from typing import List, Optional
from pydantic_settings import BaseSettings
from pydantic import validator
import os


class Settings(BaseSettings):
    # API information
    PROJECT_NAME: str = "RESTAPIService"
    DESCRIPTION: str = "A RESTful API service built with FastAPI and SQLite"
    VERSION: str = "0.1.0"
    API_V1_PREFIX: str = "/api/v1"

    # Security
    SECRET_KEY: str = os.environ.get("SECRET_KEY", "supersecretkey")
    ALGORITHM: str = "HS256"
    ACCESS_TOKEN_EXPIRE_MINUTES: int = 30

    # CORS
    ALLOWED_HOSTS: List[str] = ["*"]

    # Database
    SQLALCHEMY_DATABASE_URI: Optional[str] = None

    @validator("SQLALCHEMY_DATABASE_URI", pre=True)
    def assemble_db_uri(cls, v, values):
        if v:
            return v

        from pathlib import Path

        # Set up database directory
        db_dir = Path("/app") / "storage" / "db"
        db_dir.mkdir(parents=True, exist_ok=True)

        return f"sqlite:////{db_dir}/db.sqlite"

    class Config:
        env_file = ".env"
        case_sensitive = True


settings = Settings()