from __future__ import annotations

import hashlib
import time
from collections import OrderedDict


class EmailDeduplicator:
    def __init__(self, max_entries: int = 100_000, ttl_seconds: int = 259200):
        self._seen: OrderedDict[str, float] = OrderedDict()
        self._max_entries = max_entries
        self._ttl = ttl_seconds

    def is_duplicate(self, message_id: str, uid: str = "") -> bool:
        key = self._make_key(message_id, uid)
        self._expire()
        return key in self._seen

    def mark(self, message_id: str, uid: str = ""):
        key = self._make_key(message_id, uid)
        self._expire()
        self._seen[key] = time.monotonic()
        if len(self._seen) > self._max_entries:
            self._seen.popitem(last=False)

    def _make_key(self, message_id: str, uid: str) -> str:
        raw = f"{message_id}|{uid}".strip().lower()
        return hashlib.sha256(raw.encode()).hexdigest()[:32]

    def _expire(self):
        now = time.monotonic()
        while self._seen:
            key, ts = next(iter(self._seen.items()))
            if now - ts > self._ttl:
                self._seen.popitem(last=False)
            else:
                break

    def handle_uidvalidity_change(self):
        self._seen.clear()