import os
import logging
import httpx
import asyncio
from typing import Optional
from services.service_designer_alert import designer_alert_service

logger = logging.getLogger("cs_agent")

class DispatchService:
    """
    8006 即时派发服务 API 接入 (正式对齐版)
    """
    
    def __init__(self):
        self.base_url = os.getenv("DISPATCH_BASE_URL", "http://1.12.50.92:8006").rstrip("/")
        self.api_key = os.getenv("DISPATCH_API_KEY", "tuhui_dispatch_key_2026")
        self.timeout = float(os.getenv("DISPATCH_TIMEOUT_SECONDS", "10"))
        self.max_retries = int(os.getenv("DISPATCH_MAX_RETRIES", "3"))

    @staticmethod
    def _clip_text(text: str, limit: int = 500) -> str:
        if text is None:
            return ""
        if len(text) <= limit:
            return text
        return f"{text[:limit]}...(截断, 共{len(text)}字)"

    async def assign_designer(self, user_id: str = "") -> Optional[str]:
        """
        调用 /assign 接口，一键获取当前可用持有的设计师名字
        """
        url = f"{self.base_url}/assign"
        headers = {"X-API-Key": self.api_key}

        u_tag = f" user={user_id}" if user_id else ""
        logger.info(f"[Dispatch]{u_tag} 请求开始: GET {url}")
        async with httpx.AsyncClient(timeout=self.timeout, trust_env=False) as client:
            for attempt in range(1, self.max_retries + 1):
                try:
                    response = await client.get(url, headers=headers)
                    body = self._clip_text(response.text)

                    if response.status_code == 200:
                        try:
                            data = response.json()
                        except Exception:
                            logger.error(f"[Dispatch]{u_tag} 200但响应非JSON: {body}")
                            return None

                        if data.get("success"):
                            designer = data.get("assigned_to")
                            logger.info(f"[Dispatch]{u_tag} 派单成功！设计师: {designer}")
                            return designer

                        logger.warning(f"[Dispatch]{u_tag} 派单被拒: {data.get('reason')} body={body}")
                        await designer_alert_service.notify_if_needed(
                            trigger=f"dispatch_rejected:{data.get('reason') or 'unknown'}",
                            customer_id=user_id,
                        )
                        return None

                    if response.status_code == 401:
                        logger.error(f"[Dispatch]{u_tag} 授权失败(401)，请检查 DISPATCH_API_KEY。Body={body}")
                        return None

                    logger.error(f"[Dispatch]{u_tag} API 异常，状态码: {response.status_code} body={body}")
                    if response.status_code < 500:
                        return None

                except Exception as e:
                    logger.error(f"[Dispatch]{u_tag} 网络请求失败 attempt={attempt}/{self.max_retries}: {e}")

                if attempt < self.max_retries:
                    await asyncio.sleep(0.8 * attempt)

        return None

# 全局单例
dispatch_service = DispatchService()