"""SQLite engine + session helpers.

SQLModel (SQLAlchemy + Pydantic) is used rather than Jason's usual Prisma — Prisma
is JS-first and its Python client is unofficial, whereas SQLModel is the FastAPI-
native ORM. SQLite stays the DB, single-file under the data volume.
"""
from sqlmodel import SQLModel, Session, create_engine

from .config import DATA_DIR, DB_PATH, MODELS_DIR

# check_same_thread=False: the worker thread shares the engine with request handlers.
engine = create_engine(
    f"sqlite:///{DB_PATH}",
    connect_args={"check_same_thread": False},
)


def init_db() -> None:
    DATA_DIR.mkdir(parents=True, exist_ok=True)
    MODELS_DIR.mkdir(parents=True, exist_ok=True)
    # Import models so they register on SQLModel.metadata before create_all.
    from . import models  # noqa: F401
    SQLModel.metadata.create_all(engine)


def get_session():
    with Session(engine) as session:
        yield session