from __future__ import annotations

import time
from typing import Dict, Set


class DedupManager:
    def __init__(self):
        self.inflight_message_keys: Set[str] = set()
        self.recent_message_keys: Dict[str, float] = {}
        self.recent_reply_signatures: Dict[str, float] = {}

    def begin_message_processing(self, message_key: str, expiry_sec: int) -> bool:
        if not message_key:
            return True
        now = time.time()
        stale_keys = [key for key, ts in self.recent_message_keys.items() if now - ts > expiry_sec]
        for key in stale_keys:
            self.recent_message_keys.pop(key, None)
        if message_key in self.inflight_message_keys:
            return False
        if message_key in self.recent_message_keys:
            return False
        self.inflight_message_keys.add(message_key)
        return True

    def finish_message_processing(self, message_key: str) -> None:
        if not message_key:
            return
        self.inflight_message_keys.discard(message_key)
        self.recent_message_keys[message_key] = time.time()

    def should_skip_duplicate_reply(
        self,
        *,
        room_id: str,
        sender: str,
        reply_text: str,
        expiry_sec: int,
        scope: str = "sender",
    ) -> bool:
        text = str(reply_text or "").strip()
        if not text:
            return False
        now = time.time()
        stale_keys = [key for key, ts in self.recent_reply_signatures.items() if now - ts > expiry_sec]
        for key in stale_keys:
            self.recent_reply_signatures.pop(key, None)
        signature = f"{room_id}:{text}" if scope == "room" else f"{room_id}:{sender}:{text}"
        if signature in self.recent_reply_signatures:
            return True
        self.recent_reply_signatures[signature] = now
        return False