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

DEFAULT_DB_URL = "postgresql+psycopg2://postgres:postgres@postgres:5432/auth_db"

class Base(DeclarativeBase):
    pass

DATABASE_URL = os.getenv("DATABASE_URL", DEFAULT_DB_URL)

engine = create_engine(
    DATABASE_URL,
    pool_pre_ping=True,
    future=True,
)

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

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