Source code for sni.utils

"""
Various utilities
"""

from importlib import import_module
from typing import Any, Callable, Tuple
import logging
import random
import string

from datetime import datetime, timedelta

from pytz import utc


MINUTE = 60
HOUR = 60 * MINUTE
DAY = 24 * HOUR


# pylint: disable=dangerous-default-value
def catch_all(
    function: Callable,
    error_message: str,
    *,
    args: Tuple[Any, ...] = tuple(),
    kwargs: dict = {},
) -> None:
    """
    Calls a function but catches all the exceptions. If any were raised, logs
    an error message, followed by the string representation of the exception.
    """
    try:
        function(*args, **kwargs)
    except Exception as error:
        logging.error("%s: %s", error_message, str(error))


def catches_all(error_message: str = "Error") -> Callable:
    """
    Decorator version of :meth:`sni.utils.catch_all`.
    """

    def decorator(function: Callable) -> Callable:
        def wrapper(*args, **kwargs) -> None:
            catch_all(function, error_message, args=args, kwargs=kwargs)

        return wrapper

    return decorator


# pylint: disable=dangerous-default-value
async def catch_all_async(
    function: Callable,
    error_message: str,
    *,
    args: Tuple[Any, ...] = tuple(),
    kwargs: dict = {},
) -> None:
    """
    Calls a function but catches all the exceptions. If any were raised, logs
    an error message, followed by the string representation of the exception.
    """
    try:
        await function(*args, **kwargs)
    except Exception as error:
        logging.error("%s: %s", error_message, str(error))


def from_timestamp(timestamp: int) -> datetime:
    """
    Returns a UTC datetime from a UNIX timestamp.
    """
    return datetime.utcfromtimestamp(timestamp)


def now() -> datetime:
    """
    Returns the current UTC datetime.
    """
    return datetime.now(utc)


def now_plus(**kwargs) -> datetime:
    """
    Returns the current UTC datetime plus a specified timedelta.

    See also:
        `datetime.timedelta <https://docs.python.org/3/library/datetime.html?highlight=timedelta#datetime.timedelta>`_
    """
    return now() + timedelta(**kwargs)


def object_from_name(name: str) -> Any:
    """
    Returns a callable from its name, e.g. ``sni.esi.jobs:refresh_tokens``.
    """
    try:
        module_name, function_name = name.split(":")
        module = import_module(module_name)
        return getattr(module, function_name)
    except Exception as error:
        raise ValueError(f'Could not load object "{name}": {str(error)}')


def random_code(length: int) -> str:
    """
    Returns a random string made of digits, lowercase letters, and uppercase
    letters, of a given length.

    Warning:
        Not cryptographically secure.
    """
    return "".join(
        [
            random.choice(string.ascii_letters + string.digits)  # nosec
            for _ in range(length)
        ]
    )