"""Phase 177 E2E (Playwright): the tab icon carries the effective
palette — the route, the pre-paint tag, the live preview, the
restore contract.

Source: TODO.md L3 — "We need the favicon to change colors to
match the theme." (owner roadmap confirmation 2026-10-13, A1–A4.)

Run in isolation (DB must be up: ``podman compose up -d db``):

    uv run pytest tests/e2e/test_themed_favicon.py -v --no-cov

Test → contract mapping (one story, one phase, one isolated file):

1. ``test_default_state_serves_the_golden_route`` — the default
   (no ``ui_settings`` row) deployment: ``GET /favicon.svg`` is 200
   ``image/svg+xml`` + ``no-cache`` with the body byte-identical
   to the golden art (``FAVICON_GOLDEN`` from
   ``tests.unit.test_theming`` — ONE source); the five pages'
   served HTML reference the route (``href="/favicon.svg"`` —
   bare, never ``/assets/favicon.svg``); the deleted static file
   is 404.
2. ``test_themed_state_serves_the_effective_palette`` — with a
   saved palette (the 3 driving colors distinct): the route's SVG
   carries the three hexes in their EXACT roles (attribute-parsed,
   never substring) and is byte-equal to the server renderer's
   output; a fresh page load STILL injects the ``#bor-theme`` tag
   immediately before ``</head>`` with the full 17-var content +
   the phase-91 CSP hash (the tag/CSP contract is untouched by the
   favicon work), and the browser's first paint is the themed
   paint (the computed ``--surface`` / ``--brand``).
3. ``test_live_preview_repaints_the_favicon`` — an admin's live
   (unsaved) pick of the three driving fields sets
   ``link[rel="icon"]`` to a ``data:image/svg+xml`` URI that,
   decoded, carries the three picked hexes in their exact roles
   (attribute-parsed). Headless Chromium never fetches favicons
   (probe-verified — zero request events, not even for the
   initial ``/favicon.svg``), so the suite pins the href state +
   the decoded art as the repaint contract and guards the CSP
   path NEGATIVELY: no CSP violation is ever reported against a
   ``data:`` URI (the phase-123 ``img-src 'self' data:``
   carve-out makes a ``data:`` favicon legal — CSP3 governs
   ``link[rel=icon]`` by ``img-src``; a blocked fetch would
   surface as a ``requestfailed`` with a CSP error or a console
   violation, which the suite asserts does not happen). A
   non-driving pick (``#theme-bg``) never touches the href.
4. ``test_save_restores_the_route_url`` — Save: the href is
   EXACTLY ``/favicon.svg`` and the route now serves the saved
   palette's bytes (the settled palette governs).
5. ``test_reset_restores_the_route_url`` — after a Save, Reset:
   the href is ``/favicon.svg`` and the route serves the built-in
   golden bytes.
6. ``test_view_refresh_restores_the_route_url`` — a user-initiated
   re-show (the router's ``bor:view-refresh`` dispatch — the
   phase-77 hook) restores the href after a live pick.

Zero external requests across the whole suite (AGENTS rule 6 — the
house E2E assertion idiom): a ``page.on("request")`` collector
asserts every http(s) URL is the local origin (a ``data:`` URI is
exempt by design — the phase-123 carve-out).

DB isolation: the shared e2e Postgres keeps ``ui_settings`` (the
single row the caching middleware + the favicon route read for
EVERY request — a leftover themed row would repaint other suites'
pages and icons) and ``api_tokens`` rows across suites. An autouse
fixture truncates ``ui_settings`` and deletes the ``e2e-``-labeled
tokens before AND after every test (never a TRUNCATE on
``api_tokens`` — the shared DB may hold the owner's real tokens).

