from __future__ import annotations

from sqlalchemy import create_engine, event
from sqlalchemy.orm import DeclarativeBase, sessionmaker
from sqlalchemy.pool import StaticPool

from .config import settings


class Base(DeclarativeBase):
    pass


def make_engine(url: str):
    kw = {"pool_pre_ping": True}
    if url.startswith("sqlite"):
        kw = {"connect_args": {"check_same_thread": False}}
        if ":memory:" in url or url.endswith("sqlite://"):
            kw["poolclass"] = StaticPool
    eng = create_engine(url, **kw)
    if url.startswith("sqlite"):

        @event.listens_for(eng, "connect")
        def _fk(dbapi_con, _):  # enforce foreign keys on SQLite (tests)
            dbapi_con.execute("PRAGMA foreign_keys=ON")

    return eng


engine = make_engine(settings.database_url)
SessionLocal = sessionmaker(bind=engine, autoflush=False, expire_on_commit=False)


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()