import secrets
import time
import logging

logger = logging.getLogger(__name__)

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


class SlackPairing:
    id_label = "slackSenderId"

    async def generate_code(self, peer_id: str) -> str:
        code = f"{secrets.randbelow(1_000_000):06d}"
        _PAIRING_CODES[peer_id] = (code, time.monotonic())
        logger.info("Slack pairing code generated for peer %s", peer_id)
        return code

    async def verify_code(self, peer_id: str, code: str) -> bool:
        stored = _PAIRING_CODES.get(peer_id)
        if stored is None:
            return False
        stored_code, created_at = stored
        if time.monotonic() - created_at > _CODE_TTL_SECONDS:
            _PAIRING_CODES.pop(peer_id, None)
            logger.info("Slack pairing code expired for peer %s", peer_id)
            return False
        if not secrets.compare_digest(stored_code, code):
            return False
        _PAIRING_CODES.pop(peer_id, None)
        logger.info("Slack pairing code verified for peer %s", peer_id)
        return True

    def normalize_allow_entry(self, entry: str) -> str:
        stripped = entry.strip()
        for prefix in ("slack:", "user:"):
            if stripped.lower().startswith(prefix):
                stripped = stripped[len(prefix) :].strip()
        return stripped.upper()

    async def notify_approval(self, config: dict, peer_id: str, account_id: str | None = None) -> None:
        logger.info("Slack pairing approved for peer %s (account=%s)", peer_id, account_id or "default")
        try:
            from yuxi.channel.extensions.slack.config import SlackConfigAdapter

            adapter = SlackConfigAdapter()
            account = await adapter.resolve_account(account_id or "default", config)
            bot_token = account.get("bot_token", "")
            if not bot_token:
                logger.warning("Cannot notify approval: no bot_token for account %s", account_id)
                return

            from slack_sdk.web.async_client import AsyncWebClient

            client = AsyncWebClient(token=bot_token)
            await client.chat_postMessage(
                channel=peer_id,
                text=":white_check_mark: 您的 DM 访问请求已被批准。现在可以直接向我发送消息了！",
            )
        except Exception:
            logger.warning("Failed to send approval notification to peer %s", peer_id, exc_info=True)