"""Database configuration and session management."""

from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
from sqlalchemy.orm import declarative_base
import os

# Database URL - SQLite for simplicity
DATABASE_URL = os.getenv("DATABASE_URL", "sqlite+aiosqlite:///./conversations.db")

# Create async engine
engine = create_async_engine(
    DATABASE_URL,
    echo=False,  # Set to True for SQL debugging
    future=True,
)

# Session factory
async_session_maker = async_sessionmaker(
    engine,
    class_=AsyncSession,
    expire_on_commit=False,
)

# Base class for models
Base = declarative_base()


async def get_db() -> AsyncSession:
    """Get database session."""
    async with async_session_maker() as session:
        try:
            yield session
        finally:
            await session.close()


async def init_db():
    """Initialize database tables."""
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)