Source code for bout_runners.utils.logs

"""Contains methods which deals with logging."""


import inspect
import logging
import logging.config
from typing import Any, Dict, Optional

# NOTE: pip imports bout_runners/__init__.py which sets up the log
#       If the environment does not contain pyyaml, pip install will fail
try:
    from yaml import safe_load

    YAML = True
except ModuleNotFoundError:
    YAML = False

    # NOTE: Ignoring type due to https://github.com/python/mypy/issues/1168
    def safe_load(_: Any) -> Dict[str, Any]:  # type: ignore
        """
        Mock the signature if YAML is False.

        Parameters
        ----------
        _ : object
            Dummy load

        Returns
        -------
        dict
            Dummy return
        """
        return {"": None}


from bout_runners.utils.paths import get_log_file_path, get_logger_config_path


class IndentFormatter(logging.Formatter):
    """
    Class which adds the indent formatter to the logging formatter.

    References
    ----------
    https://code.activestate.com/recipes/412603-stack-based-indentation-of-formatted-logging/
    """

    def __init__(
        self, fmt: Optional[str] = None, datefmt: Optional[str] = None
    ) -> None:
        """
        Call constructor and set member data.

        Parameters
        ----------
        fmt : str or None
            String to format
        datefmt : str or None
            Format of date
        """
        logging.Formatter.__init__(self, fmt, datefmt)
        self.subtract = len(inspect.stack())

    def format(self, record: logging.LogRecord) -> str:
        """
        Format the log string.

        Parameters
        ----------
        record : LogRecord
            The record to modify

        Returns
        -------
        out : str
            Formatted log record
        """
        # WARNING: indent will only be available in record if the format
        #          string contains indent
        spaces = len(inspect.stack()) - self.subtract
        record.indent = "  " * spaces  # type: ignore
        out = logging.Formatter.format(self, record)
        return out


# NOTE: Looks like mypy has trouble with recursive objects, thus this using Any looks
#       like a good solution for now
#       See also
#       https://github.com/python/typing/issues/182
def get_log_config() -> Dict[str, Any]:
    """
    Get the logging configuration.

    Returns
    -------
    config : dict
        A dictionary containing the logging configuration
    """
    log_config_path = get_logger_config_path()

    with log_config_path.open("r") as config_file:
        config: Dict[str, Any] = safe_load(config_file.read())
    return config


def set_up_logger(config: Optional[Dict[str, Any]] = None) -> None:
    """
    Set up the logger.

    Parameters
    ----------
    config : None or dict
        A dictionary containing the logging configuration
    """
    if YAML:
        if config is None:
            config = get_log_config()
        config["handlers"]["file_handler"]["filename"] = str(
            get_log_file_path(name="bout_runners.log")
        )
        logging.config.dictConfig(config)
        for handler in logging.getLogger().handlers:
            handler.setFormatter(
                IndentFormatter(config["formatters"]["simple"]["format"])
            )