from __future__ import annotations

import secrets
import time


class LazadaPairingStore:
    def __init__(self, code_ttl: int = 300):
        self._codes: dict[str, tuple[str, float]] = {}
        self._ttl = code_ttl

    async def generate(self, account_id: str) -> str:
        code = secrets.token_hex(3).upper()
        self._codes[code] = (account_id, time.time())
        self._evict_expired()
        return code

    async def verify(self, account_id: str, code: str) -> bool:
        self._evict_expired()
        entry = self._codes.get(code)
        if entry is None:
            return False
        stored_id, _ = entry
        if stored_id != account_id:
            return False
        del self._codes[code]
        return True

    def revoke(self, code: str) -> None:
        self._codes.pop(code, None)

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