Per-module app env (the tuning/tokens/archive-upload pattern): the
module-scoped ``app_server`` override boots the same env block as
the shared conftest server with the branding vars pinned to the
CODE defaults (an operator's local ``.env`` may carry the owner's
name/placeholder/footer, and "the effective strings start at the
template defaults" must hold regardless — the phase-61/62
leak-guard pattern, extended to ``BOR_APP_NAME``) and
``BOR_GIT_SOURCES`` forced empty (the dev ``.env``'s git repo must
not render as env rows in this suite's app). The phase-92 file
(test_theme_save_and_coverage.py) is the copy source — the two
modules' scaffolds stay in lockstep so a future conftest refactor
touches both at once.
"""
from __future__ import annotations

import json
import os
import subprocess
import sys
import xml.etree.ElementTree as ET
from collections.abc import Iterator
from urllib.parse import unquote

import httpx
import pytest
from playwright.sync_api import Page, expect
from sqlalchemy import text

from app.config import Settings
from app.core import theming
from app.db import SessionLocal
from e2e.auth_helpers import login
from e2e.conftest import (
    ADMIN_PASSWORD,
    APP_PORT,
    REPO,
    SESSION_SECRET,
    USE_REAL_LLM,
    _wait_http,
)
from tests.unit.test_theming import FAVICON_GOLDEN

APP_URL = f"http://127.0.0.1:{APP_PORT}"

# The three driving fields (A1 — the artwork's color roles: hexagon
# fill, hexagon stroke + center dot, 4 spokes) with E2E values
# distinct from every built-in.
DRIVING: dict[str, str] = {
    "surface": "#102030",
    "brand": "#4f46e5",
    "brand_ink": "#a5b4fc",
}
#: The E2E-stable color-input ids (the form's own markup — the
#: static E2E-stable-selectors house convention).
INPUT_IDS = {
    field: f"#theme-{field.replace('_', '-')}" for field in theming.COLOR_FIELDS
}
#: The five templates whose served HTML must reference the route.
PAGES = ("/", "/document.html", "/login.html", "/shared.html", "/doc-edit.html")
#: The data: URI prefix the live preview sets (the phase-123
#: img-src 'self' data: carve-out makes it CSP-legal).
DATA_PREFIX = "data:image/svg+xml,"


# ---------------------------------------------------------------------------
# In-test constants (single sources of truth — never duplicated)
# ---------------------------------------------------------------------------


def _expected_tag(colors: dict[str, str]) -> str:
    """The EXACT inline tag ``theme_style_tag`` renders for
    ``colors``: one ``:root`` override, all 17 vars in COLOR_FIELDS
    order, no whitespace (the byte the middleware injects)."""
    declarations = "".join(
        f"--{k.replace('_', '-')}:{colors[k]};" for k in theming.COLOR_FIELDS
    )
    return f'<style id="bor-theme">:root{{{declarations}}}</style>'


def _expected_favicon_bytes(colors: dict[str, str]) -> bytes:
    """The route's body for a palette: the SERVER renderer's output
    (imported — ONE source, never a test-side mirror of the art)."""
    return theming.favicon_svg(colors).encode("utf-8")


def _attr(element: ET.Element, name: str) -> str:
    """An SVG attribute, asserted non-null (a missing role attribute
    is a test failure, not a parseable value)."""
    value = element.get(name)
    assert value is not None, f"missing the {name} attribute"
    return value


def _parse_roles(svg: str) -> dict[str, str]:
    """The three color roles, ATTRIBUTE-parsed (the unit pin's
    idiom — never substring): the hexagon's fill (surface), the
    hexagon's stroke (brand), the center circle's fill (brand),
    the spokes' stroke (brand_ink)."""
    ns = "{http://www.w3.org/2000/svg}"
    root = ET.fromstring(svg)
    assert root.tag == f"{ns}svg", root.tag
    hexagon, circle, spokes = list(root)
    return {
        "surface": _attr(hexagon, "fill"),
        "brand": _attr(hexagon, "stroke"),
        "brand_circle": _attr(circle, "fill"),
        "brand_ink": _attr(spokes, "stroke"),
    }


def _login_to_theme(page: Page, app_url: str) -> None:
    """Log in straight into the Theme view AND wait for its mount-time
    ``GET /api/ui-settings`` to ANSWER — the settle signal.

