import copy

import multiprocessing

import unittest

from unittest import mock

from django.db import DEFAULT_DB_ALIAS, NotSupportedError, connection, connections

from django.test import SimpleTestCase

@unittest.skipUnless(connection.vendor == "sqlite", "SQLite tests")

class TestDbSignatureTests(SimpleTestCase):

    def test_custom_test_name(self):

        test_connection = copy.copy(connections[DEFAULT_DB_ALIAS])

        test_connection.settings_dict = copy.deepcopy(

            connections[DEFAULT_DB_ALIAS].settings_dict

        )

        test_connection.settings_dict["NAME"] = None

        test_connection.settings_dict["TEST"]["NAME"] = "custom.sqlite.db"

        signature = test_connection.creation_class(test_connection).test_db_signature()

        self.assertEqual(signature, (None, "custom.sqlite.db"))

    def test_get_test_db_clone_settings_name(self):

        test_connection = copy.copy(connections[DEFAULT_DB_ALIAS])

        test_connection.settings_dict = copy.deepcopy(

            connections[DEFAULT_DB_ALIAS].settings_dict,

        )

        tests = [

            ("test.sqlite3", "test_1.sqlite3"),

            ("test", "test_1"),

        ]

        for test_db_name, expected_clone_name in tests:

            with self.subTest(test_db_name=test_db_name):

                test_connection.settings_dict["NAME"] = test_db_name

                test_connection.settings_dict["TEST"]["NAME"] = test_db_name

                creation_class = test_connection.creation_class(test_connection)

                clone_settings_dict = creation_class.get_test_db_clone_settings("1")

                self.assertEqual(clone_settings_dict["NAME"], expected_clone_name)

    @mock.patch.object(multiprocessing, "get_start_method", return_value="forkserver")

    def test_get_test_db_clone_settings_not_supported(self, *mocked_objects):

        msg = "Cloning with start method 'forkserver' is not supported."

        with self.assertRaisesMessage(NotSupportedError, msg):

            connection.creation.get_test_db_clone_settings(1)