from functools import lru_cache
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    """集中管理项目配置，来源于 .env / 环境变量。"""

    model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")

    # 说明：项目迁移到 Convex 的过程中，后端可能暂时不依赖 Supabase。
    # 因此这里给出空字符串默认值，避免本地未配置 .env 时无法启动开发服务器。
    supabase_url: str = ""
    supabase_service_role_key: str = ""
    redis_url: str = "redis://localhost:6379/0"
    frontend_url: str = "http://localhost:3000"
    openai_api_key: str = ""
    lightrag_db_url: str = ""
    lightrag_collection: str = "wolai-docs"


@lru_cache
def get_settings() -> Settings:
    """惰性实例化设置，避免重复读取文件。"""
    return Settings()


settings = get_settings()