from backend.database.wrappers import Wrapper, MySQLWrapper
from backend.logger import Logger

from time import sleep


def initialize_databases(configs, schemes):
    timeout = 5
    max_retries = 7

    for config in configs:
        if config['type'] == 'mysql':
            for _ in range(max_retries):
                try:
                    Logger.get_logger().info(f'Trying to connect to database "{config["db_name"]}@{config["host"]}"...')
                    wrapper = MySQLWrapper(config['host'], config['username'], config['password'], config['db_name'])
                    Logger.get_logger().info('Connected.')
                    break
                except Exception as e:
                    Logger.get_logger().info(f'Connection failed. Reason: "{e}";\nTrying again...')
                    sleep(timeout)
            else:
                Logger.get_logger().critical(
                    f'Failed to connect to "{config["db_name"]}@{config["host"]}". '
                    f'Check that database and then restart this service.'
                )
                continue

            wrappers[config['name']] = wrapper
            cursor = wrapper.connection.cursor()
            for scheme in schemes:
                Logger.get_logger().info(f'Preparing table "{scheme.meta["name"]}"...')
                cursor.execute(scheme.get_create_line())
                wrapper.schemes[scheme.meta['name']] = scheme
            cursor.close()
            wrapper.connection.commit()


def shutdown_databases():
    Logger.get_logger().info('Shutting down databases...')
    for wrapper in wrappers:
        wrapper.close_connection()


def get_wrapper_for(database_name) -> Wrapper:
    return wrappers.get(database_name, None)


wrappers = {}