Files
KoalaSync/extension/content.js
T
KoalaDev aa52d319e1 Redesign website and extension with koala nature theme
v3.0.0 "The Greens Update" palette: forest-green oklch color system
(accent green + terracotta secondary) replaces the indigo/slate scheme
across the landing page and the extension popup/options. The blob
background becomes an animated bamboo forest overlay (parallax stalks,
falling leaves, canopy, ground mist, fireflies, light sweep, grain)
with prefers-reduced-motion support. Layout, structure and copy are
unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-10 19:18:40 +02:00

1658 lines
76 KiB
JavaScript

/**
* KoalaSync Content Script
* Injected into video tabs to control playback and detect events.
*/
(function() {
// Injection Guard: Check if already injected AND context is valid
try {
if (window.koalaSyncInjected && chrome.runtime.id) {
return;
}
} catch (_e) {
// Context invalidated, proceed with re-injection
}
window.koalaSyncInjected = true;
// --- SHARED_EVENTS_INJECT_START ---
// This block is automatically updated by /scripts/build-extension.cjs
const EVENTS = {
PLAY: "play",
PAUSE: "pause",
SEEK: "seek",
FORCE_SYNC_PREPARE: "force_sync_prepare",
FORCE_SYNC_ACK: "force_sync_ack",
FORCE_SYNC_EXECUTE: "force_sync_execute",
PEER_STATUS: "peer_status",
EPISODE_LOBBY: "episode_lobby",
EPISODE_READY: "episode_ready"
};
// --- SHARED_EVENTS_INJECT_END ---
// Suppresses native event reporting after a programmatic action.
// Each entry is a per-type timer (key = 'playing'|'paused'|'seek').
// While a timer exists, matching native events are consumed and not relayed.
// Timers self-clean after 300ms if the native event never fires.
let _suppressTimers = {};
function _setSuppress(state) {
if (_suppressTimers[state]) clearTimeout(_suppressTimers[state]);
_suppressTimers[state] = setTimeout(() => {
delete _suppressTimers[state];
}, 300);
}
function _clearSuppress(state) {
if (_suppressTimers[state]) {
clearTimeout(_suppressTimers[state]);
delete _suppressTimers[state];
}
}
// --- Seek Relay Filtering ---
// Minimum seek delta (seconds) to report. Prevents HLS/DASH buffering micro-seeks
// from being relayed to peers as user-initiated seeks.
const MIN_SEEK_DELTA = 2.0;
let lastReportedSeekTime = null; // last currentTime we relayed as a SEEK
let seekDebounceTimer = null; // debounce timer for rapid seek events
let expectedSeekTime = null; // strictly track programmatic seeks
const PAGE_API_SEEK_BRIDGE = 1;
// Accurate Disney+ playhead pushed by the MAIN-world page-API bridge
// (background.js installPageApiSeekBridge). The isolated content world
// can't read the page's media player directly.
let disneyPageApiTime = null;
if (typeof window !== 'undefined' && typeof window.addEventListener === 'function') {
window.addEventListener('message', (event) => {
if (event.source !== window) return;
const data = event.data;
if (data && data.__koalaPlayerTime === 1 && data.provider === 'disney'
&& Number.isFinite(data.position) && Number.isFinite(data.duration) && data.duration > 0) {
disneyPageApiTime = { position: data.position, duration: data.duration, at: Date.now() };
}
});
}
function hostMatchesUrl(host, url) {
const normalized = String(url || '')
.replace(/^https?:\/\//i, '')
.split('/')[0]
.toLowerCase();
return normalized && (host === normalized || host.endsWith(`.${normalized}`));
}
function matchesPlayerUrls(urls) {
const host = window.location.hostname.toLowerCase();
return Array.isArray(urls) && urls.some(url => hostMatchesUrl(host, url));
}
function isDisneyPlusHost() {
return matchesPlayerUrls(['disneyplus.com']);
}
function getDisneyPlusTimeline() {
if (!isDisneyPlusHost()) return null;
// Exact playhead/duration from the page media player, relayed by the
// MAIN-world bridge. No Disney DOM scraping fallback.
if (disneyPageApiTime && (Date.now() - disneyPageApiTime.at) < 2000 && disneyPageApiTime.duration > 0) {
const cur = Math.max(0, Math.min(disneyPageApiTime.duration, disneyPageApiTime.position));
return { start: 0, end: disneyPageApiTime.duration, duration: disneyPageApiTime.duration, current: cur, nativeScale: 1, nativeStart: 0 };
}
return null;
}
// Site-specific player exceptions live here. The default HTML5 path stays below.
function getSiteQuirkAdapters() {
return [{
name: 'disneyplus-page-api',
key: 'disneyPlus',
urls: ['disneyplus.com'],
matches() { return matchesPlayerUrls(this.urls); },
getTimeline: getDisneyPlusTimeline,
getDebug(video) {
return {
name: this.name,
key: 'disneyPlus',
urls: this.urls,
timeline: getDisneyPlusTimeline(video)
};
}
}];
}
function getActiveSiteQuirk() {
return getSiteQuirkAdapters().find(adapter => adapter.matches()) || null;
}
function getSiteQuirkTimeline(video) {
const adapter = getActiveSiteQuirk();
return adapter ? adapter.getTimeline(video) : null;
}
function getSiteQuirkDebug(video) {
const adapter = getActiveSiteQuirk();
return adapter ? adapter.getDebug(video) : null;
}
function getSyncCurrentTime(video) {
const siteTimeline = getSiteQuirkTimeline(video);
if (siteTimeline) return siteTimeline.current;
if (isDisneyPlusHost()) return null;
const current = video.currentTime;
return Number.isFinite(current) ? current : null;
}
function getSyncDuration(video) {
const siteTimeline = getSiteQuirkTimeline(video);
if (siteTimeline) return siteTimeline.duration;
if (isDisneyPlusHost()) return 0;
return Number.isFinite(video.duration) && video.duration > 0 ? video.duration : 0;
}
function toNativeSeekTime(video, targetTime) {
if (!Number.isFinite(targetTime)) return targetTime;
const siteTimeline = getSiteQuirkTimeline(video);
if (!siteTimeline) return targetTime;
const nativeTarget = siteTimeline.nativeStart + targetTime * siteTimeline.nativeScale;
const max = Number.isFinite(siteTimeline.end) ? siteTimeline.end : nativeTarget;
const min = Number.isFinite(siteTimeline.start) ? siteTimeline.start : 0;
return Math.max(min, Math.min(max, nativeTarget));
}
function shouldUsePageApiSeek() {
return window.KOALA_PAGE_API_SEEK_ENABLED === true &&
typeof window.koalaFindPageApiSeekProvider === 'function' &&
!!window.koalaFindPageApiSeekProvider(window.location.hostname);
}
function seekVideo(video, targetTime) {
// Prefer a precise page-level seek API when available (Netflix, Disney+);
// for those players the DOM/button seek path is imprecise or impossible.
if (shouldUsePageApiSeek()) {
expectedSeekTime = targetTime;
window.postMessage({ __koalaPageApiSeek: PAGE_API_SEEK_BRIDGE, kind: 'seek', time: targetTime }, '*');
return;
}
expectedSeekTime = targetTime;
video.currentTime = toNativeSeekTime(video, targetTime);
}
// --- Play/Pause Coalescing (leading + trailing) ---
// Media players (HLS/DASH, ad insertion, ABR/quality switches, source swaps,
// page teardown) fire bursts of native play/pause events within a few hundred
// ms. Relaying each as a distinct command spams peers and the relay.
//
// Strategy: emit the FIRST event immediately (leading edge → a deliberate
// single play/pause has zero added latency), then hold a short window. If
// more play/pause events arrive during the window it's a burst — we suppress
// the intermediate churn and, once it settles, emit the FINAL state on the
// trailing edge.
