"""Registrable-domain comparison, which is what the same-site rules rest on."""

import pytest

from mews.fetch import registered_domain, same_site

CASES = [
    ("example.com", "example.com"),
    ("img.example.com", "example.com"),
    ("a.b.example.co.uk", "example.co.uk"),
    ("EXAMPLE.COM", "example.com"),
    ("example.com.", "example.com"),
    ("a.github.io", "a.github.io"),
    ("not-a-tld", None),
    ("", None),
]


@pytest.mark.parametrize(("host", "expected"), CASES)
def test_registrable_domain(host, expected):
    assert registered_domain(host) == expected


def test_subdomains_of_one_domain_are_one_site():
    assert same_site("example.com", "img.example.com")


def test_two_sites_on_a_shared_suffix_are_not_one_site():
    """The reason this uses a public suffix list rather than counting labels."""
    assert not same_site("a.github.io", "b.github.io")
    assert not same_site("example.co.uk", "evil.co.uk")