import secrets
import time

from yuxi.channel.extensions.alipay.constants import (
    ALIPAY_PAIRING_CODE_LENGTH,
    ALIPAY_PAIRING_CODE_TTL_SECONDS,
)


class AlipayPairing:
    def __init__(self):
        self._codes: dict[str, tuple[str, float]] = {}

    def generate_code(self, peer_id: str) -> str:
        import random

        code = "".join(str(random.randint(0, 9)) for _ in range(ALIPAY_PAIRING_CODE_LENGTH))
        self._codes[peer_id] = (code, time.time())
        return code

    def verify_code(self, peer_id: str, code: str) -> bool:
        entry = self._codes.get(peer_id)
        if not entry:
            return False
        stored_code, created_at = entry
        if time.time() - created_at > ALIPAY_PAIRING_CODE_TTL_SECONDS:
            del self._codes[peer_id]
            return False
        if not secrets.compare_digest(stored_code, code):
            return False
        del self._codes[peer_id]
        return True