"""
Database connection and session management.
"""

from typing import AsyncGenerator
from sqlalchemy.ext.asyncio import AsyncEngine, create_async_engine
from sqlalchemy.orm import sessionmaker
from sqlmodel import SQLModel
from sqlmodel.ext.asyncio.session import AsyncSession

DATABASE_URL = "sqlite+aiosqlite:///./database.db"

async_engine: AsyncEngine = create_async_engine(
    DATABASE_URL,
    echo=False,
    future=True,
)

async def create_db_and_tables():
    """Create database tables defined in SQLModel models."""
    async with async_engine.begin() as conn:
        await conn.run_sync(SQLModel.metadata.create_all)

async def get_session() -> AsyncGenerator[AsyncSession, None]:
    """
    Dependency to provide async database session.
    Yields:
        AsyncSession: Database session
    """
    async_session = sessionmaker(
        bind=async_engine,
        class_=AsyncSession,
        expire_on_commit=False
    )
    async with async_session() as session:
        yield session