import os
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, DeclarativeBase

DATABASE_URL = os.environ.get("DATABASE_URL")

if not DATABASE_URL:
    raise ValueError("DATABASE_URL environment variable is not set")

engine = create_engine(
    DATABASE_URL,
    pool_recycle=300,
    pool_pre_ping=True,
)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


class Base(DeclarativeBase):
    pass


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


def init_db():
    import app.models  # noqa: F401
    Base.metadata.create_all(bind=engine)