from __future__ import annotations

from gateway.core.channels.feishu.types import IncomingFeishuEvent


class DefaultUserIdentityResolver:
    """
    飞书用户身份解析：feishu:{tenant_key}:{app_id}:{open_id}。

    无 open_id 时退化为 chat_id，便于群场景或异常事件仍可按会话隔离。
    """

    def __init__(self, *, tenant_fallback: str = "_") -> None:
        self._tenant_fallback = tenant_fallback

    def resolve_user_id(self, event: IncomingFeishuEvent) -> str:
        tenant = event.tenant_id or self._tenant_fallback
        app = event.app_id
        if event.open_id:
            return f"feishu:{tenant}:{app}:{event.open_id}"
        if event.chat_id:
            return f"feishu:{tenant}:{app}:chat:{event.chat_id}"
        return f"feishu:{tenant}:{app}:unknown"