import logging

import os
import sqlite3 as sql
import shutil

class LogHandlerSQLite(logging.Handler):
    """logging handler for sqlite3"""
    __AUTHOR__                          = 'anima'
    __VERSION__                         = '1.0.0'

    def __init__(self, level: int | str = 0, dbfile: str = 'logs.db') -> None:
        """logging handler for sqlite3 

        :params level: loglevel (see logging lib)
        :type level: int | str
        :params dbfile: filename for sqlite db
        :type dbfile: str
        """
        self._dbfile    : str           = dbfile
        self._sqlfiles  : str           = os.path.dirname(os.path.realpath(__file__)) + '/sql'
        self.dbVersion  : str           = '1.0'   # needed db version
        self.__setup_db()
        super().__init__(level)

    ##> db general
    def __db_con(self) -> sql.Connection:
        """connection handler for with statements

        :return: connection object 
        :rtype: sqlite3.Connection
        """
        return sql.connect(self._dbfile, detect_types=sql.PARSE_DECLTYPES | sql.PARSE_COLNAMES)
    
    def __db_query(self, queryfile: str, payload: list = None, getId: bool = False) -> list | None:
        """send a query to db set at `dbfile`

        :param queryfile: filename for sql file (without .sql) multible querys per file possable (split with ;)
        :type queryfile: str
        :param payload: send payload to sql query
        :type payload: list
        :param getId: if True this will return the id of newest row inerst form this query
        :type getId: bool

        :return: db data is query was select or None if no data matches # known bug: works only if payload set (empty possable)
        :rtype: list | None
        """
        with open(f'{self._sqlfiles}/{queryfile}.sql', 'r') as sqlfile:
            sqlscript = sqlfile.read()

        with self.__db_con() as con:
            cur = con.cursor()
            if isinstance(payload, list):
                cur.execute(sqlscript, payload)
                id = cur.lastrowid
            else:
                cur.executescript(sqlscript)
            data = cur.fetchall()
        if getId:
            return id
        elif len(data) > 0:
            return data

    def __setup_db(self) -> None:
        """init a new db if need check version of db and start update  until `dbVersion` match
        
        :return: none
        """
        self.__db_query('tables')
        if self.__get_db_version() is None:
            self.__db_query('insertDbVersion')
        
        while not self.dbVersion == self.__get_db_version():
            self.__update_db(self.__get_db_version())

    def __update_db(self, version) -> None:
        """update db file; create a backup for every version
        
        :param version: needed version; version structure conroled by sql files
        :type version: str

        :return: none
        """
        shutil.copyfile(f'{self._dbfile}', f'{self._dbfile}.v-{version}.bak')
        self.__db_query(f'update/updateDb-{version}')

    ##> select (get) querys
    def __get_db_version(self) -> str | None:
        """read dbVersion from db

        :return: version from db
        :rtype: str
        
        """
        data = self.__db_query('selectDbVersion', [])
        if data is None:
            return data
        else:
            return data[0][0]

    def get_log(self) -> list[tuple] | None:
        """get all logs from db
        
        :return: all logs from db
        :rtype: list[tuple]
        """
        return self.__db_query('selectLogs', [])

    def get_log_by_pid(self, pid: int = os.getpid()) -> list[tuple] | None:
        """get all logs from db match the pid
        
        :param pid: process id (default is own from running instance)
        :type pid: int 

        :return: all logs match the pid or none
        :rtype: list[tuple] | None
        """
        if isinstance(pid, int):
            return self.__db_query('selectLogsByPID', [pid])
        else: return None

    ##> logging methods
    def emit(self, record: logging.LogRecord) -> None:
        """save log to db

        :param record: logging record called from logging lib
        :type record: logging.LogRecord
        
        """
        data = [
            record.created,
            record.process,
            record.name,
            record.levelname,
            record.levelno,
            record.filename,
            record.lineno,
            record.msg,
        ]
        self.__db_query('insertLogs', data)

if __name__ == "__main__":
    log = logging.getLogger(__name__)
    log.setLevel(10)

    logDB = LogHandlerSQLite()
    log.addHandler(logDB)
    
    log.error('Here is a info')
    print(logDB.get_log_by_pid())

    t = LogHandlerSQLite()