from pathlib import Path
from iottb.main import load_config


class TestLoadConfig:

    #  Loads configuration from an existing file
    def test_loads_config_from_existing_file(self, mocker):
        cfg_file = mocker.Mock()
        cfg_file.is_file.return_value = True
        mock_open = mocker.mock_open(
            read_data=f'{{"DefaultDatabase": "test_db", "DefaultDatabasePath": "{Path.home()}/user"}}')
        mocker.patch('builtins.open', mock_open)

        result = load_config(cfg_file)

        assert result == {"DefaultDatabase": "test_db", "DefaultDatabasePath": f"{Path.home()}/user"}
        cfg_file.is_file.assert_called_once()
        mock_open.assert_called_once_with(cfg_file, 'r')

    #  File path is invalid or inaccessible
    def test_file_path_invalid_or_inaccessible(self, mocker):
        cfg_file = mocker.Mock()
        cfg_file.is_file.return_value = False
        mock_create_default_config = mocker.patch('iottb.main.create_default_config',
                                                  return_value={"DefaultDatabase": "default_db",
                                                                "DefaultDatabasePath": f"{Path.home()}/default"})

        result = load_config(cfg_file)

        assert result == {"DefaultDatabase": "default_db", "DefaultDatabasePath": f"{Path.home()}/default"}
        cfg_file.is_file.assert_called_once()
        mock_create_default_config.assert_called_once_with(cfg_file)