"""`hidden` has to mean hidden.

Eight elements carried the `hidden` attribute and rendered anyway, because the
UA sheet's `[hidden] { display: none }` loses to ANY author `display:` on the
element — it is an author-vs-UA contest, not a specificity one, so a plain
`.run-meta { display: flex }` cancels it.

What that looked like: an empty bordered box, 888x30 with one pixel of border
and nothing in it, sitting under "How to read this" on every library painted
from a conversation (renderRunMeta re-hides the box when the payload has no
`settings_used`, which an agent-painted run never does). A reviewing scientist
photographed it. Measured on a fresh load the same fault was also rendering a
92px CRISPR base-editor row, a 136px primer organism block, two clone panes, a
stray filter-clear glyph, and the entire 946x401 primer results card.

This test re-derives the list from the markup rather than hard-coding it, so
the next class that acquires a `display:` fails here instead of in a
screenshot.
"""
import re

_HTML = "dee/static/index.html"
_SHEETS = ("dee/static/app.css", "dee/static/catalog.css")

_EXEMPT = {
    # Deliberate, and says so in a comment: the scrim keeps its box while it
    # fades out, so `.sidebar-scrim[hidden] { display: block }` is the point.
    "sidebar-scrim":
        "keeps its box during the fade-out transition, on purpose",
    # These get a display ONLY from `body[data-ui="bench"][data-bench="open"]
    # .bench-strip`, and app.js clears their `hidden` in the same block that
    # sets data-bench. The state and the attribute never co-occur, and a bare
    # `.bench-strip[hidden]` guard is (0,2,0) — it would lose to that (0,3,1)
    # selector anyway, so adding one would look like protection and be none.
    "bench-strip":
        "display comes only from a body[data-bench=open] rule; JS clears "
        "hidden in the same block",
    "bench-canvashead":
        "same as .bench-strip",
}


def _read(path):
    with open(path, encoding="utf-8") as fh:
        return fh.read()


def _classes_rendered_with_hidden(html):
    """Every class that appears on an element written with a bare `hidden`."""
    out = set()
    for m in re.finditer(r"<\w+([^>]*)>", html):
        attrs = m.group(1)
        if not re.search(r"(^|\s)hidden(\s|=|/|$)", attrs):
            continue
        cm = re.search(r'class="([^"]*)"', attrs)
        if cm:
            out.update(cm.group(1).split())
    return out


def _strip_comments(css):
    return re.sub(r"/\*.*?\*/", " ", css, flags=re.S)


def _classes_given_a_display(css):
    """Classes that are the SUBJECT of a rule declaring `display:`.

    Subject means the last compound selector — `.brand-mark svg` styles the
    svg, not `.brand-mark`, so it cannot cancel `hidden` on `.brand-mark`.
    Selectors already qualified with `[hidden]` are the fix, not the fault.
    """
    css = _strip_comments(css)
    out = {}
    for rule in re.finditer(r"([^{}]+)\{([^{}]*)\}", css):
        selector, body = rule.group(1), rule.group(2)
        decl = re.search(r"(?:^|[;{\s])display\s*:\s*([a-z-]+)", body)
        if not decl:
            continue
        # `display: none` cannot cancel `hidden` — it agrees with it.
        if decl.group(1) == "none":
            continue
        for part in selector.split(","):
            part = part.strip()
            if not part or part.startswith("@"):
                continue
            subject = re.split(r"[\s>+~]+", part)[-1]
            if "[hidden]" in subject:
                continue
            for cls in re.findall(r"\.([A-Za-z0-9_-]+)", subject):
                out.setdefault(cls, part)
    return out


def _guarded(css):
    return set(re.findall(r"\.([A-Za-z0-9_-]+)\[hidden\]", _strip_comments(css)))


def test_no_class_silently_cancels_the_hidden_attribute():
    html = _read(_HTML)
    displays, guards = {}, set()
    for sheet in _SHEETS:
        css = _read(sheet)
        displays.update(_classes_given_a_display(css))
        guards |= _guarded(css)

    unguarded = sorted(
        cls for cls in _classes_rendered_with_hidden(html)
        if cls in displays and cls not in guards and cls not in _EXEMPT
    )
    assert not unguarded, (
        "these classes are written with `hidden` in index.html but a stylesheet "
        "gives them a display:, which beats the UA [hidden] rule, so they render "
        "anyway — add `.<class>[hidden] { display: none; }`: "
        + ", ".join(f"{c} (from `{displays[c]}`)" for c in unguarded)
    )


def test_the_run_meta_box_is_the_one_from_the_review():
    """Named explicitly: this is the empty bordered box in the screenshots, and
    it appears twice (#runMeta on Directed Evolution, #primerRunMeta on Primer
    Analysis) because both use the .run-meta class."""
    css = _read("dee/static/app.css")
    assert re.search(r"\.run-meta\[hidden\][^{]*\{[^}]*display\s*:\s*none", _strip_comments(css)), (
        ".run-meta[hidden] must resolve to display:none; without it the box "
        "renders empty on any library painted from a conversation."
    )
    html = _read(_HTML)
    assert html.count('class="run-meta"') >= 2