from __future__ import annotations

import time
from collections import OrderedDict

DEFAULT_CACHE_TTL_S = 3600.0
DEFAULT_MAX_ENTRIES = 2048


class SentMessageCache:
    def __init__(self, max_entries: int = DEFAULT_MAX_ENTRIES, ttl_s: float = DEFAULT_CACHE_TTL_S):
        self._cache: OrderedDict[str, tuple[str, float]] = OrderedDict()
        self._max_entries = max_entries
        self._ttl = ttl_s

    def put(self, key: str, thread_ts: str) -> None:
        self._evict_expired()
        if key in self._cache:
            self._cache.move_to_end(key)
        elif len(self._cache) >= self._max_entries:
            self._cache.popitem(last=False)
        self._cache[key] = (thread_ts, time.monotonic())

    def get(self, key: str) -> str | None:
        self._evict_expired()
        entry = self._cache.get(key)
        if entry is None:
            return None
        ts, stored_at = entry
        if time.monotonic() - stored_at > self._ttl:
            self._cache.pop(key, None)
            return None
        self._cache.move_to_end(key)
        return ts

    def clear(self) -> None:
        self._cache.clear()

    def _evict_expired(self) -> None:
        now = time.monotonic()
        expired = [k for k, (_, t) in self._cache.items() if now - t > self._ttl]
        for k in expired:
            self._cache.pop(k, None)

    @property
    def size(self) -> int:
        self._evict_expired()
        return len(self._cache)