    Phase 190 (task 02) moved it with the tab's string fieldset: the
    settle used to be read off the (now removed) ``#theme-app-name``
    input, the only input the static markup shipped empty. The network
    is the source of truth now."""
    with page.expect_response(
        lambda r: "/api/ui-settings" in r.url, timeout=30_000
    ) as info:
        login(page, app_url, next="/theme.html")
    assert info.value.status == 200, "the mount's GET /api/ui-settings failed"
    expect(page.locator("#theme-content")).to_be_visible(timeout=15_000)


def _favicon_href(page: Page) -> str:
    """The tab icon's current href (the attribute's raw state)."""
    return page.evaluate(
        "() => document.querySelector('link[rel=icon]').getAttribute('href')"
    )


def _wait_data_href(page: Page) -> None:
    """The href is a ``data:`` URI (the live preview has landed)."""
    page.wait_for_function(
        f"() => (document.querySelector('link[rel=icon]')"
        f".getAttribute('href') || '').startsWith('{DATA_PREFIX}')",
        timeout=15_000,
    )


def _wait_route_href(page: Page) -> None:
    """The href is EXACTLY the route URL (the restore has landed —
    the settled palette governs)."""
    page.wait_for_function(
        "() => (document.querySelector('link[rel=icon]')"
        '.getAttribute(\'href\') || \'\') === \'/favicon.svg\'',
        timeout=15_000,
    )


def _seed_theme_via_api(app_url: str, cookies: dict[str, str]) -> None:
    """Admin ``PUT /api/ui-settings`` with the 3 driving colors
    (the rest null → the built-ins — the route's bytes need only
    the three colors in the artwork)."""
    body: dict[str, object] = {}
    for field in theming.STRING_FIELDS:
        body[field] = None
    for field in theming.COLOR_FIELDS:
        body[field] = None
    body.update(DRIVING)
    r = httpx.put(f"{app_url}/api/ui-settings", json=body, cookies=cookies, timeout=10)
    assert r.status_code == 200, r.text


# ---------------------------------------------------------------------------
# Per-module app env (the tuning/tokens/archive-upload pattern)
# ---------------------------------------------------------------------------


@pytest.fixture(scope="module")
def app_server(mock_llm: int) -> Iterator[str]:
    """The real app under test — per-module env: the branding vars
    are pinned to the CODE defaults (the effective strings start at
    the template defaults regardless of an operator's local
    ``.env`` — the phase-61/62 leak-guard pattern the shared
    conftest server applies to its two string vars; this one pins
    all three, including ``BOR_APP_NAME``, which the shared server
    leaves to the process) and ``BOR_GIT_SOURCES`` is forced empty
    (the dev ``.env``'s git repo must not render as env rows in
    this suite's app)."""
    env = dict(os.environ)
    env.pop("DEBUGPY", None)
    env["BOR_ENVIRONMENT"] = "e2e"
    env["BOR_STATIC_DIR"] = str(REPO / "frontend")
    env["BOR_LLM_BASE_URL"] = (
        "https://aipi.reeseapps.com/v1"
        if USE_REAL_LLM
        else f"http://127.0.0.1:{mock_llm}/v1"
    )
    # Mock-calibrated threshold (conftest pattern) — no chat turn is
    # ever sent in this suite, but the app boots with the same shape.
    env["BOR_RELEVANCE_THRESHOLD"] = "0.30"
    env["BOR_LLM_RETRY_DELAY"] = "0"
    env["BOR_LLM_RETRIES"] = str(Settings.model_fields["llm_retries"].default)
    env.setdefault(
        "BOR_DATABASE_URL",
        "postgresql+psycopg://reese:reese@localhost:5432/brain_of_reese",
    )
    # Phase 16: admin auth must be set or create_app() refuses to boot.
    env["BOR_ADMIN_PASSWORD"] = ADMIN_PASSWORD
    env["BOR_SESSION_SECRET"] = SESSION_SECRET
    env["BOR_DOCS_REPO"] = ""
    env["BOR_SUGGESTIONS"] = json.dumps(
        Settings.model_fields["suggestions"].default
    )
    # The branding vars: "unset" = the template defaults (the code
    # defaults, derived from the class fields — the local ``.env``
    # may carry the owner's values, and this suite's assertions need
    # the TEMPLATE defaults, not the owner's).
    env["BOR_APP_NAME"] = Settings.model_fields["app_name"].default
    env["BOR_INPUT_PLACEHOLDER"] = (
        Settings.model_fields["input_placeholder"].default
    )
    env["BOR_FOOTER_TEXT"] = Settings.model_fields["footer_text"].default
    env["BOR_GIT_SOURCES"] = ""
    proc = subprocess.Popen(
        [sys.executable, "-m", "uvicorn", "app.main:app",
         "--host", "127.0.0.1", "--port", str(APP_PORT), "--log-level", "warning"],
        cwd=REPO,
        env=env,
    )
    try:
        _wait_http(f"{APP_URL}/api/health")
        yield APP_URL
    finally:
        proc.terminate()
        try:
            proc.wait(timeout=10)
        except subprocess.TimeoutExpired:
            proc.kill()


