from influxdb_client import InfluxDBClient
from influxdb_client.client.write_api import SYNCHRONOUS
import logging, os
from typing import List, Dict, Any

logger = logging.getLogger(__name__)


class InfluxDBMgr:
    """
    influxdb链接管理
    """
    
    _instance = None
    _initialized = False
    
    def __new__(cls):
        """
        单例模式
        """
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance
    
    def init_app(self, app):
        """
        初始化
        """
        if self._initialized:
            logger.warning("influxdb连接已初始化，跳过重复初始化")
            return
        
        logger.info("influxdb初始化...........")
        url = os.getenv("INFLUXDB_URL", "")
        token = os.getenv("INFLUXDB_TOKEN", "")
        org = os.getenv("INFLUXDB_ORG", "")
        self.bucket = os.getenv("INFLUXDB_BUCKET", "")
        if len(url) == 0:
            logger.error("influxdb未配置，初始化失败")
            self._initialized = False
            return
        self.client = InfluxDBClient(url=url, token=token, org=org)
    
    def query_table(self, query_measurement: str, query_filed: str)-> List[Dict[str, Any]]:
        query_api = self.client.query_api()
        flux_query = f'''
        from(bucket: "{self.bucket}")
          |> range(start: -15m)
          |> filter(fn: (r) => r._measurement == "{query_measurement}")
          |> filter(fn: (r) => r._field == "{query_filed}")
          |> yield(name: "mean")
        '''

        query_tables = query_api.query(flux_query)

        result_records = []
        
        for _table in query_tables:
            for record in _table.records:
                dict = {}
                # record 包含时间、measurement、field、value 和 tags
                dict["time"] = record.get_time()
                dict["measurement"] = record.get_measurement()
                dict["field"] = record.get_field()
                dict["value"] = record.get_value()
                # dict["tags"] = record.values  # 包含所有 tags 和系统字段
                # logger.info(f"时间: {time}, measurement: {measurement}, field: {field}, 值: {value}, tags: {tags}")
                result_records.append(dict)
        
        return result_records

    def close_client(self):
        """
        关闭客户端连接，释放资源
        """
        if hasattr(self, 'client') and self.client:
            self.client.close()
            logger.info("InfluxDB 客户端已关闭")

    def __del__(self):
        """
        析构时自动关闭连接，有用?
        """
        self.close_client()

iot_influxdb = InfluxDBMgr()