"""WhatsApp Pairing 适配器 — DM 配对码管理"""

import secrets
import logging
import time

logger = logging.getLogger(__name__)

_pending_codes: dict[str, tuple[str, float]] = {}
_CODE_TTL_SECONDS = 300


class WhatsAppPairing:
    id_label = "whatsappSenderId"

    async def generate_code(self, peer_id: str) -> str:
        code = f"{secrets.randbelow(1_000_000):06d}"
        _pending_codes[peer_id] = (code, time.monotonic())
        logger.info(f"Generated pairing code for {peer_id}")
        _cleanup_expired()
        return code

    async def verify_code(self, peer_id: str, code: str) -> bool:
        _cleanup_expired()
        entry = _pending_codes.pop(peer_id, None)
        if entry is None:
            logger.warning(f"No pending code for {peer_id}")
            return False
        stored_code, _ = entry
        return stored_code == code

    def normalize_allow_entry(self, entry: str) -> str:
        stripped = entry.strip().lstrip("+")
        return stripped

    async def notify_approval(self, config: dict, peer_id: str, account_id: str | None = None) -> None:
        logger.info(f"whatsapp pairing approved for peer {peer_id}")


def _cleanup_expired():
    now = time.monotonic()
    expired = [k for k, (_, ts) in _pending_codes.items() if now - ts > _CODE_TTL_SECONDS]
    for k in expired:
        del _pending_codes[k]