import logging
import time
from threading import Thread, Event
from PySide6.QtCore import QTimer
from utils.modbus_utils import ModbusUtils
from utils.modbus_monitor import RegisterHandler
from dao.electricity_dao import ElectricityDAO
from utils.config_loader import ConfigLoader

class ElectricityHandler(RegisterHandler):
    """电力消耗寄存器处理器"""
    
    def __init__(self):
        """初始化处理器"""
        self.dao = ElectricityDAO()
        # 确保表已创建
        self.dao.create_table_if_not_exists()
    
    def handle_change(self, value):
        """处理寄存器值变化
        
        Args:
            value: 寄存器值
        """
        try:
            # 保存电力消耗数据
            self.dao.save_electricity_data(value)
            logging.info(f"已记录电力消耗数据: {value}")
        except Exception as e:
            logging.error(f"处理电力消耗数据时发生错误: {str(e)}")


class ElectricityMonitor:
    """电力消耗监控器"""
    
    _instance = None
    
    @classmethod
    def get_instance(cls):
        """获取单例实例"""
        if cls._instance is None:
            cls._instance = ElectricityMonitor()
        return cls._instance
    
    def __init__(self):
        """初始化电力监控器"""
        if ElectricityMonitor._instance:
            raise Exception("ElectricityMonitor is a singleton class.")
        
        self.modbus = ModbusUtils()
        self.dao = ElectricityDAO()
        self.config = ConfigLoader.get_instance()
        
        # 确保表已创建
        self.dao.create_table_if_not_exists()
        
        # 创建定时器
        self.timer = None
        self.client = None
        self.stop_event = Event()
        self.monitor_thread = None
        
        # 电力寄存器地址
        self.electricity_register = 30
        
        # 从配置中读取监听间隔（分钟）
        self.interval_minutes = self.config.get_value('electricity.interval_minutes', 1)
        
        # 从配置中读取是否自动启动
        self.auto_start = self.config.get_value('electricity.auto_start', True)
        
        # 上次读取时间
        self.last_read_time = None
        
        # 如果配置为自动启动，则启动监控
        if self.auto_start:
            self.start()
    
    def start(self):
        """启动监控"""
        if self.timer and self.timer.isActive():
            logging.warning("电力监控器已经在运行中")
            return
        
        # 创建并启动定时器，每分钟读取一次
        self.timer = QTimer()
        self.timer.timeout.connect(self._read_electricity_data)
        self.timer.start(self.interval_minutes * 60000)  # 转换为毫秒
        
        # 立即执行一次读取
        self._read_electricity_data()
        
        # 更新配置
        self.config.set_value('electricity.auto_start', True)
        
        logging.info(f"电力监控器已启动，每{self.interval_minutes}分钟读取一次寄存器30的数据")
    
    def stop(self):
        """停止监控"""
        if self.timer:
            self.timer.stop()
        
        if self.client:
            self.modbus.close_client(self.client)
            self.client = None
        
        # 更新配置
        self.config.set_value('electricity.auto_start', False)
        
        logging.info("电力监控器已停止")
    
    def set_interval(self, minutes):
        """设置监听间隔
        
        Args:
            minutes: 间隔分钟数
        """
        if minutes < 1:
            minutes = 1
        
        self.interval_minutes = minutes
        
        # 更新配置
        self.config.set_value('electricity.interval_minutes', minutes)
        
        # 如果定时器正在运行，则更新间隔
        if self.timer and self.timer.isActive():
            self.timer.setInterval(minutes * 60000)  # 转换为毫秒
            logging.info(f"电力监控间隔已更新为{minutes}分钟")
    
    def is_monitoring(self):
        """检查是否正在监控
        
        Returns:
            bool: 是否正在监控
        """
        return self.timer is not None and self.timer.isActive()
    
    def get_last_read_time(self):
        """获取上次读取时间
        
        Returns:
            datetime: 上次读取时间，如果未读取过则返回None
        """
        return self.last_read_time
    
    def get_next_read_time(self):
        """获取下次读取时间
        
        Returns:
            datetime: 下次读取时间，如果未在监控则返回None
        """
        if not self.is_monitoring() or not self.last_read_time:
            return None
        
        from datetime import datetime, timedelta
        return self.last_read_time + timedelta(minutes=self.interval_minutes)
    
    def _read_electricity_data(self):
        """读取电力消耗数据"""
        try:
            # 如果客户端未连接，则创建连接
            if not self.client:
                self.client = self.modbus.get_client()
                if not self.client:
                    logging.error("无法连接到Modbus服务器，电力数据读取失败")
                    return
            
            # 读取寄存器30的值
            result = self.modbus.read_holding_register(self.client, self.electricity_register)
            if result is None or len(result) == 0:
                logging.warning(f"读取寄存器D{self.electricity_register}失败")
                return
            
            # 获取电力消耗值
            electricity_value = result[0]
            
            # 保存到数据库
            success = self.dao.save_electricity_data(electricity_value)
            if success:
                logging.info(f"已记录电力消耗数据: {electricity_value}")
                # 更新上次读取时间
                from datetime import datetime
                self.last_read_time = datetime.now()
            else:
                logging.error("保存电力消耗数据失败")
                
        except Exception as e:
            logging.error(f"读取或保存电力消耗数据时发生错误: {str(e)}")
            # 关闭连接，下次重新尝试
            if self.client:
                self.modbus.close_client(self.client)
                self.client = None