"""Helpers shared by the online Alembic environment and its tests."""

from __future__ import annotations

import os
from typing import Any

from sqlalchemy import text


def configure_mysql_migration_lock_waits(connection: Any) -> None:
    """Set bounded MySQL DDL lock waits without leaving a transaction open.

    SQLAlchemy starts an implicit transaction for ``SET SESSION`` on MySQL.
    Alembic's migration transaction then reuses it, and closing the connection
    rolls back the ``alembic_version`` updates even though MySQL DDL itself has
    already committed. Commit the session-local settings before Alembic starts
    its transaction so successful migrations are recorded durably.
    """

    try:
        lock_wait = int(os.getenv("DEER_FLOW_ALEMBIC_LOCK_WAIT", "15"))
    except ValueError:
        lock_wait = 15

    connection.execute(text(f"SET SESSION lock_wait_timeout = {lock_wait}"))
    connection.execute(text(f"SET SESSION innodb_lock_wait_timeout = {lock_wait}"))
    connection.commit()