"""Common module."""

import logging
import os
import sys
import time
from functools import wraps

LOGGER_LEVEL = getattr(
    logging,
    os.environ.get('LOGGER_LEVEL', logging.getLevelName(logging.WARNING))
)
logger = logging.getLogger()
logger.setLevel(LOGGER_LEVEL)
stream_handler = logging.StreamHandler(sys.stdout)
stream_handler.setLevel(logging.DEBUG)
logger.handlers = [stream_handler]


def timer(func):
    """Log the runtime of the decorated function."""
    @wraps(func)
    def inner(*args, **kwargs):
        start_time = time.time()
        retval = func(*args, **kwargs)
        logger.debug(f'{time.time() - start_time:.2f} seconds elapsed')
        return retval
    return inner