@pytest.fixture(scope="module")
def app_url(app_server: str) -> str:
    return app_server


# ---------------------------------------------------------------------------
# DB isolation + helpers
# ---------------------------------------------------------------------------


def _clean_ui_state() -> None:
    """Fresh theme + token state per test: truncate the single-row
    ``ui_settings`` (the middleware + the favicon route read it for
    EVERY request — a leftover themed row would repaint other
    suites' pages and icons) and delete this suite's issued tokens
    (label-scoped on ``e2e-`` — never a TRUNCATE: the shared DB
    may hold the owner's real tokens)."""
    with SessionLocal() as db:
        db.execute(text("TRUNCATE ui_settings"))
        db.execute(text("DELETE FROM api_tokens WHERE label LIKE 'e2e-%'"))
        db.commit()


@pytest.fixture(autouse=True)
def _clean(db_ready: None) -> Iterator[None]:
    _clean_ui_state()
    yield
    _clean_ui_state()


def _cookies(page: Page) -> dict[str, str]:
    """The session cookies the browser context holds (the test's API
    side sees exactly what that browser sees)."""
    return {
        c["name"]: c["value"]
        for c in page.context.cookies()
        if "name" in c and "value" in c
    }


def _zero_external(
    page: Page,
) -> tuple[list[str], list[str], list[str], list[str]]:
    """AGENTS rule 6 (the house E2E assertion idiom): every http(s)
    request is the local origin; ``data:`` URIs are exempt by
    design (the phase-123 ``img-src 'self' data:`` carve-out).
    Also collects the CSP-failure signals: a failed ``data:``
    fetch (a blocked fetch carries a CSP error in its failure
    message) and console CSP violations ("Refused to …" / "CSP"
    against a ``data:`` URI). Returns (externals, data_requests,
    failed_data, csp_violations). Headless Chromium never fetches
    favicons (probe-verified), so ``data_requests`` is expected to
    stay empty — the negative assertions (``failed_data`` +
    ``csp_violations``) are the CSP guard: a future change that
    blocks the ``data:`` URI surfaces here, and a real
    (non-headless) browser run additionally sees the fetch in
    ``data_requests``."""
    externals: list[str] = []
    data_requests: list[str] = []
    failed_data: list[str] = []
    csp_violations: list[str] = []

    def _watch(request: object) -> None:
        url = getattr(request, "url", "")
        if url.startswith("data:"):
            data_requests.append(url)
            return
        if url.startswith(("http://", "https://")) and "127.0.0.1" not in url:
            externals.append(url)

    def _watch_failed(request: object) -> None:
        url = getattr(request, "url", "")
        failure = getattr(request, "failure", None)
        if url.startswith("data:") and failure:
            failed_data.append(str(failure))

    def _watch_console(message: object) -> None:
        msg = getattr(message, "text", "")
        if ("CSP" in msg or "Refused to" in msg) and "data:" in msg:
            csp_violations.append(msg)

    page.on("request", _watch)
    page.on("requestfailed", _watch_failed)
    page.on("console", _watch_console)
    return externals, data_requests, failed_data, csp_violations


def _assert_zero_external(
    externals: list[str], failed_data: list[str], csp_violations: list[str]
) -> None:
    """The suite's tail assertion: zero external requests, no
    ``data:`` URI CSP-blocked (a blocked fetch carries a CSP error
    in its failure message), and no CSP violation reported
    against a ``data:`` URI (the phase-123 carve-out holds)."""
    assert not externals, f"external requests: {externals}"
    assert not failed_data, f"data: URIs blocked (CSP?): {failed_data}"
    assert not csp_violations, f"CSP violations: {csp_violations}"


