Backend/app/utils/logger.py

import logging
import os
from logging.handlers import RotatingFileHandler

# ── Log directory ────────────────────────────────────────────────────────────
LOG_DIR = os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(__file__))), "logs")
os.makedirs(LOG_DIR, exist_ok=True)

LOG_FILE = os.path.join(LOG_DIR, "app.log")

# ── Formatter ────────────────────────────────────────────────────────────────
LOG_FORMAT = "%(asctime)s | %(levelname)-8s | %(name)s | %(message)s"
DATE_FORMAT = "%Y-%m-%d %H:%M:%S"

formatter = logging.Formatter(LOG_FORMAT, datefmt=DATE_FORMAT)

# ── Handlers ─────────────────────────────────────────────────────────────────
# Rotating file: max 10 MB per file, keep 5 backups
file_handler = RotatingFileHandler(
    LOG_FILE,
    maxBytes=10 * 1024 * 1024,  # 10 MB
    backupCount=5,
    encoding="utf-8"
)
file_handler.setFormatter(formatter)
file_handler.setLevel(logging.DEBUG)

console_handler = logging.StreamHandler()
console_handler.setFormatter(formatter)
console_handler.setLevel(logging.INFO)


def get_logger(name: str) -> logging.Logger:
    """
    Get a named logger that writes to both console and logs/app.log.

    Usage:
        from app.utils.logger import get_logger
        logger = get_logger(__name__)
        logger.info("Hello")
    """
    logger = logging.getLogger(name)

    if not logger.handlers:
        logger.setLevel(logging.DEBUG)
        logger.addHandler(file_handler)
        logger.addHandler(console_handler)
        logger.propagate = False

    return logger