"""简化版代理获取器（替代 ProxyManager）。

专为短效代理设计：无池、无冷却、无复用。
每次调用 fetch_new_proxy() 从 API 取 1 个新代理，用完即弃。

线程安全：白名单同步有全局锁 + IP缓存避免重复同步。
"""

import threading
from typing import Optional

from loguru import logger

from .proxy_resolver import ProxyResolver
from .proxy_whitelist import DouyuWhitelistSyncer


class ProxyFetcher:
    """每次从代理 API 取 1 个新代理，无缓存无复用。"""

    def __init__(
        self,
        api_url: str,
        whitelist_platform: str = "xiequ",
        whitelist_credentials: dict = None,
    ):
        self.api_url = api_url

        _wl_platform = whitelist_platform or "xiequ"
        _wl_credentials = whitelist_credentials

        self._whitelist_syncer = (
            DouyuWhitelistSyncer(platform=_wl_platform, credentials=_wl_credentials)
            if _wl_credentials
            else None
        )
        # 跨线程共享：已同步白名单的IP，避免5个线程重复同步同一个IP
        self._synced_ip: Optional[str] = None
        self._sync_lock = threading.Lock()

    def fetch_new_proxy(self, max_attempts: int = 3) -> Optional[str]:
        """从代理 API 获取 1 个可用代理，失败返回 None。"""
        # 快速检查：是否已经同步过白名单
        skip_sync = False
        if self._whitelist_syncer:
            with self._sync_lock:
                if self._synced_ip:
                    skip_sync = True

        resolver = ProxyResolver(
            api_url=self.api_url,
            whitelist_syncer=self._whitelist_syncer,
            sync_local_exit_ip=bool(self._whitelist_syncer) and not skip_sync,
            sync_whitelist_once=False,
        )
        result, msg = resolver.fetch_verified(
            max_attempts=max_attempts,
            return_all=False,
        )

        # 记录已同步的IP
        if self._whitelist_syncer and result:
            with self._sync_lock:
                self._synced_ip = self._synced_ip or "done"

        if isinstance(result, str):
            logger.info(f"获取新代理: {result}")
            return result
        if isinstance(result, list) and result:
            logger.info(f"获取新代理: {result[0]}")
            return result[0]
        logger.warning(f"获取代理失败: {msg}")
        return None


def get_proxy_fetcher(
    api_url: str,
    whitelist_platform: str = "xiequ",
    whitelist_credentials: dict = None,
) -> ProxyFetcher:
    """获取代理获取器实例。"""
    return ProxyFetcher(
        api_url,
        whitelist_platform=whitelist_platform,
        whitelist_credentials=whitelist_credentials,
    )