import logging
from logging.handlers import RotatingFileHandler
import os

LOG_DIR = "logs"
LOG_FILE = "app.log"
LOG_PATH = os.path.join(LOG_DIR, LOG_FILE)
MAX_BYTES = 5 * 1024 * 1024  # 5MB
BACKUP_COUNT = 5

# 全局共用的 handler，只初始化一次
_handler = None

def setup_logger(name: str, level=logging.INFO) -> logging.Logger:
    global _handler

    if not os.path.exists(LOG_DIR):
        os.makedirs(LOG_DIR)

    logger = logging.getLogger(name)
    logger.setLevel(level)  # 设置这个 logger 的最低级别

    # 避免重复添加 handler（只添加一次）
    if not _handler:
        _handler = RotatingFileHandler(LOG_PATH, maxBytes=MAX_BYTES, backupCount=BACKUP_COUNT, encoding='utf-8')
        formatter = logging.Formatter('[%(asctime)s] %(levelname)s [%(name)s] %(message)s')
        _handler.setFormatter(formatter)
        _handler.setLevel(logging.DEBUG)  # Handler 设置最低等级，捕获所有内容

    if not logger.handlers:
        logger.addHandler(_handler)
        logger.propagate = False  # 避免日志冒泡打印两遍

    return logger