import logging
from logging.config import dictConfig
from os import environ, path

from yaml import safe_load

logging_path = environ.get("ONNX_WEB_LOGGING_PATH", "./logging.yaml")


def add_logging_level(level_name, level_num, method_name=None):
    """
    From https://stackoverflow.com/a/35804945

    Comprehensively adds a new logging level to the `logging` module and the
    currently configured logging class.

    `levelName` becomes an attribute of the `logging` module with the value
    `levelNum`. `methodName` becomes a convenience method for both `logging`
    itself and the class returned by `logging.getLoggerClass()` (usually just
    `logging.Logger`). If `methodName` is not specified, `levelName.lower()` is
    used.

    To avoid accidental clobberings of existing attributes, this method will
    raise an `AttributeError` if the level name is already an attribute of the
    `logging` module or if the method name is already present

    Example
    -------
    >>> addLoggingLevel('TRACE', logging.DEBUG - 5)
    >>> logging.getLogger(__name__).setLevel("TRACE")
    >>> logging.getLogger(__name__).trace('that worked')
    >>> logging.trace('so did this')
    >>> logging.TRACE
    5

    """
    if not method_name:
        method_name = level_name.lower()

    if hasattr(logging, level_name):
        raise AttributeError("{} already defined in logging module".format(level_name))
    if hasattr(logging, method_name):
        raise AttributeError("{} already defined in logging module".format(method_name))
    if hasattr(logging.getLoggerClass(), method_name):
        raise AttributeError("{} already defined in logger class".format(method_name))

    # This method was inspired by the answers to Stack Overflow post
    # http://stackoverflow.com/q/2183233/2988730, especially
    # http://stackoverflow.com/a/13638084/2988730
    def logForLevel(self, message, *args, **kwargs):
        if self.isEnabledFor(level_num):
            self._log(level_num, message, args, **kwargs)

    def logToRoot(message, *args, **kwargs):
        logging.log(level_num, message, *args, **kwargs)

    logging.addLevelName(level_num, level_name)
    setattr(logging, level_name, level_num)
    setattr(logging.getLoggerClass(), method_name, logForLevel)
    setattr(logging, method_name, logToRoot)


# setup logging config before anything else loads
try:
    if path.exists(logging_path):
        with open(logging_path, "r") as f:
            config_logging = safe_load(f)
            dictConfig(config_logging)
            add_logging_level("TRACE", logging.DEBUG - 5)
except Exception as err:
    print("error loading logging config: %s" % (err))