import logging
import time


logger = logging.getLogger(__name__)

_WINDOW_SECONDS = 48 * 3600


class PinduoduoWindowTracker:

    def __init__(self):
        self._last_msg_time: dict[str, float] = {}

    def record(self, buyer_id: str) -> None:
        self._last_msg_time[buyer_id] = time.time()

    def can_reply(self, buyer_id: str) -> bool:
        last = self._last_msg_time.get(buyer_id, 0)
        now = time.time()
        if now - last > _WINDOW_SECONDS:
            logger.info(
                "拼多多 48h 互动窗口已过期，用户 %s，最后消息时间戳=%s",
                buyer_id,
                last,
            )
            return False

        return True

    def remaining_seconds(self, buyer_id: str) -> float:
        last = self._last_msg_time.get(buyer_id, 0)
        if last == 0:
            return 0
        elapsed = time.time() - last
        remaining = _WINDOW_SECONDS - elapsed
        return max(0.0, remaining)

    def cleanup(self) -> None:
        now = time.time()
        expired = [
            k for k, ts in self._last_msg_time.items()
            if now - ts > _WINDOW_SECONDS
        ]
        for k in expired:
            del self._last_msg_time[k]