import logging
import os
from pathlib import Path
from logging.handlers import RotatingFileHandler

_LOGGER = None


def get_log_file() -> Path:
    try:
        tmp = Path(os.getenv("TEMP") or os.getenv("TMP") or ".")
    except Exception:
        tmp = Path(".")
    return tmp / "docx_creator.log"


def get_logger(name: str = "docx_creator") -> logging.Logger:
    global _LOGGER
    if _LOGGER is not None:
        return _LOGGER
    logger = logging.getLogger(name)
    logger.setLevel(logging.DEBUG)
    log_file = get_log_file()
    log_file.parent.mkdir(parents=True, exist_ok=True)
    handler = RotatingFileHandler(str(log_file), maxBytes=2 * 1024 * 1024, backupCount=2, encoding="utf-8")
    fmt = logging.Formatter("%(asctime)s [%(levelname)s] %(name)s: %(message)s")
    handler.setFormatter(fmt)
    logger.addHandler(handler)
    # also log warnings+ to stderr for debugging
    stream = logging.StreamHandler()
    stream.setLevel(logging.WARNING)
    stream.setFormatter(fmt)
    logger.addHandler(stream)
    _LOGGER = logger
    logger.info("Logger initialized at %s", log_file)
    return logger