"""Phase 46 E2E (Playwright): the mobile hamburger dropdown nav.

Story: ``.agents/user_stories/mobile-hamburger-nav.md``
TODO.md L9 (owner permission 2026-08-27): "The navbar on mobile is way
too squished. Make it a hamburger dropdown menu with a nice animation."

Run in isolation (mock LLM; DB up: ``podman compose up -d db``):

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

Contract under test: at ≤640px the nav links LEAVE the bar — a 44px
``#nav-toggle`` hamburger opens ``#app-nav`` as an animated (180ms
slide+fade) edge-to-edge dropdown with comfortable rows, the auth
visibility contract intact INSIDE the menu; at >640px the bar is
byte-identical to pre-phase-46 (hamburger absent, inline pills). No
document is ever needed — the suite exercises the shared header only.

The conftest ``page`` fixture is 1280×800, so the mobile tests create
fresh 375×812 pages via the session ``browser`` fixture (one page per
test; the reduced-motion test gets its own context).

Test → story mapping (Playwright Mapping Rule):

1. ``test_mobile_hamburger_visible_and_bar_roomy`` — 375px: the toggle
   is a ≥44px visible button (``aria-expanded="false"``, closed), the
   inline nav links are not visible in the bar (the closed dropdown is
   opacity 0 + visibility hidden), and the page does not overflow
   horizontally.
2. ``test_anonymous_menu_contents`` — anonymous at 375px: the menu
   shows EXACTLY one visible link ("Chat"); the three admin-only links
   stay ``hidden`` inside the menu; the open flips ``aria-expanded``.
3. ``test_admin_menu_contents`` — admin at 375px: the menu shows all
   four links (the whoami reveal works inside the menu).
4. ``test_link_click_navigates_and_closes`` — admin at 375px: clicking
   "RAG" navigates to /sources.html and the menu on the arrival
   page ships closed.
5. ``test_esc_and_outside_close`` — Esc closes AND returns focus to the
   toggle; an outside click does NOT close (accepted — see the test
   docstring for why).
6. ``test_animation_and_reduced_motion`` — motion allowed: the
   180ms opacity/transform transition pair is live and the open flips
   class + aria; ``reducedMotion: "reduce"``: no transition in EITHER
   state (the .is-open state included — the specificity trap) and
   open/close still works.
7. ``test_desktop_unchanged`` — 1280×800 regression: the hamburger is
   ``display: none`` and the inline nav renders in the bar exactly as
   before (admin: all four links, all inside the header band).
"""
from __future__ import annotations

import re

from playwright.sync_api import Browser, Page, ViewportSize, expect

from e2e.auth_helpers import login

MOBILE: ViewportSize = {"width": 375, "height": 812}  # the story's phone viewport
DESKTOP: ViewportSize = {"width": 1280, "height": 800}  # the conftest page size

NAV_LINKS = ("#app-nav a[href='/']", "#nav-sources", "#nav-git-sources", "#nav-tuning")
LINK_TEXTS = ("Chat", "RAG", "Sources", "Tuning")


def _mobile_page(browser: Browser) -> Page:
    """A fresh 375×812 page (the conftest ``page`` is 1280×800)."""
    return browser.new_page(viewport=MOBILE)


def _wait_settled_anonymous(page: Page) -> None:
    """Wait until whoami has resolved for the anonymous visitor: the bar
    Sign in copy (``#sign-in-link``) loses its ship-hidden attribute —
    the phase-16 settled state, probed by attribute (not visibility):
    at ≤640px the bar copy is CSS-hidden behind the ``#sign-in-link-mobile``
    dropdown copy (phase 46), so visibility is viewport-dependent."""
    page.wait_for_function(
        "() => !document.querySelector('#sign-in-link').hasAttribute('hidden')",
        timeout=10_000,
    )


def _wait_settled_admin(page: Page) -> None:
    """Wait until whoami has resolved for the admin: the whoami reveal
    has un-hidden the admin-only nav links (the menu-contents assertions
    must run on a settled auth state). The nav link is the
    viewport-independent settled signal — the sign-out control is the
    bar copy on desktop but the #sign-out-btn-mobile dropdown copy at
    ≤640px (phase-46 UX revision), so it is not a cross-viewport
    probe."""
    page.wait_for_function(
        "() => !document.querySelector('#nav-sources').hasAttribute('hidden')",
        timeout=10_000,
    )


