from pathlib import Path
from typing import Any, Dict, Optional

from pydantic import BaseSettings, validator


class Settings(BaseSettings):
    PROJECT_NAME: str = "Todo App API"
    API_V1_STR: str = "/api/v1"

    # Database
    DB_DIR: Path = Path("/app") / "storage" / "db"
    SQLALCHEMY_DATABASE_URL: Optional[str] = None

    @validator("SQLALCHEMY_DATABASE_URL", pre=True)
    def assemble_db_url(cls, v: Optional[str], values: Dict[str, Any]) -> str:
        if v:
            return v

        db_dir = values.get("DB_DIR")
        if db_dir:
            db_dir.mkdir(parents=True, exist_ok=True)
            return f"sqlite:///{db_dir}/db.sqlite"

        return "sqlite:///./db.sqlite"

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


settings = Settings()