/**
 * diora — radio player
 * Handles playback, SSE metadata, search, station management, and affiliate links.
 */

'use strict';

// ---------------------------------------------------------------------------
// State
// ---------------------------------------------------------------------------

let currentStation = null;   // { url, name, id } | null
let currentTrack = '';
let sseSource = null;
let isPlaying = false;
let currentPlayId = null;

// Podcast state
let podcastMode = false;
let currentEpisode = null;   // {id, title, audioUrl, durationSeconds, feedId}
let seekSaveTimer = null;
let podcastFeeds = [];
let podcastQueue = [];
let podcastCurrentView = 'feeds';
let podcastCurrentFeedId = null;
const podcastEpCache = {};   // id → episode data, avoids encoding strings in onclick attrs

const audio = new Audio();

// ---------------------------------------------------------------------------
// DOM helpers
// ---------------------------------------------------------------------------

function $(id) { return document.getElementById(id); }

function getCsrfToken() {
  const cookie = document.cookie.split('; ').find(r => r.startsWith('csrftoken='));
  return cookie ? cookie.split('=')[1] : '';
}

function formatDateTime(iso) {
  if (!iso) return '';
  const d = new Date(iso);
  const pad = n => String(n).padStart(2, '0');
  return `${d.getFullYear()}-${pad(d.getMonth()+1)}-${pad(d.getDate())} `
       + `${pad(d.getHours())}:${pad(d.getMinutes())}`;
}

function escapeHtml(str) {
  return String(str)
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

// ---------------------------------------------------------------------------
// Play / Stop
// ---------------------------------------------------------------------------

function playStation(url, name, stationId) {
  stopPlayback(false);

  currentStation = { url, name, id: stationId || null };
  isPlaying = true;

  audio.src = url;
  const volSlider = document.getElementById('volume');
  if (volSlider) audio.volume = volSlider.value / 255;
  audio.play().catch(() => {
    // Browser may block autoplay; the user needs to interact first
    console.warn('Audio play blocked by browser policy.');
  });

  $('now-playing-station').textContent = name;
  $('now-playing-track').textContent = '';
  $('play-stop-btn').style.display = '';
  $('play-stop-btn').textContent = '⏹ Stop';
  $('play-stop-btn').classList.add('playing');
  $('save-station-btn').style.display = '';

  startMetadataSSE(url);
  startPlaySession(name, url);
  maybeShowDonationHint(url, name);
}

function stopPlayback(clearStation = true) {
  // Save podcast progress before stopping
  if (podcastMode && currentEpisode) {
    savePodcastProgress();
  }
  if (seekSaveTimer) { clearInterval(seekSaveTimer); seekSaveTimer = null; }

  audio.pause();
  audio.src = '';
  audio.ontimeupdate = null;
  isPlaying = false;
  podcastMode = false;

  const seekBar = $('podcast-seek-bar');
  if (seekBar) seekBar.style.display = 'none';

  if (sseSource) {
    sseSource.close();
    sseSource = null;
  }

  $('play-stop-btn').textContent = '▶ Play';
  $('play-stop-btn').classList.remove('playing');
  $('save-station-btn').style.display = 'none';
  $('affiliate-section').style.display = 'none';

  stopPlaySession();

  const stationEl = $('now-playing-station');
  stationEl.classList.remove('podcast-station-link');
  stationEl.onclick = null;

  const trackEl = $('now-playing-track');
  trackEl.classList.remove('podcast-track-link');
  trackEl.onclick = null;

  if (clearStation) {
    currentStation = null;
    currentTrack = '';
    stationEl.textContent = '— no station —';
    trackEl.textContent = '';
    $('play-stop-btn').style.display = 'none';
  }
}

function togglePlayStop() {
  if (isPlaying) {
    stopPlayback(true);
  } else if (currentStation) {
    playStation(currentStation.url, currentStation.name, currentStation.id);
  }
}

// ---------------------------------------------------------------------------
// Play session tracking
// ---------------------------------------------------------------------------

async function startPlaySession(stationName, stationUrl) {
  try {
    const res = await fetch('/radio/play/start/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({station_name: stationName, station_url: stationUrl})
    });
    if (res.ok) {
      const data = await res.json();
      currentPlayId = data.play_id;
    }
  } catch (e) {}
}

async function stopPlaySession() {
  if (!currentPlayId) return;
  try {
    await fetch('/radio/play/stop/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({play_id: currentPlayId})
    });
  } catch (e) {}
  currentPlayId = null;
}

window.addEventListener('beforeunload', () => {
  if (currentPlayId) {
    navigator.sendBeacon('/radio/play/stop/', JSON.stringify({play_id: currentPlayId}));
  }
  if (podcastMode && currentEpisode) {
    navigator.sendBeacon('/podcasts/progress/save/', JSON.stringify({
      episode_id: currentEpisode.id,
      position_seconds: Math.floor(audio.currentTime),
    }));
  }
  // Flush cached encrypted payloads for reader data (encryption is async so we
  // use pre-computed blobs stored by the debounced savers)
  if (_lastProgressBeacon) navigator.sendBeacon(_lastProgressBeacon.url, _lastProgressBeacon.body);
  if (_lastBookmarkBeacon) navigator.sendBeacon(_lastBookmarkBeacon.url, _lastBookmarkBeacon.body);
  if (_lastHighlightBeacon) navigator.sendBeacon(_lastHighlightBeacon.url, _lastHighlightBeacon.body);
});

document.addEventListener('visibilitychange', () => {
  if (document.visibilityState === 'hidden' && currentBookId) {
    if (bookmarksDirty) saveBookmarks();
    if (highlightsDirty) saveHighlights();
    saveReaderProgress();
  }
});

// Cached beacon payloads — updated after each successful encrypt in save functions
let _lastBookmarkBeacon = null;
let _lastHighlightBeacon = null;
let _lastProgressBeacon = null;

// ---------------------------------------------------------------------------
// Recommendations
// ---------------------------------------------------------------------------

async function loadRecommendations() {
  const container = document.getElementById('recommendations');
  if (!container) return;
  try {
    const res = await fetch('/radio/recommendations/');
    const data = await res.json();
    if (!data.recommendations.length) {
      container.innerHTML = '<p class="muted">Play more stations to get recommendations.</p>';
      return;
    }
    const label = data.context;
    let html = `<p class="recommendations-context">Based on your ${label} listening:</p><ul class="recommendations-list">`;
    for (const r of data.recommendations) {
      html += `<li>
          <button class="btn btn-sm" onclick="playStation('${escapeAttr(r.station_url)}', '${escapeAttr(r.station_name)}', ${r.saved_id || 'null'})">
              &#9654; ${escapeHtml(r.station_name)}
          </button>
          <span class="muted">${r.play_count}&times;</span>
      </li>`;
    }
    html += '</ul>';
    container.innerHTML = html;
  } catch (e) {}
}

function escapeAttr(s) {
  return String(s).replace(/'/g, "\\'").replace(/"/g, '&quot;');
}

// ---------------------------------------------------------------------------
// Volume
// ---------------------------------------------------------------------------

function setVolume(val) {
  val = Math.max(0, Math.min(255, Math.round(val)));
  audio.volume = val / 255;
  localStorage.setItem('diora_volume', val);
  const slider = $('volume');
  const numInput = $('volume-num');
  if (slider) slider.value = val;
  if (numInput) numInput.value = val;
}

const volSliderEl = document.getElementById('volume');
if (volSliderEl) {
  ['input', 'change', 'mousemove', 'touchmove'].forEach(evt =>
    volSliderEl.addEventListener(evt, function () { setVolume(this.value); })
  );
}

const volNumEl = document.getElementById('volume-num');
if (volNumEl) {
  volNumEl.addEventListener('change', function () { setVolume(this.value); });
  volNumEl.addEventListener('input', function () { setVolume(this.value); });
  volNumEl.addEventListener('click', function () { this.select(); });
}

const volSliderEl2 = document.getElementById('volume');
const volWheelTarget = volSliderEl2 || volNumEl;
if (volWheelTarget) {
  volWheelTarget.addEventListener('wheel', function (e) {
    e.preventDefault();
    const current = parseInt(document.getElementById('volume').value, 10);
    setVolume(current + (e.deltaY < 0 ? 4 : -4));
  }, { passive: false });
}

// ---------------------------------------------------------------------------
// SSE metadata
// ---------------------------------------------------------------------------

function startMetadataSSE(streamUrl) {
  if (sseSource) { sseSource.close(); sseSource = null; }

  const endpoint = '/radio/sse/?url=' + encodeURIComponent(streamUrl);
  sseSource = new EventSource(endpoint);

  sseSource.onmessage = function (e) {
    let data;
    try { data = JSON.parse(e.data); } catch (_) { return; }

    if (data.error) {
      console.warn('SSE stream ended:', data.error);
      return;
    }

    if (data.track && data.track !== currentTrack) {
      currentTrack = data.track;
      updateNowPlayingUI(data.track);
      recordTrack(currentStation ? currentStation.name : '', data.track);
      fetchAffiliateLinks(data.track);
    }
  };

  sseSource.onerror = function () {
    // Connection dropped; the browser will attempt to reconnect automatically
    console.warn('SSE connection error, browser will retry.');
  };
}

function updateNowPlayingUI(track) {
  $('now-playing-track').textContent = track;
}

// ---------------------------------------------------------------------------
// Record track
// ---------------------------------------------------------------------------

async function recordTrack(stationName, track) {
  try {
    const res = await fetch('/radio/record/', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'X-CSRFToken': getCsrfToken(),
      },
      body: JSON.stringify({ station_name: stationName, track, scrobble: true }),
    });
    if (res.ok) {
      addHistoryRow(stationName, track);
    }
  } catch (err) {
    console.error('recordTrack error:', err);
  }
}

function addHistoryRow(stationName, track) {
  const tbody = $('history-tbody');
  if (!tbody) return;

  // Remove the "no history" placeholder row if present
  const emptyRow = $('history-empty-row');
  if (emptyRow) emptyRow.remove();

  const tr = document.createElement('tr');
  const now = new Date().toISOString();
  tr.innerHTML = `
    <td class="history-time">${escapeHtml(formatDateTime(now))}</td>
    <td>${escapeHtml(stationName)}</td>
    <td>${escapeHtml(track)}</td>
    <td></td>
    <td><button class="btn-delete-history" onclick="deleteHistoryEntry(null, this)" title="Remove">✕</button></td>
  `;
  tbody.insertBefore(tr, tbody.firstChild);
}

async function deleteHistoryEntry(id, btn) {
  const tr = btn.closest('tr');
  if (!id) { tr.remove(); return; }
  try {
    const res = await fetch(`/radio/history/${id}/delete/`, {
      method: 'POST',
      headers: {'X-CSRFToken': getCsrfToken()},
    });
    if (res.ok) tr.remove();
  } catch (e) {}
}

// ---------------------------------------------------------------------------
// Affiliate links
// ---------------------------------------------------------------------------

async function fetchAffiliateLinks(track) {
  const section = $('affiliate-section');
  if (section && section.dataset.disabled) return;
  try {
    const res = await fetch('/radio/affiliate/?track=' + encodeURIComponent(track));
    if (!res.ok) return;
    const data = await res.json();

    const itunes = data.itunes_data || {};

    $('affiliate-track-name').textContent = itunes.name || track;
    $('affiliate-artist-name').textContent = itunes.artist || '';
    $('affiliate-album-name').textContent = itunes.album || '';

    const artEl = $('affiliate-artwork');
    if (itunes.artwork) {
      artEl.src = itunes.artwork;
      artEl.style.display = '';
    } else {
      artEl.style.display = 'none';
    }

    const amzLink = $('affiliate-amazon-link');
    if (data.amazon_url) {
      amzLink.href = data.amazon_url;
      amzLink.style.display = '';
    } else {
      amzLink.style.display = 'none';
    }

    section.style.display = 'flex';
  } catch (err) {
    console.error('fetchAffiliateLinks error:', err);
    section.style.display = 'none';
  }
}

// ---------------------------------------------------------------------------
// Search (radio-browser.info)
// ---------------------------------------------------------------------------

async function doSearch() {
  const query = $('search-input').value.trim();
  if (!query) return;

  const statusEl = $('search-status');
  const tableEl = $('search-results-table');
  const tbody = $('search-results-body');

  statusEl.textContent = 'Searching…';
  tableEl.style.display = 'none';
  tbody.innerHTML = '';

  try {
    const url = `https://de1.api.radio-browser.info/json/stations/search?name=${encodeURIComponent(query)}&limit=50&hidebroken=true&order=clickcount&reverse=true`;
    const res = await fetch(url);
    if (!res.ok) throw new Error(`HTTP ${res.status}`);
    const stations = await res.json();

    if (!stations.length) {
      statusEl.textContent = 'No stations found.';
      return;
    }

    statusEl.textContent = `${stations.length} result(s)`;
    tableEl.style.display = '';
    const curated = document.getElementById('curated-lists');
    if (curated) curated.style.display = 'none';

    stations.forEach(st => {
      const tr = document.createElement('tr');
      const safeName = escapeHtml(st.name || '');
      const safeUrl  = escapeHtml(st.url_resolved || st.url || '');
      const safeBr   = escapeHtml(st.bitrate ? st.bitrate + ' kbps' : '');
      const safeCC   = escapeHtml(st.countrycode || st.country || '');
      const safeTags = escapeHtml((st.tags || '').split(',').slice(0, 3).join(', '));

      tr.innerHTML = `
        <td title="${safeName}">${safeName}</td>
        <td>${safeBr}</td>
        <td>${safeCC}</td>
        <td title="${escapeHtml(st.tags || '')}">${safeTags}</td>
        <td>
          <button class="btn btn-sm btn-play"
                  onclick='searchPlay(${JSON.stringify(safeUrl)}, ${JSON.stringify(safeName)}, ${JSON.stringify({
                    name: st.name,
                    url: st.url_resolved || st.url,
                    bitrate: st.bitrate ? String(st.bitrate) : '',
                    country: st.country || '',
                    tags: st.tags || '',
                    favicon_url: st.favicon || '',
                  })})'>
            &#9654; Play
          </button>
        </td>
      `;
      tbody.appendChild(tr);
    });
  } catch (err) {
    statusEl.textContent = 'Search failed: ' + err.message;
  }
}

function searchPlay(url, name, stationData) {
  // Store station data on the window so saveCurrentStation() can use it
  window._pendingStationData = stationData;
  playStation(url, name, null);
}

// ---------------------------------------------------------------------------
// Save current station
// ---------------------------------------------------------------------------

async function saveCurrentStation() {
  if (!currentStation) return;

  // Use the rich data from search results if available, otherwise minimal data
  const data = window._pendingStationData || {
    name: currentStation.name,
    url: currentStation.url,
    bitrate: '',
    country: '',
    tags: '',
    favicon_url: '',
  };

  await saveStation(data);
}

async function saveStation(station) {
  try {
    const res = await fetch('/radio/save/', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'X-CSRFToken': getCsrfToken(),
      },
      body: JSON.stringify(station),
    });

    if (res.status === 401) {
      alert('Please log in to save stations.');
      return;
    }

    const data = await res.json();
    if (data.ok) {
      if (data.created) {
        addSavedRow({ id: data.id, ...station, is_favorite: false });
      }
    }
  } catch (err) {
    console.error('saveStation error:', err);
  }
}

function addSavedRow(station) {
  const tbody = $('saved-tbody');
  if (!tbody) return;

  const emptyRow = $('saved-empty-row');
  if (emptyRow) emptyRow.remove();

