"""虎牙 Cookie 规范化工具。"""

from __future__ import annotations

from collections.abc import Iterable, Mapping

import requests


def cookie_pairs(cookie: str) -> list[tuple[str, str]]:
    """把浏览器 Cookie 字符串拆成 key/value 对。"""
    pairs: list[tuple[str, str]] = []
    for part in (cookie or "").split(";"):
        item = part.strip()
        if not item or "=" not in item:
            continue
        key, value = item.split("=", 1)
        key = key.strip()
        if not key:
            continue
        pairs.append((key, value.strip()))
    return pairs


def normalize_cookie_pairs(pairs: Iterable[tuple[str, str]]) -> str:
    """按 Cookie key 去重，保留最后一次出现的值。"""
    ordered_keys: list[str] = []
    values: dict[str, str] = {}
    for raw_key, raw_value in pairs:
        key = str(raw_key).strip()
        if not key:
            continue
        if key not in values:
            ordered_keys.append(key)
        values[key] = "" if raw_value is None else str(raw_value).strip()
    return "; ".join(f"{key}={values[key]}" for key in ordered_keys)


def normalize_huya_cookie(cookie: str | Mapping[str, str] | requests.cookies.RequestsCookieJar | None) -> str:
    """把 Cookie 字符串、dict 或 CookieJar 转成去重后的浏览器 Cookie 字符串。"""
    if not cookie:
        return ""
    if isinstance(cookie, str):
        return normalize_cookie_pairs(cookie_pairs(cookie))
    return normalize_cookie_pairs(cookie.items())


def cookie_value(cookie: str | Mapping[str, str] | requests.cookies.RequestsCookieJar | None, key: str) -> str:
    """从 Cookie 中读取 key；有重复时以最后一次出现为准。"""
    if not cookie or not key:
        return ""
    if isinstance(cookie, str):
        pairs = cookie_pairs(cookie)
    else:
        pairs = list(cookie.items())
    value = ""
    for item_key, item_value in pairs:
        if item_key == key:
            value = "" if item_value is None else str(item_value).strip()
    return value