//
// We deliberately do NOT dedup the trailing send against the leading one. A
// remote play/pause may be applied mid-window (e.g. I pause, peer plays, I
// pause again within 150ms): the settled state then equals my last *sent*
// state yet is a genuine change versus the now-shared state — suppressing it
// would desync. Re-sending an unchanged state is a harmless no-op on peers,
// so re-sending is always the safe choice. Echo-suppression and seek-flush
// still run synchronously on event arrival (see reportEvent) — only the
// network emit is governed here.
const PLAY_PAUSE_COALESCE_MS = 150;
let playPauseCoalesceTimer = null; // non-null = a coalescing window is open
let pendingPlayPauseAction = null; // last play/pause seen during the window, awaiting trailing flush
// --- Episode Auto-Sync State ---
let lastKnownMediaTitle = null;
let episodeTransitionDebounce = null;
let _pendingLobbyTitle = null; // Title we're waiting to match (from remote lobby)
let lobbyPollTimer = null;
let _autoSyncEnabled = true; // Cached setting, updated via storage.onChanged
let _audioSettings = null;
let _audioProcessingAllowed = true;
// Cache the autoSyncNextEpisode setting (local-only; never read from sync)
chrome.storage.local.get(['autoSyncNextEpisode', 'audioSettings'], (data) => {
_autoSyncEnabled = data.autoSyncNextEpisode !== false;
_audioSettings = mergeAudioSettings(data.audioSettings);
const video = findVideo();
if (video && _audioProcessingAllowed) applyAudioSettings(video, _audioSettings);
});
chrome.storage.onChanged.addListener((changes, area) => {
if (area === 'local' && changes.autoSyncNextEpisode) {
_autoSyncEnabled = changes.autoSyncNextEpisode.newValue !== false;
}
});
// --- Host Control Mode (guest-side) ---
// When a room is in 'host-only' mode and we're a guest, a deliberate local
// pause/seek must not drive the room (background/server already drop it). Here
// we handle the *local* UX: snap back to the host's position, or — if the user
// really wants to — let them go solo (desync) with a resync escape hatch.
let hcmControlMode = 'everyone'; // mirror of room control mode
let hcmAmController = false; // are we allowed to drive (owner or co-host)?
let hcmHostPeerId = null; // last known host peerId (room/host identity)
let hcmDesynced = false; // user chose to go solo
let hcmSnapBackCooldownUntil = 0; // suppress re-trigger right after a snap-back
let hcmDeferredSnapPending = false; // a buffer-aware snap-back is waiting for readiness
let hcmLastUserGestureAt = 0; // for deliberate-vs-involuntary classification
let hcmBufferingUntil = 0; // set on 'waiting' — buffering grace window
let hcmDialogTimer = null; // 8s auto-stay timer — cleared on dialog replace (H-4)
// Localized strings for the in-page dialog/badge (content has no i18n loader;
// background resolves them via GET_HCM_STRINGS on init). English fallbacks here.
const hcmStrings = {
title: 'KoalaSync · Host controls this room',
body: 'Only the host can control playback in this room. Keep watching together, or watch on your own?',
stay: 'Stay in sync',
solo: 'Watch on my own',
badge: 'Watching on your own',
resync: 'Resync'
};
const HCM_USER_GESTURE_MS = 1000;
const HCM_BUFFERING_GRACE_MS = 1500;
const HCM_SNAP_BACK_COOLDOWN_MS = 1000;
const HCM_BUFFER_WAIT_MS = 8000; // cap on waiting for a buffering player before snapping anyway
// Track genuine user input so we can tell a deliberate pause/seek from a
// player-/browser-initiated one. Capturing + passive so we never interfere.
const _hcmGesture = () => { hcmLastUserGestureAt = Date.now(); };
document.addEventListener('keydown', _hcmGesture, { capture: true, passive: true });
document.addEventListener('pointerdown', _hcmGesture, { capture: true, passive: true });
function hcmIsGuestGated() {
return hcmControlMode === 'host-only' && !hcmAmController;
}
// EC-9 intent classifier: only a *clearly deliberate* guest action triggers the
// dialog/snap-back. Anything that smells involuntary (buffering, seeking, tab
// refocus, no recent gesture) is treated as involuntary. Bias intentional —
// in host-only the guest never broadcasts anyway, so this only tunes UX.
function hcmClassifyIntent() {
const video = findVideo();
if (!video) return 'involuntary';
if (hcmIsLive(video)) return 'live'; // EC-15: degrade, don't gate
if (video.readyState < 3) return 'involuntary'; // buffering / not enough data
if (video.seeking) return 'involuntary';
if (Date.now() < hcmBufferingUntil) return 'involuntary';
if (Date.now() < visibilityGraceUntil) return 'involuntary';
if (Date.now() - hcmLastUserGestureAt > HCM_USER_GESTURE_MS) return 'involuntary';
return 'deliberate';
}
// Live detection (EC-15 + DVR). Pure live reports duration Infinity/NaN. Live-DVR
// (Twitch/YouTube-live with rewind) reports a *finite, sliding* duration — its
// seekable window doesn't start at 0, which we use as the DVR signal.
function hcmIsLive(video) {
// Don't trust duration before metadata has loaded (readyState >= 1) —
// otherwise pre-loaded videos report NaN and get misclassified as live,
// which suppresses the desync dialog (L-2).
if (video.readyState < 1) return false;
if (!isDisneyPlusHost() && !Number.isFinite(video.duration)) return true;
try {
const s = video.seekable;
if (s && s.length > 0 && s.start(0) > 1) return true; // sliding DVR window
} catch (_e) { /* seekable may throw if empty */ }
return false;
}
// Snap the local player back to the host's current position/state.
function hcmSnapBackToHost(target) {
if (hcmDesynced) return; // user opted out — never yank them back automatically
hcmSnapBackCooldownUntil = Date.now() + HCM_SNAP_BACK_COOLDOWN_MS;
const video = findVideo();
if (!video) return;
if (target && Number.isFinite(target.targetTime)) {
tryMediaAction(EVENTS.SEEK, { targetTime: target.targetTime });
}
// Adopt the host's play/pause state — but ONLY if we actually know it.
// Defaulting to PLAY when the state is unknown would auto-resume a paused
// video against the host's real state (H-1).
if (target && target.playbackState === 'paused') {
tryMediaAction(EVENTS.PAUSE);
} else if (target && target.playbackState === 'playing') {
tryMediaAction(EVENTS.PLAY);
}
reportLog('Host-only: snapped back to host position', 'info');
}
// Resync to the host's current position, retrying briefly if the host's state
// isn't known yet (e.g. they just paused and no heartbeat has propagated) —
// otherwise the request is a silent no-op and the user thinks they're synced
// when they aren't. Shared by the dialog's "Stay in sync" and the Resync badge.
function hcmRequestHostSyncWithRetry() {
let attempts = 0;
const tryOnce = () => {
chrome.runtime.sendMessage({ type: 'REQUEST_HOST_SYNC' }, (res) => {
if (chrome.runtime.lastError || !res || !res.target) {
if (++attempts < 5) setTimeout(tryOnce, 250);
else reportLog('Host-only: resync requested but host state unavailable', 'warn');
return;
}
hcmSnapBackToHost(res.target);
});
};
tryOnce();
}
// Buffer-aware snap-back (#3). An involuntary pause/seek often coincides with the
// player buffering — and a player can't actually play while it's stalled. Snapping
// immediately just fights the buffer (seek → re-buffer → another pause → …), which
// looks like stutter. Instead: if the player isn't ready, wait until it can play
// (readyState>=3, not seeking), then snap ONCE to the host's *current* position
// (re-queried, since the captured target may be stale by the time buffering ends).
// Player-agnostic on purpose — we can't enumerate every site, so this must be safe
// regardless of whether a given player fires 'pause' or only 'waiting'.
function hcmDeferredSnapBack() {
if (hcmDeferredSnapPending) return; // already waiting — don't stack polls
hcmDeferredSnapPending = true;
const deadline = Date.now() + HCM_BUFFER_WAIT_MS;
const poll = () => {
// Abort if the reason to snap is gone: user went solo, we're no longer a
// gated guest, or the video vanished.
if (hcmDesynced || !hcmIsGuestGated()) { hcmDeferredSnapPending = false; return; }
const video = findVideo();
const ready = video && video.readyState >= 3 && !video.seeking;
if (ready || Date.now() >= deadline) {
hcmDeferredSnapPending = false;
hcmRequestHostSyncWithRetry(); // fresh host position + snap once
return;
}
setTimeout(poll, 300);
};
poll();
}
// Entry point: background told us our local action was blocked in host-only.
function hcmHandleBlocked(action, target) {
// HOST_BLOCKED is only ever sent to a gated guest (background verifies
// host-only + !host before sending), so it's authoritative. Adopt the
// role/mode from it in case our CONTROL_MODE broadcast hasn't landed yet
// (join race, EC-5) — otherwise we'd miss the dialog/snap-back.