  // Check for duplicate
  if (document.getElementById(`saved-row-${station.id}`)) return;

  const tr = document.createElement('tr');
  tr.id = `saved-row-${station.id}`;
  tr.dataset.id = station.id;
  tr.dataset.url = station.url;
  tr.dataset.name = station.name;

  const safeName = escapeHtml(station.name || '');
  const safeBr   = escapeHtml(station.bitrate || '');
  const safeCC   = escapeHtml(station.country || '');
  const safeUrl  = escapeHtml(station.url || '');

  tr.innerHTML = `
    <td>
      <button class="btn-icon fav-btn${station.is_favorite ? ' active' : ''}"
              onclick="toggleFav(${station.id}, this)"
              title="Toggle favorite">&#9733;</button>
    </td>
    <td class="station-name-cell">${safeName}</td>
    <td>${safeBr}</td>
    <td>${safeCC}</td>
    <td class="notes-cell" onclick="editNotes(${station.id}, this.textContent.trim())" title="" style="cursor:pointer; color:#666; max-width:120px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap;"></td>
    <td>
      <button class="btn btn-sm"
              onclick="playStation('${safeUrl}', '${safeName}', ${station.id})">
        &#9654; Play
      </button>
    </td>
    <td>
      <button class="btn btn-sm btn-danger"
              onclick="removeStation(${station.id})">
        Remove
      </button>
    </td>
  `;
  tbody.appendChild(tr);
}

// ---------------------------------------------------------------------------
// Remove station
// ---------------------------------------------------------------------------

async function toggleFav(pk) {
  try {
    const res = await fetch(`/radio/favorite/${pk}/`, {
      method: 'POST',
      headers: { 'X-CSRFToken': getCsrfToken() },
    });
    if (!res.ok) return;
    const data = await res.json();

    // Flip the star button state
    const btn = document.querySelector(`#saved-row-${pk} .fav-btn`);
    if (btn) btn.classList.toggle('active', data.is_favorite);

    // Re-sort rows in the DOM: favorites first, then alphabetically
    const tbody = $('saved-tbody');
    if (!tbody) return;
    const rows = Array.from(tbody.querySelectorAll('tr[data-id]'));
    rows.sort((a, b) => {
      const aFav = a.querySelector('.fav-btn')?.classList.contains('active') ? 0 : 1;
      const bFav = b.querySelector('.fav-btn')?.classList.contains('active') ? 0 : 1;
      if (aFav !== bFav) return aFav - bFav;
      return a.dataset.name.localeCompare(b.dataset.name);
    });
    rows.forEach(row => tbody.appendChild(row));
  } catch (err) {
    console.error('toggleFav error', err);
  }
}

async function removeStation(pk) {
  try {
    const res = await fetch(`/radio/remove/${pk}/`, {
      method: 'POST',
      headers: { 'X-CSRFToken': getCsrfToken() },
    });
    if (res.ok) {
      const row = $(`saved-row-${pk}`);
      if (row) row.remove();

      const tbody = $('saved-tbody');
      if (tbody && tbody.querySelectorAll('tr').length === 0) {
        const tr = document.createElement('tr');
        tr.id = 'saved-empty-row';
        tr.innerHTML = '<td colspan="7" class="empty-msg">No saved stations yet.</td>';
        tbody.appendChild(tr);
      }
    }
  } catch (err) {
    console.error('removeStation error:', err);
  }
}

// ---------------------------------------------------------------------------
// Toggle favorite
// ---------------------------------------------------------------------------

async function toggleFav(pk, btnEl) {
  try {
    const res = await fetch(`/radio/favorite/${pk}/`, {
      method: 'POST',
      headers: { 'X-CSRFToken': getCsrfToken() },
    });
    if (res.ok) {
      const data = await res.json();
      if (data.is_favorite) {
        btnEl.classList.add('active');
      } else {
        btnEl.classList.remove('active');
      }
    }
  } catch (err) {
    console.error('toggleFav error:', err);
  }
}

// ---------------------------------------------------------------------------
// Focus Timer
// ---------------------------------------------------------------------------

const TIMER_WORK = 25 * 60;
const TIMER_BREAK = 5 * 60;
let timerSeconds = TIMER_WORK;
let timerRunning = false;
let timerIsBreak = false;
let timerInterval = null;

function timerTick() {
  timerSeconds--;
  renderTimer();
  if (timerSeconds <= 0) {
    clearInterval(timerInterval);
    timerInterval = null;
    timerRunning = false;
    if (!timerIsBreak) {
      // work session ended → start break
      timerIsBreak = true;
      recordFocusSession();
      timerSeconds = TIMER_BREAK;
      showTimerNotification('Break time! 5 minutes.');
      // auto-pause playback during break
      if (audio.src && !audio.paused) audio.pause();
    } else {
      // break ended → reset to work
      timerIsBreak = false;
      timerSeconds = TIMER_WORK;
      showTimerNotification('Break over. Back to work.');
    }
    renderTimer();
  }
}

function toggleTimer() {
  if (timerRunning) {
    clearInterval(timerInterval);
    timerInterval = null;
    timerRunning = false;
  } else {
    if ('Notification' in window && Notification.permission === 'default') {
      Notification.requestPermission();
    }
    timerRunning = true;
    timerInterval = setInterval(timerTick, 1000);
  }
  renderTimer();
}

function resetTimer() {
  clearInterval(timerInterval);
  timerInterval = null;
  timerRunning = false;
  timerIsBreak = false;
  timerSeconds = TIMER_WORK;
  renderTimer();
}

function renderTimer() {
  const m = String(Math.floor(timerSeconds / 60)).padStart(2, '0');
  const s = String(timerSeconds % 60).padStart(2, '0');
  const display = $('timer-display');
  const btn = $('timer-toggle-btn');
  const label = $('timer-phase-label');
  if (display) display.textContent = `${m}:${s}`;
  if (btn) btn.textContent = timerRunning ? '⏸' : '▶';
  if (label) label.textContent = timerIsBreak ? 'break' : 'focus';
  // colour the display red when break
  if (display) display.style.color = timerIsBreak ? '#e63946' : '';
}

function showTimerNotification(msg) {
  if ('Notification' in window && Notification.permission === 'granted') {
    new Notification('diora', { body: msg });
  }
  // also flash in the timer label
  const label = $('timer-phase-label');
  if (label) { label.textContent = msg; setTimeout(() => renderTimer(), 3000); }
}

// ---------------------------------------------------------------------------
// Focus session recording
// ---------------------------------------------------------------------------

async function recordFocusSession() {
  try {
    await fetch('/radio/focus/record/', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken() },
      body: JSON.stringify({
        station_name: currentStation ? currentStation.name : '',
        duration_minutes: 25,
      }),
    });
    loadFocusStats();
  } catch (e) {}
}

async function loadFocusStats() {
  try {
    const res = await fetch('/radio/focus/stats/');
    const data = await res.json();
    const widget = document.getElementById('focus-today-widget');
    if (widget) {
      if (data.today_sessions > 0) {
        widget.textContent = `Today: ${data.today_sessions} session${data.today_sessions !== 1 ? 's' : ''} · ${data.today_minutes} min`;
        widget.style.display = '';
      } else {
        widget.style.display = 'none';
      }
    }
    // populate focus tab
    const tbody = document.getElementById('focus-tbody');
    if (!tbody) return;
    tbody.innerHTML = '';
    if (!data.sessions.length) {
      tbody.innerHTML = '<tr><td colspan="3" class="empty-msg">No focus sessions yet. Start the timer!</td></tr>';
      return;
    }
    data.sessions.forEach(s => {
      const tr = document.createElement('tr');
      const dt = new Date(s.completed_at).toLocaleString([], {dateStyle: 'short', timeStyle: 'short'});
      tr.innerHTML = `<td>${dt}</td><td>${escapeHtml(s.station_name || '—')}</td><td>${s.duration_minutes} min</td>`;
      tbody.appendChild(tr);
    });
  } catch (e) {}
}

// ---------------------------------------------------------------------------
// Do Not Disturb / focus mode
// ---------------------------------------------------------------------------

let dndActive = false;

function toggleDNDLight() {
  document.body.classList.toggle('dnd-dark');
  const btn = $('dnd-light-btn');
  if (btn) btn.style.opacity = document.body.classList.contains('dnd-dark') ? '0.4' : '1';
}

function toggleDND() {
  dndActive = !dndActive;
  if (!dndActive) document.body.classList.remove('dnd-dark');
  document.body.classList.toggle('dnd-mode', dndActive);
  const btn = $('dnd-btn');
  if (btn) btn.classList.toggle('active', dndActive);
  if (dndActive) {
    const el = document.documentElement;
    if (el.requestFullscreen) el.requestFullscreen();
    else if (el.webkitRequestFullscreen) el.webkitRequestFullscreen();
  } else {
    if (document.fullscreenElement && document.exitFullscreen) document.exitFullscreen();
    else if (document.webkitFullscreenElement && document.webkitExitFullscreen) document.webkitExitFullscreen();
  }
}

// Exit DND on Escape (browser also exits fullscreen on Escape, so sync state)
document.addEventListener('fullscreenchange', () => {
  if (!document.fullscreenElement && dndActive) {
    dndActive = false;
    document.body.classList.remove('dnd-mode');
    const btn = $('dnd-btn');
    if (btn) btn.classList.remove('active');
  }
});

document.addEventListener('keydown', e => {
  if (e.key === 'Escape' && dndActive) toggleDND();
});

// ---------------------------------------------------------------------------
// Mood / genre tag filter
// ---------------------------------------------------------------------------

const MOOD_TAGS = [
  { label: '🎯 Focus', tag: 'ambient' },
  { label: '☕ Lo-fi', tag: 'lofi' },
  { label: '🎷 Jazz', tag: 'jazz' },
  { label: '🎻 Classical', tag: 'classical' },
  { label: '🌧 Ambient', tag: 'ambient' },
  { label: '🤘 Metal', tag: 'metal' },
  { label: '🎉 Electronic', tag: 'electronic' },
  { label: '📻 Talk', tag: 'talk' },
];

function initMoodChips() {
  const container = $('mood-chips');
  if (!container) return;
  MOOD_TAGS.forEach(({ label, tag }) => {
    const btn = document.createElement('button');
    btn.className = 'mood-chip';
    btn.textContent = label;
    btn.onclick = () => {
      const input = $('search-input');
      if (input) input.value = tag;
      doSearch();
    };
    container.appendChild(btn);
  });
}

// ---------------------------------------------------------------------------
// Curated station lists
// ---------------------------------------------------------------------------

const CURATED_LISTS = [
  {
    id: 'focus',
    label: '🎯 Focus',
    stations: [
      { name: 'SomaFM Drone Zone', url: 'https://ice6.somafm.com/dronezone-256-mp3' },
      { name: 'SomaFM Groove Salad', url: 'https://ice5.somafm.com/groovesalad-128-aac' },
      { name: 'Nightride FM', url: 'https://stream.nightride.fm/nightride.mp3' },
      { name: 'Nightride FM Chillsynth', url: 'https://stream.nightride.fm/chillsynth.mp3' },
    ],
  },
  {
    id: 'lofi',
    label: '☕ Lo-fi / Chill',
    stations: [
      { name: 'SomaFM Groove Salad Classic', url: 'https://ice6.somafm.com/gsclassic-128-mp3' },
      { name: 'SomaFM Secret Agent', url: 'https://ice4.somafm.com/secretagent-128-mp3' },
      { name: 'dublab DE', url: 'https://dublabde.out.airtime.pro/dublabde_a' },
    ],
  },
  {
    id: 'dark',
    label: '🌑 Dark / Industrial',
    stations: [
      { name: 'SomaFM Doomed', url: 'https://ice2.somafm.com/doomed-256-mp3' },
      { name: 'Nightride FM Darksynth', url: 'https://stream.nightride.fm/darksynth.mp3' },
      { name: 'Radio Caprice Industrial', url: 'http://79.120.39.202:9095/' },
    ],
  },
  {
    id: 'classical',
    label: '🎻 Classical',
    stations: [
      { name: 'BR Klassik', url: 'https://dispatcher.rndfnk.com/br/brklassik/live/mp3/high' },
      { name: 'SWR Kultur', url: 'https://f111.rndfnk.com/ard/swr/swr2/live/mp3/256/stream.mp3?aggregator=web' },
      { name: 'Deutschlandfunk Kultur', url: 'https://st02.sslstream.dlf.de/dlf/02/high/aac/stream.aac?aggregator=web' },
    ],
  },
];

function initCuratedLists() {
  const container = document.getElementById('curated-lists');
  if (!container) return;

  if (INITIAL_FEATURED && INITIAL_FEATURED.length) {
    const section = document.createElement('div');
    section.className = 'curated-section';
    section.innerHTML = `<div class="curated-label">&#9733; Featured</div>`;
    const ul = document.createElement('ul');
    ul.className = 'curated-stations';
    INITIAL_FEATURED.forEach(s => {
      const li = document.createElement('li');
      li.innerHTML = `<button class="btn btn-sm" onclick="playStation('${escapeAttr(s.url)}', '${escapeAttr(s.name)}', null)">▶</button>
                      <span class="curated-name">${escapeHtml(s.name)}</span>
                      ${s.description ? `<span class="muted" style="font-size:0.78rem">${escapeHtml(s.description)}</span>` : ''}`;
      ul.appendChild(li);
    });
    section.appendChild(ul);
    container.appendChild(section);
  }

  CURATED_LISTS.forEach(list => {
    const section = document.createElement('div');
    section.className = 'curated-section';
    section.innerHTML = `<div class="curated-label">${list.label}</div>`;
    const ul = document.createElement('ul');
    ul.className = 'curated-stations';
    list.stations.forEach(s => {
      const li = document.createElement('li');
      li.innerHTML = `<button class="btn btn-sm" onclick="playStation('${escapeAttr(s.url)}', '${escapeAttr(s.name)}', null)">▶</button>
                      <span class="curated-name">${escapeHtml(s.name)}</span>`;
      ul.appendChild(li);
    });
    section.appendChild(ul);
    container.appendChild(section);
  });
}

// ---------------------------------------------------------------------------
// Donation hint
// ---------------------------------------------------------------------------

const DONATION_HINT_THRESHOLD = 10;
const DONATION_HINT_COOLDOWN_MS = 7 * 24 * 60 * 60 * 1000; // 7 days

function maybeShowDonationHint(stationUrl, stationName) {
  const station = INITIAL_SAVED.find(s => s.url === stationUrl);
  if (!station || station.play_count < DONATION_HINT_THRESHOLD) return;

  const key = `diora_donation_hint_${stationUrl}`;
  const last = parseInt(localStorage.getItem(key) || '0', 10);
  if (Date.now() - last < DONATION_HINT_COOLDOWN_MS) return;

  const existing = document.getElementById('donation-hint');
  if (existing) existing.remove();

  const el = document.createElement('div');
  el.id = 'donation-hint';
  el.innerHTML = `
    <span>You listen to <strong>${escapeHtml(stationName)}</strong> a lot — consider supporting them ❤️</span>
    <button onclick="dismissDonationHint('${escapeAttr(stationUrl)}')" title="Dismiss">✕</button>
  `;
  document.body.appendChild(el);

  setTimeout(() => dismissDonationHint(stationUrl), 12000);
}

function dismissDonationHint(stationUrl) {
  localStorage.setItem(`diora_donation_hint_${stationUrl}`, Date.now());
  const el = document.getElementById('donation-hint');
  if (el) { el.classList.add('hiding'); setTimeout(() => el.remove(), 400); }
}

