# core/logger_helper.py
import logging
from logging.handlers import RotatingFileHandler
from pathlib import Path

def setup_logger(log_folder: Path, log_file_name: str = "conversion.log", level=logging.INFO) -> logging.Logger:
    """
    Sets up a logger that prints to console and writes to a rotating log file.
    """
    log_folder.mkdir(parents=True, exist_ok=True)
    log_file = log_folder / log_file_name

    logger = logging.getLogger("conversion_logger")
    logger.setLevel(level)
    logger.propagate = False  # Prevent duplicate logging if root logger exists

    # Formatter with timestamp
    formatter = logging.Formatter("%(asctime)s [%(levelname)s] %(message)s", datefmt="%Y-%m-%d %H:%M:%S")

    # Console handler
    console_handler = logging.StreamHandler()
    console_handler.setFormatter(formatter)
    console_handler.setLevel(level)

    # File handler with rotation (max 5 MB per file, keep 3 backups)
    file_handler = RotatingFileHandler(log_file, maxBytes=5*1024*1024, backupCount=3, encoding="utf-8")
    file_handler.setFormatter(formatter)
    file_handler.setLevel(level)

    # Add handlers
    if not logger.handlers:
        logger.addHandler(console_handler)
        logger.addHandler(file_handler)

    return logger