import { streamUrl, getPlaybackOptions, auth } from '../embyApi.js';
import { getParty, leaveParty, connectParty } from '../party.js';
import { navigate } from '../router.js';
import { escapeHtml, colorForName, initialsFor } from '../tiles.js';
import { renderMusicPlayer } from './musicPlayer.js';

const TICKS_PER_SECOND = 10000000; // Emby/.NET convention: 1 tick = 100ns
const DRIFT_TOLERANCE_SECONDS = 1.5;
const PAUSE_REQUEST_COOLDOWN_MS = 5000; // matches the server's own throttle in socketHandler.js
const PAUSE_REQUEST_HIGHLIGHT_MS = 4000; // how long the banner + the orange badge stay up

// "Quality" is really "max transcoding bitrate", the same simplification
// Emby's/Jellyfin's own web clients use - not true adaptive-bitrate
// switching. See docs/architecture.md.
const QUALITY_PRESETS = [
  { label: 'Auto (qualité source)', value: '' },
  { label: '1080p (~8 Mbps)', value: '8000000' },
  { label: '720p (~4 Mbps)', value: '4000000' },
  { label: '480p (~1.5 Mbps)', value: '1500000' }
];

// Plain inline SVG rather than a Unicode glyph (unlike the settings gear)
// specifically so this small a badge stays a crisp two-bar shape regardless
// of the platform's emoji font - pause/play glyphs default to emoji
// presentation on several platforms, which looks muddy at 10px.
const PAUSE_ICON_SVG = `
  <svg viewBox="0 0 10 10" width="10" height="10" aria-hidden="true">
    <rect x="1.5" y="1" width="2.4" height="8" fill="#fff"></rect>
    <rect x="6.1" y="1" width="2.4" height="8" fill="#fff"></rect>
  </svg>`;

/**
 * Route `/party/:id` - dispatches on the party's mediaType, fetched here
 * once, since both renderVideoPlayer and renderMusicPlayer need to know it
 * before they can render anything at all.
 *
 * Has to return its cleanup function *synchronously* (route()'s contract -
 * see router.js), but which cleanup function that even is depends on a
 * fetch that hasn't resolved yet at the time this returns. Solved with a
 * mutable box: an outer cleanup wrapper is handed back immediately, and it
 * calls whatever the real cleanup turns out to be once the fetch settles -
 * or nothing at all, correctly, if the fetch is still pending or failed
 * when it runs (nothing was ever set up in that case - no socket, no
 * timer, nothing to leak).
 */
export function renderPartyPlayer(root, params) {
  const partyId = params.id;
  root.innerHTML = '<p class="hint">Chargement...</p>';

  let cleanup = () => {};
  let cancelled = false;

  getParty(partyId).then((party) => {
    if (cancelled) return;
    cleanup = (party.mediaType === 'music' ? renderMusicPlayer : renderVideoPlayer)(root, partyId, party) || (() => {});
  }).catch((err) => {
    if (cancelled) return;
    // Full error (not just .message) to the console - this also catches a
    // rendering bug in renderVideoPlayer/renderMusicPlayer itself, not just
    // a genuine "party not found", so the stack trace matters here.
    console.error('[watchparty player] failed to open party', err);
    alert(err.message);
    navigate('/home');
  });

  return function outerCleanup() {
    cancelled = true;
    cleanup();
  };
}

/**
 * Renders the video half of a party - called by the dispatcher above once
 * it already knows (from a fetched `party`) that mediaType isn't 'music'.
 * Takes the already-fetched party instead of fetching it itself: the
 * dispatcher needs to fetch it anyway just to read mediaType, and
 * route()'s contract needs its cleanup function back *synchronously* (see
 * router.js) - an async renderVideoPlayer awaiting its own fetch would
 * return a Promise instead, which router.js's `typeof cleanup ===
 * 'function'` check would silently skip, reintroducing the exact leak
 * class this app already spent real effort fixing once.
 */
function renderVideoPlayer(root, partyId, party) {
  root.innerHTML = `
    <div class="playerWrap">
      <video id="video" playsinline></video>

      <p id="loadingNotice" class="loadingNotice">Chargement du flux...</p>
      <div id="playerError" class="playerError hide">
        <p id="playerErrorText"></p>
        <button id="playerErrorRetry" class="linklike">Réessayer</button>
      </div>

