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


class Config:
    """配置类（单例模式）"""
    
    _instance: Optional["Config"] = None
    _config: Dict[str, Any] = {}
    
    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
            cls._instance._load_config()
        return cls._instance
    
    def _load_config(self) -> None:
        """加载配置文件"""
        yaml_paths = [
            Path("config.yaml"),
            Path(__file__).parent.parent / "config.yaml",
            Path.cwd() / "config.yaml",
        ]
        
        for path in yaml_paths:
            if path.exists():
                with open(path, "r", encoding="utf-8") as f:
                    self._config = yaml.safe_load(f) or {}
                self._resolve_env_vars()
                return
        
        self._config = {}
    
    def _resolve_env_vars(self) -> None:
        """解析环境变量引用"""
        def resolve(value: Any) -> Any:
            if isinstance(value, str) and value.startswith("${") and value.endswith("}"):
                return os.environ.get(value[2:-1], "")
            elif isinstance(value, dict):
                return {k: resolve(v) for k, v in value.items()}
            elif isinstance(value, list):
                return [resolve(item) for item in value]
            return value
        
        self._config = resolve(self._config)
    
    def get(self, key: str, default: Any = None) -> Any:
        """获取配置值，支持点号分隔的键"""
        keys = key.split(".")
        value = self._config
        for k in keys:
            if isinstance(value, dict):
                value = value.get(k)
            else:
                return default
        if value is None:
            return default
        return value
    
    # App配置
    @property
    def secret_key(self) -> str:
        return self.get("app.secret_key", "change-me-in-production")
    
    @property
    def debug(self) -> bool:
        return self.get("app.debug", True)
    
    @property
    def app_host(self) -> str:
        return self.get("app.host", "0.0.0.0")
    
    @property
    def app_port(self) -> int:
        return self.get("app.port", 8000)
    
    # 数据库配置
    @property
    def database_url(self) -> str:
        return self.get("database.url", "sqlite:///./chat.db")
    
    # LLM配置
    @property
    def llm_api_key(self) -> str:
        return self.get("llm.api_key", "") or os.environ.get("DEEPSEEK_API_KEY", "")
    
    @property
    def llm_api_url(self) -> str:
        return self.get("llm.api_url", "https://api.deepseek.com/v1")
    
    @property
    def llm_provider(self) -> str:
        return self.get("llm.provider", "deepseek")
    
    # 工具配置
    @property
    def tools_enable_cache(self) -> bool:
        return self.get("tools.enable_cache", True)
    
    @property
    def tools_cache_ttl(self) -> int:
        return self.get("tools.cache_ttl", 300)
    
    @property
    def tools_max_workers(self) -> int:
        return self.get("tools.max_workers", 4)
    
    @property
    def tools_max_iterations(self) -> int:
        return self.get("tools.max_iterations", 10)


# 全局配置实例
config = Config()