// ---------------------------------------------------------------------------
// Station notes
// ---------------------------------------------------------------------------

function editNotes(pk, current) {
  const note = prompt('Station note:', current || '');
  if (note === null) return; // cancelled
  fetch(`/radio/notes/${pk}/`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken() },
    body: JSON.stringify({ notes: note }),
  }).then(r => {
    if (r.ok) {
      const cell = document.querySelector(`#saved-row-${pk} .notes-cell`);
      if (cell) cell.textContent = note;
    }
  });
}

// ---------------------------------------------------------------------------
// Tabs
// ---------------------------------------------------------------------------

const TOP_TABS = ['radio', 'focus', 'podcasts', 'books'];
const RADIO_SUB_TABS = ['search', 'saved', 'history'];

function showTab(name) {
  TOP_TABS.forEach(p => {
    const panel = $(`tab-${p}`);
    if (panel) panel.style.display = (p === name) ? '' : 'none';
  });

  document.querySelectorAll('#tabs .tab-btn').forEach((btn, i) => {
    btn.classList.toggle('active', TOP_TABS[i] === name);
  });

  localStorage.setItem('diora_active_tab', name);

  if (name === 'podcasts') loadPodcastTab();
  if (name === 'books') loadBookList();
}

function showRadioTab(name) {
  RADIO_SUB_TABS.forEach(p => {
    const panel = $(`tab-${p}`);
    if (panel) panel.style.display = (p === name) ? '' : 'none';
  });

  document.querySelectorAll('#radio-sub-tabs .tab-btn').forEach((btn, i) => {
    btn.classList.toggle('active', RADIO_SUB_TABS[i] === name);
  });

  localStorage.setItem('diora_active_radio_tab', name);

  if (name === 'saved') loadRecommendations();
}

// ---------------------------------------------------------------------------
// Podcasts
// ---------------------------------------------------------------------------

function loadPodcastTab() {
  loadFeedList().then(() => {
    showPodcastView(podcastCurrentView);
  });
}

function showPodcastView(view) {
  podcastCurrentView = view;
  const panes = ['search', 'feeds', 'inbox', 'episodes', 'queue'];
  panes.forEach(p => {
    const el = document.getElementById(`podcast-${p}-pane`);
    if (el) el.style.display = (p === view) ? '' : 'none';
  });

  if (view === 'feeds') renderFeedList();
  if (view === 'inbox') loadAndRenderInbox();
  if (view === 'queue') loadAndRenderQueue();
}

async function doPodcastSearch() {
  const q = $('podcast-search-input').value.trim();
  if (!q) return;
  const statusEl = $('podcast-search-status');
  const listEl = $('podcast-search-list');
  statusEl.textContent = 'Searching…';
  listEl.innerHTML = '';

  try {
    const res = await fetch('/podcasts/search/?q=' + encodeURIComponent(q));
    const data = await res.json();
    if (data.error) { statusEl.textContent = 'Error: ' + data.error; return; }
    const results = data.results || [];
    statusEl.textContent = results.length ? `${results.length} result(s)` : 'No results.';

    results.forEach(r => {
      const div = document.createElement('div');
      div.className = 'podcast-search-item';
      div.innerHTML = `
        ${r.artwork_url ? `<img class="podcast-thumb" src="${escapeHtml(r.artwork_url)}" alt="">` : '<div class="podcast-thumb-placeholder"></div>'}
        <div class="podcast-search-info">
          <div class="podcast-feed-title">${escapeHtml(r.title)}</div>
          <div class="muted">${escapeHtml(r.author)}</div>
        </div>
        <button class="btn btn-sm podcast-subscribe-btn">Subscribe</button>
      `;
      // Attach via addEventListener to avoid encoding strings in onclick attribute
      div.querySelector('.podcast-subscribe-btn').addEventListener('click', () => {
        subscribeFeed(r.rss_url, r.title);
      });
      listEl.appendChild(div);
    });
  } catch (e) {
    statusEl.textContent = 'Search failed.';
  }
}

function podcastSearchOpen() {
  showPodcastView('search');
}

function addFeedByUrl() {
  const url = prompt('RSS feed URL:');
  if (url) subscribeFeed(url.trim(), '');
}

async function subscribeFeed(rssUrl, title) {
  if (!rssUrl) return;
  const statusEl = $('podcast-search-status') || $('opml-status');
  try {
    const res = await fetch('/podcasts/feeds/add/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({rss_url: rssUrl, title: title || rssUrl}),
    });
    const data = await res.json();
    if (data.ok) {
      await loadFeedList();
      showPodcastView('feeds');
    } else if (statusEl) {
      statusEl.textContent = 'Error: ' + (data.error || 'unknown');
    }
  } catch (e) {
    if (statusEl) statusEl.textContent = 'Failed to subscribe.';
  }
}

async function loadFeedList() {
  try {
    const res = await fetch('/podcasts/feeds/');
    const data = await res.json();
    podcastFeeds = data.feeds || [];
  } catch (e) {
    podcastFeeds = [];
  }
}

function renderFeedList() {
  const container = $('podcast-feed-list');
  if (!container) return;

  if (!podcastFeeds.length) {
    container.innerHTML = '<p class="muted">No subscriptions yet. Search or import OPML to add feeds.</p>';
    return;
  }

  container.innerHTML = '';
  podcastFeeds.forEach(feed => {
    const div = document.createElement('div');
    div.className = 'podcast-feed-item';
    div.innerHTML = `
      ${feed.artwork_url
        ? `<img class="podcast-thumb" src="${escapeHtml(feed.artwork_url)}" alt="">`
        : '<div class="podcast-thumb-placeholder"></div>'}
      <div class="podcast-feed-info">
        <div class="podcast-feed-title">${escapeHtml(feed.title)}</div>
        ${feed.author ? `<div class="muted">${escapeHtml(feed.author)}</div>` : ''}
      </div>
      <div class="podcast-feed-actions">
        <button class="btn btn-sm" onclick="openFeed(${feed.id})">Episodes</button>
        <button class="btn btn-sm" onclick="refreshFeed(${feed.id})" title="Refresh feed">↻</button>
        <button class="btn btn-sm btn-danger" onclick="removeFeed(${feed.id})">Remove</button>
      </div>
    `;
    container.appendChild(div);
  });
}

async function openFeed(feedId) {
  podcastCurrentFeedId = feedId;
  showPodcastView('episodes');
  const headerEl = $('podcast-feed-header');
  const listEl = $('podcast-episode-list');
  if (headerEl) headerEl.innerHTML = '<p class="muted">Loading…</p>';
  if (listEl) listEl.innerHTML = '';

  try {
    const res = await fetch(`/podcasts/feeds/${feedId}/episodes/`);
    const data = await res.json();
    const feed = data.feed;
    const episodes = data.episodes || [];

    if (headerEl) {
      headerEl.innerHTML = `
        <div class="podcast-feed-header-inner">
          ${feed.artwork_url ? `<img class="podcast-thumb-lg" src="${escapeHtml(feed.artwork_url)}" alt="">` : ''}
          <div>
            <div class="podcast-feed-title">${escapeHtml(feed.title)}</div>
            ${feed.author ? `<div class="muted">${escapeHtml(feed.author)}</div>` : ''}
          </div>
        </div>
      `;
    }

    renderEpisodeList(episodes, feedId, listEl);
  } catch (e) {
    if (headerEl) headerEl.innerHTML = '<p class="muted">Failed to load episodes.</p>';
  }
}

function renderEpisodeList(episodes, feedId, container) {
  if (!container) return;
  if (!episodes.length) {
    container.innerHTML = '<p class="muted">No episodes found.</p>';
    return;
  }

  container.innerHTML = '';
  episodes.forEach(ep => {
    // Cache episode data by id so onclick attrs only need the id (avoids encoding
    // strings with quotes inside HTML attributes which breaks the attribute parser)
    podcastEpCache[ep.id] = {
      id: ep.id,
      title: ep.title,
      description: ep.description || '',
      audioUrl: ep.audio_url,
      durationSeconds: ep.duration_seconds,
      positionSeconds: ep.position_seconds || 0,
      feedId: feedId || 0,
      played: ep.played,
    };

    const div = document.createElement('div');
    div.className = 'episode-item' + (ep.played ? ' episode-played' : '');
    div.id = `episode-item-${ep.id}`;

    const artSrc = ep.artwork_url || (feedId ? (podcastFeeds.find(f => f.id === feedId) || {}).artwork_url || '' : '');
    const dur = formatDuration(ep.duration_seconds);
    const dateStr = ep.pub_date ? ep.pub_date.slice(0, 10) : '';
    const posStr = ep.position_seconds > 0 ? ` · ${formatDuration(ep.position_seconds)} played` : '';

    div.innerHTML = `
      ${artSrc ? `<img class="podcast-thumb" src="${escapeHtml(artSrc)}" alt="">` : '<div class="podcast-thumb-placeholder"></div>'}
      <div class="episode-info">
        <div class="episode-title ep-clickable" onclick="openEpisodeSidebar(${ep.id})" title="Show notes">${escapeHtml(ep.title)}</div>
        <div class="muted">${escapeHtml(dateStr)} · ${escapeHtml(dur)}${escapeHtml(posStr)}</div>
      </div>
      <div class="episode-actions">
        <button class="btn btn-sm btn-play" onclick="playEpisodeById(${ep.id})">▶</button>
        <button class="btn btn-sm" onclick="queueAddEpisode(${ep.id})" title="${ep.in_queue ? 'In queue' : 'Add to queue'}">${ep.in_queue ? '✓Q' : '+Q'}</button>
        <button class="btn btn-sm" onclick="toggleMarkPlayed(${ep.id}, this)" title="Mark played">${ep.played ? '✓' : '○'}</button>
        <button class="btn btn-sm" onclick="downloadEpisodeById(${ep.id}, this)" title="Download">⬇</button>
      </div>
    `;
    container.appendChild(div);
  });
}

function playEpisodeById(id) {
  const ep = podcastEpCache[id];
  if (!ep) return;
  playEpisode(ep.id, ep.title, ep.audioUrl, ep.durationSeconds, ep.positionSeconds, ep.feedId);
}

function downloadEpisodeById(id, btn) {
  const ep = podcastEpCache[id];
  if (!ep) return;
  downloadEpisode(ep.audioUrl, ep.title, btn);
}

function playEpisode(id, title, url, durationSeconds, positionSeconds, feedId) {
  stopPlayback(false);

  podcastMode = true;
  isPlaying = true;  // fix: was missing, causing stop button to do nothing
  currentEpisode = {id, title, audioUrl: url, durationSeconds, feedId};

  audio.src = url;
  const volSlider = $('volume');
  if (volSlider) audio.volume = volSlider.value / 255;

  if (positionSeconds > 0) {
    audio.addEventListener('loadedmetadata', function onMeta() {
      audio.currentTime = positionSeconds;
      audio.removeEventListener('loadedmetadata', onMeta);
    });
  }

  audio.play().catch(e => console.warn('Podcast play blocked:', e));

  const feedTitle = (podcastFeeds.find(f => f.id === feedId) || {}).title || 'Podcast';
  const stationEl = $('now-playing-station');
  stationEl.textContent = feedTitle;
  stationEl.classList.add('podcast-station-link');
  stationEl.onclick = () => { showTab('podcasts'); openFeed(feedId); };

  const trackEl = $('now-playing-track');
  trackEl.textContent = title;
  trackEl.classList.add('podcast-track-link');
  trackEl.onclick = () => openEpisodeSidebar(id);
  $('play-stop-btn').style.display = '';
  $('play-stop-btn').textContent = '⏹ Stop';
  $('play-stop-btn').classList.add('playing');

  const seekBar = $('podcast-seek-bar');
  if (seekBar) seekBar.style.display = '';

  const slider = $('seek-slider');
  if (slider && durationSeconds > 0) slider.max = durationSeconds;

  // Reset speed to 1× for each new episode
  setPlaybackRate(1);

  audio.ontimeupdate = podcastTimeUpdate;

  // Media Session API — maps hardware media keys & lock-screen controls
  if ('mediaSession' in navigator) {
    navigator.mediaSession.metadata = new MediaMetadata({
      title: title,
      artist: (podcastFeeds.find(f => f.id === feedId) || {}).title || '',
    });
    navigator.mediaSession.setActionHandler('seekbackward', () => skipBack());
    navigator.mediaSession.setActionHandler('seekforward',  () => skipForward());
    navigator.mediaSession.setActionHandler('play',  () => { audio.play(); });
    navigator.mediaSession.setActionHandler('pause', () => { audio.pause(); });
  }

  if (seekSaveTimer) clearInterval(seekSaveTimer);
  seekSaveTimer = setInterval(savePodcastProgress, 15000);
}

function podcastTimeUpdate() {
  const pos = Math.floor(audio.currentTime);
  const dur = currentEpisode ? currentEpisode.durationSeconds : 0;

  const curEl = $('seek-current');
  if (curEl) curEl.textContent = formatDuration(pos);

  const durEl = $('seek-duration');
  if (durEl) durEl.textContent = formatDuration(dur || Math.floor(audio.duration) || 0);

  const slider = $('seek-slider');
  if (slider) {
    if (dur > 0) {
      slider.max = dur;
    } else if (audio.duration && isFinite(audio.duration)) {
      slider.max = Math.floor(audio.duration);
    }
    slider.value = pos;
  }
}

function skipBack() {
  audio.currentTime = Math.max(0, audio.currentTime - 15);
}

function skipForward() {
  const dur = audio.duration;
  audio.currentTime = dur && isFinite(dur)
    ? Math.min(dur, audio.currentTime + 30)
    : audio.currentTime + 30;
}

function setPlaybackRate(rate) {
  audio.playbackRate = rate;
  // Keep pitch natural at non-1× speeds (supported in all modern browsers)
  audio.preservesPitch = true;

  document.querySelectorAll('.speed-btn').forEach(btn => {
    btn.classList.toggle('active', parseFloat(btn.textContent) === rate
      || (rate === 0.75 && btn.textContent.startsWith('¾'))
      || (rate === 1.25 && btn.textContent.startsWith('1¼'))
      || (rate === 1.5  && btn.textContent.startsWith('1½')));
  });
}

async function savePodcastProgress() {
  if (!currentEpisode) return;
  const pos = Math.floor(audio.currentTime);
  try {
    await fetch('/podcasts/progress/save/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({episode_id: currentEpisode.id, position_seconds: pos}),
    });
  } catch (e) {}
}

async function loadAndRenderInbox() {
  const listEl = $('podcast-inbox-list');
  if (!listEl) return;
  listEl.innerHTML = '<p class="muted">Loading…</p>';

  try {
    const res = await fetch('/podcasts/inbox/');
    const data = await res.json();
    const episodes = data.episodes || [];

    listEl.innerHTML = '';
    if (!episodes.length) {
      listEl.innerHTML = '<p class="muted">Inbox empty — all caught up!</p>';
      return;
    }

