text: str) -> list[Channel]:
    """自动识别格式并解析。"""
    if "#EXTM3U" in text or "#EXTINF" in text:
        return parse_m3u(text)
    return parse_txt(text)