import re

import pytest

from mongoengine.base.utils import LazyRegexCompiler

signal_output = []


class TestLazyRegexCompiler:
    def test_lazy_regex_compiler_verify_laziness_of_descriptor(self):
        class UserEmail:
            EMAIL_REGEX = LazyRegexCompiler("@", flags=32)

        descriptor = UserEmail.__dict__["EMAIL_REGEX"]
        assert descriptor._compiled_regex is None

        regex = UserEmail.EMAIL_REGEX
        assert regex == re.compile("@", flags=32)
        assert regex.search("user@domain.com").group() == "@"

        user_email = UserEmail()
        assert user_email.EMAIL_REGEX is UserEmail.EMAIL_REGEX

    def test_lazy_regex_compiler_verify_cannot_set_descriptor_on_instance(self):
        class UserEmail:
            EMAIL_REGEX = LazyRegexCompiler("@")

        user_email = UserEmail()
        with pytest.raises(AttributeError):
            user_email.EMAIL_REGEX = re.compile("@")

    def test_lazy_regex_compiler_verify_can_override_class_attr(self):
        class UserEmail:
            EMAIL_REGEX = LazyRegexCompiler("@")

        UserEmail.EMAIL_REGEX = re.compile("cookies")
        assert UserEmail.EMAIL_REGEX.search("Cake & cookies").group() == "cookies"