"""频道过滤与去重。"""

import re
from urllib.parse import urlparse

from .parser import Channel

# 允许的协议
_ALLOWED_SCHEMES = {"http", "https", "rtmp", "rtsp", "rtp"}

# 无效/占位 URL 关键词
_BAD_URL_KEYWORDS = (
    "example.com",
    "localhost",
    "127.0.0.1",
    "0.0.0.0",
    "test",
    "demo",
)

# 需要排除的频道名关键词（成人、赌博等）
_BAD_NAME_KEYWORDS = (
    "成人",
    "色情",
    "赌博",
    "博彩",
    "彩票",
    "porn",
    "xxx",
    "adult",
    "casino",
)

# 频道名规范化：去掉空格、标点、常见后缀
_NORMALIZE_RE = re.compile(r"[\s\-_·\|（）()\[\]【】]+")


def _normalize_name(name: str) -> str:
    """频道名归一化，用于去重。"""
    n = name.lower().strip()
    # 去掉常见画质 / 后缀标记
    for suffix in ("高清", "超清", "蓝光", "hd", "fhd", "4k", "8k", "sd"):
        n = n.replace(suffix, "")
    n = _NORMALIZE_RE.sub("", n)
    return n


def is_valid(ch: Channel) -> bool:
    """判断频道是否有效。"""
    if not ch.name or not ch.url:
        return False
    name_l = ch.name.lower()
    url_l = ch.url.lower()

    if any(k in name_l for k in _BAD_NAME_KEYWORDS):
        return False
    if any(k in url_l for k in _BAD_URL_KEYWORDS):
        return False

    try:
        scheme = urlparse(ch.url).scheme.lower()
    except Exception:  # noqa: BLE001
        return False
    if scheme not in _ALLOWED_SCHEMES:
        return False

    return True


def dedupe(channels: list[Channel]) -> list[Channel]:
    """按频道名 + URL 去重，优先保留信息更完整的条目。"""
    seen_names: set[str] = set()
    seen_urls: set[str] = set()
    result: list[Channel] = []

    # 先按信息完整度排序（有 logo / group 的优先）
    channels = sorted(
        channels,
        key=lambda c: (bool(c.logo), bool(c.group), bool(c.tvg_id)),
        reverse=True,
    )

    for ch in channels:
        key = _normalize_name(ch.name)
        if not key:
            continue
        if key in seen_names:
            continue
        if ch.url in seen_urls:
            continue
        seen_names.add(key)
        seen_urls.add(ch.url)
        result.append(ch)

    return result


def process(channels: list[Channel]) -> list[Channel]:
    """完整流程：过滤 + 去重。"""
    valid = [c for c in channels if is_valid(c)]
    return dedupe(valid)