    episodes.forEach(ep => {
      podcastEpCache[ep.id] = {
        id: ep.id,
        title: ep.title,
        audioUrl: ep.audio_url,
        durationSeconds: ep.duration_seconds,
        positionSeconds: 0,
        feedId: ep['feed__id'],
        played: false,
      };

      const div = document.createElement('div');
      div.className = 'episode-item';
      div.innerHTML = `
        ${ep['feed__artwork_url'] ? `<img class="podcast-thumb" src="${escapeHtml(ep['feed__artwork_url'])}" alt="">` : '<div class="podcast-thumb-placeholder"></div>'}
        <div class="episode-info">
          <div class="episode-title">${escapeHtml(ep.title)}</div>
          <div class="muted">${escapeHtml(ep['feed__title'])} · ${ep.pub_date ? ep.pub_date.slice(0,10) : ''} · ${formatDuration(ep.duration_seconds)}</div>
        </div>
        <div class="episode-actions">
          <button class="btn btn-sm btn-play" onclick="playEpisodeById(${ep.id})">▶</button>
          <button class="btn btn-sm" onclick="queueAddEpisode(${ep.id})" title="Add to queue">+Q</button>
          <button class="btn btn-sm" onclick="downloadEpisodeById(${ep.id}, this)" title="Download">⬇</button>
        </div>
      `;
      listEl.appendChild(div);
    });
  } catch (e) {
    listEl.innerHTML = '<p class="muted">Failed to load inbox.</p>';
  }
}

async function loadAndRenderQueue() {
  const ol = $('podcast-queue-ol');
  if (!ol) return;
  ol.innerHTML = '<li class="muted">Loading…</li>';

  try {
    const res = await fetch('/podcasts/queue/');
    const data = await res.json();
    const items = data.queue || [];
    podcastQueue = items;

    ol.innerHTML = '';
    if (!items.length) {
      ol.innerHTML = '<li class="muted">Queue is empty.</li>';
      return;
    }

    items.forEach(item => {
      const epId = item['episode__id'];
      podcastEpCache[epId] = {
        id: epId,
        title: item['episode__title'],
        audioUrl: item['episode__audio_url'],
        durationSeconds: item['episode__duration_seconds'],
        positionSeconds: 0,
        feedId: item['episode__feed__id'],
        played: false,
      };

      const li = document.createElement('li');
      li.className = 'episode-item';
      li.innerHTML = `
        <div class="episode-info">
          <div class="episode-title">${escapeHtml(item['episode__title'])}</div>
          <div class="muted">${escapeHtml(item['episode__feed__title'])} · ${formatDuration(item['episode__duration_seconds'])}</div>
        </div>
        <div class="episode-actions">
          <button class="btn btn-sm btn-play" onclick="playEpisodeById(${epId})">▶</button>
          <button class="btn btn-sm" onclick="downloadEpisodeById(${epId}, this)" title="Download">⬇</button>
          <button class="btn btn-sm btn-danger" onclick="queueRemoveEpisode(${epId})">✕</button>
        </div>
      `;
      ol.appendChild(li);
    });
  } catch (e) {
    ol.innerHTML = '<li class="muted">Failed to load queue.</li>';
  }
}

async function queueAddEpisode(id) {
  try {
    await fetch('/podcasts/queue/add/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({episode_id: id}),
    });
  } catch (e) {}
}

async function queueRemoveEpisode(id) {
  try {
    await fetch('/podcasts/queue/remove/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({episode_id: id}),
    });
    if (podcastCurrentView === 'queue') loadAndRenderQueue();
  } catch (e) {}
}

async function toggleMarkPlayed(id, btn) {
  const ep = podcastEpCache[id];
  const current = ep ? ep.played : btn.textContent === '✓';
  const newPlayed = !current;
  try {
    const res = await fetch('/podcasts/progress/mark-played/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({episode_id: id, played: newPlayed}),
    });
    if (res.ok) {
      if (ep) ep.played = newPlayed;
      btn.textContent = newPlayed ? '✓' : '○';
      const item = document.getElementById(`episode-item-${id}`);
      if (item) item.classList.toggle('episode-played', newPlayed);
    }
  } catch (e) {}
}

async function refreshFeed(feedId) {
  try {
    const res = await fetch('/podcasts/feeds/refresh/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({feed_id: feedId}),
    });
    const data = await res.json();
    if (data.ok && podcastCurrentFeedId === feedId) {
      openFeed(feedId);
    }
  } catch (e) {}
}

async function removeFeed(feedId) {
  if (!confirm('Remove this podcast?')) return;
  try {
    await fetch(`/podcasts/feeds/${feedId}/remove/`, {
      method: 'POST',
      headers: {'X-CSRFToken': getCsrfToken()},
    });
    podcastFeeds = podcastFeeds.filter(f => f.id !== feedId);
    renderFeedList();
  } catch (e) {}
}

async function importOPML(input) {
  const file = input.files[0];
  if (!file) return;
  const statusEl = $('opml-status');
  if (statusEl) statusEl.textContent = 'Importing…';

  const form = new FormData();
  form.append('file', file);
  form.append('csrfmiddlewaretoken', getCsrfToken());

  try {
    const res = await fetch('/podcasts/feeds/import/', {method: 'POST', body: form});
    const data = await res.json();
    if (data.ok) {
      if (statusEl) statusEl.textContent = `✓ ${data.added} added, ${data.skipped} already subscribed`;
      await loadFeedList();
      renderFeedList();
    } else {
      if (statusEl) statusEl.textContent = 'Error: ' + (data.error || 'unknown');
    }
  } catch (e) {
    if (statusEl) statusEl.textContent = 'Import failed.';
  }
  input.value = '';
}

async function downloadEpisode(url, title, btn) {
  if (!('caches' in window)) {
    alert('Cache API not supported in this browser.');
    return;
  }

  const origText = btn ? btn.textContent : '⬇';
  if (btn) { btn.textContent = '…'; btn.disabled = true; }

  try {
    const cache = await caches.open('diora-podcast-v1');
    const existing = await cache.match(url);
    if (existing) {
      if (btn) { btn.textContent = '✓'; btn.disabled = false; }
      return;
    }
    // Use no-cors so cross-origin audio URLs don't block the fetch
    const resp = await fetch(url, {mode: 'no-cors'});
    await cache.put(url, resp);
    if (btn) { btn.textContent = '✓'; btn.disabled = false; }
  } catch (e) {
    if (btn) { btn.textContent = origText; btn.disabled = false; }
    alert('Download failed: ' + e.message);
  }
}

// ---------------------------------------------------------------------------
// Sidebar
// ---------------------------------------------------------------------------

function openSidebar(title, htmlContent) {
  $('sidebar-title').textContent = title;
  $('sidebar-body').innerHTML = sanitizeSidebarHtml(htmlContent);
  $('sidebar-overlay').style.display = '';
  $('sidebar').classList.add('open');
}

function closeSidebar() {
  $('sidebar').classList.remove('open');
  $('sidebar-overlay').style.display = 'none';
}

document.addEventListener('keydown', e => {
  const overlay = $('reader-overlay');
  const readerOpen = overlay && overlay.style.display !== 'none';

  if (e.key === 'Escape') {
    if (readerOpen) {
      closeReader();
    } else {
      closeSidebar();
    }
  }

  if (readerOpen) {
    if ((e.ctrlKey && e.key === 'f') || e.key === 'F3') {
      e.preventDefault();
      toggleReaderSearch();
    }
    if (readerSearchOpen) {
      if (e.key === 'ArrowDown') { e.preventDefault(); readerSearchNext(); }
      if (e.key === 'ArrowUp')   { e.preventDefault(); readerSearchPrev(); }
    }
    if (readerSettings.pdfPaginated && currentPdfDoc) {
      if (e.key === 'ArrowRight') { e.preventDefault(); pdfGoToPage(pdfCurrentPage + 1); }
      if (e.key === 'ArrowLeft')  { e.preventDefault(); pdfGoToPage(pdfCurrentPage - 1); }
    }
  }
});

function sanitizeSidebarHtml(html) {
  if (!html) return '<p class="muted">No show notes available.</p>';
  const div = document.createElement('div');
  div.innerHTML = html;
  div.querySelectorAll('script, iframe, object, embed, style').forEach(el => el.remove());
  div.querySelectorAll('*').forEach(el => {
    Array.from(el.attributes).forEach(attr => {
      if (attr.name.startsWith('on')) el.removeAttribute(attr.name);
    });
    if (el.tagName === 'A') {
      el.setAttribute('target', '_blank');
      el.setAttribute('rel', 'noopener noreferrer');
    }
  });
  return div.innerHTML;
}

function openEpisodeSidebar(id) {
  const ep = podcastEpCache[id];
  if (!ep) return;
  openSidebar(ep.title, ep.description || '');
}

function formatDuration(seconds) {
  if (!seconds || seconds <= 0) return '0:00';
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = seconds % 60;
  if (h > 0) {
    return `${h}:${String(m).padStart(2, '0')}:${String(s).padStart(2, '0')}`;
  }
  return `${m}:${String(s).padStart(2, '0')}`;
}

// ---------------------------------------------------------------------------
// Service Worker
// ---------------------------------------------------------------------------

if ('serviceWorker' in navigator) {
  window.addEventListener('load', () => {
    navigator.serviceWorker.register('/static/js/sw.js').catch(err => {
      console.warn('Service worker registration failed:', err);
    });
  });
}

// ---------------------------------------------------------------------------
// M3U import
// ---------------------------------------------------------------------------

async function importM3U(input) {
  const file = input.files[0];
  if (!file) return;
  const status = document.getElementById('import-status');
  status.textContent = 'Importing…';

  const form = new FormData();
  form.append('file', file);
  form.append('csrfmiddlewaretoken', getCsrfToken());

  try {
    const res = await fetch('/radio/import/', { method: 'POST', body: form });
    const data = await res.json();
    if (data.ok) {
      status.textContent = `✓ ${data.added} added, ${data.skipped} already saved`;
      if (data.added > 0) location.reload();
    } else {
      status.textContent = `Error: ${data.error}`;
    }
  } catch (e) {
    status.textContent = 'Upload failed';
  }
  input.value = '';
}

// ---------------------------------------------------------------------------
// Contrast scheme
// ---------------------------------------------------------------------------

// Accent palette — ordered by preference. Algorithm picks the one with the
// highest WCAG contrast ratio against the detected background luminance.
const ACCENT_PALETTE = [
  { base: '#e63946', hover: '#ff4d58' }, // red
  { base: '#ff9500', hover: '#ffaa33' }, // orange
  { base: '#f1c40f', hover: '#f9d439' }, // yellow
  { base: '#2ecc71', hover: '#4ee88a' }, // green
  { base: '#00b4d8', hover: '#33c7e5' }, // cyan
  { base: '#4361ee', hover: '#6d84f4' }, // blue
  { base: '#c77dff', hover: '#d89fff' }, // purple
  { base: '#ff6b9d', hover: '#ff8fb5' }, // pink
  { base: '#ffffff', hover: '#cccccc' }, // white (last resort)
];

function _linearise(c) {
  c /= 255;
  return c <= 0.03928 ? c / 12.92 : Math.pow((c + 0.055) / 1.055, 2.4);
}
function _luminance(r, g, b) {
  return 0.2126 * _linearise(r) + 0.7152 * _linearise(g) + 0.0722 * _linearise(b);
}
function _contrast(l1, l2) {
  return (Math.max(l1, l2) + 0.05) / (Math.min(l1, l2) + 0.05);
}
function _hexRgb(hex) {
  return [parseInt(hex.slice(1,3),16), parseInt(hex.slice(3,5),16), parseInt(hex.slice(5,7),16)];
}

function analyzeBackground(url) {
  return new Promise(resolve => {
    const img = new Image();
    img.crossOrigin = 'anonymous';
    img.onload = () => {
      const canvas = document.createElement('canvas');
      canvas.width = 64; canvas.height = 64;
      const ctx = canvas.getContext('2d');
      ctx.drawImage(img, 0, 0, 64, 64);
      const data = ctx.getImageData(0, 0, 64, 64).data;
      let tR = 0, tG = 0, tB = 0, tBt601 = 0;
      const n = data.length / 4;
      for (let i = 0; i < data.length; i += 4) {
        tR += data[i]; tG += data[i+1]; tB += data[i+2];
        tBt601 += 0.299*data[i] + 0.587*data[i+1] + 0.114*data[i+2];
      }
      resolve({
        bright: (tBt601 / n) > 127,
        bgLuminance: _luminance(tR/n, tG/n, tB/n),
      });
    };
    img.onerror = () => resolve({ bright: false, bgLuminance: 0 });
    img.src = url;
  });
}

function pickBestAccent(bgLuminance) {
  let best = ACCENT_PALETTE[0], bestRatio = 0;
  for (const entry of ACCENT_PALETTE) {
    const [r, g, b] = _hexRgb(entry.base);
    const ratio = _contrast(bgLuminance, _luminance(r, g, b));
    if (ratio > bestRatio) { bestRatio = ratio; best = entry; }
  }
  return best;
}

function applyAccent(entry) {
  const root = document.documentElement;
  root.style.setProperty('--accent', entry.base);
  root.style.setProperty('--accent-hover', entry.hover);
}

function setScheme(bright) {
  document.body.classList.toggle('bright-bg', bright);
  const btn = document.getElementById('contrast-toggle');
  if (btn) btn.style.opacity = bright ? '1' : '0.5';
}

function toggleContrast() {
  setScheme(!document.body.classList.contains('bright-bg'));
}

// ---------------------------------------------------------------------------
// E2E Encryption utilities (Web Crypto API)
// ---------------------------------------------------------------------------

let _encKey = null;

function bytesToBase64(buf) {
  const bytes = new Uint8Array(buf);
  let str = '';
  for (const b of bytes) str += String.fromCharCode(b);
  return btoa(str);
}

function base64ToBytes(b64) {
  const str = atob(b64);
  const buf = new Uint8Array(str.length);
  for (let i = 0; i < str.length; i++) buf[i] = str.charCodeAt(i);
  return buf;
}

function bytesToHex(buf) {
  return Array.from(new Uint8Array(buf)).map(b => b.toString(16).padStart(2, '0')).join('');
}

function hexToBytes(hex) {
  const arr = new Uint8Array(hex.length / 2);
  for (let i = 0; i < arr.length; i++) arr[i] = parseInt(hex.slice(i*2, i*2+2), 16);
  return arr;
}

async function getOrCreateEncKey() {
  if (_encKey) return _encKey;
  const storageKey = `diora_enc_key_${window.USER_ID || 0}`;
  const stored = localStorage.getItem(storageKey);
  if (stored) {
    try {
      const raw = base64ToBytes(stored);
      _encKey = await crypto.subtle.importKey('raw', raw, {name: 'AES-GCM'}, false, ['encrypt', 'decrypt']);
      return _encKey;
    } catch (e) { /* fall through, generate new */ }
  }
  // No key found — generate one and store it
  _encKey = await crypto.subtle.generateKey({name: 'AES-GCM', length: 256}, true, ['encrypt', 'decrypt']);
  const raw = await crypto.subtle.exportKey('raw', _encKey);
  localStorage.setItem(storageKey, bytesToBase64(new Uint8Array(raw)));
  return _encKey;
}

async function encryptBytes(key, plainBytes) {
  const iv = crypto.getRandomValues(new Uint8Array(12));
  const ct = await crypto.subtle.encrypt({name: 'AES-GCM', iv}, key, plainBytes);
  return {iv: bytesToHex(iv), ciphertext: bytesToBase64(ct)};
}

async function decryptBytes(key, ivHex, ctB64) {
  const iv = hexToBytes(ivHex);
  const ct = base64ToBytes(ctB64);
  return crypto.subtle.decrypt({name: 'AES-GCM', iv}, key, ct);
}