      <div id="pauseRequestBanner" class="pauseRequestBanner hide"></div>

      <div class="topOverlay">
        <div class="actionBar">
          <span id="itemTitle" class="itemTitle"></span>
          <span id="members" class="members"></span>
          <button id="nextBtn" class="linklike hide">Épisode suivant &rarr;</button>

          <div id="settingsWrap" class="settingsWrap hide">
            <button id="settingsBtn" class="iconBtn" title="Paramètres de lecture" aria-label="Paramètres de lecture">&#9881;</button>
            <div id="settingsPanel" class="settingsPanel hide">
              <label>Langue <select id="audioSelect"></select></label>
              <label>Sous-titres <select id="subtitleSelect"><option value="">Aucun</option></select></label>
              <label>Qualité <select id="qualitySelect"></select></label>
            </div>
          </div>

          <button id="leaveBtn" class="linklike">Quitter</button>
        </div>

        <div id="presenceOverlay" class="presenceOverlay"></div>
      </div>

      <p id="followerNotice" class="followerNotice hide">L'hôte contrôle la lecture.</p>
    </div>`;

  const video = root.querySelector('#video');
  const loadingNotice = root.querySelector('#loadingNotice');
  const errorBox = root.querySelector('#playerError');
  const errorText = root.querySelector('#playerErrorText');
  const itemTitleEl = root.querySelector('#itemTitle');
  const membersEl = root.querySelector('#members');
  const presenceOverlay = root.querySelector('#presenceOverlay');
  const pauseBanner = root.querySelector('#pauseRequestBanner');
  const nextBtn = root.querySelector('#nextBtn');
  const followerNotice = root.querySelector('#followerNotice');
  const settingsWrap = root.querySelector('#settingsWrap');
  const settingsBtn = root.querySelector('#settingsBtn');
  const settingsPanel = root.querySelector('#settingsPanel');
  const audioSelect = root.querySelector('#audioSelect');
  const subtitleSelect = root.querySelector('#subtitleSelect');
  const qualitySelect = root.querySelector('#qualitySelect');

  qualitySelect.innerHTML = QUALITY_PRESETS.map((q) => `<option value="${q.value}">${q.label}</option>`).join('');

  // Named (not inline-anonymous) specifically so cleanup() below can remove
  // this exact listener - document.addEventListener is a page-lifetime
  // target, so an anonymous one added on every visit to this route would
  // never be reachable to remove, and would pile up across visits. This was
  // the actual leak: every join-a-party-then-navigate-away-without-"Quitter"
  // used to leave one of these (plus the heartbeat interval, the socket,
  // and the hls.js instance) running forever - see router.js's cleanup hook.
  function onDocumentClick(e) {
    if (!settingsWrap.contains(e.target)) settingsPanel.classList.add('hide');
  }
  document.addEventListener('click', onDocumentClick);

  settingsBtn.addEventListener('click', (e) => {
    e.stopPropagation();
    settingsPanel.classList.toggle('hide');
  });

  let isHost = false;
  let hasNextQueued = false;
  let conn = null;
  let hls = null;
  let currentItemId = null;
  let suppressLocalEvents = false; // avoid feeding our own correction back as a new event
  let heartbeat = null;
  let pauseRequestCooldownUntil = 0;
  let pauseBannerTimer = null;

  function showError(message, detail) {
    loadingNotice.classList.add('hide');
    errorText.textContent = message;
    errorBox.classList.remove('hide');
    console.error('[watchparty player]', message, detail || '');
  }

  function clearError() {
    errorBox.classList.add('hide');
  }

  function applyRemoteState(msg) {
    suppressLocalEvents = true;
    const targetSeconds = msg.positionTicks / TICKS_PER_SECOND;
    if (Math.abs(video.currentTime - targetSeconds) > DRIFT_TOLERANCE_SECONDS) {
      video.currentTime = targetSeconds;
    }
    if (msg.isPaused && !video.paused) video.pause();
    if (!msg.isPaused && video.paused) video.play().catch(() => {});
    setTimeout(() => { suppressLocalEvents = false; }, 250);
  }

  function sendLocalState() {
    if (!isHost || suppressLocalEvents || !conn) return;
    conn.sendPlaystate(video.paused, Math.round(video.currentTime * TICKS_PER_SECOND));
  }

