"""Unit: the tuning toggle ships hidden — the anonymous flash fix (phase 40).

The "Tuning" steering toggle (``#steering-toggle``) used to ship VISIBLE
in every page's shared header and was removed by ``assets/header.js``
only after ``/api/whoami`` resolved — so an anonymous user briefly saw
the button on every page load (``TODO.md`` L3). The fix mirrors the
admin-only NAV LINKS (phase 19/29/35 contract): the toggle now SHIPS
with the ``hidden`` attribute in all six pages and ``initSharedHeader``
unhides it only when whoami says admin. The browser behavior is
E2E-covered (``tests/e2e/test_tuning_toggle_flash.py``); here we pin
the source-level wiring — the ship-hidden markup on every page, the
admin unhide line inside ``initSharedHeader``, the intact anonymous
remove-from-DOM path (phase 16 "absent, not hidden"), and the
``#nav-tuning`` hidden contract this phase relies on — so a silent
regression is caught without a browser.
"""
from __future__ import annotations

import re
from pathlib import Path

FRONTEND = Path(__file__).resolve().parents[2] / "frontend"
ASSETS = FRONTEND / "assets"

HEADER_JS = ASSETS / "header.js"

#: All six pages carry the shared header block (phase 34's five pages +
#: phase 35's git-sources page).
PAGES = (
    FRONTEND / "index.html",
    FRONTEND / "sources.html",
    FRONTEND / "document.html",
    FRONTEND / "git-sources.html",
    FRONTEND / "login.html",
    FRONTEND / "tuning.html",
)


def _text(path: Path) -> str:
    assert path.is_file(), f"missing frontend file: {path}"
    return path.read_text(encoding="utf-8")


def _toggle_tag(html: Path) -> str:
    tag = re.search(r"<button[^>]*id=\"steering-toggle\"[^>]*>", _text(html))
    assert tag, f"{html.name}: missing the #steering-toggle button"
    return tag.group(0)


def _toggle_body(html: Path) -> str:
    """The full <button>…</button> block, for the icon/label/badge pins."""
    text = _text(html)
    start = text.find('id="steering-toggle"')
    assert start != -1, f"{html.name}: missing the #steering-toggle button"
    return text[start : text.find("</button>", start)]


def _init_body(js: str) -> str:
    """The source of initSharedHeader in header.js."""
    fn = js.find("function initSharedHeader")
    assert fn != -1, "initSharedHeader must be defined"
    return js[fn : js.find("\n}", fn)]


# ---------- ship-hidden markup: zero flash for anonymous ----------


def test_steering_toggle_ships_hidden_on_all_six_pages() -> None:
    """#steering-toggle carries the ``hidden`` attribute in ALL SIX
    pages — the exact ship-hidden contract the admin-only nav links
    use, so an anonymous user never sees the "Tuning" button for a
    single frame, on any page."""
    for html in PAGES:
        tag = _toggle_tag(html)
        assert re.search(r"\bhidden\b", tag), (
            f"{html.name}: #steering-toggle must ship hidden"
        )


def test_steering_toggle_keeps_its_existing_markup() -> None:
    """Only the ``hidden`` attribute was added: type, class, the
    aria-expanded / aria-controls wiring, the decorative icon, the
    "Tuning" label, and the #steering-count badge stay byte-identical
    on every page — the admin UX is unchanged."""
    for html in PAGES:
        tag = _toggle_tag(html)
        assert 'type="button"' in tag
        assert 'class="steering-toggle"' in tag
        assert 'aria-expanded="false"' in tag
        assert 'aria-controls="steering-panel"' in tag
        body = _toggle_body(html)
        assert '<svg aria-hidden="true"' in body, f"{html.name}: icon is gone"
        assert '<span class="steering-label">Tuning</span>' in body, (
            f"{html.name}: label markup changed"
        )
        assert '<span class="steering-count" id="steering-count">0</span>' in body, (
            f"{html.name}: count badge markup changed"
        )


def test_steering_panel_still_ships_hidden_on_all_six_pages() -> None:
    """The #steering-panel section already shipped hidden and stays
    that way (this phase never touches the panel)."""
    for html in PAGES:
        tag = re.search(r'<section[^>]*id="steering-panel"[^>]*>', _text(html))
        assert tag, f"{html.name}: missing the #steering-panel section"
        assert re.search(r"\bhidden\b", tag.group(0)), "the panel ships hidden"


# ---------- header.js: reveal-for-admin, anonymous removal intact ----------


def test_header_js_unhides_the_toggle_for_admin() -> None:
    """Inside initSharedHeader, the admin branch unhides the toggle —
    and that line sits BEFORE the refreshSteering() call (the count
    badge is right before the panel is ever opened)."""
    body = _init_body(_text(HEADER_JS))
    assert "if (steeringToggle) steeringToggle.hidden = false;" in body, (
        "the admin unhide is missing from initSharedHeader"
    )
    admin = body.find("if (admin)")
    unhide = body.find("steeringToggle.hidden = false")
    refresh = body.find("if (steeringPanel) refreshSteering();")
    assert -1 < admin < unhide, "the unhide must live in the admin branch"
    assert unhide < refresh, "the unhide must precede the refreshSteering() call"


def test_anonymous_removal_path_is_intact() -> None:
    """The phase-16 "absent, not hidden" contract is preserved: the
    anonymous branch still REMOVES the toggle + panel from the DOM —
    the new hidden attribute only closes the pre-whoami flash window,
    the end state (absent) is unchanged."""
    body = _init_body(_text(HEADER_JS))
    assert "steeringToggle?.remove();" in body
    assert "steeringPanel?.remove();" in body


# ---------- the nav contract this phase relies on ----------


def test_nav_tuning_still_ships_hidden_on_all_six_pages() -> None:
    """The admin-only Tuning NAV LINK (#nav-tuning) — the contract the
    toggle now mirrors — still ships hidden on every page: one
    ship-hidden / reveal-for-admin family, nav link and toggle alike."""
    for html in PAGES:
        tag = re.search(r'<a[^>]*id="nav-tuning"[^>]*>', _text(html))
        assert tag, f"{html.name}: missing the #nav-tuning nav link"
        assert re.search(r"\bhidden\b", tag.group(0)), (
            f"{html.name}: #nav-tuning must ship hidden"
        )