import threading
import time
import logging
from django.db import close_old_connections
from .offer_status_service import OfferStatusService

logger = logging.getLogger('brands')

class StatusPollingService:
    """提供定时轮询服务，定期获取并更新达人状态"""
    
    def __init__(self):
        self._polling_threads = {}  # 保存活动ID到线程的映射
        self._stop_events = {}      # 保存活动ID到停止事件的映射
    
    def start_polling(self, campaign_id, creator_product_pairs, interval=30):
        """
        开始轮询指定活动的达人状态
        :param campaign_id: 活动ID
        :param creator_product_pairs: 达人ID和产品ID的对应关系列表，格式为 [(creator_id, product_id), ...]
        :param interval: 轮询间隔时间（秒）
        """
        # 如果该活动已有轮询线程，先停止它
        if campaign_id in self._polling_threads:
            self.stop_polling(campaign_id)
        
        # 创建停止事件
        stop_event = threading.Event()
        self._stop_events[campaign_id] = stop_event
        
        # 创建并启动轮询线程
        thread = threading.Thread(
            target=self._polling_worker,
            args=(campaign_id, creator_product_pairs, interval, stop_event),
            daemon=True
        )
        self._polling_threads[campaign_id] = thread
        thread.start()
        
        logger.info(f"已启动活动 {campaign_id} 的状态轮询，间隔 {interval} 秒")
    
    def stop_polling(self, campaign_id):
        """
        停止指定活动的轮询
        :param campaign_id: 活动ID
        """
        if campaign_id in self._stop_events:
            # 设置停止事件
            self._stop_events[campaign_id].set()
            
            # 等待线程结束
            if campaign_id in self._polling_threads:
                self._polling_threads[campaign_id].join(timeout=5)
                
                # 清理资源
                del self._polling_threads[campaign_id]
            
            del self._stop_events[campaign_id]
            logger.info(f"已停止活动 {campaign_id} 的状态轮询")
    
    def stop_all(self):
        """停止所有轮询"""
        campaign_ids = list(self._polling_threads.keys())
        for campaign_id in campaign_ids:
            self.stop_polling(campaign_id)
    
    def _polling_worker(self, campaign_id, creator_product_pairs, interval, stop_event):
        """
        轮询工作线程
        :param campaign_id: 活动ID
        :param creator_product_pairs: 达人ID和产品ID的对应关系列表
        :param interval: 轮询间隔（秒）
        :param stop_event: 停止事件
        """
        while not stop_event.is_set():
            try:
                # 关闭旧的数据库连接
                close_old_connections()
                
                # 遍历每个达人-产品对，获取并发送状态更新
                for creator_id, product_id in creator_product_pairs:
                    try:
                        # 获取状态
                        status = OfferStatusService.fetch_status(creator_id, product_id)
                        
                        if status:
                            # 发送状态更新
                            OfferStatusService.send_status_update(campaign_id, creator_id, status)
                    except Exception as e:
                        logger.error(f"处理达人 {creator_id} 状态时出错: {str(e)}")
                
                # 等待指定时间间隔
                stop_event.wait(interval)
            
            except Exception as e:
                logger.error(f"轮询线程发生错误: {str(e)}")
                # 短暂休眠后继续
                time.sleep(5)

# 创建单例实例
polling_service = StatusPollingService()