database.py

"""
Database connection and session management.
"""
from sqlalchemy import create_engine
from sqlalchemy.orm import declarative_base, sessionmaker
from typing import Generator

from config import settings


# Check if database URL is configured
if settings.database_url is None:
    raise ValueError(
        "DATABASE_URL environment variable is required. "
        "Please set it in your .env file or environment."
    )

# Create sync engine
engine = create_engine(
    settings.database_url,
    echo=settings.debug,
    pool_pre_ping=True,
    pool_size=10,
    max_overflow=20,
)

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

# Base class for models
Base = declarative_base()


def get_db() -> Generator:
    """
    Dependency for getting database session.
    
    Yields:
        Session: Database session
    """
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()