import os
import time
import logging
from datetime import datetime
from typing import Dict

from db.chat_log_db import get_waiting_customer_pool
from db.pending_transfer_db import count_open_pending_transfers
from services.service_wecom_bot import wecom_bot_service

logger = logging.getLogger("cs_agent")

DESIGNER_ALERT_START_HOUR = int(os.getenv("DESIGNER_ALERT_START_HOUR", "8"))
DESIGNER_ALERT_END_HOUR = int(os.getenv("DESIGNER_ALERT_END_HOUR", "24"))
DESIGNER_ALERT_COOLDOWN_SECONDS = int(os.getenv("DESIGNER_ALERT_COOLDOWN_SECONDS", "300"))
DESIGNER_ALERT_POOL_WINDOW_MINUTES = int(os.getenv("DESIGNER_ALERT_POOL_WINDOW_MINUTES", "30"))


class DesignerAlertService:
    def __init__(self):
        self._last_alert_at = 0.0

    @staticmethod
    def _in_active_window(now: datetime) -> bool:
        hour = now.hour
        return DESIGNER_ALERT_START_HOUR <= hour < DESIGNER_ALERT_END_HOUR

    @staticmethod
    def _render_shop_lines(pool: Dict) -> str:
        shops = pool.get("shops") or []
        if not shops:
            return "- 暂无店铺明细"
        lines = []
        for item in shops[:10]:
            acc_id = str(item.get("acc_id") or "")
            waiting = int(item.get("waiting_customers") or 0)
            lines.append(f"- {acc_id}：{waiting}人")
        return "\n".join(lines)

    async def notify_if_needed(self, *, trigger: str = "", customer_id: str = "", acc_id: str = "") -> bool:
        now = datetime.now()
        if not self._in_active_window(now):
            return False

        now_ts = time.time()
        if now_ts - self._last_alert_at < max(DESIGNER_ALERT_COOLDOWN_SECONDS, 30):
            return False

        pending_count = count_open_pending_transfers()
        pool = get_waiting_customer_pool(DESIGNER_ALERT_POOL_WINDOW_MINUTES)
        waiting_total = int(pool.get("total_waiting_customers") or 0)
        if pending_count <= 0 and waiting_total <= 0:
            return False

        content = (
            "【设计师在线提醒】\n"
            f"当前时间：{now.strftime('%Y-%m-%d %H:%M:%S')}\n"
            "8点到24点内检测到暂无设计师接单，有客户待转接。\n"
            f"触发来源：{trigger or '-'}\n"
            f"当前会话：{customer_id or '-'} / {acc_id or '-'}\n"
            f"待转接池：{pending_count}人\n"
            f"当前客户池：{waiting_total}人（近{pool.get('window_minutes') or DESIGNER_ALERT_POOL_WINDOW_MINUTES}分钟最后一条仍是客户消息）\n"
            "店铺分布：\n"
            f"{self._render_shop_lines(pool)}\n"
            "群里如果有设计师在线，麻烦看一下。"
        )
        ok = await wecom_bot_service.send_text(content)
        if ok:
            self._last_alert_at = now_ts
            logger.info(
                f"[DesignerAlert] 已发送企微提醒 trigger={trigger} pending={pending_count} waiting={waiting_total}"
            )
        return ok


designer_alert_service = DesignerAlertService()