"""配置管理模块"""
import json
import os
from pathlib import Path
from typing import Any, Dict


class ConfigManager:
    """配置管理器"""

    _instance = None
    _config: Dict[str, Any] = {}

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance

    def __init__(self):
        if not self._config:
            self._load_config()

    def _load_config(self):
        """加载配置文件"""
        config_dir = Path(__file__).parent.parent / "config"
        config_file = config_dir / "database.json"

        if not config_file.exists():
            raise FileNotFoundError(f"配置文件不存在: {config_file}")

        with open(config_file, "r", encoding="utf-8") as f:
            self._config = json.load(f)

    def get(self, key: str, default: Any = None) -> Any:
        """获取配置项"""
        keys = key.split(".")
        value = self._config
        for k in keys:
            if isinstance(value, dict):
                value = value.get(k)
                if value is None:
                    return default
            else:
                return default
        return value

    def get_database_config(self) -> Dict[str, Any]:
        """获取数据库配置"""
        return self._config.get("database", {})


# 全局配置实例
config = ConfigManager()