"""配置管理模块

从环境变量加载应用配置，使用pydantic-settings进行类型验证
"""
import os
from pathlib import Path
from pydantic_settings import BaseSettings
from functools import lru_cache
from typing import Optional


# 获取项目根目录（config文件夹所在目录）
PROJECT_ROOT = Path(__file__).parent.parent.parent
CONFIG_DIR = PROJECT_ROOT / "config"


class Settings(BaseSettings):
    """应用配置类，从环境变量加载"""

    # 数据库配置
    database_host: str = "localhost"
    database_port: int = 5432
    database_name: str = "prostock"
    database_user: str
    database_password: str

    # API密钥配置
    api_key: str
    secret_key: str

    # Redis配置
    redis_host: str = "localhost"
    redis_port: int = 6379
    redis_password: Optional[str] = None

    # 应用配置
    app_env: str = "development"
    app_debug: bool = False
    app_port: int = 8000

    class Config:
        # 从 config/ 目录读取 .env.local 文件
        env_file = str(CONFIG_DIR / ".env.local")
        env_file_encoding = "utf-8"
        case_sensitive = False


@lru_cache()
def get_settings() -> Settings:
    """获取配置单例

    使用lru_cache确保配置只加载一次
    """
    return Settings()


# 导出配置实例供全局使用
settings = get_settings()