(function () {
  const audio = document.getElementById('player-audio');
  const titleEl = document.getElementById('player-title');
  const artistEl = document.getElementById('player-artist');
  const coverEl = document.getElementById('player-cover');
  const queueInfoEl = document.getElementById('player-queue-info');
  const nextBtn = document.getElementById('player-next');
  const repeatBtn = document.getElementById('player-repeat');
  const playerLikeBtn = document.getElementById('player-like');
  const playerFavBtn  = document.getElementById('player-favorite');
  let repeatOn = false;

  function updatePlayerSocial(song) {
    if (!playerLikeBtn || !playerFavBtn) return;
    const active = !!song;
    playerLikeBtn.disabled = playerFavBtn.disabled = !active;
    playerLikeBtn.dataset.socialId = playerFavBtn.dataset.socialId = active ? song.id : '';
    playerLikeBtn.classList.toggle('active', active && !!song.userLiked);
    playerLikeBtn.setAttribute('aria-pressed', String(active && !!song.userLiked));
    playerFavBtn.classList.toggle('active', active && !!song.userFavorited);
    playerFavBtn.setAttribute('aria-pressed', String(active && !!song.userFavorited));
    const lc = playerLikeBtn.querySelector('.social-count');
    const fc = playerFavBtn.querySelector('.social-count');
    if (lc) lc.textContent = active ? (song.likeCount ?? 0) : 0;
    if (fc) fc.textContent = active ? (song.favoriteCount ?? 0) : 0;
  }

  const state = {
    queue: [],      // array of {id, title, artist, cover}
    index: -1,
  };

  function render() {
    const cur = state.queue[state.index];
    if (!cur) {
      titleEl.textContent = 'Nothing playing';
      artistEl.textContent = '';
      coverEl.src = '/static/vendor/cover-placeholder.svg';
      queueInfoEl.textContent = '';
      updatePlayerSocial(null);
      return;
    }
    titleEl.textContent = cur.title;
    artistEl.textContent = cur.artist || '';
    coverEl.src = cur.cover || '/static/vendor/cover-placeholder.svg';
    queueInfoEl.textContent = state.queue.length > 1
      ? `${state.index + 1} / ${state.queue.length}`
      : '';
    updatePlayerSocial(cur);
  }

  function highlightNowPlaying(id) {
    document.querySelectorAll('.song-row').forEach(row => {
      row.classList.toggle('now-playing', String(row.dataset.songId) === String(id));
    });
  }

  function highlightPlaylistCards() {
    const id = window.briTunesActivePlaylistId;
    document.querySelectorAll('[data-playlist-id]').forEach(el => {
      el.classList.toggle('playlist-active', !!id && String(el.dataset.playlistId) === String(id));
    });
  }

  function updateMediaSession() {
    if (!('mediaSession' in navigator)) return;
    const cur = state.queue[state.index];
    if (!cur) return;
    navigator.mediaSession.metadata = new MediaMetadata({
      title:  cur.title,
      artist: cur.artist || '',
      artwork: cur.cover
        ? [{ src: new URL(cur.cover, window.location.origin).href, sizes: '512x512', type: 'image/jpeg' }]
        : [],
    });
  }

  function playCurrent() {
    const cur = state.queue[state.index];
    if (!cur) return;
    window.briTunesNowPlaying = cur;
    audio.src = `/stream/${cur.id}`;
    audio.play()
      .then(() => window.dispatchEvent(new CustomEvent('briTunes:play', { detail: cur })))
      .catch((err) => console.warn('play failed', err));
    render();
    highlightNowPlaying(cur.id);
    updateMediaSession();
  }

  function playOne(song) {
    state.queue = [song];
    state.index = 0;
    playCurrent();
  }

  function playList(list) {
    if (!Array.isArray(list) || list.length === 0) return;
    state.queue = list;
    state.index = 0;
    window.dispatchEvent(new CustomEvent('briTunes:queue', { detail: { queue: list.slice() } }));
    playCurrent();
  }

  function next() {
    if (state.index + 1 < state.queue.length) {
      state.index += 1;
      playCurrent();
    } else if (repeatOn && state.queue.length > 0) {
      state.index = 0;
      playCurrent();
    }
  }

  function prev() {
    if (state.index > 0) { state.index -= 1; playCurrent(); }
  }

  audio.addEventListener('ended', next);
  audio.addEventListener('play',  () => { if ('mediaSession' in navigator) navigator.mediaSession.playbackState = 'playing'; });
  audio.addEventListener('pause', () => { if ('mediaSession' in navigator) navigator.mediaSession.playbackState = 'paused'; });
  nextBtn.addEventListener('click', next);

  if ('mediaSession' in navigator) {
    navigator.mediaSession.setActionHandler('play',          () => audio.play());
    navigator.mediaSession.setActionHandler('pause',         () => audio.pause());
    navigator.mediaSession.setActionHandler('nexttrack',     () => next());
    navigator.mediaSession.setActionHandler('previoustrack', () => prev());
    navigator.mediaSession.setActionHandler('seekto',        (d) => { audio.currentTime = d.seekTime; });
    navigator.mediaSession.setActionHandler('seekbackward',  (d) => { audio.currentTime = Math.max(0, audio.currentTime - (d.seekOffset || 10)); });
    navigator.mediaSession.setActionHandler('seekforward',   (d) => { audio.currentTime = Math.min(audio.duration || Infinity, audio.currentTime + (d.seekOffset || 10)); });
  }

  repeatBtn.addEventListener('click', () => {
    repeatOn = !repeatOn;
    repeatBtn.classList.toggle('active', repeatOn);
    repeatBtn.setAttribute('aria-pressed', repeatOn);
  });
  window.addEventListener('briTunes:jumpto', (e) => {
    const id = e.detail && e.detail.id;
    if (!id) return;
    const idx = state.queue.findIndex(s => String(s.id) === String(id));
    if (idx === -1) return;
    state.index = idx;
    playCurrent();
  });

  window.addEventListener('briTunes:navigate', () => {
    if (window.briTunesNowPlaying) highlightNowPlaying(window.briTunesNowPlaying.id);
    highlightPlaylistCards();
  });

  // Delegated click handler for any [data-play-song] / [data-play-playlist] button.
  document.addEventListener('click', (e) => {
    const songBtn = e.target.closest('[data-play-song]');
    if (songBtn) {
      window.briTunesActivePlaylistId = null;
      highlightPlaylistCards();
      try {
        const song = JSON.parse(songBtn.getAttribute('data-play-song'));
        playOne(song);
      } catch (err) { console.error(err); }
      return;
    }
    const listBtn = e.target.closest('[data-play-playlist]');
    if (listBtn) {
      window.briTunesActivePlaylistId = listBtn.dataset.playlistId || null;
      highlightPlaylistCards();
      try {
        const list = JSON.parse(listBtn.getAttribute('data-play-playlist'));
        playList(list);
      } catch (err) { console.error(err); }
      return;
    }
    const shuffleBtn = e.target.closest('[data-shuffle-playlist]');
    if (shuffleBtn) {
      window.briTunesActivePlaylistId = shuffleBtn.dataset.playlistId || null;
      highlightPlaylistCards();
      try {
        const list = JSON.parse(shuffleBtn.getAttribute('data-shuffle-playlist'));
        for (let i = list.length - 1; i > 0; i--) {
          const j = Math.floor(Math.random() * (i + 1));
          [list[i], list[j]] = [list[j], list[i]];
        }
        playList(list);
      } catch (err) { console.error(err); }
    }
  });

  render();
})();