hcmControlMode = 'host-only';
hcmAmController = false;
if (hcmDesynced) return; // already solo, nothing to do
const intent = hcmClassifyIntent();
if (intent === 'live') return; // EC-15: leave the guest alone on live
if (intent === 'involuntary') {
// EC-4 loop guard: only the silent auto snap-back is suppressed by the
// cooldown — the deliberate dialog path below must still go through,
// otherwise a second deliberate pause inside the cooldown window leaves
// the user stuck paused with no UI (M-3).
if (Date.now() < hcmSnapBackCooldownUntil || hcmDeferredSnapPending) return;
// Buffering/ads/throttle — silently re-sync, no dialog spam.
const video = findVideo();
if (video && video.readyState >= 3 && !video.seeking) {
// Ready now → snap immediately. Use the captured target if it's
// usable, otherwise re-query+retry (host state may not be known yet)
// so we never leave the guest silently stuck (consistent with the
// deferred and "Stay in sync" paths).
if (target && Number.isFinite(target.targetTime)) hcmSnapBackToHost(target);
else hcmRequestHostSyncWithRetry();
} else {
hcmDeferredSnapBack(); // buffering → wait for ready, then snap once (#3)
}
return;
}
// Deliberate: offer the choice (Teleparty-style), default = snap back.
hcmShowDesyncDialog(action, target);
}
// --- In-page UI (dialog + persistent desync badge) ---
// Built with the DOM API (CSSOM .style is CSP-safe; inline style="" in innerHTML
// is stripped by strict style-src on Netflix/YouTube/Disney+). Hosted in a
// Shadow DOM so the page's CSS can't restyle or hide our controls.
let hcmDialogHost = null; // shadow host element for the dialog
let hcmBadgeHost = null; // shadow host element for the persistent badge
let hcmBadgePending = false; // retry flag for early-injection badge creation (L-4)
function hcmEl(tag, css, text) {
const el = document.createElement(tag);
if (css) el.style.cssText = css; // CSSOM assignment — not gated by CSP
if (text != null) el.textContent = text;
return el;
}
function hcmRemoveDialog() {
// Cancel any pending auto-stay timer so a replaced dialog's stale closure
// can't later remove its successor / snap to an outdated target (H-4).
if (hcmDialogTimer) { clearTimeout(hcmDialogTimer); hcmDialogTimer = null; }
if (hcmDialogHost) { hcmDialogHost.remove(); hcmDialogHost = null; }
}
function hcmShowDesyncDialog(action, target) {
if (!document.body) { hcmSnapBackToHost(target); return; }
hcmRemoveDialog();
const host = hcmEl('div', 'all:initial');
const root = host.attachShadow({ mode: 'open' });
const wrap = hcmEl('div', 'position:fixed;z-index:2147483647;left:50%;bottom:32px;transform:translateX(-50%);background:#1f2937;color:#f9fafb;font:14px/1.4 system-ui,sans-serif;padding:16px 18px;border-radius:12px;box-shadow:0 8px 30px rgba(0,0,0,.45);max-width:360px;border:1px solid #374151');
wrap.setAttribute('role', 'dialog');
const title = hcmEl('div', 'font-weight:600;margin-bottom:6px', hcmStrings.title);
const body = hcmEl('div', 'margin-bottom:12px;color:#d1d5db', hcmStrings.body);
const btnRow = hcmEl('div', 'display:flex;gap:8px;justify-content:flex-end');
const soloBtn = hcmEl('button', 'background:#374151;color:#f9fafb;border:0;padding:8px 12px;border-radius:8px;cursor:pointer', hcmStrings.solo);
const stayBtn = hcmEl('button', 'background:#56ae6c;color:#0a1a0d;border:0;padding:8px 12px;border-radius:8px;cursor:pointer;font-weight:600', hcmStrings.stay);
btnRow.append(soloBtn, stayBtn);
wrap.append(title, body, btnRow);
root.appendChild(wrap);
document.body.appendChild(host);
hcmDialogHost = host;
let settled = false;
// Re-query the host's current position on click instead of using the
// potentially stale target captured at HOST_BLOCKED time (M-1).
const stay = () => {
if (settled) return; settled = true; hcmRemoveDialog();
hcmRequestHostSyncWithRetry();
};
const solo = () => { if (settled) return; settled = true; hcmRemoveDialog(); hcmEnterDesync(); };
stayBtn.addEventListener('click', stay);
soloBtn.addEventListener('click', solo);
// EC-18: if the user ignores the prompt, default to staying in sync.
hcmDialogTimer = setTimeout(() => { if (!settled) stay(); }, 8000);
}
function hcmEnterDesync() {
hcmDesynced = true;
reportLog('Host-only: you chose to watch on your own (desynced)', 'warn');
// Notify background so it can relay our desynced state to the host via
// heartbeats — the host's UI then knows we're not following commands
// instead of appearing silently un-ACK'd.
chrome.runtime.sendMessage({ type: 'HCM_DESYNC_STATE', desynced: true }).catch(() => {});
hcmShowBadge();
}
function hcmExitDesync() {
const wasDesynced = hcmDesynced;
hcmDesynced = false;
hcmRemoveBadge();
if (wasDesynced) {
chrome.runtime.sendMessage({ type: 'HCM_DESYNC_STATE', desynced: false }).catch(() => {});
}
// Resync to the host's current position (retries if host state not yet known).
hcmRequestHostSyncWithRetry();
reportLog('Host-only: resynced with the host', 'info');
}
function hcmShowBadge() {
if (hcmBadgeHost) return;
if (!document.body) {
// Body not ready yet (very early injection). Defer until DOMReady,
// otherwise the desynced user silently never sees the badge (L-4).
if (!hcmBadgePending) {
hcmBadgePending = true;
const retry = () => {
hcmBadgePending = false;
if (hcmDesynced && !hcmBadgeHost) hcmShowBadge();
};
if (document.readyState === 'loading') {
document.addEventListener('DOMContentLoaded', retry, { once: true });
} else {
setTimeout(retry, 50);
}
}
return;
}
const host = hcmEl('div', 'all:initial');
const root = host.attachShadow({ mode: 'open' });
const b = hcmEl('div', 'position:fixed;z-index:2147483646;right:16px;bottom:16px;background:#b45309;color:#fff;font:13px/1.3 system-ui,sans-serif;padding:8px 12px;border-radius:10px;box-shadow:0 6px 20px rgba(0,0,0,.4);cursor:pointer;display:flex;align-items:center;gap:8px');
b.append(hcmEl('span', null, '● ' + hcmStrings.badge), hcmEl('span', 'text-decoration:underline', hcmStrings.resync));
b.addEventListener('click', hcmExitDesync);
root.appendChild(b);
document.body.appendChild(host);
hcmBadgeHost = host;
}
function hcmRemoveBadge() {
if (hcmBadgeHost) { hcmBadgeHost.remove(); hcmBadgeHost = null; }
}
function hcmReset() {
const wasDesynced = hcmDesynced;
hcmDesynced = false;
hcmDeferredSnapPending = false;
hcmSnapBackCooldownUntil = 0; // don't let a stale cooldown swallow the next snap-back
hcmBufferingUntil = 0;
hcmRemoveDialog();
hcmRemoveBadge();
// If we were desynced, notify background so it stops reporting us as
// desynced in heartbeats (otherwise the host's UI keeps showing the
// stale Solo badge until the next state change).
if (wasDesynced) {
chrome.runtime.sendMessage({ type: 'HCM_DESYNC_STATE', desynced: false }).catch(() => {});
}
}
function reportLog(message, level = 'info') {
chrome.runtime.sendMessage({ type: 'LOG', message, level }).catch(() => {});
}
// --- Helper: find the best video element on the page ---
// Prefers larger, visible videos over tiny preview/trailer elements.
function findVideo(root = document) {
const candidates = Array.from(root.querySelectorAll('video'));
// Scan likely media hosts even when light-DOM videos exist; many players
// expose a tiny preview/ad video outside Shadow DOM and the real player inside.
