sirosen/SALVE

import logging

from .handler import gen_handler


def clear_handlers(logger):
    """
    Clear logger handlers.
    """
    logger.handlers = []


def add_logfile(logger, loglevel, filename):
    """
    Adds a handler which writes to a file to the logger's handlers.
    """
    hdlr = gen_handler(filename=filename)
    hdlr.setLevel(loglevel)
    logger.addHandler(hdlr)


def create_logger(name):
    l = logging.getLogger(name)
    setup_stderr(l)
    l.propagate = False
    return l


def setup_stderr(logger):
    """
    Does the bare minimum to setup a working log handler which writes to
    stderr.

    Args:
        @logger
        A logging.Logger object.
    """
    # create a handler that writes to stderr
    hdlr = gen_handler()

    # attach the handler and set the log level to DEBUG
    logger.addHandler(hdlr)
    logger.setLevel(logging.DEBUG)


def str_to_level(lvlstr):
    try:
        return dict(
            (logging.getLevelName(l), l) for l in
            [logging.DEBUG, logging.INFO, logging.WARNING, logging.ERROR,
             logging.CRITICAL]
            )[lvlstr.upper()]
    except KeyError:
        raise ValueError('{0} is not a valid log level'.format(lvlstr))