# ---------------------------------------------------------------------------
# 1. Default state: the golden route, the five page references, the
#    deleted static file
# ---------------------------------------------------------------------------


def test_default_state_serves_the_golden_route(app_url: str, db_ready: None) -> None:
    """The default (no ``ui_settings`` row) deployment: the route
    is byte-identical to the golden art (imported — ONE source),
    with the svg media type + ``no-cache``; the five pages' served
    HTML reference the route (bare — no ``?v=``, never
    ``/assets/favicon.svg``); the deleted static file is 404."""
    r = httpx.get(f"{app_url}/favicon.svg", timeout=10)
    assert r.status_code == 200
    assert r.headers["content-type"].startswith("image/svg+xml")
    assert r.headers["cache-control"] == "no-cache"
    assert r.content == FAVICON_GOLDEN.encode("utf-8")

    for path in PAGES:
        page = httpx.get(app_url + path, timeout=10)
        assert page.status_code == 200, path
        assert (
            '<link rel="icon" type="image/svg+xml" href="/favicon.svg">'
            in page.text
        ), f"{path} must reference the themed route"
        assert "/assets/favicon.svg" not in page.text, (
            f"{path} must never reference the deleted static file"
        )
        assert "favicon.svg?v=" not in page.text, (
            f"{path} must keep the favicon link bare (no ?v=)"
        )

    gone = httpx.get(app_url + "/assets/favicon.svg", timeout=10)
    assert gone.status_code == 404


# ---------------------------------------------------------------------------
# 2. Themed state: the route carries the effective palette; the
#    pre-paint tag + the first paint are untouched (phase 91)
# ---------------------------------------------------------------------------


def test_themed_state_serves_the_effective_palette(
    page: Page, app_url: str, db_ready: None
) -> None:
    """With a saved palette (the 3 driving colors distinct): the
    route's SVG carries the three hexes in their EXACT roles
    (attribute-parsed) and is byte-equal to the server renderer;
    a fresh page load STILL injects the ``#bor-theme`` tag
    (17-var content, immediately before ``</head>`` + the phase-91
    CSP hash — the tag/CSP contract is untouched by the favicon
    work) and the browser's first paint is the themed paint."""
    page.set_default_timeout(30_000)
    login(page, app_url)
    _seed_theme_via_api(app_url, _cookies(page))

    # The route: the three hexes in their exact roles…
    r = httpx.get(f"{app_url}/favicon.svg", timeout=10)
    assert r.status_code == 200
    roles = _parse_roles(r.text)
    assert roles["surface"] == DRIVING["surface"]
    assert roles["brand"] == DRIVING["brand"]
    assert roles["brand_circle"] == DRIVING["brand"]
    assert roles["brand_ink"] == DRIVING["brand_ink"]
    # …and byte-equal to the server renderer's output (ONE source).
    effective = {**theming.BUILTIN_COLORS, **DRIVING}
    assert r.content == _expected_favicon_bytes(effective)

    # The pre-paint tag non-regression (phase 91): the RAW served
    # HTML carries the 17-var tag immediately before ``</head>``…
    tag = _expected_tag(effective)
    r = httpx.get(app_url + "/", timeout=10)
    assert r.status_code == 200
    assert r.text.count(tag) == 1, "the 17-var tag must be injected exactly once"
    start = r.text.index(tag)
    assert start + len(tag) == r.text.index("</head>"), (
        "the tag must end exactly where </head> begins"
    )
    # …with the phase-91 CSP hash (the favicon work never touched
    # the tag/CSP contract).
    assert "style-src 'self' 'sha256-" in r.headers.get(
        "content-security-policy", ""
    ), "the themed page must carry the phase-91 CSP hash"