const potentialHosts = root.querySelectorAll('[id*="player" i], [class*="player" i], [id*="video" i], [class*="video" i], [id*="media" i], [class*="media" i], [id*="stream" i], [class*="stream" i], ytd-player, netflix-player, emby-player, jellyfin-player, video-player');
for (const el of potentialHosts) {
if (el.shadowRoot) {
const found = findVideo(el.shadowRoot);
if (found) candidates.push(found);
}
}
if (candidates.length === 0) return null;
// Multiple videos found → pick the best one
if (candidates.length === 1) return candidates[0];
let best = null;
let bestScore = -1;
for (const v of candidates) {
if (v.tagName !== 'VIDEO') continue;
// Score: visible area + bonus for unmuted + bonus for longer duration
const area = (v.videoWidth || v.offsetWidth || 0) * (v.videoHeight || v.offsetHeight || 0);
const unmutedBonus = v.muted ? 0 : 100000;
const durationBonus = (v.duration && isFinite(v.duration) ? v.duration : 0) * 100;
const score = area + unmutedBonus + durationBonus;
if (score > bestScore) {
bestScore = score;
best = v;
}
}
return best;
}
// --- Audio Processing Module ---
const AUDIO_PRESETS = {
recommended: { threshold: -24, ratio: 8, attack: 0.010, release: 0.300, knee: 15 },
dynamicRange: { threshold: -18, ratio: 4, attack: 0.020, release: 0.200, knee: 10 },
vocalEnhancement: { threshold: -12, ratio: 3, attack: 0.015, release: 0.150, knee: 5 },
smooth: { threshold: -30, ratio: 1.5, attack: 0.030, release: 0.250, knee: 20 },
custom: { threshold: -24, ratio: 12, attack: 0.003, release: 0.250, knee: 30 }
};
const DEFAULT_AUDIO_SETTINGS = {
enabled: false,
compressor: {
enabled: false,
preset: 'recommended',
customParams: { ...AUDIO_PRESETS.custom }
}
};
let audioCtx = null;
let audioChains = new WeakMap();
let currentAudioVideo = null;
function mergeAudioSettings(settings = {}) {
const safeSettings = settings && typeof settings === 'object' ? settings : {};
return {
...DEFAULT_AUDIO_SETTINGS,
...safeSettings,
compressor: {
...DEFAULT_AUDIO_SETTINGS.compressor,
...(safeSettings.compressor || {}),
customParams: {
...DEFAULT_AUDIO_SETTINGS.compressor.customParams,
...(safeSettings.compressor?.customParams || {})
}
}
};
}
function initAudioContext() {
if (!audioCtx) {
try {
const AudioContextClass = window.AudioContext || window.webkitAudioContext;
if (!AudioContextClass) return null;
audioCtx = new AudioContextClass({ latencyHint: 'interactive' });
} catch (e) {
reportLog(`Audio Processing unavailable: ${e.message}`, 'warn');
return null;
}
}
if (audioCtx.state === 'suspended') {
audioCtx.resume().catch(() => { reportLog('AudioContext resume failed - browser may need page interaction first', 'warn'); });
}
return audioCtx;
}
function closeAudioContext() {
if (audioCtx) {
audioCtx.close().catch(() => {});
audioCtx = null;
}
audioChains = new WeakMap();
currentAudioVideo = null;
}
function setupAudioChain(videoEl) {
if (audioChains.has(videoEl)) return audioChains.get(videoEl);
const ctx = initAudioContext();
if (!ctx) return null;
try {
const src = ctx.createMediaElementSource(videoEl);
const compressor = ctx.createDynamicsCompressor();
const dryGain = ctx.createGain();
const compGain = ctx.createGain();
src.connect(dryGain);
dryGain.connect(ctx.destination);
src.connect(compressor);
compressor.connect(compGain);
compGain.connect(ctx.destination);
dryGain.gain.value = 1;
compGain.gain.value = 0;
const chain = { compressor, dryGain, compGain, active: false };
audioChains.set(videoEl, chain);
currentAudioVideo = videoEl;
return chain;
} catch (e) {
reportLog(`Audio Processing setup failed: ${e.message}`, 'warn');
return null;
}
}
function rampGain(node, value, t) {
const current = node.gain.value;
node.gain.cancelScheduledValues(t);
node.gain.setValueAtTime(current, t);
node.gain.linearRampToValueAtTime(value, t + 0.04);
}
function applyAudioBypass(videoEl) {
const chain = audioChains.get(videoEl);
if (!chain || !chain.active) return;
const t = chain.dryGain.context.currentTime;
rampGain(chain.dryGain, 1, t);
rampGain(chain.compGain, 0, t);
chain.active = false;
reportLog('Audio compressor disabled', 'info');
}
function bypassCurrentAudioProcessing() {
if (currentAudioVideo) applyAudioBypass(currentAudioVideo);
}
function applyAudioSettings(videoEl, settings) {
const mergedSettings = mergeAudioSettings(settings);
if (!mergedSettings.enabled || !mergedSettings.compressor?.enabled) {
applyAudioBypass(videoEl);
return;
}
const chain = setupAudioChain(videoEl);
if (!chain) return;
const cSettings = mergedSettings.compressor;
const params = cSettings.preset === 'custom'
? cSettings.customParams
: AUDIO_PRESETS[cSettings.preset] || AUDIO_PRESETS.recommended;
chain.compressor.threshold.value = params.threshold ?? -24;
chain.compressor.knee.value = params.knee ?? 15;
chain.compressor.ratio.value = params.ratio ?? 8;
chain.compressor.attack.value = params.attack ?? 0.010;
chain.compressor.release.value = params.release ?? 0.300;
if (!chain.active) {
const t = chain.dryGain.context.currentTime;
rampGain(chain.dryGain, 0, t);
rampGain(chain.compGain, 1, t);
chain.active = true;
reportLog('Audio compressor enabled', 'info');
}
}
// --- Episode Auto-Sync: Detection ---
function getMediaTitle() {
return (navigator.mediaSession && navigator.mediaSession.metadata)
? navigator.mediaSession.metadata.title
: null;
}
// Extract a canonical episode identifier from a title string.
// Handles: S01E01, S1E1, S01 - E01, Season 1 Episode 1, "Folge 5", "Episode 5", "Ep. 5", "#5"
// Returns null if no episode pattern found.
// --- SHARED_EPISODE_UTILS_INJECT_START ---
// This block is automatically replaced by /scripts/build-extension.cjs
function extractEpisodeId(title) {
if (!title || typeof title !== 'string') return null;
const se = title.match(/S(?:eason\s*)?(\d+)[^a-zA-Z0-9]*E(?:pisode\s*)?(\d+)/i);
if (se) return `S${String(se[1]).padStart(2, '0')}E${String(se[2]).padStart(2, '0')}`;
const ep = title.match(/(?:Episode|Folge|Ep\.?|#)\s*(\d+)/i);
if (ep) return `EP${String(ep[1]).padStart(3, '0')}`;
return null;
}
function sameEpisode(titleA, titleB) {
if (!titleA && !titleB) return true;
if (!titleA || !titleB) return false;
const idA = extractEpisodeId(titleA);
const idB = extractEpisodeId(titleB);
if (idA && idB) return idA === idB;
if (idA || idB) return false;
return titleA === titleB;
}
// --- SHARED_EPISODE_UTILS_INJECT_END ---
// Returns true only when we are CERTAIN the episodes differ.
// Permissive: only blocks if BOTH titles have parseable IDs AND they differ.
// Films, music, unparseable titles always pass through.
function isDifferentEpisode(titleA, titleB) {
if (!titleA || !titleB) return false; // Unknown → allow
const idA = extractEpisodeId(titleA);
const idB = extractEpisodeId(titleB);
if (!idA || !idB) return false; // At least one unparseable → allow
return idA !== idB; // Both parseable → only block if different
}
function checkEpisodeTransition() {
const currentTitle = getMediaTitle();
const video = findVideo();
const current = video ? getSyncCurrentTime(video) : null;
// Only trigger if: we had a previous title, the title changed,
// a video exists, and we're near the start of new content.
if (lastKnownMediaTitle && currentTitle
&& !sameEpisode(currentTitle, lastKnownMediaTitle)
&& video
&& current !== null && current < 5
&& video.readyState >= 1) {
onEpisodeTransition(currentTitle);
}
// Always track the latest known title
if (currentTitle) lastKnownMediaTitle = currentTitle;
}
function onEpisodeTransition(newTitle) {
// Debounce: prevent duplicate fires from multiple signals
if (episodeTransitionDebounce) return;
episodeTransitionDebounce = setTimeout(() => {
episodeTransitionDebounce = null;
}, 2000);
reportLog(`Episode transition detected: "${newTitle}"`, 'info');
// EC-12: a new episode dissolves any solo/desync state — the guest rejoins
// the room for the fresh content rather than staying stuck on the old one.
if (hcmDesynced) hcmReset();
// Do NOT pause here. We notify background.js first.
