import redis
import json
import logging
from app.core.config import settings
from typing import List, Dict, Any, Optional

class RedisClient:
    """Redis 客户端"""
    
    _instance = None
    
    def __new__(cls):
        if cls._instance is None:
            cls._instance = super(RedisClient, cls).__new__(cls)
            try:
                cls._instance.client = redis.Redis(
                    host=settings.REDIS_HOST,
                    port=settings.REDIS_PORT,
                    db=settings.REDIS_DB,
                    password=settings.REDIS_PASSWORD,
                    decode_responses=True  # 自动解码为字符串
                )
                # 测试连接
                cls._instance.client.ping()
                logging.info("Redis 连接成功")
            except Exception as e:
                logging.error(f"Redis 连接失败: {str(e)}")
                cls._instance.client = None
        return cls._instance
    
    def get_client(self) -> redis.Redis:
        """获取 Redis 客户端"""
        return self.client
    
    def push_order_to_queue(self, community_id: int, order_id: str) -> bool:
        """
        添加新订单到社区队列
        
        Args:
            community_id: 社区ID
            order_id: 订单ID
            
        Returns:
            bool: 是否添加成功
        """
        try:
            key = f"community:{community_id}:new_orders"
            # 使用 LPUSH 将订单ID添加到列表头部
            self.client.lpush(key, order_id)
            # 设置过期时间为24小时
            self.client.expire(key, 86400)
            return True
        except Exception as e:
            logging.error(f"添加新订单到队列失败: {str(e)}")
            return False
    
    def get_orders_from_queue(self, community_id: int, count: int = 10) -> List[str]:
        """
        获取社区新订单列表
        
        Args:
            community_id: 社区ID
            count: 获取数量，默认10个
            
        Returns:
            List[str]: 订单ID列表
        """
        try:
            key = f"community:{community_id}:new_orders"
            # 获取订单列表，并不移除
            orders = self.client.lrange(key, 0, count-1)
            return orders
        except Exception as e:
            logging.error(f"获取社区新订单列表失败: {str(e)}")
            return []
    
    def remove_orders(self, community_id: int) -> bool:
        """
        从社区队列中移除订单
        
        Args:
            community_id: 社区ID
            
        Returns:
            bool: 是否移除成功
        """
        try:
            key = f"community:{community_id}:new_orders"
            # 使用 ltrim 移除队列中的所有元素
            self.client.ltrim(key, 0, -1)
            return True
        except Exception as e:
            logging.error(f"从队列中移除订单失败: {str(e)}")
            return False

# 创建全局实例
redis_client = RedisClient()