// ---------------------------------------------------------------------------
// Encrypted wallpaper
// ---------------------------------------------------------------------------

async function uploadBackground(file) {
  if (!file) return;
  const allowedTypes = ['image/jpeg', 'image/png', 'image/webp'];
  if (!allowedTypes.includes(file.type)) {
    alert('Only JPEG, PNG, or WebP images are allowed.');
    return;
  }
  if (file.size > 5 * 1024 * 1024) {
    alert('Image must be 5 MB or smaller.');
    return;
  }

  const key = await getOrCreateEncKey();
  const buf = await file.arrayBuffer();
  const {iv, ciphertext} = await encryptBytes(key, buf);

  const res = await fetch('/accounts/background/upload/', {
    method: 'POST',
    headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
    body: JSON.stringify({iv, ciphertext, mime_type: file.type, file_size: file.size}),
  });
  const data = await res.json();
  if (!data.ok) throw new Error(data.error || 'upload failed');
}

async function applyEncryptedBackground() {
  if (typeof ENCRYPTED_BG === 'undefined' || !ENCRYPTED_BG.ciphertext) return;
  try {
    const key = await getOrCreateEncKey();
    const plain = await decryptBytes(key, ENCRYPTED_BG.iv, ENCRYPTED_BG.ciphertext);
    const blob = new Blob([plain], {type: ENCRYPTED_BG.mime || 'image/jpeg'});
    const url = URL.createObjectURL(blob);
    document.body.style.backgroundImage = `url('${url}')`;
    document.body.style.backgroundSize = 'cover';
    document.body.style.backgroundPosition = 'center';
    document.body.style.backgroundAttachment = 'fixed';

    // Analyze brightness for accent/scheme
    analyzeBackground(url).then(({bright, bgLuminance}) => {
      setScheme(bright);
      applyAccent(pickBestAccent(bgLuminance));
    });
  } catch (e) {
    console.warn('Could not decrypt background:', e);
  }
}

// ---------------------------------------------------------------------------
// EPUB parser (requires JSZip)
// ---------------------------------------------------------------------------

function resolveEpubPath(base, relative) {
  if (!relative) return '';
  if (relative.startsWith('/')) return relative.slice(1);
  const hashIdx = relative.indexOf('#');
  const frag = hashIdx >= 0 ? relative.slice(hashIdx) : '';
  const rel = hashIdx >= 0 ? relative.slice(0, hashIdx) : relative;
  const parts = (base + rel).split('/');
  const resolved = [];
  for (const p of parts) {
    if (p === '..') resolved.pop();
    else if (p !== '.') resolved.push(p);
  }
  return resolved.join('/') + frag;
}

async function parseEpub(arrayBuffer) {
  const zip = await JSZip.loadAsync(arrayBuffer);

  // 1. Find OPF via container.xml
  const containerXml = await zip.file('META-INF/container.xml').async('text');
  const containerDoc = new DOMParser().parseFromString(containerXml, 'application/xml');
  const rootfileEl = containerDoc.querySelector('rootfile');
  if (!rootfileEl) throw new Error('No rootfile in container.xml');
  const opfPath = rootfileEl.getAttribute('full-path');
  const opfDir = opfPath.includes('/') ? opfPath.substring(0, opfPath.lastIndexOf('/') + 1) : '';

  // 2. Parse OPF
  const opfText = await zip.file(opfPath).async('text');
  const opfDoc = new DOMParser().parseFromString(opfText, 'application/xml');

  const title = opfDoc.querySelector('metadata > title, metadata > *|title')?.textContent?.trim() || 'Unknown Title';
  const author = opfDoc.querySelector('metadata > creator, metadata > *|creator')?.textContent?.trim() || 'Unknown Author';

  // 3. Build manifest: id → {href, mediaType, properties}
  const manifest = {};
  opfDoc.querySelectorAll('manifest > item').forEach(item => {
    manifest[item.getAttribute('id')] = {
      href: opfDir + item.getAttribute('href'),
      mediaType: item.getAttribute('media-type') || '',
      properties: item.getAttribute('properties') || '',
    };
  });

  // 4. Build image map: abs zip path → blob URL
  const imageMap = {};
  for (const {href, mediaType} of Object.values(manifest)) {
    if (mediaType.startsWith('image/')) {
      try {
        const buf = await zip.file(href).async('arraybuffer');
        imageMap[href] = URL.createObjectURL(new Blob([buf], {type: mediaType}));
      } catch (e) { /* missing asset */ }
    }
  }

  // 5. Parse TOC
  const toc = await _parseEpubToc(zip, opfDoc, manifest);

  // 6. Get spine and concatenate chapters
  const spineItems = Array.from(opfDoc.querySelectorAll('spine > itemref'))
    .map(ref => manifest[ref.getAttribute('idref')]?.href)
    .filter(Boolean);

  const parts = [];
  for (let i = 0; i < spineItems.length; i++) {
    const href = spineItems[i];
    try {
      const chapterText = await zip.file(href).async('text');
      const chapterDir = href.includes('/') ? href.substring(0, href.lastIndexOf('/') + 1) : '';
      const withBlobs = _injectImageBlobs(chapterText, chapterDir, imageMap);
      const sanitized = sanitizeEpubHtml(withBlobs);
      parts.push(`<div id="epub-chapter-${i}" data-epub-src="${href}">${sanitized}</div>`);
    } catch (e) { /* skip missing */ }
  }

  return {title, author, html: parts.join('\n'), toc, imageMap};
}

async function _parseEpubToc(zip, opfDoc, manifest) {
  // Try EPUB3 nav document
  const navItem = Object.values(manifest).find(m => m.properties.includes('nav'));
  if (navItem) {
    try {
      const navText = await zip.file(navItem.href).async('text');
      const navDoc = new DOMParser().parseFromString(navText, 'application/xhtml+xml');
      const tocNav = navDoc.querySelector('nav[epub\\:type="toc"]') || navDoc.querySelector('nav');
      if (tocNav) {
        const ol = tocNav.querySelector('ol');
        if (ol) return _parseTocOl(ol, navItem.href, 0);
      }
    } catch (e) {}
  }

  // Fall back to EPUB2 NCX
  const ncxItem = Object.values(manifest).find(m => m.mediaType === 'application/x-dtbncx+xml');
  if (ncxItem) {
    try {
      const ncxText = await zip.file(ncxItem.href).async('text');
      const ncxDoc = new DOMParser().parseFromString(ncxText, 'application/xml');
      const ncxDir = ncxItem.href.includes('/') ? ncxItem.href.substring(0, ncxItem.href.lastIndexOf('/') + 1) : '';
      return _parseNcxNavMap(ncxDoc.querySelector('navMap'), ncxDir, 0);
    } catch (e) {}
  }

  return [];
}

function _parseTocOl(ol, navHref, depth) {
  if (!ol || depth > 5) return [];
  const navDir = navHref.includes('/') ? navHref.substring(0, navHref.lastIndexOf('/') + 1) : '';
  const items = [];
  for (const li of Array.from(ol.children)) {
    const a = li.querySelector(':scope > a') || li.querySelector(':scope > span');
    if (a) {
      const rawHref = a.getAttribute('href') || '';
      items.push({
        label: a.textContent.trim(),
        href: rawHref ? resolveEpubPath(navDir, rawHref) : '',
        depth,
      });
    }
    const childOl = li.querySelector(':scope > ol');
    if (childOl) items.push(..._parseTocOl(childOl, navHref, depth + 1));
  }
  return items;
}

function _parseNcxNavMap(navMap, ncxDir, depth) {
  if (!navMap || depth > 5) return [];
  const items = [];
  for (const navPoint of Array.from(navMap.children)) {
    if (navPoint.tagName !== 'navPoint') continue;
    const label = navPoint.querySelector('navLabel > text')?.textContent?.trim() || '';
    const src = navPoint.querySelector('content')?.getAttribute('src') || '';
    items.push({label, href: src ? resolveEpubPath(ncxDir, src) : '', depth});
    items.push(..._parseNcxNavMap(navPoint, ncxDir, depth + 1));
  }
  return items;
}

function _resolveImageBlob(imageMap, absPath) {
  if (imageMap[absPath]) return imageMap[absPath];
  // Fallback: match by decoded filename only
  const name = decodeURIComponent(absPath.split('/').pop()).toLowerCase();
  for (const [k, v] of Object.entries(imageMap)) {
    if (decodeURIComponent(k.split('/').pop()).toLowerCase() === name) return v;
  }
  return null;
}

// Replace image src/href in raw chapter HTML text with blob URLs before DOMParser sees it.
// This avoids relying on innerHTML serialisation preserving attributes we set on DOM nodes.
function _injectImageBlobs(html, chapterDir, imageMap) {
  function subst(src) {
    if (!src || src.startsWith('blob:') || src.startsWith('data:') || src.startsWith('http')) return src;
    return _resolveImageBlob(imageMap, resolveEpubPath(chapterDir, src)) || '';
  }
  // <img src="...">
  html = html.replace(/(<img\b[^>]*?)\bsrc="([^"]*)"/gi,
    (_, pre, src) => { const b = subst(src); return b ? `${pre}src="${b}"` : pre; });
  // SVG <image xlink:href="...">
  html = html.replace(/(<image\b[^>]*?)\bxlink:href="([^"]*)"/gi,
    (_, pre, src) => { const b = subst(src); return b ? `${pre}xlink:href="${b}"` : pre; });
  // SVG <image href="...">
  html = html.replace(/(<image\b[^>]*?)\bhref="([^"]*)"/gi,
    (_, pre, src) => { const b = subst(src); return b ? `${pre}href="${b}"` : pre; });
  return html;
}

function sanitizeEpubHtml(html) {
  const doc = new DOMParser().parseFromString(html, 'text/html');

  doc.querySelectorAll('script, iframe, object, embed, style, head, meta, link').forEach(el => el.remove());

  doc.querySelectorAll('*').forEach(el => {
    Array.from(el.attributes).forEach(attr => {
      if (attr.name.startsWith('on')) el.removeAttribute(attr.name);
    });
    const tag = el.tagName.toLowerCase();
    if (tag === 'img') {
      const src = el.getAttribute('src') || '';
      // Remove any non-blob, non-data src that slipped through (broken relative paths)
      if (src && !src.startsWith('blob:') && !src.startsWith('data:')) el.removeAttribute('src');
    }
    if (el.tagName === 'A') {
      const href = el.getAttribute('href') || '';
      if (href.startsWith('http://') || href.startsWith('https://')) {
        el.setAttribute('target', '_blank');
        el.setAttribute('rel', 'noopener noreferrer');
      } else {
        el.removeAttribute('href');
        el.style.cursor = 'default';
      }
    }
  });

  return doc.body ? doc.body.innerHTML : doc.documentElement.innerHTML;
}

// ---------------------------------------------------------------------------
// Books
// ---------------------------------------------------------------------------

let currentBookId = null;
let currentBookToc = [];
let currentImageMap = {};
let readerScrollSaveTimer = null;
const bookMetaCache = {}; // id → {title, author, type}

// Reader settings
let readerSettings = { fontSize: 16, lineHeight: 1.8, maxWidth: 65, theme: 'dark',
                        pdfZoom: 100, pdfInverted: false, pdfPaginated: false };
let readerSettingsPanelOpen = false;
let currentPdfDoc = null;
let currentPdfBuffer = null;

// Bookmarks
let currentBookmarks = [];
let bookmarksDirty = false;

// Highlights
let currentHighlights = [];
let highlightsDirty = false;
let currentHighlightPopover = null;

// Search
let searchMatches = [];
let searchMatchIndex = -1;
let searchOriginalContent = null;
let readerSearchOpen = false;

// PDF paginated
let pdfCurrentPage = 1;
let pdfTotalPages = 0;
let _pdfPageTextBoxCache = {};
let _touchStartX = 0;

if (typeof pdfjsLib !== 'undefined') {
  pdfjsLib.GlobalWorkerOptions.workerSrc = '/static/js/pdf.worker.min.js';
}
const DEFAULT_FOCUS_STATION = {
  url: 'https://ice5.somafm.com/groovesalad-128-aac',
  name: 'SomaFM Groove Salad',
};

async function loadBookList() {
  if (!IS_AUTHENTICATED) return;
  const listEl = $('book-list');
  if (!listEl) return;
  listEl.innerHTML = '<p class="muted">Loading…</p>';

  try {
    const res = await fetch('/books/');
    const books = await res.json();
    if (!books.length) {
      listEl.innerHTML = '<p class="muted">No books yet. Drop an .epub or .pdf above.</p>';
      return;
    }

    const key = await getOrCreateEncKey();
    const decrypted = [];
    for (const b of books) {
      try {
        const metaBuf = await decryptBytes(key, b.meta_iv, b.meta_ct);
        const meta = JSON.parse(new TextDecoder().decode(metaBuf));
        bookMetaCache[b.id] = {title: meta.title || '?', author: meta.author || '', type: meta.type || 'epub'};
        decrypted.push({id: b.id, title: meta.title || '?', author: meta.author || '', type: meta.type || 'epub', scroll_fraction: b.scroll_fraction, uploaded_at: b.uploaded_at});
      } catch (e) {
        bookMetaCache[b.id] = {title: `Book #${b.id}`, author: '', type: 'epub'};
        decrypted.push({id: b.id, title: `Book #${b.id}`, author: '', type: 'epub', scroll_fraction: b.scroll_fraction, uploaded_at: b.uploaded_at});
      }
    }
    renderBookList(decrypted);
  } catch (e) {
    if (listEl) listEl.innerHTML = '<p class="muted">Failed to load books.</p>';
  }
}

function renderBookList(books) {
  const listEl = $('book-list');
  if (!listEl) return;
  let html = '';
  for (const b of books) {
    const pct = Math.round((b.scroll_fraction || 0) * 100);
    html += `<div class="book-item">
      <div class="book-item-info">
        <strong class="book-title">${escapeHtml(b.title)}</strong>
        <span class="muted book-author">${escapeHtml(b.author)}</span>
        ${pct > 0 ? `<span class="muted book-progress">${pct}% read</span>` : ''}
      </div>
      <div class="book-item-actions">
        <button class="btn btn-sm" onclick="openBook(${b.id})">Open</button>
        <button class="btn btn-sm btn-danger" onclick="deleteBook(${b.id})">Delete</button>
      </div>
    </div>`;
  }
  listEl.innerHTML = html;
}

function bookFileSelected(input) {
  const file = input.files[0];
  if (!file) return;
  uploadEbook(file);
  input.value = '';
}

function initBookDropZone() {
  // Prevent Firefox from opening dragged files when dropped outside the zone
  document.addEventListener('dragover', e => e.preventDefault());
  document.addEventListener('drop', e => {
    const zone = $('book-drop-zone');
    if (!zone || !zone.contains(e.target)) e.preventDefault();
  });

  const zone = $('book-drop-zone');
  if (!zone) return;

