import os

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


def _db_url() -> str:
    host = os.getenv("DB_HOST", "localhost")
    port = os.getenv("DB_PORT", "5432")
    name = os.getenv("DB_NAME", "fixture")
    user = os.getenv("DB_USER", "postgres")
    password = os.getenv("DB_PASSWORD", "fixture")
    return f"postgresql+psycopg2://{user}:{password}@{host}:{port}/{name}"


engine = create_engine(_db_url(), echo=False, future=True)
SessionLocal = sessionmaker(bind=engine, autoflush=False, autocommit=False, future=True)


class Base(DeclarativeBase):
    pass


def get_session():
    session = SessionLocal()
    try:
        yield session
    finally:
        session.close()