  /**
   * Promotes this client to host - called either at init (if we already
   * were) or on a live "hostChanged" event (the previous host left and the
   * server picked us next - see socketHandler.js's applyLeave). Safe to
   * call more than once: the early return covers the normal case, and
   * addEventListener with the same function reference is a no-op if already
   * attached, so even a re-entrant call can't double up the play/pause/
   * seeked listeners. The heartbeat is guarded separately since setInterval
   * has no such built-in idempotence - calling it twice would leak the
   * first interval's id.
   */
  function becomeHost(notify) {
    if (isHost) return;
    isHost = true;
    video.controls = true;
    settingsWrap.classList.remove('hide');
    followerNotice.classList.add('hide');
    nextBtn.classList.toggle('hide', !hasNextQueued);

    video.addEventListener('play', sendLocalState);
    video.addEventListener('pause', sendLocalState);
    video.addEventListener('seeked', sendLocalState);
    video.addEventListener('ended', () => { if (hasNextQueued) conn.next(); });
    if (!heartbeat) heartbeat = setInterval(sendLocalState, 3000);

    if (notify) alert("L'hôte précédent a quitté la party - tu es maintenant l'hôte.");
  }

  async function loadTrackOptions(itemId) {
    try {
      const options = await getPlaybackOptions(itemId);
      audioSelect.innerHTML = options.audioTracks.length
        ? options.audioTracks.map((t) => `<option value="${t.index}">${escapeHtml(t.label)}</option>`).join('')
        : '<option value="">Piste par défaut</option>';
      subtitleSelect.innerHTML = '<option value="">Aucun</option>' +
        options.subtitleTracks.map((t) => `<option value="${t.index}">${escapeHtml(t.label)}</option>`).join('');
    } catch (err) {
      console.error('[watchparty player] playback-options failed', err);
      // Non-fatal: playback can still work with Emby's own defaults, just without a picker.
    }
  }

  function loadVideo(itemId, resumeSeconds, wasPlaying) {
    currentItemId = itemId;
    clearError();
    loadingNotice.classList.remove('hide');

    if (hls) {
      hls.destroy();
      hls = null;
    }

    const src = streamUrl(itemId, {
      AudioStreamIndex: audioSelect.value,
      SubtitleStreamIndex: subtitleSelect.value,
      MaxStreamingBitrate: qualitySelect.value
    });

    const resume = () => {
      loadingNotice.classList.add('hide');
      if (resumeSeconds) video.currentTime = resumeSeconds;
      if (wasPlaying) video.play().catch(() => {});
    };

    if (window.Hls && window.Hls.isSupported()) {
      hls = new window.Hls();
      hls.on(window.Hls.Events.MANIFEST_PARSED, resume);
      hls.on(window.Hls.Events.ERROR, (event, data) => {
        if (!data.fatal) return;
        showError(
          "Erreur de lecture (HLS) - le flux n'a pas pu être chargé depuis Emby.",
          data
        );
      });
      hls.loadSource(src);
      hls.attachMedia(video);
    } else if (video.canPlayType('application/vnd.apple.mpegurl')) {
      // Safari plays HLS natively - no hls.js involved, so wire the plain
      // <video> element's own error event instead.
      video.src = src;
      video.addEventListener('loadedmetadata', resume, { once: true });
      video.addEventListener('error', () => {
        showError('Erreur de lecture vidéo.', video.error);
      });
    } else {
      showError("Ce navigateur ne sait pas lire de flux HLS et hls.js n'a pas pu se charger.");
    }
  }

  // Changing language/subtitles/quality means a fresh transcode (Emby bakes
  // the selection in server-side - see index.js) - reload at the same
  // position instead of restarting from zero.
  function reloadWithCurrentOptions() {
    loadVideo(currentItemId, video.currentTime, !video.paused);
  }

  [audioSelect, subtitleSelect, qualitySelect].forEach((sel) => {
    sel.addEventListener('change', () => {
      settingsPanel.classList.add('hide');
      reloadWithCurrentOptions();
    });
  });

  root.querySelector('#playerErrorRetry').addEventListener('click', () => {
    if (currentItemId) loadVideo(currentItemId, video.currentTime, true);
  });

  async function onItemChanged(msg) {
    itemTitleEl.textContent = msg.itemName || '';
    hasNextQueued = !!msg.hasNext;
    nextBtn.classList.toggle('hide', !(isHost && hasNextQueued));
    await loadTrackOptions(msg.itemId);
    loadVideo(msg.itemId, 0, true);
  }