def _visible_nav_links(page: Page) -> list[str]:
    """The texts of the nav links that are actually visible (Playwright
    visibility: non-empty box AND not visibility:hidden/display:none —
    so the closed dropdown and the ``hidden`` admin links both count as
    invisible)."""
    return [
        page.locator(sel).inner_text()
        for sel in NAV_LINKS
        if page.locator(sel).is_visible()
    ]


def _open_menu(page: Page) -> None:
    page.click("#nav-toggle")
    expect(page.locator("#nav-toggle")).to_have_attribute("aria-expanded", "true")
    # to_have_class(string) is an EXACT match on the class attribute —
    # the nav is "app-nav is-open", so match the token with a regex.
    expect(page.locator("#app-nav")).to_have_class(re.compile(r"\bis-open\b"))
    expect(page.locator("#app-nav")).to_have_css("opacity", "1")


def _js_open_menu(page: Page) -> None:
    """Phase 79 (task 05): the in-app token gate is a full-viewport
    overlay for ANONYMOUS visitors — it physically covers the header,
    so a real click on #nav-toggle is intercepted by the gate (the gate
    is the only interactive surface; the header is locked out with the
    rest of the page). The binding is identical, so the menu contract
    is driven programmatically: a JS-dispatched click runs the exact
    same listener a real click would."""
    page.evaluate("() => document.querySelector('#nav-toggle').click()")
    expect(page.locator("#nav-toggle")).to_have_attribute("aria-expanded", "true")
    expect(page.locator("#app-nav")).to_have_class(re.compile(r"\bis-open\b"))
    expect(page.locator("#app-nav")).to_have_css("opacity", "1")


def _assert_menu_closed(page: Page) -> None:
    expect(page.locator("#nav-toggle")).to_have_attribute("aria-expanded", "false")
    assert "is-open" not in (page.locator("#app-nav").get_attribute("class") or ""), (
        "the closed menu must not carry the .is-open state"
    )


# ---------------------------------------------------------------------------
# 1. Bar: the toggle is a roomy 44px target and the nav is out of the bar
# ---------------------------------------------------------------------------


def test_mobile_hamburger_visible_and_bar_roomy(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC1/AC5: at 375px the bar carries a ≥44px ``#nav-toggle`` (closed,
    ``aria-expanded="false"``), the inline nav links are NOT visible in
    the bar (the closed dropdown is opacity 0 + visibility hidden — the
    layout box is top:100% less the 8px slide offset, so the story's
    opacity-0 branch is what pins it), and there is no horizontal
    overflow — the old squished pills are gone, so the bar has room."""
    page = _mobile_page(browser)
    try:
        page.goto(app_url)
        _wait_settled_anonymous(page)

        # The hamburger: a visible ≥44px×44px touch target (the phase-07
        # floor), shipped closed.
        toggle = page.locator("#nav-toggle")
        expect(toggle).to_be_visible()
        box = toggle.bounding_box()
        assert box is not None, "the toggle must have a box"
        assert box["width"] >= 44 and box["height"] >= 44, (
            f"the toggle must be a ≥44px touch target, got "
            f"{box['width']:.0f}×{box['height']:.0f}"
        )
        expect(toggle).to_have_attribute("aria-expanded", "false")

        # The inline nav links are not visible in the bar: the closed
        # dropdown is opacity 0 + visibility hidden. (The layout box is
        # top:100% minus the 8px slide offset — inside the band — but
        # invisible, which is the acceptance branch: opacity 0.)
        assert page.evaluate(
            "() => getComputedStyle(document.querySelector('#app-nav')).opacity"
        ) == "0", "the closed menu must be opacity 0"
        assert page.evaluate(
            "() => getComputedStyle(document.querySelector('#app-nav')).visibility"
        ) == "hidden", "the closed menu must be visibility hidden"
        for sel in NAV_LINKS:
            assert not page.locator(sel).is_visible(), (
                f"{sel} must not be visible in the bar with the menu closed"
            )

        # No horizontal overflow at 375px (the old four squished text
        # pills are gone from the bar).
        assert page.evaluate(
            "() => document.documentElement.scrollWidth"
        ) <= page.evaluate("() => window.innerWidth"), (
            "the 375px bar must not overflow horizontally"
        )
    finally:
        page.close()


# ---------------------------------------------------------------------------
# 2. Menu contents per auth state (the whoami contract inside the menu)
# ---------------------------------------------------------------------------


def test_anonymous_menu_contents(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC2 (anonymous): at 375px the opened menu shows EXACTLY one
    visible link — "Chat". The three admin-only links keep their
    ship-hidden state INSIDE the menu (the phase-19/35 contract is
    preserved by reusing the same <nav> element); opening flips
    aria-expanded true.

