from collections import OrderedDict
import time
import logging

logger = logging.getLogger(__name__)


class MessengerMessageDeduplicator:
    def __init__(self, max_size: int = 10000, ttl_seconds: int = 300):
        self._cache: OrderedDict[str, float] = OrderedDict()
        self._max_size = max_size
        self._ttl_seconds = ttl_seconds

    def is_duplicate(self, msg_id: str) -> bool:
        if not msg_id:
            return False

        self._evict_expired()

        if msg_id in self._cache:
            logger.debug(f"messenger dedupe: duplicate {msg_id}")
            return True

        self._cache[msg_id] = time.monotonic()

        if len(self._cache) > self._max_size:
            self._cache.popitem(last=False)

        return False

    def _evict_expired(self):
        now = time.monotonic()
        cutoff = now - self._ttl_seconds

        expired = [k for k, v in self._cache.items() if v < cutoff]
        for k in expired:
            del self._cache[k]