import os

from sqlalchemy import create_engine
from sqlalchemy.orm import declarative_base, sessionmaker


DATABASE_URL = os.getenv(
    "DATABASE_URL", "postgresql+psycopg://exam_user:exam_pass@localhost:5432/exam_helper"
)

engine = create_engine(DATABASE_URL, future=True, pool_pre_ping=True)
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False, future=True)
Base = declarative_base()


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