from __future__ import annotations

import importlib.util
from pathlib import Path

import sqlalchemy as sa
from alembic.migration import MigrationContext
from alembic.operations import Operations


def _load_migration_module():
    path = (
        Path(__file__).resolve().parents[1]
        / "alembic"
        / "versions"
        / "20260405_add_mounted_ai_runtime_tables.py"
    )
    spec = importlib.util.spec_from_file_location("mounted_ai_runtime_tables_migration", path)
    module = importlib.util.module_from_spec(spec)
    assert spec is not None
    assert spec.loader is not None
    spec.loader.exec_module(module)
    return module


def test_mounted_ai_runtime_migration_adds_tables() -> None:
    migration = _load_migration_module()
    engine = sa.create_engine("sqlite:///:memory:")

    with engine.begin() as conn:
        context = MigrationContext.configure(conn)
        migration.op = Operations(context)
        migration.upgrade()

        inspector = sa.inspect(conn)
        tables = set(inspector.get_table_names())

        assert "mounted_topic_workspaces" in tables
        assert "mounted_draft_workspaces" in tables
        assert "mounted_conversation_runs" in tables
        assert "mounted_agent_traces" in tables
        assert "mounted_tool_capability_policies" in tables

        migration.downgrade()

        inspector = sa.inspect(conn)
        tables = set(inspector.get_table_names())

        assert "mounted_topic_workspaces" not in tables
        assert "mounted_draft_workspaces" not in tables
        assert "mounted_conversation_runs" not in tables
        assert "mounted_agent_traces" not in tables
        assert "mounted_tool_capability_policies" not in tables