// Background checks the setting; if enabled it creates a lobby
// and sends back PAUSE_FOR_LOBBY so we only freeze if the feature is on.
chrome.runtime.sendMessage({
type: 'EPISODE_CHANGED',
payload: { newTitle }
}).catch(() => {});
}
function checkAndReportLobbyReady(expectedTitle) {
const video = findVideo();
const currentTitle = getMediaTitle();
const current = video ? getSyncCurrentTime(video) : null;
if (video && currentTitle && sameEpisode(currentTitle, expectedTitle)
&& current !== null && current < 5 && video.readyState >= 1) {
// Match! Pause at start and report ready.
if (!video.paused) {
_setSuppress('paused');
video.pause();
}
stopLobbyPoll();
chrome.runtime.sendMessage({
type: 'EPISODE_READY_LOCAL',
payload: { title: currentTitle }
}).catch(() => {});
reportLog(`Episode lobby: Ready for "${currentTitle}"`, 'success');
return true;
}
return false;
}
function startLobbyPoll(expectedTitle) {
stopLobbyPoll();
_pendingLobbyTitle = expectedTitle;
// NOTE: Do NOT pause here. Three callers reach this function:
// 1. PAUSE_FOR_LOBBY (initiator): already paused by that handler before calling us.
// 2. EPISODE_LOBBY (non-initiator): peer may still be on the PREVIOUS episode — pausing
// would freeze them mid-episode. The pause happens inside checkAndReportLobbyReady()
// only once their title actually matches.
// 3. CONTENT_BOOT recovery: same reasoning as (2).
// Check immediately
if (checkAndReportLobbyReady(expectedTitle)) return;
// Poll every 2 seconds — no log spam, internal only
lobbyPollTimer = setInterval(() => {
checkAndReportLobbyReady(expectedTitle);
}, 2000);
}
function stopLobbyPoll() {
_pendingLobbyTitle = null;
if (lobbyPollTimer) {
clearInterval(lobbyPollTimer);
lobbyPollTimer = null;
}
}
function getPlayerActionFixes() {
return [
{
name: 'youtube-player-buttons',
urls: ['youtube.com'],
playPauseButtonSelector: '.ytp-play-button'
},
{
name: 'twitch-player-buttons',
urls: ['twitch.tv'],
playPauseButtonSelector: '[data-a-target="player-play-pause-button"]'
}
];
}
function getActivePlayerActionFix() {
return getPlayerActionFixes().find(fix => matchesPlayerUrls(fix.urls)) || null;
}
function tryPlayerActionFix(fix, action, video, data) {
if (!fix) return false;
const button = document.querySelector(fix.playPauseButtonSelector);
if (!button) return false;
const isCurrentlyPlaying = !video.paused;
if ((action === EVENTS.PLAY && !isCurrentlyPlaying) || (action === EVENTS.PAUSE && isCurrentlyPlaying)) {
_setSuppress(action === EVENTS.PLAY ? 'playing' : 'paused');
button.click();
}
if (action === EVENTS.SEEK) {
seekVideo(video, data.targetTime, data.delta);
}
return true;
}
// --- Helper: site-specific player actions, then native HTML5 fallback ---
function tryMediaAction(action, data) {
const video = findVideo();
if (!video) return;
if (action === EVENTS.SEEK) {
const target = data ? (data.targetTime !== undefined ? data.targetTime : data.currentTime) : undefined;
if (!Number.isFinite(target)) {
reportLog(`Media Action Error: Invalid seek payload - ${JSON.stringify(data)}`, 'error');
return;
}
data = { ...data, targetTime: target };
}
try {
const actionFix = getActivePlayerActionFix();
if (tryPlayerActionFix(actionFix, action, video, data)) {
return;
}
// Fallback for native HTML5
if (action === EVENTS.PLAY) {
_setSuppress('playing');
video.play().catch((e) => {
reportLog(`Playback prevented: ${e.message}`, 'warn');
_clearSuppress('playing');
});
} else if (action === EVENTS.PAUSE) {
_setSuppress('paused');
video.pause();
} else if (action === EVENTS.SEEK) {
seekVideo(video, data.targetTime, data.delta);
}
} catch (e) {
reportLog(`Media Action Error: ${e.message}`, 'error');
}
}
// --- Helper: Wait until video is ready for playback (buffered & seeked) ---
function pollSeekReady(targetTime, timeoutMs = 8000) {
return new Promise((resolve) => {
const interval = 150;
let elapsed = 0;
const timer = setInterval(() => {
const video = findVideo(); // Re-query DOM on every iteration
if (!video) {
clearInterval(timer);
resolve(false);
return;
}
elapsed += interval;
const current = getSyncCurrentTime(video);
const timeDiff = current !== null ? Math.abs(current - targetTime) : Infinity;
const ready = video.readyState >= 3 && timeDiff < 2.0;
if (ready) {
clearInterval(timer);
resolve(true);
} else if (elapsed >= timeoutMs) {
clearInterval(timer);
resolve(false);
}
}, interval);
});
}
// Listen for commands from background.js
chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
if (!message) return;
if (message.action === 'get_current_time') {
const video = findVideo();
sendResponse({ currentTime: video ? getSyncCurrentTime(video) : null });
return true;
}
if (message.action === 'APPLY_AUDIO_SETTINGS') {
_audioProcessingAllowed = true;
_audioSettings = mergeAudioSettings(message.settings);
const video = findVideo();
if (video) applyAudioSettings(video, _audioSettings);
sendResponse({ ok: true });
return true;
}
if (message.action === 'RESET_AUDIO_PROCESSING') {
_audioProcessingAllowed = false;
bypassCurrentAudioProcessing();
sendResponse({ ok: true });
return true;
}
// Host Control Mode: room mode/role changed.
if (message.type === 'CONTROL_MODE') {
const wasGated = hcmIsGuestGated();
const prevHostPeerId = hcmHostPeerId;
hcmControlMode = message.controlMode || 'everyone';
hcmAmController = !!message.amController;
hcmHostPeerId = message.hostPeerId || null;
// Reset guest-side state when leaving the gated state, OR when the
// host identity changes (room switch, host-leave fallback, missed
// teardown broadcast) — clears stale desync so a rejoin starts clean (H-3).
const hostChanged = prevHostPeerId !== null && hcmHostPeerId !== prevHostPeerId;
if ((wasGated && !hcmIsGuestGated()) || hostChanged) hcmReset();
sendResponse({ ok: true });
return true;
}
// Host Control Mode: background blocked our local action — handle UX locally.
if (message.type === 'HOST_BLOCKED') {
hcmHandleBlocked(message.action, message.target || null);
sendResponse({ ok: true });
return true;
}
// Background asks for an immediate state push (e.g. the first peer just
// joined while we were solo) so the newcomer syncs without waiting.
if (message.type === 'REQUEST_HEARTBEAT') {
sendHeartbeat();
sendResponse({ ok: true });
return true;
}
if (message.type === 'SERVER_COMMAND') {
const { action, payload } = message;
let actionCompleted = false;
// Host Control Mode: while watching on our own (desynced), don't apply
// host commands. Only ACK FORCE_SYNC_PREPARE — that's the one the host's
// force-sync flow actually waits on. Skipping CMD_ACKs for PLAY/PAUSE/SEEK
// is intentional so the host's UI honestly reflects that we didn't apply
// the command (M-2); sending them would make the host think we're synced.
if (hcmDesynced) {
const soloIgnored = [EVENTS.PLAY, EVENTS.PAUSE, EVENTS.SEEK, EVENTS.FORCE_SYNC_PREPARE, EVENTS.FORCE_SYNC_EXECUTE];
if (soloIgnored.includes(action)) {
if (action === EVENTS.FORCE_SYNC_PREPARE) {
chrome.runtime.sendMessage({ type: 'FORCE_SYNC_ACK' }).catch(() => {});
}
return;
}
}
// Guard: Don't execute sync commands if peers are on different episodes.
// Only active when autoSyncNextEpisode setting is enabled (default: on).
// Only blocks when BOTH sides have parseable S01E01-style IDs that differ.