  zone.addEventListener('dragover', e => {
    e.preventDefault();
    zone.classList.add('drag-over');
  });
  zone.addEventListener('dragleave', () => zone.classList.remove('drag-over'));
  zone.addEventListener('drop', e => {
    e.preventDefault();
    zone.classList.remove('drag-over');
    const file = e.dataTransfer.files[0];
    if (file) uploadEbook(file);
  });
}

async function deriveAndStoreKey() {
  const pwInput = document.getElementById('enc-key-password');
  const statusEl = $('enc-key-status');
  const pw = pwInput ? pwInput.value : '';
  if (!pw) { if (statusEl) statusEl.textContent = 'Please enter your password.'; return; }

  if (statusEl) statusEl.textContent = 'Deriving key…';
  try {
    const enc = new TextEncoder();
    const username = document.querySelector('meta[name="username"]')?.content || '';
    const mat = await crypto.subtle.importKey('raw', enc.encode(pw), 'PBKDF2', false, ['deriveKey']);
    const key = await crypto.subtle.deriveKey(
      {name: 'PBKDF2', salt: enc.encode('diora:' + username), iterations: 200000, hash: 'SHA-256'},
      mat, {name: 'AES-GCM', length: 256}, true, ['encrypt', 'decrypt']
    );
    const raw = await crypto.subtle.exportKey('raw', key);
    const storageKey = `diora_enc_key_${window.USER_ID || 0}`;
    localStorage.setItem(storageKey, bytesToBase64(new Uint8Array(raw)));
    _encKey = null; // reset cached key
    if (statusEl) statusEl.textContent = '✓ Unlocked';
    const prompt = $('enc-key-prompt');
    const uploadArea = $('book-upload-area');
    if (prompt) prompt.style.display = 'none';
    if (uploadArea) uploadArea.style.display = '';
    loadBookList();
  } catch (err) {
    if (statusEl) statusEl.textContent = 'Error: ' + err.message;
  }
}

async function uploadEbook(file) {
  const statusEl = $('book-upload-status');
  const isPdf = /\.pdf$/i.test(file.name);
  const isEpub = /\.epub$/i.test(file.name);
  if (!isPdf && !isEpub) {
    if (statusEl) statusEl.textContent = 'Only .epub and .pdf files are supported.';
    return;
  }
  if (file.size > 10 * 1024 * 1024) {
    if (statusEl) statusEl.textContent = 'File too large (max 10 MB).';
    return;
  }

  if (statusEl) statusEl.textContent = 'Encrypting…';

  try {
    const buf = await file.arrayBuffer();

    let title = file.name.replace(/\.(epub|pdf)$/i, '');
    let author = '';
    const type = isPdf ? 'pdf' : 'epub';

    if (isPdf) {
      try {
        const pdfDoc = await pdfjsLib.getDocument({data: new Uint8Array(buf.slice(0))}).promise;
        const meta = await pdfDoc.getMetadata();
        title = meta.info?.Title?.trim() || title;
        author = meta.info?.Author?.trim() || '';
      } catch (e) { /* use filename as title */ }
    } else {
      try {
        const zip = await JSZip.loadAsync(buf.slice(0));
        const containerXml = await zip.file('META-INF/container.xml').async('text');
        const containerDoc = new DOMParser().parseFromString(containerXml, 'application/xml');
        const opfPath = containerDoc.querySelector('rootfile')?.getAttribute('full-path');
        if (opfPath) {
          const opfText = await zip.file(opfPath).async('text');
          const opfDoc = new DOMParser().parseFromString(opfText, 'application/xml');
          title = opfDoc.querySelector('metadata > title, metadata > *|title')?.textContent?.trim() || title;
          author = opfDoc.querySelector('metadata > creator, metadata > *|creator')?.textContent?.trim() || '';
        }
      } catch (e) { /* use filename as title */ }
    }

    const key = await getOrCreateEncKey();
    const metaJson = new TextEncoder().encode(JSON.stringify({title, author, filename: file.name, type}));
    const [metaEnc, dataEnc] = await Promise.all([
      encryptBytes(key, metaJson),
      encryptBytes(key, buf),
    ]);

    if (statusEl) statusEl.textContent = 'Uploading…';

    const res = await fetch('/books/upload/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({
        meta_ct: metaEnc.ciphertext,
        meta_iv: metaEnc.iv,
        data_ct: dataEnc.ciphertext,
        data_iv: dataEnc.iv,
      }),
    });
    const data = await res.json();
    if (data.ok) {
      if (statusEl) statusEl.textContent = `✓ "${title}" uploaded`;
      loadBookList();
    } else {
      if (statusEl) statusEl.textContent = 'Error: ' + (data.error || 'upload failed');
    }
  } catch (e) {
    if (statusEl) statusEl.textContent = 'Upload failed: ' + e.message;
  }
}

async function _parsePdfOutline(pdf, items, depth) {
  depth = depth || 0;
  const result = [];
  for (const item of items) {
    let href = '';
    if (item.dest) {
      try {
        const dest = typeof item.dest === 'string' ? await pdf.getDestination(item.dest) : item.dest;
        if (dest) {
          const pageIndex = await pdf.getPageIndex(dest[0]);
          href = `#pdf-page-${pageIndex + 1}`;
        }
      } catch (e) {}
    }
    result.push({label: item.title || '(untitled)', href, depth});
    if (item.items && item.items.length) {
      result.push(...await _parsePdfOutline(pdf, item.items, depth + 1));
    }
  }
  return result;
}

async function renderPdf(arrayBuffer, contentEl, scaleOverride) {
  const pdf = currentPdfDoc || await pdfjsLib.getDocument({data: new Uint8Array(arrayBuffer)}).promise;
  currentPdfDoc = pdf;

  let pdfTitle = '', pdfAuthor = '';
  try {
    const meta = await pdf.getMetadata();
    pdfTitle = meta.info?.Title?.trim() || '';
    pdfAuthor = meta.info?.Author?.trim() || '';
  } catch (e) {}

  let toc = [];
  try {
    const outline = await pdf.getOutline();
    if (outline && outline.length) toc = await _parsePdfOutline(pdf, outline);
  } catch (e) {}

  contentEl.innerHTML = '';

  const containerWidth = contentEl.clientWidth - 32;

  for (let pageNum = 1; pageNum <= pdf.numPages; pageNum++) {
    const page = await pdf.getPage(pageNum);
    const naturalVp = page.getViewport({scale: 1});
    const scale = scaleOverride != null ? scaleOverride
      : Math.max(0.5, (containerWidth / naturalVp.width) * (readerSettings.pdfZoom / 100));
    const viewport = page.getViewport({scale});

    const wrapper = document.createElement('div');
    wrapper.className = 'pdf-page-wrapper';
    wrapper.id = `pdf-page-${pageNum}`;

    // Inner container gives canvas + text layer a shared position:relative origin,
    // independent of the outer flex wrapper's centering.
    const inner = document.createElement('div');
    inner.className = 'pdf-page-inner';

    const canvas = document.createElement('canvas');
    canvas.className = 'pdf-page';
    canvas.width = viewport.width;
    canvas.height = viewport.height;
    inner.appendChild(canvas);
    wrapper.appendChild(inner);
    contentEl.appendChild(wrapper);

    await page.render({canvasContext: canvas.getContext('2d'), viewport}).promise;

    // Text layer disabled — re-enable once overlay rendering is resolved
  }

  pdfTotalPages = pdf.numPages;
  return {title: pdfTitle, author: pdfAuthor, toc, numPages: pdf.numPages};
}

async function openBook(bookId) {
  const overlay = $('reader-overlay');
  const contentEl = $('reader-content');
  const titleEl = $('reader-title');
  if (!overlay || !contentEl) return;

  titleEl.textContent = 'Loading…';
  contentEl.innerHTML = '';
  overlay.style.display = '';

  try {
    loadReaderSettings();
    const key = await getOrCreateEncKey();
    const res = await fetch(`/books/${bookId}/data/`);
    const {data_ct, data_iv} = await res.json();
    const plain = await decryptBytes(key, data_iv, data_ct);

    // Revoke any previous image blob URLs
    for (const url of Object.values(currentImageMap)) URL.revokeObjectURL(url);
    currentImageMap = {};

    const cachedMeta = bookMetaCache[bookId] || {};
    let title = cachedMeta.title || '';
    let author = cachedMeta.author || '';
    let toc = [];
    let numPages = 0;
    const isPdfBook = cachedMeta.type === 'pdf';

    if (isPdfBook) {
      currentPdfDoc = null; // reset so renderPdf creates fresh doc
      const result = await renderPdf(plain, contentEl);
      title = result.title || title;
      author = result.author || author;
      toc = result.toc;
      numPages = result.numPages;
      currentPdfBuffer = plain;
    } else {
      currentPdfBuffer = null;
      const result = await parseEpub(plain);
      title = result.title || title;
      author = result.author || author;
      toc = result.toc;
      currentImageMap = result.imageMap;
      contentEl.innerHTML = result.html;
    }

    currentBookToc = toc;
    titleEl.textContent = title + (author ? ` — ${author}` : '');

    currentBookId = bookId;

    // Load bookmarks and highlights
    await Promise.all([
      loadBookmarks(bookId),
      loadHighlights(bookId),
    ]);

    // Apply reader settings (theme, font size, etc.)
    applyReaderSettings(isPdfBook);

    // Enable PDF paginated mode if configured (auto on mobile)
    if (isPdfBook && readerSettings.pdfPaginated) {
      enterPdfPaginatedMode();
    }

    // Wire highlight selection listener for EPUB
    if (!isPdfBook) {
      contentEl.addEventListener('mouseup', handleReaderSelection);
    }

    // Swipe for PDF paginated
    contentEl.addEventListener('touchstart', e => { _touchStartX = e.touches[0].clientX; }, {passive: true});
    contentEl.addEventListener('touchend', e => {
      if (!readerSettings.pdfPaginated) return;
      const delta = e.changedTouches[0].clientX - _touchStartX;
      if (delta > 50) pdfGoToPage(pdfCurrentPage - 1);
      else if (delta < -50) pdfGoToPage(pdfCurrentPage + 1);
    }, {passive: true});

    // Set up progress input
    const progressInput = $('reader-progress-input');
    const progressSuffix = $('reader-progress-suffix');
    const isPdf = isPdfBook;

    if (progressInput) {
      progressInput.style.display = '';
      if (isPdf) {
        progressInput.min = 1;
        progressInput.max = numPages;
        progressInput.value = 1;
        if (progressSuffix) progressSuffix.textContent = `/ ${numPages}`;
      } else {
        progressInput.min = 0;
        progressInput.max = 100;
        progressInput.value = 0;
        if (progressSuffix) progressSuffix.textContent = '%';
      }

      progressInput.addEventListener('change', function () {
        if (isPdf) {
          const page = Math.min(numPages, Math.max(1, parseInt(this.value, 10) || 1));
          this.value = page;
          const target = contentEl.querySelector(`#pdf-page-${page}`);
          if (target) {
            const top = target.getBoundingClientRect().top - contentEl.getBoundingClientRect().top;
            contentEl.scrollBy({top: top - 8, behavior: 'smooth'});
          }
        } else {
          const pct = Math.min(100, Math.max(0, parseInt(this.value, 10) || 0));
          this.value = pct;
          contentEl.scrollTop = (pct / 100) * contentEl.scrollHeight;
        }
      });

      progressInput.addEventListener('click', function () { this.select(); });
    }

    // Restore scroll position
    try {
      const progressRes = await fetch('/books/');
      const allBooks = await progressRes.json();
      const bookData = allBooks.find(b => b.id === bookId);
      const fraction = bookData ? (bookData.scroll_fraction || 0) : 0;
      if (fraction > 0) {
        if (isPdf && readerSettings.pdfPaginated && pdfTotalPages > 1) {
          pdfCurrentPage = Math.max(1, Math.round(fraction * (pdfTotalPages - 1)) + 1);
        } else {
          // For EPUB: wait for all images to load so scrollHeight is final
          if (!isPdf) {
            const imgs = Array.from(contentEl.querySelectorAll('img'));
            if (imgs.length) {
              await Promise.all(imgs.map(img =>
                img.complete ? Promise.resolve()
                  : new Promise(r => { img.onload = r; img.onerror = r; })
              ));
            }
          }
          // One more rAF to let the browser recalculate layout after image load
          await new Promise(r => requestAnimationFrame(r));
          contentEl.scrollTop = fraction * (contentEl.scrollHeight - contentEl.clientHeight);
        }
      }
    } catch (e) {}

    // Update progress input on scroll
    contentEl.addEventListener('scroll', () => {
      if (!progressInput) return;
      if (isPdf) {
        const wrappers = contentEl.querySelectorAll('.pdf-page-wrapper');
        const cTop = contentEl.getBoundingClientRect().top;
        let currentPage = 1;
        for (const w of wrappers) {
          if (w.getBoundingClientRect().bottom > cTop + 20) {
            currentPage = parseInt(w.id.replace('pdf-page-', ''), 10) || 1;
            break;
          }
        }
        progressInput.value = currentPage;
      } else {
        const f = contentEl.scrollTop / (contentEl.scrollHeight - contentEl.clientHeight || 1);
        progressInput.value = Math.round(f * 100);
      }
    });

    // Auto-save progress every 10s and on scroll (debounced 2s)
    readerScrollSaveTimer = setInterval(saveReaderProgress, 10000);
    let _scrollDebounce = null;
    contentEl.addEventListener('scroll', () => {
      clearTimeout(_scrollDebounce);
      _scrollDebounce = setTimeout(saveReaderProgress, 2000);
    }, {passive: true});

    // Determine which station to play (null = use default, {url:''} = disabled)
    const focusStation = USER_FOCUS_STATION === null ? DEFAULT_FOCUS_STATION
      : (USER_FOCUS_STATION.url ? USER_FOCUS_STATION : null);

    if (focusStation) {
      if (isPlaying) {
        // Don't interrupt — highlight button, play on click instead
        const btn = $('focus-station-btn');
        if (btn) {
          btn.classList.add('focus-pending');
          btn.title = `Click to play focus station: ${focusStation.name}`;
          btn._pendingFocusStation = focusStation;
          btn.onclick = function () {
            playStation(focusStation.url, focusStation.name, null);
            btn.classList.remove('focus-pending');
            btn.title = 'Focus station';
            btn._pendingFocusStation = null;
            btn.onclick = openFocusStationSidebar;
          };
        }
      } else {
        playStation(focusStation.url, focusStation.name, null);
      }
    }

