import logging
import os
import sqlite3

DEFAULT_SEPARATOR = '|'
DEFAULT_DATA_TYPE = 'TEXT'


#WARNING: attributes must be choosen from https://docs.python.org/3/library/logging.html#formatter-objects
DEFAULT_ATTRIBUTES_LIST = ['asctime', 'levelname', 'name', 'message']


class SQLiteHandler(logging.Handler):
    """
    Logging handler for SQLite
    Based on Yarin Kessler's sqlite_handler.py https://gist.github.com/ykessler/2662203#file_sqlite_handler.py
    """

    def __init__(self, database:str = "local.db", table = "log", attributes_list=None):
        """
        SQLiteHandler class constructor
        Parameters:
            self: instance of the class
            database: database
            table: log table name
            attributes_list: log table columns
        Returns:
            None
        """
        #super(SQLiteHandler, self).__init__() # for python 2.X
        super().__init__() # for python 3.X
        if attributes_list is None:
            attributes_list = DEFAULT_ATTRIBUTES_LIST
        self.database = database
        self.table = table
        self.attributes = attributes_list

        # Create table if needed
        create_table_sql = 'CREATE TABLE IF NOT EXISTS ' + self.table + ' (' + ((' ' + DEFAULT_DATA_TYPE + ', ').join(self.attributes)) + ' ' + DEFAULT_DATA_TYPE + ');'
        #print(create_table_sql)
        conn = sqlite3.connect(self.database)
        conn.execute(create_table_sql)
        conn.commit()
        conn.close()


    def emit(self, record):
        """
        Save the log record
        Parameters:
            self: instance of the class
            record: log record to be saved
        Returns:
            None
        """
        # Use default formatting if no formatter is set
        self.format(record)

        #print(record.__dict__)
        record_values = [record.__dict__[k] for k in self.attributes]
        str_record_values = ', '.join("'{0}'".format(v.replace("'", '').replace('"', '').replace('\n', ' ')) for v in record_values)
        #print(str_record_values)

        insert_sql = 'INSERT INTO ' + self.table + ' (' + (', '.join(self.attributes)) + ') VALUES (' + str_record_values + ');'
        #print(insert_sql)
        conn = sqlite3.connect(self.database)
        conn.execute(insert_sql)
        conn.commit()
        conn.close()


def init_logger() -> logging.Logger:
    # changing level we can change frome what level we want to log the events

    logger = logging.getLogger(__name__)
    logger.setLevel(logging.DEBUG)

    attributes_list = ['asctime', 'levelname', 'message']
    formatter = logging.Formatter('%(' + ((')s' + DEFAULT_SEPARATOR + '%(').join(attributes_list)) + ')s')

    console_handler = logging.StreamHandler()
    console_handler.setLevel(logging.DEBUG)
    console_handler.setFormatter(formatter)

    sql_handler = SQLiteHandler()
    sql_handler.setLevel(logging.INFO)
    sql_handler.setFormatter(formatter)

    logger.addHandler(console_handler)
    logger.addHandler(sql_handler)

    return logger