from sqlmodel import SQLModel, create_engine, Session

from db.models import Chat, Message
from core.config import get_settings

settings = get_settings()

engine = create_engine(
    settings.DATABASE_URL,
    pool_pre_ping=True,
    connect_args=settings.DB_CONNECT_ARGS
)

def get_db():
    """
    Dependency function to get a database session.
    Ensures the session is always closed after the request.
    """
    with Session(engine) as session:
        yield session

def create_db_and_tables():
    """
    Utility function to create database tables.
    """
    SQLModel.metadata.create_all(engine)