"""Centralized logging setup.

Project rule (see memory ``no-silent-failures``): every error or unexpected
state must reach the log. Never swallow an exception silently. Secrets
(tokens, service-account keys, sessions) must NEVER be logged.
"""
import logging
import os

_LEVEL = os.getenv("LOG_LEVEL", "INFO").upper()

_configured = False


def configure_logging() -> None:
    """Configure root logging once. Safe to call multiple times."""
    global _configured
    if _configured:
        return
    logging.basicConfig(
        level=_LEVEL,
        format="%(asctime)s %(levelname)s %(name)s %(message)s",
    )
    _configured = True


def get_logger(name: str) -> logging.Logger:
    """Return a module logger. Use ``get_logger(__name__)``."""
    configure_logging()
    return logging.getLogger(name)