# -*- coding: utf-8 -*-
"""按账号角色提供 B 站客户端，并在凭据变化时自动重建。"""

from __future__ import annotations

from typing import Any, Callable

from ..config import ConfigStore
from .client import BilibiliClient


class ClientProvider:
    """缓存客户端；仅当 ``mid`` / ``cookie`` / ``csrf`` 变化时重建。

    ``factory`` 负责固化该角色的限速与重试策略，因此重建不会丢失这些设置。
    """

    def __init__(
        self,
        store: ConfigStore,
        role: str,
        factory: Callable[[Any], BilibiliClient],
    ) -> None:
        if role not in {"read", "write"}:
            raise ValueError(f"未知账号角色: {role}")
        self.store = store
        self.role = role
        self.factory = factory
        self._key: tuple[int, str, str] | None = None
        self._client: BilibiliClient | None = None

    def get(self) -> BilibiliClient:
        credentials = getattr(self.store.get().bilibili, self.role)
        key = (credentials.mid, credentials.cookie, credentials.csrf)
        if self._client is None or key != self._key:
            if self._client is not None:
                close = getattr(self._client, "close", None)
                if callable(close):
                    close()
            self._client = self.factory(credentials)
            self._key = key
        return self._client