from __future__ import annotations

import time
from collections import OrderedDict


class InboundDedupe:
    MAX_ENTRIES = 2048
    TTL_SECONDS = 300

    def __init__(self) -> None:
        self._seen: OrderedDict[str, float] = OrderedDict()

    def is_duplicate(self, message_guid: str) -> bool:
        self._evict_expired()
        return message_guid in self._seen

    def mark_seen(self, message_guid: str) -> None:
        self._evict_expired()
        if len(self._seen) >= self.MAX_ENTRIES:
            self._seen.popitem(last=False)
        self._seen[message_guid] = time.monotonic()
        self._seen.move_to_end(message_guid)

    def _evict_expired(self) -> None:
        now = time.monotonic()
        expired = [k for k, v in self._seen.items() if now - v > self.TTL_SECONDS]
        for k in expired:
            del self._seen[k]