from ptrace.tools import minmax
from logging import ERROR, WARNING, INFO, DEBUG

def getLogFunc(logger, level):
    """
    Get the logger function for the specified logging level.
    """
    if level == ERROR:
        return logger.error
    elif level == WARNING:
        return logger.warning
    elif level == INFO:
        return logger.info
    elif level == DEBUG:
        return logger.debug
    else:
        return logger.error

def changeLogLevel(level, delta):
    """
    Compute log level and make sure that the result is in DEBUG..ERROR.

    >>> changeLogLevel(ERROR, -1) == WARNING
    True
    >>> changeLogLevel(DEBUG, 1) == INFO
    True
    """
    return minmax(DEBUG, level + delta*10, ERROR)