    Phase 79 (task 05): the anonymous visitor meets the token gate — a
    full-viewport overlay that covers the header — so the toggle is
    driven programmatically (the binding is identical; see
    _js_open_menu)."""
    page = _mobile_page(browser)
    try:
        page.goto(app_url)
        _wait_settled_anonymous(page)
        _assert_menu_closed(page)

        _js_open_menu(page)
        assert _visible_nav_links(page) == ["Chat"], (
            "anonymous: the menu must show exactly one visible link (Chat)"
        )
        for sel in ("#nav-sources", "#nav-git-sources", "#nav-tuning"):
            expect(page.locator(sel)).to_be_hidden()

        # A second click closes it again — aria-expanded round-trips.
        page.evaluate("() => document.querySelector('#nav-toggle').click()")
        _assert_menu_closed(page)
    finally:
        page.close()


def test_admin_menu_contents(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC2 (admin): at 375px the opened menu shows ALL FOUR links —
    Chat / RAG / Sources / Tuning — i.e. the whoami reveal
    works inside the menu exactly as it does inline (one <nav>, one
    set of links, the same hidden attributes header.js drives)."""
    page = _mobile_page(browser)
    try:
        login(page, app_url, next="/")
        _wait_settled_admin(page)

        _open_menu(page)
        assert _visible_nav_links(page) == list(LINK_TEXTS), (
            f"admin: the menu must show all four links, got {_visible_nav_links(page)}"
        )
        for sel in NAV_LINKS:
            expect(page.locator(sel)).to_be_visible()
    finally:
        page.close()


# ---------------------------------------------------------------------------
# 3. Link close + navigation
# ---------------------------------------------------------------------------


def test_link_click_navigates_and_closes(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC4: a menu link click navigates AND closes the menu — and the
    arrival page ships the fresh (closed) header: aria-expanded false,
    no .is-open, menu invisible."""
    page = _mobile_page(browser)
    try:
        login(page, app_url, next="/")
        _wait_settled_admin(page)

        _open_menu(page)
        expect(page.locator("#nav-sources")).to_be_visible()
        page.click("#nav-sources")
        expect(page).to_have_url(app_url + "/sources.html", timeout=15_000)

        # The arrival page: a fresh header, shipped closed.
        _assert_menu_closed(page)
        expect(page.locator("#app-nav")).to_be_hidden()
    finally:
        page.close()


# ---------------------------------------------------------------------------
# 4. Esc close (+ focus return) and the accepted outside-click behavior
# ---------------------------------------------------------------------------


def test_esc_and_outside_close(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC4: Esc closes the menu AND returns focus to the toggle (the
    opener — a keyboard user never loses their place).

    Accepted behavior (NOT a defect, per the task-02 contract and story
    AC 4): an OUTSIDE click does not close the menu. The locked close
    set is Esc + link + resize — the story's AC 4 lists exactly those
    three, and the owner-locked scope (2026-08-27) does not include a
    backdrop click (there is no backdrop element at all — the menu is
    the nav itself dropping out of the sticky header). This test pins
    the menu STAYING OPEN on an outside click so an accidental
    backdrop-close implementation cannot sneak in later."""
    page = _mobile_page(browser)
    try:
        page.goto(app_url)
        _wait_settled_anonymous(page)

        # Phase 79 (task 05): the anonymous visitor's toggle click is
        # intercepted by the gate overlay — drive the identical binding
        # programmatically (see _js_open_menu).
        # Esc closes + refocuses the opener.
        _js_open_menu(page)
        page.keyboard.press("Escape")
        _assert_menu_closed(page)
        assert page.evaluate("() => document.activeElement.id") == "nav-toggle", (
            "Esc-close must return focus to the #nav-toggle opener"
        )

        # Outside click: the menu STAYS open (accepted behavior — the
        # locked close set is Esc + link + resize, not backdrop click).
        # Phase 79 (task 05): for the anonymous visitor the "outside"
        # point is the gate overlay itself — a REAL mouse click below
        # the centered card (outside the nav, intercepted by the gate).
        _js_open_menu(page)
        page.mouse.click(10, 780)  # the gate overlay — a neutral, non-nav point
        expect(page.locator("#nav-toggle")).to_have_attribute("aria-expanded", "true")
        assert "is-open" in (page.locator("#app-nav").get_attribute("class") or ""), (
            "accepted behavior: an outside click must NOT close the menu"
        )
        # …and the menu is still fully usable (Esc still settles it).
        page.keyboard.press("Escape")
        _assert_menu_closed(page)
    finally:
        page.close()


