"""Application settings, read from environment variables.

Single SQLite database (see docs/DECISIONS.md D15 for why this isn't the two-role Postgres+RLS
setup Phase 0 originally shipped with) — one DSN, one engine, no BYPASSRLS/NOBYPASSRLS split.
Isolation between users is enforced entirely by the repository-layer scope now; see db.py and
CLAUDE.md's invariant #4.
"""

from functools import lru_cache

from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(env_prefix="VELODROME_", extra="ignore")

    # A SQLAlchemy URL, e.g. sqlite+aiosqlite:////data/velodrome.db. Not typed as a stricter DSN
    # (pydantic has no built-in sqlite+aiosqlite validator) — Alembic and the app both read this
    # same setting, so keep it a plain string rather than inventing a validator neither needs.
    database_url: str = "sqlite+aiosqlite:///./velodrome.db"

    # AES-GCM key for encrypting third-party credentials (e.g. the Bryton digest, added in a later
    # phase). Not used yet in Phase 0, but declared now so the settings shape is stable.
    secret_key: str = "dev-only-insecure-placeholder-change-me"

    session_cookie_name: str = "vd_session"
    session_ttl_days: int = 90
    public_url: str = "http://localhost:5173"

    environment: str = "development"


@lru_cache
def get_settings() -> Settings:
    return Settings()