import logging
import sys


def setup_logging(*, level: str = "info") -> None:
    numeric_level = getattr(logging, level.upper(), logging.INFO)

    root = logging.getLogger()
    root.setLevel(numeric_level)

    for h in root.handlers:
        if _is_stderr_stream_handler(h):
            h.setLevel(numeric_level)
            h.setFormatter(_build_formatter(numeric_level))
            return

    handler = logging.StreamHandler(sys.stderr)
    handler.setLevel(numeric_level)
    handler.setFormatter(_build_formatter(numeric_level))

    root.addHandler(handler)


def _build_formatter(level: int) -> logging.Formatter:
    if level <= logging.DEBUG:
        fmt = "%(asctime)s %(levelname)-8s %(name)s:%(funcName)s:%(lineno)d — %(message)s"
    else:
        fmt = "%(asctime)s %(levelname)-8s %(name)s — %(message)s"

    return logging.Formatter(fmt=fmt, datefmt="%H:%M:%S")


def _is_stderr_stream_handler(h: logging.Handler) -> bool:
    """
    Return True only for a StreamHandler writing to stderr.

    Excludes FileHandler and other subclasses that happen to
    inherit from StreamHandler.
    """
    return type(h) is logging.StreamHandler and getattr(h, "stream", None) is sys.stderr