from __future__ import annotations

import importlib
import unittest
from unittest.mock import patch

from alembic.migration import MigrationContext
from alembic.operations import Operations
from sqlalchemy import create_mock_engine
from sqlalchemy.dialects import postgresql


class ExternalSystemMigrationTests(unittest.TestCase):
    def test_0027_upgrade_compiles_as_postgresql_ddl(self):
        statements: list[str] = []

        def capture(sql, *multiparams, **params):
            statements.append(str(sql.compile(dialect=postgresql.dialect())))

        engine = create_mock_engine("postgresql+psycopg://", capture)
        connection = engine.connect()
        operations = Operations(MigrationContext.configure(connection))
        migration = importlib.import_module(
            "db.migrations.versions.20260807_1000_0027_external_system_governance"
        )
        with patch.object(migration, "op", operations):
            migration.upgrade()

        rendered = "\n".join(statements)
        self.assertIn("external_system_grants", rendered)
        self.assertIn("external_system_audits", rendered)
        self.assertIn("operation_policies", rendered)
        self.assertIn("operation_mode", rendered)


if __name__ == "__main__":
    unittest.main()