import pytest

from account.models import UserAccount
from account.usecases import (
    RegisterUserAccount,
    UsernameAlreadyExistError
)


def create_user(username, email, password, **extra_fields):
    # mock for "create_user" method on the UserAccount model
    # to avoind touching the database. Unit tests should not
    # touch databases :)

    return UserAccount(
        username=username,
        email=email,
        password=password,
        **extra_fields
    )


@pytest.fixture
def mock_execute_dependencies(mocker):
    mocker.patch.object(UserAccount.objects, 'create_user', side_effect=create_user)
    mocker.patch.object(RegisterUserAccount, 'valid_data', return_value=None)
    mocker.patch.object(WelcomeEmail, 'send_to', return_value=None)


class TestExecute:
    # Test the execute method on RegisterUserAccount use case

    def setup_method(self):
        # setup method will be executed on each test
        self._use_case = RegisterUserAccount(
            username='john.smith',
            email='john.smith@example.com',
            password='P@ssword',
            first_name='John',
            last_name='Smith',
        )

    def test_return_user_account_type(self, mock_execute_dependencies):
        result = self._use_case.execute()
        assert isinstance(result, UserAccount)

    def test_create_user_account_with_first_name(self, mock_execute_dependencies):
        expected_result = 'John'
        user_account = self._use_case.execute()
        assert user_account.first_name == expected_result

    def test_create_user_account_with_last_name(self, mock_execute_dependencies):
        expected_result = 'Smith'
        user_account = self._use_case.execute()
        assert user_account.last_name == expected_result


class TestValidData:
    # Test the valid_data method on RegisterUserAccount use case

    def test_when_username_already_exists_raise_username_already_exist_error(self, mocker):
        qs_mock = MockSet(
            UserAccount(
                username='john.smith',
                email='john.smith@example.com'
            )
        )

        mocker.patch.object(
            UserAccount.objects,
            'find_by_username',
            return_value=qs_mock
        )

        with pytest.raises(UsernameAlreadyExistError):
            use_case = RegisterUserAccount(
                'john.smith',
                'john.smith@example.com',
                'P@ssword9'
            )

            use_case.valid_data()

    def test_when_username_does_not_exists_returns_true(self, mocker):
        expected_result = True
        qs_mock = MockSet()

        mocker.patch.object(
            UserAccount.objects,
            'find_by_username',
            return_value=qs_mock
        )

        use_case = RegisterUserAccount(
            'john.smith',
            'john.smith@example.com',
            'P@ssword9'
        )

        result = use_case.valid_data()
        assert result == expected_result