// Films and unparseable titles always pass through.
const syncActions = [EVENTS.PLAY, EVENTS.PAUSE, EVENTS.SEEK,
EVENTS.FORCE_SYNC_PREPARE, EVENTS.FORCE_SYNC_EXECUTE];
if (_autoSyncEnabled && syncActions.includes(action)) {
const senderTitle = payload?.mediaTitle;
const myTitle = getMediaTitle();
if (isDifferentEpisode(senderTitle, myTitle)) {
reportLog(`Episode mismatch: sender="${senderTitle || '?'}" vs mine="${myTitle || '?'}" — skipping ${action}. Disable "Auto-Sync next Episode" in settings if this causes issues.`, 'warn');
if (action !== EVENTS.FORCE_SYNC_PREPARE && action !== EVENTS.FORCE_SYNC_EXECUTE) {
chrome.runtime.sendMessage({ type: 'CMD_ACK', actionTimestamp: message.actionTimestamp, commandSenderId: message.commandSenderId }).catch(() => {});
}
return;
}
}
if (action === EVENTS.PLAY) {
tryMediaAction(EVENTS.PLAY);
chrome.runtime.sendMessage({ type: 'CMD_ACK', actionTimestamp: message.actionTimestamp, commandSenderId: message.commandSenderId });
actionCompleted = true;
} else if (action === EVENTS.PAUSE) {
tryMediaAction(EVENTS.PAUSE);
chrome.runtime.sendMessage({ type: 'CMD_ACK', actionTimestamp: message.actionTimestamp, commandSenderId: message.commandSenderId });
actionCompleted = true;
} else if (action === EVENTS.SEEK) {
tryMediaAction(EVENTS.SEEK, payload);
chrome.runtime.sendMessage({ type: 'CMD_ACK', actionTimestamp: message.actionTimestamp, commandSenderId: message.commandSenderId });
actionCompleted = true;
} else if (action === EVENTS.FORCE_SYNC_PREPARE) {
if (!payload || payload.targetTime === undefined) return;
const video = findVideo();
if (video) {
if (!Number.isFinite(payload.targetTime)) {
reportLog(`Media Action Error: Invalid force sync payload - ${JSON.stringify(payload)}`, 'error');
return;
}
_setSuppress('paused');
video.pause();
try {
seekVideo(video, payload.targetTime);
} catch (e) {
reportLog(`Force Sync Seek Error: ${e.message}`, 'error');
}
pollSeekReady(payload.targetTime).then((ready) => {
chrome.runtime.sendMessage({ type: 'FORCE_SYNC_ACK' }).catch(() => {});
if (ready) {
scheduleProactiveHeartbeat();
} else {
reportLog('Force Sync: Seek ready timeout, proceeding anyway', 'warn');
}
}).catch(() => {});
}
} else if (action === EVENTS.FORCE_SYNC_EXECUTE) {
stopLobbyPoll();
tryMediaAction(EVENTS.PLAY);
chrome.runtime.sendMessage({ type: 'CMD_ACK', actionTimestamp: message.actionTimestamp, commandSenderId: message.commandSenderId });
actionCompleted = true;
}
if (actionCompleted) {
scheduleProactiveHeartbeat();
}
}
// Episode Auto-Sync: Lobby notification from background
if (message.type === 'EPISODE_LOBBY') {
// Host Control Mode: a desynced guest is watching on their own and must
// not join the lobby flow. Otherwise they'd pause on title match, report
// ready, but then ignore the host's FORCE_SYNC_* (hcmDesynced skip in
// SERVER_COMMAND) and end up frozen in pause. They also can't be counted
// toward lobby completion (background filters them out).
if (hcmDesynced) {
sendResponse({ status: 'ignored_desynced' });
return true;
}
const expectedTitle = message.expectedTitle;
if (expectedTitle) {
reportLog(`Episode lobby received: waiting for "${expectedTitle}"`, 'info');
startLobbyPoll(expectedTitle);
}
sendResponse({ status: 'ok' });
return true;
}
// Episode Auto-Sync: Lobby cancelled by background
if (message.type === 'EPISODE_LOBBY_CANCEL') {
stopLobbyPoll();
sendResponse({ status: 'ok' });
return true;
}
// Episode Auto-Sync: Background confirmed lobby created, pause the video
if (message.type === 'PAUSE_FOR_LOBBY') {
const video = findVideo();
if (video && !video.paused) {
_setSuppress('paused');
video.pause();
}
// Start lobby poll now that we know the feature is enabled
if (message.expectedTitle) {
startLobbyPoll(message.expectedTitle);
}
sendResponse({ status: 'ok' });
return true;
}
if (message.type === 'GET_VIDEO_STATE') {
const video = findVideo();
const platform = (() => {
const h = window.location.hostname.toLowerCase();
if (h === 'youtube.com' || h.endsWith('.youtube.com')) return 'YouTube';
if (h === 'twitch.tv' || h.endsWith('.twitch.tv')) return 'Twitch';
if (h === 'netflix.com' || h.endsWith('.netflix.com')) return 'Netflix';
if (h === 'primevideo.com' || h.endsWith('.primevideo.com') || /(^|\.)amazon\.(com\.[a-z]{2}|co\.[a-z]{2}|[a-z]{2,})$/.test(h)) return 'Prime Video';
if (h === 'disneyplus.com' || h.endsWith('.disneyplus.com')) return 'Disney+';
if (h === 'hulu.com' || h.endsWith('.hulu.com')) return 'Hulu';
if (h === 'hbomax.com' || h.endsWith('.hbomax.com') || h === 'max.com' || h.endsWith('.max.com')) return 'Max/HBO';
if (h === 'vimeo.com' || h.endsWith('.vimeo.com')) return 'Vimeo';
if (h === 'dailymotion.com' || h.endsWith('.dailymotion.com')) return 'Dailymotion';
return 'Generic';
})();
const networkStates = ['NETWORK_EMPTY', 'NETWORK_IDLE', 'NETWORK_LOADING', 'NETWORK_NO_SOURCE'];
const readyStates = ['HAVE_NOTHING', 'HAVE_METADATA', 'HAVE_CURRENT_DATA', 'HAVE_FUTURE_DATA', 'HAVE_ENOUGH_DATA'];
const videoCount = document.querySelectorAll('video').length;
const inShadowDom = (() => {
let el = video;
while (el) {
if (el.toString() === '[object ShadowRoot]') return true;
el = el.parentNode;
}
// Also check if any potential host has shadow root (even if no video found)
if (!video) {
const hosts = document.querySelectorAll('[id*="player" i], [class*="player" i], [id*="video" i], [class*="video" i]');
for (const host of hosts) {
if (host.shadowRoot) return true;
}
}
return false;
})();
// Build multi-video summary for debug reports
const allVideos = [];
const allVideoEls = document.querySelectorAll('video');
for (let i = 0; i < allVideoEls.length; i++) {
const v = allVideoEls[i];
allVideos.push({
index: i,
width: v.videoWidth || v.offsetWidth || 0,
height: v.videoHeight || v.offsetHeight || 0,
muted: v.muted,
paused: v.paused,
duration: (v.duration && isFinite(v.duration)) ? Math.round(v.duration) : 0,
readyState: v.readyState,
src: (v.currentSrc || v.src || '').substring(0, 80),
selected: v === video
});
}
if (video) {
const dataAttributes = {};
if (video.attributes) {
for (const attr of video.attributes) {
if (attr.name.startsWith('data-')) {
dataAttributes[attr.name] = attr.value;
}
}
}
const metadata = (navigator.mediaSession && navigator.mediaSession.metadata) ? {
title: navigator.mediaSession.metadata.title,
artist: navigator.mediaSession.metadata.artist,
album: navigator.mediaSession.metadata.album,
artwork: Array.from(navigator.mediaSession.metadata.artwork || []).map(a => a.src)
} : null;
const errorInfo = video.error ? {
code: video.error.code,
message: video.error.message
} : null;
sendResponse({
found: true,
paused: video.paused,
currentTime: getSyncCurrentTime(video),
duration: getSyncDuration(video),
nativeCurrentTime: video.currentTime,
nativeDuration: Number.isFinite(video.duration) ? video.duration : 0,
readyState: video.readyState,
readyStateLabel: readyStates[video.readyState] || 'UNKNOWN',
networkState: video.networkState,
networkStateLabel: networkStates[video.networkState] || 'UNKNOWN',
muted: video.muted,
volume: video.volume,
playbackRate: video.playbackRate,
videoWidth: video.videoWidth,
videoHeight: video.videoHeight,
seeking: video.seeking,
ended: video.ended,
error: errorInfo,
buffered: video.buffered && video.buffered.length > 0
? Array.from({ length: video.buffered.length }, (_, i) =>
`${video.buffered.start(i).toFixed(1)}-${video.buffered.end(i).toFixed(1)}s`).join(', ')
: 'none',
loop: video.loop,
url: window.location.href,
pageTitle: document.title,
id: video.id || 'none',
className: video.className || 'none',
src: video.src || 'none',
currentSrc: video.currentSrc || 'none',
dataAttributes,
metadata,
videoCount,
inShadowDom,
platform,
siteQuirk: getSiteQuirkDebug(video),
allVideos
});
} else {
sendResponse({
found: false,
videoCount,
inShadowDom,
platform,
allVideos,
url: window.location.href,
pageTitle: document.title,
metadata: (navigator.mediaSession && navigator.mediaSession.metadata) ? {
title: navigator.mediaSession.metadata.title,
artist: navigator.mediaSession.metadata.artist,
album: navigator.mediaSession.metadata.album
} : null
});
}
}
});
// Detect native events
// Build the relay payload from the *current* media state and send it to
// background.js. Re-reads the video each call so deferred (coalesced) emits
// carry an up-to-date position. Safe with no/invalid video — it no-ops.