    # A fresh page load: the first paint IS the themed paint.
    page.goto(app_url + "/")
    page.wait_for_function(
        """(d) => {
            const cs = getComputedStyle(document.documentElement);
            return cs.getPropertyValue('--surface').trim() === d.surface
                && cs.getPropertyValue('--brand').trim() === d.brand;
        }""",
        arg=DRIVING,
        timeout=15_000,
    )


# ---------------------------------------------------------------------------
# 3. Live preview: an unsaved pick repaints the favicon via the
#    CSP-legal data: URI; a non-driving pick never touches it
# ---------------------------------------------------------------------------


def test_live_preview_repaints_the_favicon(
    page: Page, app_url: str, db_ready: None
) -> None:
    """An admin's live (unsaved) pick of the three driving fields
    sets ``link[rel="icon"]`` to a ``data:`` URI that, decoded,
    carries the three picked hexes in their exact roles; the
    browser FETCHES the ``data:`` URI (the phase-123 carve-out —
    a blocked fetch would be a ``requestfailed`` with a CSP error);
    a non-driving pick (``#theme-bg``) never touches the href."""
    page.set_default_timeout(30_000)
    externals, _data_requests, failed_data, csp_violations = _zero_external(page)
    _login_to_theme(page, app_url)

    # A clean start: the href is the route (no row → the golden
    # art served by the route).
    assert _favicon_href(page) == "/favicon.svg"

    # Set the three driving fields (page.fill fires the input event
    # — the house _fill_theme_form idiom).
    for field in ("surface", "brand", "brand_ink"):
        page.fill(INPUT_IDS[field], DRIVING[field])
    _wait_data_href(page)

    # The href is a data: URI, and — decoded — carries the three
    # picked hexes in their exact roles (attribute-parsed).
    href = _favicon_href(page)
    assert href.startswith(DATA_PREFIX)
    svg = unquote(href[len(DATA_PREFIX):])
    roles = _parse_roles(svg)
    assert roles["surface"] == DRIVING["surface"]
    assert roles["brand"] == DRIVING["brand"]
    assert roles["brand_circle"] == DRIVING["brand"]
    assert roles["brand_ink"] == DRIVING["brand_ink"]

    # A non-driving pick never touches the href.
    page.fill(INPUT_IDS["bg"], "#000000")
    assert _favicon_href(page) == href, "a non-driving pick must not touch the href"

    # The CSP guard (negative — headless never fetches favicons):
    # no failed data: fetch, no CSP violation against the URI.
    _assert_zero_external(externals, failed_data, csp_violations)


# ---------------------------------------------------------------------------
# 4. Restore: Save — the href is EXACTLY /favicon.svg and the route
#    serves the saved palette's bytes (the settled palette governs)
# ---------------------------------------------------------------------------


def test_save_restores_the_route_url(
    page: Page, app_url: str, db_ready: None
) -> None:
    """After a live pick, Save: the §7.4 lifecycle lands and the
    href is EXACTLY ``/favicon.svg``; the route now serves the
    saved palette's bytes (the settled palette governs — the route
    re-reads the DB per request, no process cache)."""
    page.set_default_timeout(30_000)
    externals, _d, failed_data, csp = _zero_external(page)
    _login_to_theme(page, app_url)

    # A live pick first — so the save has a data: href to restore.
    for field in ("surface", "brand", "brand_ink"):
        page.fill(INPUT_IDS[field], DRIVING[field])
    _wait_data_href(page)

    # Save through the real form.
    page.click("#theme-save")
    expect(page.locator("#theme-result")).to_have_text(
        "Theme saved.", timeout=30_000
    )
    expect(page.locator("#theme-result")).to_have_attribute("role", "status")
    # The restore: the href is EXACTLY the route URL.
    _wait_route_href(page)
    assert _favicon_href(page) == "/favicon.svg"

    # The settled palette governs: the route serves the saved
    # palette's bytes (the PUT saved the 17 form colors — the 3
    # driving colors + the 14 built-ins (→ NULL); the brand strings are
    # the Settings panel's since phase 190 (A1) and this body carried
    # none, so the effective palette is the 3 + the built-ins).
    effective = {**theming.BUILTIN_COLORS, **DRIVING}
    r = httpx.get(f"{app_url}/favicon.svg", timeout=10)
    assert r.status_code == 200
    assert r.content == _expected_favicon_bytes(effective)