  } catch (e) {
    contentEl.innerHTML = `<p class="muted">Failed to open book: ${escapeHtml(e.message)}</p>`;
  }
}

async function exportEncKey() {
  const statusEl = $('book-key-status');
  try {
    const key = await getOrCreateEncKey();
    const raw = await crypto.subtle.exportKey('raw', key);
    const b64 = bytesToBase64(raw);
    await navigator.clipboard.writeText(b64);
    if (statusEl) statusEl.textContent = '✓ Key copied to clipboard';
    setTimeout(() => { if (statusEl) statusEl.textContent = ''; }, 3000);
  } catch (e) {
    if (statusEl) statusEl.textContent = 'Export failed: ' + e.message;
  }
}

function showImportKey() {
  const body = $('sidebar-body');
  openSidebar('Import encryption key', `
    <p class="muted">Paste the key exported from your other browser:</p>
    <textarea id="import-key-input" class="search-input" rows="3" style="width:100%;resize:none;font-family:monospace;font-size:0.75rem;"></textarea>
    <button class="btn" style="margin-top:8px;" data-import-key-apply>Apply</button>
    <p class="muted" style="margin-top:8px;">This replaces the key in this browser. Books uploaded here won't be readable until you sync the key back.</p>
  `);
  body.addEventListener('click', async function _importClick(e) {
    if (!e.target.closest('[data-import-key-apply]')) return;
    body.removeEventListener('click', _importClick);
    const b64 = (body.querySelector('#import-key-input')?.value || '').trim();
    const statusEl = $('book-key-status');
    try {
      const raw = base64ToBytes(b64);
      const importedKey = await crypto.subtle.importKey('raw', raw, {name: 'AES-GCM', length: 256}, true, ['encrypt', 'decrypt']);
      const re_exported = await crypto.subtle.exportKey('raw', importedKey);
      localStorage.setItem(`diora_enc_key_${window.USER_ID}`, bytesToBase64(re_exported));
      closeSidebar();
      if (statusEl) statusEl.textContent = '✓ Key imported — reloading books…';
      await loadBookList();
      if (statusEl) setTimeout(() => { statusEl.textContent = ''; }, 3000);
    } catch (e) {
      if ($('book-key-status')) $('book-key-status').textContent = 'Import failed: invalid key';
    }
  });
}

async function deleteBook(bookId) {
  if (!confirm('Delete this book? This cannot be undone.')) return;
  try {
    const res = await fetch(`/books/${bookId}/delete/`, {
      method: 'POST',
      headers: {'X-CSRFToken': getCsrfToken()},
    });
    const data = await res.json();
    if (data.ok) loadBookList();
  } catch (e) {}
}

async function saveReaderProgress() {
  if (!currentBookId) return;
  const contentEl = $('reader-content');
  if (!contentEl) return;

  let fraction;
  if (readerSettings.pdfPaginated && currentPdfDoc && pdfTotalPages > 1) {
    fraction = (pdfCurrentPage - 1) / (pdfTotalPages - 1);
  } else {
    fraction = contentEl.scrollTop / (contentEl.scrollHeight - contentEl.clientHeight || 1);
  }
  fraction = Math.min(1.0, Math.max(0.0, fraction));

  // Cache for sendBeacon on unload
  _lastProgressBeacon = {
    url: `/books/${currentBookId}/progress/`,
    body: JSON.stringify({scroll_fraction: fraction}),
  };

  try {
    await fetch(`/books/${currentBookId}/progress/`, {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: _lastProgressBeacon.body,
    });
  } catch (e) {}
}

function closeReader() {
  // Save progress BEFORE hiding — scrollHeight/clientHeight return 0 once display:none
  saveReaderProgress();
  if (bookmarksDirty) saveBookmarks();
  if (highlightsDirty) saveHighlights();

  const overlay = $('reader-overlay');
  if (overlay) overlay.style.display = 'none';
  if (readerScrollSaveTimer) {
    clearInterval(readerScrollSaveTimer);
    readerScrollSaveTimer = null;
  }

  // Clear search before wiping content
  clearReaderSearch();

  // Close settings panel if open
  readerSettingsPanelOpen = false;
  const sp = document.getElementById('reader-settings-panel');
  if (sp) sp.remove();

  // Reset progress input
  const progressInput = $('reader-progress-input');
  if (progressInput) { progressInput.style.display = 'none'; progressInput.value = 0; }
  const progressSuffix = $('reader-progress-suffix');
  if (progressSuffix) progressSuffix.textContent = '';

  // Free image blob URLs
  const contentEl = $('reader-content');
  if (contentEl) contentEl.innerHTML = '';
  for (const url of Object.values(currentImageMap)) URL.revokeObjectURL(url);
  currentImageMap = {};

  // Reset all state
  currentBookId = null;
  currentBookToc = [];
  currentPdfDoc = null;
  currentPdfBuffer = null;
  currentBookmarks = [];
  bookmarksDirty = false;
  currentHighlights = [];
  highlightsDirty = false;
  _lastProgressBeacon = null;
  _lastBookmarkBeacon = null;
  _lastHighlightBeacon = null;
  dismissHighlightPopover();
  pdfCurrentPage = 1;
  pdfTotalPages = 0;
  _pdfPageTextBoxCache = {};

  // Remove PDF invert class
  if (overlay) overlay.classList.remove('pdf-inverted');

  // Clear any pending focus station highlight
  const btn = $('focus-station-btn');
  if (btn && btn._pendingFocusStation) {
    btn.classList.remove('focus-pending');
    btn.title = 'Focus station';
    btn._pendingFocusStation = null;
    btn.onclick = openFocusStationSidebar;
  }
}

function openTocSidebar() {
  if (!currentBookToc.length) {
    openSidebar('Table of Contents', '<p class="muted">No table of contents found in this book.</p>');
    return;
  }
  let html = '<ul class="toc-list">';
  for (const entry of currentBookToc) {
    const indent = entry.depth * 14;
    // Use data-toc-href — onclick would be stripped by sanitizeSidebarHtml
    html += `<li style="padding-left:${indent}px">
      <button class="btn-link toc-entry" data-toc-href="${escapeHtml(entry.href)}">${escapeHtml(entry.label)}</button>
    </li>`;
  }
  html += '</ul>';
  openSidebar('Table of Contents', html);
  // Attach delegated listener after sidebar body is populated
  const body = $('sidebar-body');
  body.addEventListener('click', function _tocClick(e) {
    const btn = e.target.closest('.toc-entry');
    if (btn) {
      body.removeEventListener('click', _tocClick);
      jumpToTocEntry(btn.getAttribute('data-toc-href') || '');
    }
  });
}

function jumpToTocEntry(href) {
  closeSidebar();
  setTimeout(() => {
    const contentEl = $('reader-content');
    if (!contentEl) return;

    // PDF page jump
    if (href.startsWith('#pdf-page-')) {
      const target = contentEl.querySelector(href);
      if (target) {
        const top = target.getBoundingClientRect().top - contentEl.getBoundingClientRect().top;
        contentEl.scrollBy({top: top - 16, behavior: 'smooth'});
      }
      return;
    }

    const hashIdx = href.indexOf('#');
    const fragment = hashIdx >= 0 ? href.slice(hashIdx + 1) : '';
    const filePath = hashIdx >= 0 ? href.slice(0, hashIdx) : href;

    let target = null;
    if (fragment) {
      target = contentEl.querySelector(`#${CSS.escape(fragment)}`);
    }
    if (!target && filePath) {
      target = Array.from(contentEl.querySelectorAll('[data-epub-src]'))
        .find(el => el.getAttribute('data-epub-src') === filePath) || null;
    }
    if (target) {
      const top = target.getBoundingClientRect().top - contentEl.getBoundingClientRect().top;
      contentEl.scrollBy({top: top - 16, behavior: 'smooth'});
    }
  }, 50);
}

// ---------------------------------------------------------------------------
// Reader Settings
// ---------------------------------------------------------------------------

function loadReaderSettings() {
  try {
    const saved = JSON.parse(localStorage.getItem('diora_reader_settings') || '{}');
    Object.assign(readerSettings, saved);
    // Auto-paginate on mobile if not explicitly set
    if (saved.pdfPaginated === undefined) {
      readerSettings.pdfPaginated = window.innerWidth < 768;
    }
  } catch (e) {}
}

function saveReaderSettings() {
  localStorage.setItem('diora_reader_settings', JSON.stringify(readerSettings));
}

function applyReaderSettings(isPdf) {
  const overlay = $('reader-overlay');
  const contentEl = $('reader-content');
  if (!overlay || !contentEl) return;

  if (!isPdf) {
    contentEl.style.fontSize = readerSettings.fontSize + 'px';
    contentEl.style.lineHeight = readerSettings.lineHeight;
    contentEl.style.setProperty('--reader-max-width', readerSettings.maxWidth + 'ch');
  }

  // Theme
  overlay.classList.remove('reader-theme-sepia', 'reader-theme-bright');
  if (readerSettings.theme === 'sepia') overlay.classList.add('reader-theme-sepia');
  else if (readerSettings.theme === 'bright') overlay.classList.add('reader-theme-bright');

  // PDF invert
  if (isPdf && readerSettings.pdfInverted) overlay.classList.add('pdf-inverted');
  else overlay.classList.remove('pdf-inverted');
}

function toggleSettingsPanel() {
  const overlay = $('reader-overlay');
  const contentEl = $('reader-content');
  if (!overlay || !contentEl) return;

  const existing = document.getElementById('reader-settings-panel');
  if (existing) {
    existing.remove();
    readerSettingsPanelOpen = false;
    return;
  }

  readerSettingsPanelOpen = true;
  const isPdf = !!currentPdfDoc;

  const panel = document.createElement('div');
  panel.id = 'reader-settings-panel';
  panel.className = 'reader-settings-panel';

  if (!isPdf) {
    panel.innerHTML = `
      <label>Font <input type="range" id="rs-font" min="12" max="24" step="1" value="${readerSettings.fontSize}"> <span id="rs-font-val">${readerSettings.fontSize}px</span></label>
      <label>Line <input type="range" id="rs-line" min="12" max="30" step="1" value="${Math.round(readerSettings.lineHeight * 10)}"> <span id="rs-line-val">${readerSettings.lineHeight}</span></label>
      <label>Width <input type="range" id="rs-width" min="40" max="90" step="5" value="${readerSettings.maxWidth}"> <span id="rs-width-val">${readerSettings.maxWidth}ch</span></label>
      <button class="btn btn-sm" id="rs-width-full">Full</button>
      <button class="btn btn-sm ${readerSettings.theme === 'dark'   ? 'active' : ''}" data-rs-theme="dark">Dark</button>
      <button class="btn btn-sm ${readerSettings.theme === 'sepia'  ? 'active' : ''}" data-rs-theme="sepia">Sepia</button>
      <button class="btn btn-sm ${readerSettings.theme === 'bright' ? 'active' : ''}" data-rs-theme="bright">Bright</button>
    `;
  } else {
    panel.innerHTML = `
      <label>Zoom <input type="range" id="rs-zoom" min="50" max="200" step="10" value="${readerSettings.pdfZoom}"> <span id="rs-zoom-val">${readerSettings.pdfZoom}%</span></label>
      <button class="btn btn-sm ${readerSettings.pdfInverted ? 'active' : ''}" id="rs-invert">Invert</button>
      <button class="btn btn-sm ${readerSettings.pdfPaginated ? 'active' : ''}" id="rs-paginated">Paginated</button>
    `;
  }

  overlay.insertBefore(panel, contentEl);

  if (!isPdf) {
    const fontRange = panel.querySelector('#rs-font');
    const fontVal   = panel.querySelector('#rs-font-val');
    fontRange.addEventListener('input', () => {
      readerSettings.fontSize = parseInt(fontRange.value, 10);
      fontVal.textContent = readerSettings.fontSize + 'px';
      applyReaderSettings(false);
      saveReaderSettings();
    });

    const lineRange = panel.querySelector('#rs-line');
    const lineVal   = panel.querySelector('#rs-line-val');
    lineRange.addEventListener('input', () => {
      readerSettings.lineHeight = (parseInt(lineRange.value, 10) / 10).toFixed(1);
      lineVal.textContent = readerSettings.lineHeight;
      applyReaderSettings(false);
      saveReaderSettings();
    });

    const widthRange = panel.querySelector('#rs-width');
    const widthVal   = panel.querySelector('#rs-width-val');
    widthRange.addEventListener('input', () => {
      readerSettings.maxWidth = parseInt(widthRange.value, 10);
      widthVal.textContent = readerSettings.maxWidth + 'ch';
      applyReaderSettings(false);
      saveReaderSettings();
    });

    panel.querySelector('#rs-width-full').addEventListener('click', () => {
      readerSettings.maxWidth = 999;
      widthRange.value = 90;
      widthVal.textContent = 'full';
      applyReaderSettings(false);
      saveReaderSettings();
    });

    panel.querySelectorAll('[data-rs-theme]').forEach(btn => {
      btn.addEventListener('click', () => {
        readerSettings.theme = btn.dataset.rsTheme;
        panel.querySelectorAll('[data-rs-theme]').forEach(b => b.classList.toggle('active', b === btn));
        applyReaderSettings(false);
        saveReaderSettings();
      });
    });
  } else {
    const zoomRange = panel.querySelector('#rs-zoom');
    const zoomVal   = panel.querySelector('#rs-zoom-val');
    zoomRange.addEventListener('change', () => {
      readerSettings.pdfZoom = parseInt(zoomRange.value, 10);
      zoomVal.textContent = readerSettings.pdfZoom + '%';
      saveReaderSettings();
      reRenderPdf();
    });

    panel.querySelector('#rs-invert').addEventListener('click', function () {
      readerSettings.pdfInverted = !readerSettings.pdfInverted;
      this.classList.toggle('active', readerSettings.pdfInverted);
      applyReaderSettings(true);
      saveReaderSettings();
    });

    panel.querySelector('#rs-paginated').addEventListener('click', function () {
      readerSettings.pdfPaginated = !readerSettings.pdfPaginated;
      this.classList.toggle('active', readerSettings.pdfPaginated);
      saveReaderSettings();
      if (readerSettings.pdfPaginated) {
        enterPdfPaginatedMode();
      } else {
        exitPdfPaginatedMode();
      }
    });
  }
}

async function reRenderPdf() {
  if (!currentPdfBuffer) return;
  const contentEl = $('reader-content');
  if (!contentEl) return;
  currentPdfDoc = null; // force re-parse with same buffer
  await renderPdf(currentPdfBuffer, contentEl);
  if (readerSettings.pdfPaginated) enterPdfPaginatedMode();
}

// ---------------------------------------------------------------------------
// PDF Paginated Mode
// ---------------------------------------------------------------------------

function enterPdfPaginatedMode() {
  const contentEl = $('reader-content');
  if (!contentEl) return;
  contentEl.classList.add('pdf-paginated');
  contentEl.style.overflow = 'hidden';

  const wrappers = contentEl.querySelectorAll('.pdf-page-wrapper');
  wrappers.forEach((w, i) => {
    w.style.display = (i + 1 === pdfCurrentPage) ? '' : 'none';
  });

  pdfSmartZoomPage(pdfCurrentPage);

