"""Async SQLAlchemy pripojenie a inicializacia schemy.

Connection string z env DATABASE_URL. Default je lokalny SQLite subor (dev);
v produkcii staci nastavit DATABASE_URL na PostgreSQL (asyncpg), kod sa nemeni.
"""

import os

from sqlalchemy.ext.asyncio import (
    AsyncSession,
    async_sessionmaker,
    create_async_engine,
)
from sqlalchemy.orm import DeclarativeBase

DATABASE_URL = os.environ.get("DATABASE_URL", "sqlite+aiosqlite:///bridzik.db")


class Base(DeclarativeBase):
    pass


engine = create_async_engine(DATABASE_URL, echo=False)
async_session: async_sessionmaker[AsyncSession] = async_sessionmaker(
    engine, expire_on_commit=False
)


async def init_db() -> None:
    """Vytvori tabulky, ak este neexistuju. Vola sa pri starte servera."""
    # Import modelov registruje tabulky na Base.metadata.
    from db import models  # noqa: F401

    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)