import os
from dataclasses import dataclass
from decimal import Decimal
from functools import lru_cache
from pathlib import Path


@dataclass(frozen=True)
class Settings:
    database_url: str
    api_key: str
    gui_user: str
    gui_password_hash: str
    session_secret: str
    inbox_dir: Path
    uploads_dir: Path
    warn_threshold: Decimal
    horizon_days: int


@lru_cache
def get_settings() -> Settings:
    e = os.environ.get
    return Settings(
        database_url=e("FB_DATABASE_URL", "sqlite:///./fb.sqlite"),
        api_key=e("FB_API_KEY", ""),
        gui_user=e("FB_GUI_USER", "admin"),
        gui_password_hash=e("FB_GUI_PASSWORD_HASH", ""),
        session_secret=e("FB_SESSION_SECRET", "dev-secret"),
        inbox_dir=Path(e("FB_INBOX_DIR", "./inbox")),
        uploads_dir=Path(e("FB_UPLOADS_DIR", "./uploads")),
        warn_threshold=Decimal(e("FB_WARN_THRESHOLD", "0")),
        horizon_days=int(e("FB_HORIZON_DAYS", "548")),
    )