"""Alembic migration environment (async, driven by DATABASE_URL)."""

import asyncio
import os
from logging.config import fileConfig

from alembic import context
from sqlalchemy.ext.asyncio import create_async_engine

from intervals_mcp_server.db.models import Base

config = context.config
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

target_metadata = Base.metadata


def _database_url() -> str:
    url = os.environ.get("DATABASE_URL") or config.get_main_option("sqlalchemy.url")
    if not url:
        raise RuntimeError("DATABASE_URL is not set")
    return url


def run_migrations_offline() -> None:
    context.configure(
        url=_database_url(),
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
        compare_type=True,
    )
    with context.begin_transaction():
        context.run_migrations()


def _run(connection) -> None:
    context.configure(connection=connection, target_metadata=target_metadata, compare_type=True)
    with context.begin_transaction():
        context.run_migrations()


async def run_migrations_online() -> None:
    engine = create_async_engine(_database_url())
    async with engine.connect() as connection:
        await connection.run_sync(_run)
    await engine.dispose()


if context.is_offline_mode():
    run_migrations_offline()
else:
    asyncio.run(run_migrations_online())