function sendContentEvent(action) {
const video = findVideo();
if (!video) return;
const current = getSyncCurrentTime(video);
if (current === null) return;
const mediaTitle = (navigator.mediaSession && navigator.mediaSession.metadata) ? navigator.mediaSession.metadata.title : null;
chrome.runtime.sendMessage({
type: 'CONTENT_EVENT',
action,
payload: {
currentTime: current,
targetTime: current,
mediaTitle: mediaTitle,
timestamp: Date.now()
}
}).catch(() => {});
// Trigger proactive heartbeat to push stabilized state
scheduleProactiveHeartbeat();
}
// Trailing-edge flush of a coalesced play/pause burst: emit the final settled
// state. No-ops only when no burst followed the leading edge. We do NOT skip
// when the state matches the leading send — a remote command may have changed
// the shared state mid-window, so re-sending is the safe (idempotent) choice.
function flushPlayPause() {
playPauseCoalesceTimer = null;
const finalAction = pendingPlayPauseAction;
pendingPlayPauseAction = null;
// No burst follow-up (only the leading edge fired), or invalid state.
if (finalAction !== EVENTS.PLAY && finalAction !== EVENTS.PAUSE) return;
sendContentEvent(finalAction);
}
function reportEvent(action) {
if (seekDebounceTimer && (action === EVENTS.PLAY || action === EVENTS.PAUSE)) {
clearTimeout(seekDebounceTimer);
seekDebounceTimer = null;
const v = findVideo();
if (v) {
const syncTime = getSyncCurrentTime(v);
if (syncTime === null) return;
lastReportedSeekTime = syncTime;
reportLog(`[Seek] Debounce flushed immediately due to ${action.toUpperCase()}`, 'info');
reportEvent(EVENTS.SEEK);
}
}
const video = findVideo();
if (!video) return;
const current = getSyncCurrentTime(video);
if (current === null) return;
const eventState = action === EVENTS.PLAY ? 'playing' : (action === EVENTS.PAUSE ? 'paused' : (action === EVENTS.SEEK ? 'seek' : null));
// Echo-suppression for remotely-applied commands. MUST stay synchronous
// on event arrival: the suppress timer is short-lived (300ms) and would
// expire if deferred, leaking an echo back to peers.
if (_suppressTimers[eventState]) {
_clearSuppress(eventState);
return;
}
// Suppress only SEEK during visibility grace period (tab re-focus ghost jump).
// Play/Pause pass through — user may want to immediately pause after tabbing back.
if (Date.now() < visibilityGraceUntil && action === EVENTS.SEEK) return;
// Coalesce play/pause bursts (source swaps, ABR, ads, teardown). The
// synchronous gates above have already run; only the network emit is
// governed here. Leading edge sends the first event instantly; further
// events within the window are collapsed to the final state by the
// trailing flush. A pending burst is REPLACED, never dropped — the last
// event in the window always wins.
if (action === EVENTS.PLAY || action === EVENTS.PAUSE) {
if (playPauseCoalesceTimer === null) {
// Window closed → fresh action. Emit now (zero added latency).
sendContentEvent(action);
pendingPlayPauseAction = null;
} else {
// Window open → part of a burst. Defer to the trailing flush.
pendingPlayPauseAction = action;
clearTimeout(playPauseCoalesceTimer);
}
playPauseCoalesceTimer = setTimeout(flushPlayPause, PLAY_PAUSE_COALESCE_MS);
return;
}
// SEEK (and any non play/pause action): emit immediately.
sendContentEvent(action);
}
// --- Tab Visibility Handling ---
// Browsers (especially Firefox) aggressively throttle background tabs.
// When the user returns to a video tab, the video element may have lost
// time-sync and fires spurious seek events as it recovers (jumping back).
// We suppress only SEEK for a short grace period after tab re-focus.
// Play/Pause are NOT suppressed — the user may legitimately want to
// pause immediately after switching back.
let pageVisible = !document.hidden;
let visibilityGraceUntil = 0;
const VISIBILITY_GRACE_MS = 300;
document.addEventListener('visibilitychange', () => {
if (document.hidden) {
pageVisible = false;
} else if (!pageVisible) {
pageVisible = true;
visibilityGraceUntil = Date.now() + VISIBILITY_GRACE_MS;
reportLog(`Tab re-focused — suppressing seeks for ${VISIBILITY_GRACE_MS / 1000}s to prevent ghost relay`, 'warn');
}
});
// Reset on page hide/show (bfcache, tab discard)
window.addEventListener('pagehide', () => {
pageVisible = false;
closeAudioContext();
if (keepAlivePort) { try { keepAlivePort.disconnect(); } catch (_e) { /* ignore */ } keepAlivePort = null; }
if (lobbyPollTimer) { clearInterval(lobbyPollTimer); lobbyPollTimer = null; }
if (heartbeatTimeout) { clearTimeout(heartbeatTimeout); heartbeatTimeout = null; }
if (proactiveHeartbeatTimeout) { clearTimeout(proactiveHeartbeatTimeout); proactiveHeartbeatTimeout = null; }
// Drop any pending coalesced play/pause: we are tearing down and will
// disconnect — peers learn we are gone via PEER_STATUS 'left'. This also
// intentionally suppresses the teardown play/pause burst at the source.
if (playPauseCoalesceTimer) { clearTimeout(playPauseCoalesceTimer); playPauseCoalesceTimer = null; pendingPlayPauseAction = null; }
observer.disconnect();
});
window.addEventListener('pageshow', (event) => {
// event.persisted is true ONLY when restored from bfcache, not on initial load
if (event.persisted && !pageVisible) {
pageVisible = true;
visibilityGraceUntil = Date.now() + VISIBILITY_GRACE_MS;
reportLog(`Page restored from cache — suppressing seeks for ${VISIBILITY_GRACE_MS / 1000}s`, 'warn');
}
});
const handlePlay = () => reportEvent(EVENTS.PLAY);
const handlePause = () => reportEvent(EVENTS.PAUSE);
// Host Control Mode: a 'waiting' (buffering) event opens a grace window so the
// pause it may trigger isn't misread as a deliberate guest action (EC-1).
const handleWaiting = () => { hcmBufferingUntil = Date.now() + HCM_BUFFERING_GRACE_MS; };
// Seek filtering: ignore HLS/DASH buffering micro-seeks.
