import logging
import random
import string
import time
from collections import defaultdict

logger = logging.getLogger(__name__)

CODE_LENGTH = 6
CODE_TTL_SECONDS = 600


class TaobaoPairing:
    id_label = "buyer_nick"

    def __init__(self):
        self._codes: dict[str, dict[str, tuple[str, float]]] = defaultdict(dict)

    async def generate_code(self, peer_id: str, account_id: str = "default") -> str:
        code = "".join(random.choices(string.digits, k=CODE_LENGTH))
        self._codes[account_id][code] = (peer_id, time.monotonic())
        self._cleanup_expired(account_id)
        logger.info("Pairing code generated for %s:%s: %s", account_id, peer_id, code)
        return code

    async def verify_code(self, peer_id: str, code: str, account_id: str = "default") -> bool:
        self._cleanup_expired(account_id)

        account_codes = self._codes.get(account_id, {})
        entry = account_codes.get(code)
        if entry is None:
            return False

        stored_peer_id, created_at = entry
        if time.monotonic() - created_at > CODE_TTL_SECONDS:
            account_codes.pop(code, None)
            return False

        if stored_peer_id != peer_id:
            return False

        account_codes.pop(code, None)
        logger.info("Pairing code verified for %s:%s", account_id, peer_id)
        return True

    def normalize_allow_entry(self, entry: str) -> str:
        return entry.strip().lower()

    async def notify_approval(self, config: dict, peer_id: str, account_id: str | None = None) -> None:
        logger.info("Pairing approval notification for %s:%s", account_id, peer_id)
        try:
            from yuxi.channel.extensions.taobao.outbound import get_client

            client = get_client()
            if client is None:
                logger.warning("Cannot notify approval: client not initialized")
                return

            await client.send_customer_message(
                to_user=peer_id,
                content="您的配对已通过审批，现在可以开始与我对话了！请问有什么可以帮助您的？",
                msg_type=0,
            )
        except Exception as e:
            logger.error("Failed to send approval notification to %s: %s", peer_id, e)

    def _cleanup_expired(self, account_id: str):
        now = time.monotonic()
        account_codes = self._codes.get(account_id, {})
        expired = [k for k, (_, created) in account_codes.items() if now - created > CODE_TTL_SECONDS]
        for k in expired:
            account_codes.pop(k, None)