from cron_converter import Cron
from configparser import ConfigParser
from pathlib import Path
from datetime import datetime
import dateutil
import time
import functools
import logging

# load default values
config = ConfigParser()
config.read(Path(__file__).parent / 'defaults.ini')
SCHEDULE = config.get('cron', 'schedule')
TZ = config.get('cron', 'tz')


def cronjob(
    schedule: str = SCHEDULE,
    tz: str = TZ
):
    """
    decorator for running function as a cronjob.
    """
    logging.info(f'started cronjob with schedule {schedule} and tz {tz}')

    def decorator_cronjob(func):
        @functools.wraps(func)
        def wrapper_cronjob(*args, **kwargs):
            scheduler = Cron(schedule).schedule(timezone_str=tz)
            trigger_time = scheduler.next()
            while True:
                while trigger_time > datetime.now(tz=dateutil.tz.gettz(tz)):
                    # waiting loop
                    time.sleep(1)
                # actual execution
                try:
                    func(*args, **kwargs)
                except Exception as e:
                    logging.warning(f'failed executing {func}: {e}')
                    raise
                else:
                    # update trigger time
                    trigger_time = scheduler.next()
        return wrapper_cronjob
    return decorator_cronjob


if __name__ == '__main__':
    @cronjob(schedule='* * * * *', tz=TZ)
    def test_loop(msg: str):
        print(msg)

    test_loop('hello world')