    _assert_zero_external(externals, failed_data, csp)


# ---------------------------------------------------------------------------
# 5. Restore: Reset — the href is /favicon.svg and the route serves
#    the built-in golden bytes
# ---------------------------------------------------------------------------


def test_reset_restores_the_route_url(
    page: Page, app_url: str, db_ready: None
) -> None:
    """After a Save (the route is themed), a fresh live pick, then
    Reset: the §7.4 lifecycle lands and the href is
    ``/favicon.svg``; the route serves the built-in golden bytes
    (the reset nulled the row — the built-ins govern)."""
    page.set_default_timeout(30_000)
    externals, _d, failed_data, csp = _zero_external(page)
    _login_to_theme(page, app_url)

    # Save first — the route is themed (the reset then has a real
    # state to settle back from).
    for field in ("surface", "brand", "brand_ink"):
        page.fill(INPUT_IDS[field], DRIVING[field])
    _wait_data_href(page)
    page.click("#theme-save")
    expect(page.locator("#theme-result")).to_have_text(
        "Theme saved.", timeout=30_000
    )
    _wait_route_href(page)
    r = httpx.get(f"{app_url}/favicon.svg", timeout=10)
    assert r.content == _expected_favicon_bytes(
        {**theming.BUILTIN_COLORS, **DRIVING}
    )

    # A fresh live pick — the href is the data: one the reset
    # restores (a distinct value, so the repaint is guaranteed).
    page.fill(INPUT_IDS["surface"], "#0a1525")
    _wait_data_href(page)

    # Reset to defaults: the §7.4 lifecycle (the all-null PUT — the
    # API's documented "defaults" operation).
    page.click("#theme-reset")
    expect(page.locator("#theme-result")).to_have_text(
        "Reset to the built-in theme.", timeout=30_000
    )
    expect(page.locator("#theme-result")).to_have_attribute("role", "status")
    # The restore: the href is EXACTLY the route URL…
    _wait_route_href(page)
    assert _favicon_href(page) == "/favicon.svg"
    # …and the route serves the built-in golden bytes.
    r = httpx.get(f"{app_url}/favicon.svg", timeout=10)
    assert r.status_code == 200
    assert r.content == FAVICON_GOLDEN.encode("utf-8")

    _assert_zero_external(externals, failed_data, csp)


# ---------------------------------------------------------------------------
# 6. Restore: the bor:view-refresh re-show (the phase-77 hook)
# ---------------------------------------------------------------------------


def test_view_refresh_restores_the_route_url(
    page: Page, app_url: str, db_ready: None
) -> None:
    """After a live pick, a user-initiated re-show (leave the Theme
    view, come back — the router dispatches ``bor:view-refresh``
    on the already-mounted section): the handler re-runs the load,
    reconciles, and the href is restored to ``/favicon.svg`` (the
    settled palette governs — in this test's row-less state, the
    golden bytes)."""
    page.set_default_timeout(30_000)
    externals, _d, failed_data, csp = _zero_external(page)
    _login_to_theme(page, app_url)

    # A live pick — the href is the data: one the re-show restores.
    for field in ("surface", "brand", "brand_ink"):
        page.fill(INPUT_IDS[field], DRIVING[field])
    _wait_data_href(page)

    # A user-initiated re-show: away (the RAG view — a real view
    # switch), then back — the router's phase-77 hook dispatches
    # bor:view-refresh on the mounted Theme section.
    page.click("#nav-sources")
    expect(page.locator("#view-rag")).to_be_visible(timeout=15_000)
    page.click("#nav-theme")
    expect(page.locator("#view-theme")).to_be_visible(timeout=15_000)
    # The restore: the href is EXACTLY the route URL.
    _wait_route_href(page)
    assert _favicon_href(page) == "/favicon.svg"

    # The settled palette governs: no row was saved, so the route
    # still serves the golden bytes.
    r = httpx.get(f"{app_url}/favicon.svg", timeout=10)
    assert r.status_code == 200
    assert r.content == FAVICON_GOLDEN.encode("utf-8")

    _assert_zero_external(externals, failed_data, csp)