  // Presence overlay: one semi-transparent circle per member, initials only
  // (no photos - Emby accounts don't reliably have one). Your own circle
  // doubles as the "request a pause" button when you're not the host - the
  // host already has direct controls, so their own circle is just presence.
  // The pause-badge <span> is always in the markup, just hidden by
  // .avatarPauseRequested's CSS - see onPauseRequested(), which is the only
  // thing that ever shows it.
  function renderMembers(members) {
    membersEl.textContent = members
      .map((m) => m.userName + (m.isHost ? ' (hôte)' : ''))
      .join(', ');

    presenceOverlay.innerHTML = members.map((m) => {
      const isMe = m.userName === auth.userName;
      const clickable = isMe && !m.isHost;
      return `
        <div
          class="avatar${clickable ? ' avatarClickable' : ''}"
          style="background:${colorForName(m.userName)}"
          data-user-id="${escapeHtml(m.userId)}"
          title="${escapeHtml(m.userName)}${clickable ? ' - demander une pause' : ''}"
        >${escapeHtml(initialsFor(m.userName))}<span class="avatarPauseBadge">${PAUSE_ICON_SVG}</span></div>`;
    }).join('');

    if (isHost) return; // the host pauses directly, no need for the request affordance
    const mine = presenceOverlay.querySelector('.avatarClickable');
    if (mine) {
      mine.addEventListener('click', () => {
        const now = Date.now();
        if (now < pauseRequestCooldownUntil || !conn) return;
        pauseRequestCooldownUntil = now + PAUSE_REQUEST_COOLDOWN_MS;
        conn.requestPause();
      });
    }
  }

  // Broadcast to everyone in the party, including the requester and the
  // host (see socketHandler.js) - so this always flags the right circle no
  // matter whose screen it renders on.
  function onPauseRequested(msg) {
    pauseBanner.textContent = `${msg.userName} demande une pause`;
    pauseBanner.classList.remove('hide');
    if (pauseBannerTimer) clearTimeout(pauseBannerTimer);
    pauseBannerTimer = setTimeout(() => pauseBanner.classList.add('hide'), PAUSE_REQUEST_HIGHLIGHT_MS);

    const avatar = presenceOverlay.querySelector(`.avatar[data-user-id="${CSS.escape(msg.userId)}"]`);
    if (avatar) {
      avatar.classList.add('avatarPauseRequested');
      setTimeout(() => avatar.classList.remove('avatarPauseRequested'), PAUSE_REQUEST_HIGHLIGHT_MS);
    }
  }

  async function init() {
    itemTitleEl.textContent = party.itemName || '';
    hasNextQueued = !!party.hasNext;
    followerNotice.classList.toggle('hide', party.youAreHost);

    await loadTrackOptions(party.itemId);
    loadVideo(party.itemId, 0, false);

    conn = connectParty(partyId, {
      onMembers: renderMembers,
      onPlaystate: applyRemoteState,
      onItemChanged,
      onHostChanged: () => becomeHost(true),
      onPauseRequested,
      onError: (message) => alert(message),
      onClose: () => {}
    });

    if (party.youAreHost) becomeHost(false);
  }

  nextBtn.addEventListener('click', () => { if (conn) conn.next(); });
  root.querySelector('#leaveBtn').addEventListener('click', () => navigate('/home'));

  init();

  // Called by router.js right before it renders whatever route comes next -
  // whether that's from clicking "Quitter" (navigate above) or leaving any
  // other way (sidebar link, browser back, ...). This is the fix for the
  // actual leak: previously, only the "Quitter" button ran any of this.
  return function cleanup() {
    if (heartbeat) clearInterval(heartbeat);
    if (pauseBannerTimer) clearTimeout(pauseBannerTimer);
    if (hls) hls.destroy();
    document.removeEventListener('click', onDocumentClick);
    if (conn) conn.leave();
    leaveParty(partyId).catch(() => {});
  };
}