"""logging 配置：降级到 stderr，避免污染 stdout（stdout 留给结构化输出如 JSON）。

优先用 jiangchang_skill_core 提供的 logging；本地无该包时降级到 stderr。

v1.1.18：本地降级路径追加 RotatingFileHandler（按 LOG_FILE env 决定是否落文件）。
"""

from __future__ import annotations

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

from util.constants import (
    LOG_LOGGER_NAME,
    SKILL_SLUG,
    SKILL_VERSION,
)

_configured = False


def setup_skill_logging() -> logging.Logger:
    """初始化 skill logger（幂等）。

    本地降级行为（无 jiangchang_skill_core 时）：
      - 若 LOG_FILE 已设：追加 RotatingFileHandler（LOG_MAX_BYTES × LOG_BACKUP_COUNT）
      - 始终追加 StreamHandler(sys.stderr)
      - logger level 取自 LOG_LEVEL（默认 INFO）
    """
    global _configured
    logger = logging.getLogger(LOG_LOGGER_NAME)
    if _configured:
        return logger

    # 优先用宿主提供的 skill logger 配置
    try:
        from jiangchang_skill_core.logging_config import setup_skill_logging as _host_setup

        _host_setup(SKILL_SLUG, LOG_LOGGER_NAME)
        _configured = True
        return logging.getLogger(LOG_LOGGER_NAME)
    except ImportError:
        pass

    # logger 级别
    level_name = os.environ.get("LOG_LEVEL", "INFO").upper()
    logger.setLevel(getattr(logging, level_name, logging.INFO))

    formatter = logging.Formatter(
        fmt=f"%(asctime)s [{SKILL_SLUG}] %(levelname)s %(message)s",
        datefmt="%Y-%m-%d %H:%M:%S",
    )

    # 本地降级：可选 RotatingFileHandler
    log_file_str = os.environ.get("LOG_FILE")
    if log_file_str:
        log_path = Path(log_file_str)
        if not log_path.is_absolute():
            from util.runtime_paths import get_logs_dir

            log_path = get_logs_dir() / log_file_str
        log_path.parent.mkdir(parents=True, exist_ok=True)
        max_bytes = int(os.environ.get("LOG_MAX_BYTES", str(5 * 1024 * 1024)))
        backup_count = int(os.environ.get("LOG_BACKUP_COUNT", "5"))
        file_handler = logging.handlers.RotatingFileHandler(
            log_path,
            maxBytes=max_bytes,
            backupCount=backup_count,
            encoding="utf-8",
        )
        file_handler.setFormatter(formatter)
        logger.addHandler(file_handler)

    # 始终保留 stderr handler
    handler = logging.StreamHandler(sys.stderr)
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    logger.propagate = False
    _configured = True
    logger.info("logging initialized (local fallback) v%s", SKILL_VERSION)
    return logger


def get_skill_logger() -> logging.Logger:
    """获取 skill logger（不会重复 setup）。"""
    if not _configured:
        return setup_skill_logging()
    return logging.getLogger(LOG_LOGGER_NAME)


def reset_for_tests() -> None:
    """测试用：重置 _configured flag，让 setup_skill_logging 重新初始化。

    必须在每个修改日志配置的测试 fixture 里调用，否则 env 改动不会生效。
    """
    global _configured
    logger = logging.getLogger(LOG_LOGGER_NAME)
    for h in list(logger.handlers):
        try:
            h.close()
        except Exception:
            pass
        logger.removeHandler(h)
    _configured = False