"""
结构化日志配置

使用 structlog 实现结构化、可观测的日志，便于生产环境排查与聚合。
"""

import logging
import sys
import json
from typing import Any

# 尝试使用 structlog，若未安装则回退到标准 logging
try:
    import structlog

    USE_STRUCTLOG = True
except ImportError:
    USE_STRUCTLOG = False


def configure_logging(debug: bool = False) -> None:
    """
    配置应用日志

    Args:
        debug: 是否为调试模式
    """
    log_level = logging.DEBUG if debug else logging.INFO

    if USE_STRUCTLOG:
        structlog.configure(
            processors=[
                structlog.stdlib.filter_by_level,
                structlog.stdlib.add_logger_name,
                structlog.stdlib.add_log_level,
                structlog.stdlib.PositionalArgumentsFormatter(),
                structlog.processors.TimeStamper(fmt="iso"),
                structlog.processors.StackInfoRenderer(),
                structlog.processors.format_exc_info,
                structlog.processors.UnicodeDecoder(),
                structlog.dev.ConsoleRenderer() if debug else structlog.processors.JSONRenderer(),
            ],
            wrapper_class=structlog.stdlib.BoundLogger,
            context_class=dict,
            logger_factory=structlog.stdlib.LoggerFactory(),
            cache_logger_on_first_use=True,
        )
    else:
        logging.basicConfig(
            level=log_level,
            format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
            stream=sys.stdout,
        )


class _StdLoggerCompat:
    """兼容 structlog 风格 kwargs 的标准 logging 适配器。"""

    _PASSTHROUGH_KEYS = {"exc_info", "stack_info", "stacklevel", "extra"}

    def __init__(self, logger: logging.Logger):
        self._logger = logger

    def _split_kwargs(self, kwargs: dict[str, Any]) -> tuple[dict[str, Any], dict[str, Any]]:
        passthrough: dict[str, Any] = {}
        fields: dict[str, Any] = {}
        for key, value in kwargs.items():
            if key in self._PASSTHROUGH_KEYS:
                passthrough[key] = value
            else:
                fields[key] = value
        return passthrough, fields

    @staticmethod
    def _format_fields(fields: dict[str, Any]) -> str:
        try:
            return json.dumps(fields, ensure_ascii=False, default=str)
        except Exception:
            return str(fields)

    def _log(self, method: str, msg: Any, *args: Any, **kwargs: Any) -> None:
        passthrough, fields = self._split_kwargs(kwargs)
        text = str(msg)
        if fields:
            text = f"{text} | {self._format_fields(fields)}"
        getattr(self._logger, method)(text, *args, **passthrough)

    def debug(self, msg: Any, *args: Any, **kwargs: Any) -> None:
        self._log("debug", msg, *args, **kwargs)

    def info(self, msg: Any, *args: Any, **kwargs: Any) -> None:
        self._log("info", msg, *args, **kwargs)

    def warning(self, msg: Any, *args: Any, **kwargs: Any) -> None:
        self._log("warning", msg, *args, **kwargs)

    def error(self, msg: Any, *args: Any, **kwargs: Any) -> None:
        self._log("error", msg, *args, **kwargs)

    def exception(self, msg: Any, *args: Any, **kwargs: Any) -> None:
        kwargs.setdefault("exc_info", True)
        self._log("error", msg, *args, **kwargs)

    def critical(self, msg: Any, *args: Any, **kwargs: Any) -> None:
        self._log("critical", msg, *args, **kwargs)

    def __getattr__(self, item: str) -> Any:
        return getattr(self._logger, item)


def get_logger(name: str):
    """获取 logger 实例"""
    if USE_STRUCTLOG:
        return structlog.get_logger(name)
    return _StdLoggerCompat(logging.getLogger(name))