"""Video side shell: the Music ↔ Video toggle + video sidebar (experimental branch).

This is the first slice of the video side. It must be ADDITIVE and ISOLATED:
the music sidebar/nav is untouched, the toggle + video nav are wired purely via
data-attributes (no inline onclick — which would also break the script-split
integrity contract), and the controller is a self-contained IIFE that adds no
globals. These pin all of that so a regression can't silently couple the two
sides or break the music shell.
"""

from __future__ import annotations

import re
from pathlib import Path

_ROOT = Path(__file__).resolve().parent.parent
_INDEX = (_ROOT / "webui" / "index.html").read_text(encoding="utf-8", errors="replace")
_JS = (_ROOT / "webui" / "static" / "video" / "video-side.js").read_text(encoding="utf-8")
_CSS_PATH = _ROOT / "webui" / "static" / "video" / "video-side.css"

EXPECTED_VIDEO_PAGES = {
    "video-dashboard", "video-search", "video-discover", "video-library",
    "video-watchlist", "video-wishlist", "video-downloads", "video-calendar",
    "video-import", "video-settings", "video-issues", "video-help",
}


def _block(html: str, open_tag_re: str, close_tag: str) -> str:
    """Return the substring from the first match of open_tag_re to the next close_tag."""
    m = re.search(open_tag_re, html)
    assert m, f"could not find {open_tag_re!r}"
    end = html.index(close_tag, m.end())
    return html[m.start():end + len(close_tag)]


# --- the toggle ------------------------------------------------------------

def test_side_toggle_has_music_and_video():
    block = _block(_INDEX, r'<div class="side-toggle"', "</div>")
    assert 'data-side-target="music"' in block
    assert 'data-side-target="video"' in block
    # Wired by JS, not inline handlers (isolation + integrity contract).
    assert "onclick" not in block


# --- the video nav ---------------------------------------------------------

def test_video_nav_has_all_expected_pages():
    block = _block(_INDEX, r'<nav class="sidebar-nav video-nav"', "</nav>")
    found = set(re.findall(r'data-video-page="([^"]+)"', block))
    assert found == EXPECTED_VIDEO_PAGES, f"video nav pages mismatch: {found ^ EXPECTED_VIDEO_PAGES}"
    assert "onclick" not in block  # data-attr wired, no inline handlers


def test_video_page_host_present():
    assert 'id="video-page-host"' in _INDEX
    assert 'class="page video-page"' in _INDEX


def test_video_assets_referenced():
    assert "video/video-side.js" in _INDEX
    assert "video/video-side.css" in _INDEX
    assert _CSS_PATH.exists() and _CSS_PATH.stat().st_size > 0


# --- isolation: music side untouched --------------------------------------

def test_music_sidebar_nav_still_intact():
    # The original music nav (a sibling .sidebar-nav WITHOUT the video-nav class)
    # must still carry its pages — the video side is additive, not a rewrite.
    music_nav = _block(_INDEX, r'<nav class="sidebar-nav">', "</nav>")
    for page in ("dashboard", "sync", "library", "settings", "issues", "help"):
        assert f'data-page="{page}"' in music_nav, f"music nav lost '{page}'"
    # The music subtitle is still the default in markup (JS swaps it at runtime).
    assert "Music Sync & Manager" in _INDEX


def test_controller_is_isolated_iife_with_no_globals():
    stripped = _JS.strip()
    # Wrapped in an IIFE → declares no module-level globals that could collide
    # with or shadow music functions.
    assert stripped.startswith("/*") or stripped.startswith("(function")
    assert "(function" in _JS and "})();" in _JS
    # No window.X assignments (the cross-file leak pattern) and no inline-handler
    # dependence — everything is addEventListener.
    assert "window." not in _JS or "window.location" in _JS  # tolerate none; none expected
    assert "addEventListener" in _JS