import logging
from datetime import datetime
from utils.sql_utils import SQLUtils

class ElectricityDAO:
    """电力消耗数据访问对象"""
    
    def __init__(self):
        """初始化数据访问对象"""
        self.db = SQLUtils('sqlite', database='db/jtDB.db')
    
    def __del__(self):
        """析构函数，确保数据库连接关闭"""
        if hasattr(self, 'db'):
            self.db.close()
    
    def create_table_if_not_exists(self):
        """创建电力消耗表（如果不存在）"""
        try:
            sql = """
            CREATE TABLE IF NOT EXISTS wsbz_electricity_consumption (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                sync_time TIMESTAMP,
                electricity_number REAL
            )
            """
            self.db.execute_query(sql)
            logging.info("电力消耗表检查/创建成功")
            return True
        except Exception as e:
            logging.error(f"创建电力消耗表失败: {str(e)}")
            return False
    
    def save_electricity_data(self, electricity_number):
        """保存电力消耗数据
        
        Args:
            electricity_number: 电力消耗数值
            
        Returns:
            bool: 保存是否成功
        """
        try:
            current_time = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
            
            sql = """
            INSERT INTO wsbz_electricity_consumption (
                sync_time, electricity_number
            ) VALUES (?, ?)
            """
            params = (current_time, electricity_number)
            
            self.db.execute_update(sql, params)
            logging.info(f"保存电力消耗数据成功: {electricity_number}")
            return True
        except Exception as e:
            logging.error(f"保存电力消耗数据失败: {str(e)}")
            return False
    
    def get_latest_electricity_data(self):
        """获取最新的电力消耗数据
        
        Returns:
            dict: 最新的电力消耗数据，未找到则返回None
        """
        try:
            sql = """
            SELECT id, sync_time, electricity_number
            FROM wsbz_electricity_consumption
            ORDER BY id DESC
            LIMIT 1
            """
            
            self.db.cursor.execute(sql)
            row = self.db.cursor.fetchone()
            
            if row:
                data = {
                    'id': row[0],
                    'sync_time': row[1],
                    'electricity_number': row[2]
                }
                return data
            else:
                return None
        except Exception as e:
            logging.error(f"获取最新电力消耗数据失败: {str(e)}")
            return None
    
    def get_electricity_data_by_date_range(self, start_date, end_date):
        """根据日期范围获取电力消耗数据
        
        Args:
            start_date: 开始日期（YYYY-MM-DD格式）
            end_date: 结束日期（YYYY-MM-DD格式）
            
        Returns:
            list: 电力消耗数据列表
        """
        try:
            sql = """
            SELECT id, sync_time, electricity_number
            FROM wsbz_electricity_consumption
            WHERE sync_time BETWEEN ? AND ?
            ORDER BY sync_time
            """
            params = (f"{start_date} 00:00:00", f"{end_date} 23:59:59")
            
            self.db.cursor.execute(sql, params)
            results = self.db.cursor.fetchall()
            
            data_list = []
            for row in results:
                data = {
                    'id': row[0],
                    'sync_time': row[1],
                    'electricity_number': row[2]
                }
                data_list.append(data)
            
            return data_list
        except Exception as e:
            logging.error(f"获取电力消耗数据失败: {str(e)}")
            return []
            
    def get_electricity_statistics(self):
        """获取电力消耗统计数据（日/月/年/累计）
        
        Returns:
            dict: 包含日、月、年、累计用电量的字典
        """
        try:
            # 使用提供的SQL查询
            sql = """
            SELECT CASE
                   WHEN sync_time >= DATE('now') AND sync_time < DATE('now', '+1 day')
                       THEN MAX(electricity_number) - MIN(electricity_number)
                   ELSE 0 END                                    AS electricity_number_day,
               CASE
                   WHEN sync_time >= DATE('now', 'start of month') AND sync_time < DATE('now', 'start of month', '+1 month')
                       THEN MAX(electricity_number) - MIN(electricity_number)
                   ELSE 0 END                                    AS electricity_number_month,
               CASE
                   WHEN sync_time >= DATE('now', 'start of year') AND sync_time < DATE('now', 'start of year', '+1 year')
                       THEN MAX(electricity_number) - MIN(electricity_number)
                   ELSE 0 END                                    AS electricity_number_year,
               MAX(electricity_number) - MIN(electricity_number) AS electricity_number_all
            FROM wsbz_electricity_consumption
            """
            
            self.db.cursor.execute(sql)
            row = self.db.cursor.fetchone()
            
            if row:
                data = {
                    'day': row[0] if row[0] is not None else 0,
                    'month': row[1] if row[1] is not None else 0,
                    'year': row[2] if row[2] is not None else 0,
                    'all': row[3] if row[3] is not None else 0
                }
                return data
            else:
                return {
                    'day': 0,
                    'month': 0,
                    'year': 0,
                    'all': 0
                }
        except Exception as e:
            logging.error(f"获取电力消耗统计数据失败: {str(e)}")
            return {
                'day': 0,
                'month': 0,
                'year': 0,
                'all': 0
            }