#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
# @Version     : Python 3.11.4
# @Software    : Sublime Text 4
# @Author      : StudentCWZ
# @Email       : StudentCWZ@outlook.com
# @Date        : 2023/11/20 09:57
# @File        : log.py
# @Description :
"""


from loguru import logger

from application.libs.helper import MySQLHelper
from application.models import Log
from application.utils import ElasticsearchUtil, ParseUtil


class LogDao:
    """
    Data Access Object for logs.
    This class includes methods to get data from Elasticsearch, process it and save it to MySQL.
    """

    @classmethod
    def get_data_from_es(cls, index=None, dsl=None, sid=None) -> dict:
        """
        Get data from Elasticsearch by either scroll searching or direct searching.

        Args:
            index (str): The name of the Elasticsearch index.
            dsl (dict): The DSL query for Elasticsearch.
            sid (str): The scroll id for Elasticsearch scroll search.

        Returns:
            dict: The data returned from Elasticsearch.

        Raises:
            SystemError: If none of the required parameters are provided.
        """
        if sid is not None:
            return ElasticsearchUtil.scroll_search(sid)
        elif index is not None and dsl is not None:
            return ElasticsearchUtil.search(index, dsl)
        else:
            raise SystemError('Could not get data from Elasticsearch')

    @classmethod
    def get_mdata(cls, data: dict) -> list:
        """
        Get metadata from the data returned by Elasticsearch.

        Args:
            data (dict): The data returned from Elasticsearch.

        Returns:
            list: The metadata extracted from the data.

        Raises:
            SystemError: If the metadata is empty.
        """
        mdata = data.get('hits').get('hits')
        if not mdata:
            logger.error('the mdata is an empty list ...')
            raise SystemError('the mdata is an empty list ...')
        return mdata

    @classmethod
    def get_intent_from_mysql(cls, sql: str, cfg: dict) -> list:
        """
        Get the intent mapping from MySQL using the provided SQL.

        Args:
            sql (str): The SQL query to execute.
            cfg (dict): The configuration for MySQL.

        Returns:
            list: The intent mapping list.
        """
        with MySQLHelper(**cfg) as helper:
            result = helper.execute(sql)
        mapping_list = [item[0] for item in result]
        return mapping_list

    @classmethod
    def process_and_save_data(cls, lst: list, mapping_list: list):
        """
        Process the given list using the mapping list and save the result to the database.

        Args:
            lst (list): The list to process.
            mapping_list (list): The mapping list to use for processing.
        """
        if not lst:
            return
        result_generator = ParseUtil(mapping_list=mapping_list).filter(lst)
        _ = Log.batch_save(result_generator)

    @classmethod
    def parse(cls, start: str, end: str, index: str, sql: str, cfg: dict) -> int:
        """
        Parse logs from Elasticsearch and save them to MySQL.

        Args:
            start (str): The start date for the logs.
            end (str): The end date for the logs.
            index (str): The Elasticsearch index to get logs from.
            sql (str): The SQL query to get the intent mapping from MySQL.
            cfg (dict): The configuration for MySQL.

        Returns:
            int: The total number of logs parsed.

        Raises:
            SystemError: If there is an error during the process.
        """

        # Get the DSL for the given start and end dates.
        dsl = ElasticsearchUtil.dsl(start, end)

        # Get data from Elasticsearch.
        data = cls.get_data_from_es(index=index, dsl=dsl)

        # Extract metadata from the data.
        mdata = cls.get_mdata(data)

        # Get the total number of logs.
        total = data.get('hits').get('total').get('value')
        logger.debug(f'The numbers of data by searching data from ES: {total}')

        # Log the start of the searching and saving process.
        logger.debug('The data is inserting ...')

        # Get the intent mapping from MySQL.
        mapping_list = cls.get_intent_from_mysql(sql, cfg)

        # Process and save the metadata.
        cls.process_and_save_data(mdata, mapping_list)

        # Get the scroll id for scroll searching in Elasticsearch.
        scroll_id = data.get('_scroll_id')

        try:
            for _ in range(0, int(total / dsl.get('size', 10000) + 1)):
                # Get more data from Elasticsearch using scroll searching.
                res = cls.get_data_from_es(sid=scroll_id)
                lst = res.get('hits').get('hits')

                if not lst:
                    continue

                # Process and save the data.
                cls.process_and_save_data(lst, mapping_list)
        except Exception as e:
            # Log the error and raise a SystemError.
            logger.error(f'The error: {e}')
            raise SystemError()
        else:
            # Log the success of the process.
            logger.debug('The process of inserting data succeed!')
        finally:
            # Log the end of the process.
            logger.debug('The inserting of the data finished!')

        return total