"""Alembic environment. Runs on a connection handed over by app.db.migrate (or the CLI via alembic.ini)."""

import asyncio

from alembic import context
from sqlalchemy.engine import Connection

from app.config import DatabaseSettings
from app.db.models import Base
from app.db.session import make_engine

target_metadata = Base.metadata


def _run(connection: Connection) -> None:
    context.configure(
        connection=connection,
        target_metadata=target_metadata,
        render_as_batch=connection.dialect.name == "sqlite",  # SQLite can't ALTER most things in place
        compare_type=True,
    )
    with context.begin_transaction():
        context.run_migrations()


async def _run_cli() -> None:
    engine = make_engine(DatabaseSettings().url)
    try:
        async with engine.begin() as conn:
            await conn.run_sync(_run)
    finally:
        await engine.dispose()


connection = context.config.attributes.get("connection")
if connection is not None:
    _run(connection)
else:
    asyncio.run(_run_cli())