"""Central logging configuration for xIQA."""

from __future__ import annotations

import logging
import os
import sys

_CONFIGURED = False


def setup_logging(level: int | str | None = None) -> None:
    """Configure root logger with a standard format.
    """
    global _CONFIGURED

    if level is None:
        level_name = os.environ.get('XIQA_LOG_LEVEL', 'INFO').upper()
        level = getattr(logging, level_name, logging.INFO)

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

    if _CONFIGURED:
        return

    handler = logging.StreamHandler(sys.stderr)
    handler.setFormatter(logging.Formatter('%(levelname)s [%(name)s] %(message)s'))
    root.addHandler(handler)
    _CONFIGURED = True


def get_logger(name: str) -> logging.Logger:
    """Return a module logger, configuring root logging on first use."""
    setup_logging()
    return logging.getLogger(name)