"""Centralized logger configuration for the application.

Configures the 'app' logger with a rotating file handler and console handler.
Importing `logger` from this module gives a configured logger instance.
"""
import logging
import os
from logging.handlers import RotatingFileHandler

# Determine project base directory (app/..)
base_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
log_dir = os.path.join(base_dir, "logs")
os.makedirs(log_dir, exist_ok=True)
log_file = os.path.join(log_dir, "app.log")

logger = logging.getLogger("app")
# Avoid reconfiguration if imported multiple times
if not logger.handlers:
    formatter = logging.Formatter("%(asctime)s %(levelname)s %(name)s: %(message)s")

    # Resolve log level from environment (default INFO)
    log_level_name = os.getenv("LOG_LEVEL", "INFO").upper()
    try:
        log_level = getattr(logging, log_level_name)
    except Exception:
        log_level = logging.INFO

    # Rotating file handler
    file_handler = RotatingFileHandler(log_file, maxBytes=10 * 1024 * 1024, backupCount=7, encoding="utf-8")
    file_handler.setFormatter(formatter)
    file_handler.setLevel(log_level)
    logger.addHandler(file_handler)

    # Console handler
    console_handler = logging.StreamHandler()
    console_handler.setFormatter(formatter)
    console_handler.setLevel(log_level)
    logger.addHandler(console_handler)

    logger.setLevel(log_level)

# Expose a helper to get child loggers if needed
def get_logger(name: str = None):
    if name:
        return logging.getLogger(f"app.{name}")
    return logger