"""
Database session management for the sim-search API.

This module provides utilities for creating and managing database sessions.
"""

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

from app.core.config import settings

# Create SQLAlchemy engine
engine = create_engine(
    settings.SQLALCHEMY_DATABASE_URI,
    pool_pre_ping=True,
    connect_args={"check_same_thread": False} if settings.SQLALCHEMY_DATABASE_URI.startswith("sqlite") else {},
)

# Create session factory
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# Create base class for models
Base = declarative_base()


def get_db():
    """
    Get a database session.
    
    Yields:
        SQLAlchemy session
    """
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()