# ---------------------------------------------------------------------------
# 5. Animation + prefers-reduced-motion
# ---------------------------------------------------------------------------


def test_animation_and_reduced_motion(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC3: motion allowed — the menu carries the 180ms opacity/transform
    transition pair and opening flips the .is-open class + aria-expanded
    in lockstep. reducedMotion: "reduce" — no transition in EITHER state
    (the .is-open rule is higher-specificity than a bare .app-nav rule,
    so the override must name both — pinned here against the live
    computed style) and open/close still works, instantly."""
    # Motion allowed: the 180ms slide+fade pair is live.
    page = _mobile_page(browser)
    try:
        page.goto(app_url)
        _wait_settled_anonymous(page)
        report = page.evaluate(
            "() => { const cs = getComputedStyle(document.querySelector('#app-nav'));"
            " return { duration: cs.transitionDuration, property: cs.transitionProperty };"
            " }"
        )
        assert "0.18s" in report["duration"], (
            f"the menu must transition in 180ms, got {report['duration']!r}"
        )
        assert "opacity" in report["property"] and "transform" in report["property"], (
            f"the transition must cover the opacity/transform slide+fade, "
            f"got {report['property']!r}"
        )
        # Opening flips class + aria together (the animated state).
        # Phase 79 (task 05): the anonymous toggle click is intercepted
        # by the gate overlay — programmatic drive, same binding.
        _js_open_menu(page)
        page.keyboard.press("Escape")
        _assert_menu_closed(page)
    finally:
        page.close()

    # Reduced motion: stills in both states, open/close still works.
    context = browser.new_context(
        reduced_motion="reduce", viewport=MOBILE
    )
    rpage = context.new_page()
    try:
        rpage.goto(app_url)
        _wait_settled_anonymous(rpage)

        def _stilled(el: str) -> str:
            return rpage.evaluate(
                f"() => getComputedStyle(document.querySelector('{el}')).transitionDuration"
            )

        assert _stilled("#app-nav") == "0s", (
            f"reduced motion: closed state must not transition, got {_stilled('#app-nav')!r}"
        )
        # Phase 79 (task 05): programmatic drive (the gate overlay
        # intercepts the anonymous real click — same binding).
        _js_open_menu(rpage)
        expect(rpage.locator("#nav-toggle")).to_have_attribute("aria-expanded", "true")
        expect(rpage.locator("#app-nav")).to_have_class(re.compile(r"\bis-open\b"))
        assert _stilled("#app-nav") == "0s", (
            "reduced motion: the .is-open state must not transition either "
            "(the override must out-specificity .app-nav.is-open)"
        )
        rpage.keyboard.press("Escape")
        _assert_menu_closed(rpage)
        assert not rpage.locator("#app-nav").is_visible(), (
            "reduced motion: the closed menu must be invisible"
        )
    finally:
        context.close()


# ---------------------------------------------------------------------------
# 6. Desktop regression: the bar is byte-identical to pre-phase-46
# ---------------------------------------------------------------------------


def test_desktop_unchanged(
    browser: Browser, app_url: str, db_ready: None
) -> None:
    """AC6 (regression): at 1280×800 the hamburger is absent
    (``display: none`` — outside the ≤640px block) and the inline nav
    renders in the bar exactly as before — admin sees all four links,
    every one of them INSIDE the header band (no dropdown at this
    width; the phase-34/35 bar contract is intact)."""
    page = browser.new_page(viewport=DESKTOP)
    try:
        login(page, app_url, next="/")
        _wait_settled_admin(page)

        # The hamburger is absent on desktop (global display:none).
        toggle = page.locator("#nav-toggle")
        expect(toggle).to_be_hidden()
        assert page.evaluate(
            "() => getComputedStyle(document.querySelector('#nav-toggle')).display"
        ) == "none", "the toggle must be display:none outside the ≤640px block"

        # The inline nav: all four links visible, each box inside the
        # header band (the dropdown positioning only applies ≤640px).
        expect(page.locator("#app-nav")).to_be_visible()
        header_box = page.locator("header.app-header").bounding_box()
        assert header_box is not None
        for sel in NAV_LINKS:
            link = page.locator(sel)
            expect(link).to_be_visible()
            box = link.bounding_box()
            assert box is not None
            assert box["y"] >= header_box["y"] - 1, f"{sel}: link is above the header"
            assert box["y"] + box["height"] <= header_box["y"] + header_box["height"] + 1, (
                f"{sel}: the inline link must sit inside the header band"
            )
        assert _visible_nav_links(page) == list(LINK_TEXTS)
    finally:
        page.close()