// Only relay if delta >= MIN_SEEK_DELTA AND not already debouncing.
const handleSeeked = () => {
const video = findVideo();
if (!video) return;
const current = getSyncCurrentTime(video);
if (current === null) return;
// Step 1: Check expectedSeekTime (programmatic seek from remote peer)
if (expectedSeekTime !== null) {
if (Math.abs(current - expectedSeekTime) < 1.0) {
// Video arrived at expected time. Safely clear and ignore.
expectedSeekTime = null;
lastReportedSeekTime = current;
return;
} else {
// User manually scrubbed to a DIFFERENT time while we were buffering
expectedSeekTime = null;
}
}
// Step 2: Suppress during visibility grace period (tab re-focus ghost events)
if (Date.now() < visibilityGraceUntil) return;
const delta = lastReportedSeekTime !== null ? Math.abs(current - lastReportedSeekTime) : null;
const deltaStr = delta !== null ? `Δ${delta.toFixed(2)}s` : 'Δ?';
// Step 3: Delta check — skip micro-seeks (buffering, chapter markers, etc.)
if (lastReportedSeekTime !== null && delta < MIN_SEEK_DELTA) {
reportLog(`[Seek] Filtered (${deltaStr} < ${MIN_SEEK_DELTA}s threshold) @ ${current.toFixed(2)}s — not relayed`, 'warn');
return;
}
// Step 4: Debounce rapid consecutive seeks (e.g. scrubbing)
// — wait 300ms for the user to settle before relaying
if (seekDebounceTimer) clearTimeout(seekDebounceTimer);
seekDebounceTimer = setTimeout(() => {
seekDebounceTimer = null;
const v = findVideo();
if (!v) return;
const settled = getSyncCurrentTime(v);
if (settled === null) return;
const finalDelta = lastReportedSeekTime !== null ? Math.abs(settled - lastReportedSeekTime) : null;
const finalDeltaStr = finalDelta !== null ? `Δ${finalDelta.toFixed(2)}s` : 'Δ?';
lastReportedSeekTime = settled;
reportLog(`[Seek] Relayed @ ${settled.toFixed(2)}s (${finalDeltaStr})`, 'info');
reportEvent(EVENTS.SEEK);
}, 300);
};
let lastVideoSrc = undefined;
// Episode detection handler for loadeddata event
const handleLoadedData = () => {
checkEpisodeTransition();
};
function setupListeners() {
const video = findVideo();
if (video) {
if (currentAudioVideo && currentAudioVideo !== video) {
bypassCurrentAudioProcessing();
}
const existing = video._koalaHandlers;
if (existing) {
video.removeEventListener('play', existing.play);
video.removeEventListener('pause', existing.pause);
video.removeEventListener('seeked', existing.seeked);
video.removeEventListener('loadeddata', existing.loadeddata);
if (existing.waiting) video.removeEventListener('waiting', existing.waiting);
}
video._koalaHandlers = { play: handlePlay, pause: handlePause, seeked: handleSeeked, loadeddata: handleLoadedData, waiting: handleWaiting };
video.addEventListener('play', handlePlay);
video.addEventListener('pause', handlePause);
video.addEventListener('seeked', handleSeeked);
video.addEventListener('loadeddata', handleLoadedData);
video.addEventListener('waiting', handleWaiting);
video.dataset.koalaAttached = 'true';
lastVideoSrc = video.currentSrc || video.src || null;
if (!lastKnownMediaTitle) {
lastKnownMediaTitle = getMediaTitle();
}
if (_audioSettings && _audioProcessingAllowed) applyAudioSettings(video, _audioSettings);
}
}
// SPA Navigation Handler (MutationObserver)
let lastMutate = 0;
let observerTimeout = null;
function checkVideo() {
lastMutate = Date.now();
const video = findVideo();
if (!video && lastVideoSrc !== undefined) {
reportLog('Video element removed from page', 'warn');
lastVideoSrc = undefined;
closeAudioContext();
return;
}
if (!video) return;
const currentSrc = video.currentSrc || video.src || null;
if (!video.dataset.koalaAttached || (lastVideoSrc !== undefined && currentSrc && lastVideoSrc !== currentSrc)) {
if (lastVideoSrc !== undefined && currentSrc && lastVideoSrc !== currentSrc) {
checkEpisodeTransition();
}
setupListeners();
}
}
const observer = new MutationObserver(() => {
const now = Date.now();
if (now - lastMutate >= 1000) {
checkVideo();
} else {
if (observerTimeout) clearTimeout(observerTimeout);
observerTimeout = setTimeout(checkVideo, 1000 - (now - lastMutate));
}
});
observer.observe(document.documentElement, { childList: true, subtree: true });
// --- SHARED_HEARTBEAT_INJECT_START ---
const HEARTBEAT_INTERVAL_VAL = 15000;
// --- SHARED_HEARTBEAT_INJECT_END ---
// Heartbeat Refactoring (Self-scheduling setTimeout with proactive heartbeat scheduling)
let heartbeatTimeout = null;
let proactiveHeartbeatTimeout = null;
let heartbeatErrorCount = 0;
function sendHeartbeat() {
const video = findVideo();
if (!video) return;
const mediaTitle = (navigator.mediaSession && navigator.mediaSession.metadata) ? navigator.mediaSession.metadata.title : null;
chrome.runtime.sendMessage({
type: 'HEARTBEAT',
payload: {
playbackState: video.paused ? 'paused' : 'playing',
currentTime: getSyncCurrentTime(video),
mediaTitle: mediaTitle,
volume: video.volume,
muted: video.muted
}
}).catch(err => {
if (err.message.includes('Extension context invalidated')) {
heartbeatErrorCount++;
if (heartbeatErrorCount === 1) {
reportLog('Extension reloaded. Please refresh the page if sync stops working.', 'warn');
}
if (heartbeatTimeout) clearTimeout(heartbeatTimeout);
if (proactiveHeartbeatTimeout) clearTimeout(proactiveHeartbeatTimeout);
observer.disconnect();
}
});
}
function schedulePeriodicHeartbeat() {
if (heartbeatTimeout) clearTimeout(heartbeatTimeout);
heartbeatTimeout = setTimeout(() => {
sendHeartbeat();
schedulePeriodicHeartbeat();
}, HEARTBEAT_INTERVAL_VAL);
}
function scheduleProactiveHeartbeat() {
if (proactiveHeartbeatTimeout) clearTimeout(proactiveHeartbeatTimeout);
proactiveHeartbeatTimeout = setTimeout(() => {
sendHeartbeat();
schedulePeriodicHeartbeat(); // Reschedules the next periodic check to be exactly 15s from now
}, 500); // 500ms stabilization delay
}
// Initial Setup
setupListeners();
// Maintain a persistent keep-alive port connection to prevent background SW suspension
let keepAlivePort = null;
function connectKeepAlivePort() {
try {
if (chrome.runtime.id) {
keepAlivePort = chrome.runtime.connect({ name: 'keepAlive' });
keepAlivePort.onDisconnect.addListener(() => {
keepAlivePort = null;
setTimeout(connectKeepAlivePort, 1000);
});
}
} catch (_e) {
// Extension context invalidated or disabled
}
}
connectKeepAlivePort();
schedulePeriodicHeartbeat();
// Immediate heartbeat on injection — populate peer data without waiting 15s
setTimeout(() => sendHeartbeat(), 300);
// Episode Auto-Sync: Boot recovery — check if background has an active lobby
chrome.runtime.sendMessage({ type: 'CONTENT_BOOT' }, (res) => {
if (chrome.runtime.lastError) return;
if (res && res.lobbyActive && res.expectedTitle) {
reportLog(`Boot: Active lobby detected for "${res.expectedTitle}"`, 'info');
startLobbyPoll(res.expectedTitle);
}
});
// Host Control Mode: fetch current room mode/role on injection (we may have
// been injected after ROOM_DATA already arrived, missing the broadcast).
chrome.runtime.sendMessage({ type: 'GET_CONTROL_MODE' }, (res) => {
if (chrome.runtime.lastError || !res) return;
hcmControlMode = res.controlMode || 'everyone';
hcmAmController = !!res.amController;
hcmHostPeerId = res.hostPeerId || null;
// Re-adopt persisted desync after a page reload so we don't start synced
// while background still relays us as "Solo" to the host (split-brain).
// Only when we're actually a gated guest — never adopt a stale flag as a
// controller or in 'everyone' mode (would self-label "Solo" / ignore commands).
if (res.desynced && res.controlMode === 'host-only' && !res.amController && !hcmDesynced) {
hcmDesynced = true;
hcmShowBadge();
}
});
// Pull localized strings for the in-page dialog/badge (English fallback above).
chrome.runtime.sendMessage({ type: 'GET_HCM_STRINGS' }, (res) => {
if (chrome.runtime.lastError || !res) return;
Object.keys(hcmStrings).forEach(k => { if (res[k]) hcmStrings[k] = res[k]; });
// If the badge is already showing (early desync), refresh its text in place.
// Re-creating the host element nukes the click target mid-poll and can drop a
// click that landed between remove() and the re-create (L-4).
if (hcmBadgeHost) {
const span = hcmBadgeHost.shadowRoot && hcmBadgeHost.shadowRoot.querySelector('span');
if (span) span.textContent = '● ' + hcmStrings.badge;
}
});
})();