"""
utils/logger.py
统一日志工具 —— 所有模块通过 get_logger(name) 获取 logger
日志级别、输出目录、文件名均来自 config.yaml logging 节
"""

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

# 避免循环导入：logger 初始化时不能 import settings
# 改为延迟读取，首次调用时从环境变量 / 默认值获取
_LOG_LEVEL_ENV  = os.getenv("LOG_LEVEL", "DEBUG").upper()
_LOG_DIR_ENV    = os.getenv("LOG_DIR",   "./logs")
_LOG_FILE_ENV   = os.getenv("LOG_FILE",  "agent.log")
_ENABLE_FILE    = os.getenv("LOG_FILE_ENABLE", "true").lower() == "true"

_FORMATTER = logging.Formatter(
    fmt="%(asctime)s [%(levelname)-8s] %(name)-24s │ %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
)

# 全局 handler 缓存（避免重复添加）
_handlers_initialized: bool = False
_root_logger = logging.getLogger("agent")


def _init_handlers() -> None:
    global _handlers_initialized
    if _handlers_initialized:
        return

    # 尝试从 settings 读取配置（settings 已加载后才有效）
    try:
        from config.settings import settings
        level      = getattr(logging, settings.logging.level, logging.DEBUG)
        log_dir    = settings.logging.log_dir
        log_file   = settings.logging.log_file
        enable_file= settings.logging.enable_file
    except Exception:
        level      = getattr(logging, _LOG_LEVEL_ENV, logging.DEBUG)
        log_dir    = _LOG_DIR_ENV
        log_file   = _LOG_FILE_ENV
        enable_file= _ENABLE_FILE

    _root_logger.setLevel(level)

    # ── 控制台 Handler ────────────────────────────────────────
    if not any(isinstance(h, logging.StreamHandler) for h in _root_logger.handlers):
        console_handler = logging.StreamHandler(sys.stdout)
        console_handler.setFormatter(_FORMATTER)
        console_handler.setLevel(level)
        _root_logger.addHandler(console_handler)

    # ── 文件 Handler（RotatingFile）──────────────────────────
    if enable_file:
        log_path = Path(log_dir)
        log_path.mkdir(parents=True, exist_ok=True)
        file_handler = RotatingFileHandler(
            filename=log_path / log_file,
            maxBytes=10 * 1024 * 1024,   # 10 MB
            backupCount=5,
            encoding="utf-8",
        )
        file_handler.setFormatter(_FORMATTER)
        file_handler.setLevel(level)
        _root_logger.addHandler(file_handler)

    _root_logger.propagate = False
    _handlers_initialized  = True


def get_logger(name: str) -> logging.Logger:
    """
    获取命名 logger

    用法:
        logger = get_logger("MCP.SkillClient")
        logger = get_logger("TOOL.StaticAnalyzer")
        logger = get_logger("Agent")
    """
    _init_handlers()
    return logging.getLogger(f"agent.{name}")