from __future__ import annotations

import time
from collections import OrderedDict


class ViberEventDeduplicator:
    def __init__(self, max_size: int = 4096, ttl_seconds: int = 3600):
        self._cache: OrderedDict[str, float] = OrderedDict()
        self._max_size = max_size
        self._ttl = ttl_seconds

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

        now = time.monotonic()
        self._evict_expired(now)

        if event_key in self._cache:
            return True

        self._cache[event_key] = now
        while len(self._cache) > self._max_size:
            self._cache.popitem(last=False)

        return False

    def _evict_expired(self, now: float) -> None:
        expired = [k for k, v in self._cache.items() if now - v > self._ttl]
        for k in expired:
            del self._cache[k]

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


def build_event_dedupe_key(account_id: str, callback: dict) -> str:
    message_token = callback.get("message_token")
    if message_token:
        return f"{account_id}|token:{message_token}"

    event_type = callback.get("event", "unknown")
    sender = callback.get("sender", {})
    sender_id = sender.get("id", "")
    timestamp = callback.get("timestamp", 0)
    return f"{account_id}|{event_type}|{sender_id}|{timestamp}"