"""Every admin page links to every other admin page.

Two pages had drifted in opposite directions -- providers.html was missing
Proficiency and proficiency.html was missing Providers -- so you could not
navigate between them in either direction without editing the URL. Neither
gap was noticeable from the page you were on, which is why a test is worth
more here than care.

The page list is derived from the routes the router actually serves, so a
new admin page fails this until it is linked from the others, rather than
quietly launching unreachable.
"""

from __future__ import annotations

import re
from pathlib import Path

import pytest

FRONTEND = Path(__file__).resolve().parent.parent / "admin" / "frontend"

# href -> file that serves it. Kept explicit rather than globbed so that
# adding a page is a deliberate two-line edit here, not an accident.
PAGES = {
    "/admin/": "index.html",
    "/admin/models": "models.html",
    "/admin/profiles": "profiles.html",
    "/admin/proficiency": "proficiency.html",
    "/admin/decisions": "decisions.html",
    "/admin/quota": "quota.html",
    "/admin/controls": "controls.html",
    "/admin/providers": "providers.html",
}

NAV_RE = re.compile(r'<header class="navbar.*?</header>', re.DOTALL)


def _nav_hrefs(filename: str) -> set[str]:
    html = (FRONTEND / filename).read_text(encoding="utf-8")
    nav = NAV_RE.search(html)
    assert nav, f"{filename}: no <header class=\"navbar\"> block found"
    return set(re.findall(r'href="(/admin[^"]*)"', nav.group(0)))


@pytest.mark.parametrize("filename", sorted(set(PAGES.values())))
def test_every_page_links_to_every_page(filename):
    missing = set(PAGES) - _nav_hrefs(filename)
    assert not missing, (
        f"{filename} nav is missing {sorted(missing)} -- a page you cannot "
        f"reach from here"
    )


@pytest.mark.parametrize("filename", sorted(set(PAGES.values())))
def test_no_nav_link_points_at_a_page_that_does_not_exist(filename):
    """The other direction: a typo'd href is a dead link, not a missing one."""
    unknown = {h for h in _nav_hrefs(filename) if h not in PAGES}
    assert not unknown, f"{filename} nav links to unknown {sorted(unknown)}"


@pytest.mark.parametrize("filename", sorted(set(PAGES.values())))
def test_each_page_marks_itself_active(filename):
    """A nav that never highlights leaves you unsure which page you are on."""
    html = (FRONTEND / filename).read_text(encoding="utf-8")
    nav = NAV_RE.search(html).group(0)
    if filename == "index.html":
        # The landing page is reached by the logo, not by a nav entry -- a
        # second door to the same place, in the row where width is scarcest.
        # So there is nothing for it to mark, and nothing may claim active.
        assert 'nav-link" href="/admin/"' not in nav, "the landing page has no nav entry"
        assert 'class="nav-item active"' not in nav
        return
    assert 'class="nav-item active"' in nav, f"{filename}: no active nav item"