  // Tap left/right to navigate
  contentEl.addEventListener('click', _pdfPaginatedClick);
}

function exitPdfPaginatedMode() {
  const contentEl = $('reader-content');
  if (!contentEl) return;
  contentEl.classList.remove('pdf-paginated');
  contentEl.style.overflow = '';
  contentEl.removeEventListener('click', _pdfPaginatedClick);
  const wrappers = contentEl.querySelectorAll('.pdf-page-wrapper');
  wrappers.forEach(w => {
    w.style.display = '';
    const canvas = w.querySelector('canvas');
    if (canvas) canvas.style.transform = '';
  });
}

function _pdfPaginatedClick(e) {
  const w = e.currentTarget.clientWidth;
  if (e.clientX < w * 0.4) pdfGoToPage(pdfCurrentPage - 1);
  else if (e.clientX > w * 0.6) pdfGoToPage(pdfCurrentPage + 1);
}

function pdfGoToPage(n) {
  if (!currentPdfDoc) return;
  n = Math.max(1, Math.min(pdfTotalPages, n));
  if (n === pdfCurrentPage) return;
  const contentEl = $('reader-content');
  if (!contentEl) return;

  const oldWrapper = contentEl.querySelector(`#pdf-page-${pdfCurrentPage}`);
  if (oldWrapper) oldWrapper.style.display = 'none';

  pdfCurrentPage = n;
  const newWrapper = contentEl.querySelector(`#pdf-page-${pdfCurrentPage}`);
  if (newWrapper) newWrapper.style.display = '';

  pdfSmartZoomPage(pdfCurrentPage);

  const progressInput = $('reader-progress-input');
  if (progressInput) progressInput.value = pdfCurrentPage;
}

async function pdfSmartZoomPage(pageNum) {
  if (!currentPdfDoc) return;
  const contentEl = $('reader-content');
  if (!contentEl) return;
  const wrapper = contentEl.querySelector(`#pdf-page-${pageNum}`);
  if (!wrapper) return;
  const canvas = wrapper.querySelector('canvas');
  if (!canvas) return;

  const page = await currentPdfDoc.getPage(pageNum);
  const naturalVp = page.getViewport({scale: 1});
  const pageW = naturalVp.width;
  const pageH = naturalVp.height;

  let bbox = _pdfPageTextBoxCache[pageNum];
  if (!bbox) {
    bbox = await _computePdfTextBox(page, pageW, pageH);
    _pdfPageTextBoxCache[pageNum] = bbox;
  }

  const containerW = contentEl.clientWidth;
  const containerH = contentEl.clientHeight;
  const contentW = bbox.x2 - bbox.x1;
  const contentH = bbox.y2 - bbox.y1;
  const pad = 12;
  const scale = Math.min(
    (containerW - pad * 2) / contentW,
    (containerH - pad * 2) / contentH
  );

  // Re-render canvas at new scale if significantly different
  const currentScale = canvas.width / naturalVp.width;
  if (Math.abs(scale - currentScale) / currentScale > 0.05) {
    const vp = page.getViewport({scale});
    canvas.width = vp.width;
    canvas.height = vp.height;
    await page.render({canvasContext: canvas.getContext('2d'), viewport: vp}).promise;
  }

  // Position canvas to center the text bounding box
  const renderedScale = canvas.width / naturalVp.width;
  const offsetX = -renderedScale * (bbox.x1 - pad) + (containerW - renderedScale * contentW - pad * 2) / 2;
  // PDF y-axis is bottom-up; canvas is top-down
  const offsetY = -renderedScale * (pageH - bbox.y2 - pad) + (containerH - renderedScale * contentH - pad * 2) / 2;
  canvas.style.transform = `translate(${offsetX}px, ${offsetY}px)`;
  wrapper.style.overflow = 'hidden';
  wrapper.style.width = containerW + 'px';
  wrapper.style.height = containerH + 'px';
}

async function _computePdfTextBox(page, pageW, pageH) {
  // Tier 1: text-based
  try {
    const tc = await page.getTextContent();
    if (tc.items && tc.items.length) {
      let x1 = Infinity, y1 = Infinity, x2 = -Infinity, y2 = -Infinity;
      for (const item of tc.items) {
        if (!item.transform) continue;
        const tx = item.transform[4], ty = item.transform[5];
        const iw = item.width || 0, ih = item.height || 0;
        if (tx < x1) x1 = tx;
        if (ty < y1) y1 = ty;
        if (tx + iw > x2) x2 = tx + iw;
        if (ty + ih > y2) y2 = ty + ih;
      }
      const area = (x2 - x1) * (y2 - y1);
      if (isFinite(x1) && area > pageW * pageH * 0.25) {
        return {x1, y1, x2, y2};
      }
    }
  } catch (e) {}

  // Tier 2: pixel analysis at scale 0.3
  try {
    const lowScale = 0.3;
    const vp = page.getViewport({scale: lowScale});
    const offCanvas = document.createElement('canvas');
    offCanvas.width = vp.width;
    offCanvas.height = vp.height;
    const ctx = offCanvas.getContext('2d');
    await page.render({canvasContext: ctx, viewport: vp}).promise;
    const {data, width, height} = ctx.getImageData(0, 0, vp.width, vp.height);

    let rMin = height, rMax = 0, cMin = width, cMax = 0;
    for (let r = 0; r < height; r++) {
      for (let c = 0; c < width; c++) {
        const idx = (r * width + c) * 4;
        if (data[idx] + data[idx+1] + data[idx+2] < 720) {
          if (r < rMin) rMin = r;
          if (r > rMax) rMax = r;
          if (c < cMin) cMin = c;
          if (c > cMax) cMax = c;
        }
      }
    }
    if (rMin < rMax && cMin < cMax) {
      return {
        x1: cMin / lowScale,
        y1: (height - rMax) / lowScale,
        x2: cMax / lowScale,
        y2: (height - rMin) / lowScale,
      };
    }
  } catch (e) {}

  // Fallback: full page
  return {x1: 0, y1: 0, x2: pageW, y2: pageH};
}

// ---------------------------------------------------------------------------
// Bookmarks
// ---------------------------------------------------------------------------

async function loadBookmarks(bookId) {
  try {
    const res = await fetch(`/books/${bookId}/bookmarks/`);
    const {ct, iv} = await res.json();
    if (ct) {
      const key = await getOrCreateEncKey();
      const plain = await decryptBytes(key, iv, ct);
      currentBookmarks = JSON.parse(new TextDecoder().decode(plain));
    } else {
      currentBookmarks = [];
    }
  } catch (e) {
    currentBookmarks = [];
  }
}

async function saveBookmarks() {
  if (!currentBookId) return;
  try {
    const key = await getOrCreateEncKey();
    const plain = new TextEncoder().encode(JSON.stringify(currentBookmarks));
    const {iv, ciphertext} = await encryptBytes(key, plain);
    const body = JSON.stringify({ct: ciphertext, iv});
    const url = `/books/${currentBookId}/bookmarks/`;
    _lastBookmarkBeacon = {url, body};
    await fetch(url, {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body,
    });
    bookmarksDirty = false;
  } catch (e) {}
}

function addBookmark() {
  const contentEl = $('reader-content');
  if (!contentEl || !currentBookId) return;

  let label, anchor, scrollFraction;

  if (currentPdfDoc) {
    const page = pdfCurrentPage || parseInt($('reader-progress-input')?.value, 10) || 1;
    label = `Page ${page}`;
    anchor = `pdf-page-${page}`;
    scrollFraction = (page - 1) / Math.max(1, pdfTotalPages - 1);
  } else {
    // Find first visible chapter div
    const chapters = contentEl.querySelectorAll('[data-epub-src]');
    let visibleChapter = null;
    for (const ch of chapters) {
      const rect = ch.getBoundingClientRect();
      if (rect.bottom > 0 && rect.top < window.innerHeight) {
        visibleChapter = ch;
        break;
      }
    }
    const src = visibleChapter?.getAttribute('data-epub-src') || '';
    label = src.split('/').pop().replace(/\.x?html?$/i, '') || 'Bookmark';
    anchor = src;
    scrollFraction = contentEl.scrollTop / (contentEl.scrollHeight - contentEl.clientHeight || 1);
  }

  const bm = {
    id: crypto.randomUUID(),
    label,
    anchor,
    scrollFraction,
    createdAt: new Date().toISOString(),
  };
  currentBookmarks.unshift(bm);
  bookmarksDirty = true;
  saveBookmarks();

  // Toast
  const toast = document.createElement('div');
  toast.className = 'reader-toast';
  toast.textContent = `★ Bookmarked: ${label}`;
  document.body.appendChild(toast);
  setTimeout(() => toast.remove(), 2200);
}

function openBookmarksSidebar() {
  if (!currentBookmarks.length) {
    openSidebar('Bookmarks', '<p class="muted">No bookmarks yet. Press ★ while reading.</p>');
    return;
  }
  let html = '<ul style="list-style:none;padding:0;">';
  for (const bm of currentBookmarks) {
    html += `<li class="bookmark-entry">
      <button class="btn-link" data-jump-bookmark="${escapeHtml(bm.id)}" style="flex:1;text-align:left;">
        ${escapeHtml(bm.label)}
      </button>
      <button class="btn-icon" data-delete-bookmark="${escapeHtml(bm.id)}" title="Delete">✕</button>
    </li>`;
  }
  html += '</ul>';
  openSidebar('Bookmarks', html);

  const body = $('sidebar-body');
  body.addEventListener('click', function _bmClick(e) {
    const jumpBtn = e.target.closest('[data-jump-bookmark]');
    const delBtn  = e.target.closest('[data-delete-bookmark]');
    if (jumpBtn) {
      body.removeEventListener('click', _bmClick);
      jumpToBookmark(jumpBtn.dataset.jumpBookmark);
    }
    if (delBtn) {
      const id = delBtn.dataset.deleteBookmark;
      currentBookmarks = currentBookmarks.filter(b => b.id !== id);
      bookmarksDirty = true;
      saveBookmarks();
      openBookmarksSidebar(); // re-render
    }
  });
}

function jumpToBookmark(id) {
  const bm = currentBookmarks.find(b => b.id === id);
  if (!bm) return;
  closeSidebar();
  setTimeout(() => {
    const contentEl = $('reader-content');
    if (!contentEl) return;
    if (bm.anchor.startsWith('pdf-page-')) {
      if (readerSettings.pdfPaginated) {
        pdfGoToPage(parseInt(bm.anchor.replace('pdf-page-', ''), 10) || 1);
      } else {
        const target = contentEl.querySelector('#' + bm.anchor);
        if (target) {
          const top = target.getBoundingClientRect().top - contentEl.getBoundingClientRect().top;
          contentEl.scrollBy({top: top - 16, behavior: 'smooth'});
        }
      }
    } else {
      const target = Array.from(contentEl.querySelectorAll('[data-epub-src]'))
        .find(el => el.getAttribute('data-epub-src') === bm.anchor);
      if (target) {
        const top = target.getBoundingClientRect().top - contentEl.getBoundingClientRect().top;
        contentEl.scrollBy({top: top - 16, behavior: 'smooth'});
      } else {
        contentEl.scrollTop = bm.scrollFraction * (contentEl.scrollHeight - contentEl.clientHeight);
      }
    }
  }, 50);
}

// ---------------------------------------------------------------------------
// Reader Search
// ---------------------------------------------------------------------------

let _readerSearchDebounce = null;

function toggleReaderSearch() {
  const overlay = $('reader-overlay');
  const contentEl = $('reader-content');
  if (!overlay || !contentEl) return;

  const existing = document.getElementById('reader-search-bar');
  if (existing) {
    existing.remove();
    readerSearchOpen = false;
    clearReaderSearch();
    return;
  }

  readerSearchOpen = true;
  const bar = document.createElement('div');
  bar.id = 'reader-search-bar';
  bar.className = 'reader-search-bar';
  bar.innerHTML = `
    <input type="text" id="reader-search-input" class="search-input" placeholder="Search…" style="width:160px;">
    <button class="btn-icon" id="rs-search-prev" title="Previous">↑</button>
    <button class="btn-icon" id="rs-search-next" title="Next">↓</button>
    <span id="rs-search-count" class="muted"></span>
    <button class="btn-icon" id="rs-search-clear" title="Close">✕</button>
  `;
  overlay.insertBefore(bar, contentEl);

  const input = bar.querySelector('#reader-search-input');
  input.focus();
  input.addEventListener('input', () => {
    clearTimeout(_readerSearchDebounce);
    _readerSearchDebounce = setTimeout(() => doReaderSearch(input.value.trim()), 300);
  });
  input.addEventListener('keydown', e => {
    if (e.key === 'Enter') { e.shiftKey ? readerSearchPrev() : readerSearchNext(); }
    if (e.key === 'Escape') { toggleReaderSearch(); }
  });
  bar.querySelector('#rs-search-prev').addEventListener('click', readerSearchPrev);
  bar.querySelector('#rs-search-next').addEventListener('click', readerSearchNext);
  bar.querySelector('#rs-search-clear').addEventListener('click', toggleReaderSearch);
}

async function doReaderSearch(query) {
  const contentEl = $('reader-content');
  if (!contentEl) return;
  const countEl = document.getElementById('rs-search-count');

  clearReaderSearchHighlights();
  searchMatches = [];
  searchMatchIndex = -1;

  if (!query) { if (countEl) countEl.textContent = ''; return; }

  if (!currentPdfDoc) {
    // EPUB: snapshot original content
    if (!searchOriginalContent) {
      searchOriginalContent = contentEl.innerHTML;
    } else {
      contentEl.innerHTML = searchOriginalContent;
      applyHighlightsToContent();
    }

    const walker = document.createTreeWalker(contentEl, NodeFilter.SHOW_TEXT);
    const lq = query.toLowerCase();
    const ranges = [];
    let node;
    while ((node = walker.nextNode())) {
      const text = node.textContent;
      const lt = text.toLowerCase();
      let idx = 0;
      while ((idx = lt.indexOf(lq, idx)) !== -1) {
        const range = document.createRange();
        range.setStart(node, idx);
        range.setEnd(node, idx + query.length);
        ranges.push(range);
        idx += query.length;
      }
    }

    // Insert marks in reverse to preserve range validity
    for (let i = ranges.length - 1; i >= 0; i--) {
      try {
        const mark = document.createElement('mark');
        mark.className = 'reader-search-match';
        ranges[i].surroundContents(mark);
        searchMatches.unshift(mark);
      } catch (e) {}
    }
  } else {
    // PDF: collect text layer spans
    const spans = contentEl.querySelectorAll('.pdf-text-layer > span');
    const lq = query.toLowerCase();
    for (const span of spans) {
      if (span.textContent.toLowerCase().includes(lq)) {
        span.classList.add('reader-search-match');
        searchMatches.push(span);
      }
    }
  }

  if (countEl) countEl.textContent = searchMatches.length ? `1 / ${searchMatches.length}` : '0';
  if (searchMatches.length) {
    searchMatchIndex = 0;
    scrollToSearchMatch(0);
  }
}

function clearReaderSearchHighlights() {
  if (!currentPdfDoc) {
    // EPUB: restore from snapshot
    if (searchOriginalContent !== null) {
      const contentEl = $('reader-content');
      if (contentEl) {
        contentEl.innerHTML = searchOriginalContent;
        applyHighlightsToContent();
      }
      searchOriginalContent = null;
    } else {
      // Just remove marks without full restore
      document.querySelectorAll('mark.reader-search-match').forEach(m => {
        const parent = m.parentNode;
        while (m.firstChild) parent.insertBefore(m.firstChild, m);
        parent.removeChild(m);
      });
    }
  } else {
    // PDF: remove highlight class from spans
    document.querySelectorAll('.reader-search-match').forEach(el => {
      el.classList.remove('reader-search-match', 'active');
    });
  }
  searchMatches = [];
  searchMatchIndex = -1;
}

function clearReaderSearch() {
  clearTimeout(_readerSearchDebounce);
  clearReaderSearchHighlights();
  readerSearchOpen = false;
  const countEl = document.getElementById('rs-search-count');
  if (countEl) countEl.textContent = '';
}

function scrollToSearchMatch(idx) {
  if (!searchMatches.length) return;
  searchMatches.forEach((m, i) => m.classList.toggle('active', i === idx));
  searchMatches[idx].scrollIntoView({behavior: 'smooth', block: 'center'});
  const countEl = document.getElementById('rs-search-count');
  if (countEl) countEl.textContent = `${idx + 1} / ${searchMatches.length}`;
}

function readerSearchNext() {
  if (!searchMatches.length) return;
  searchMatchIndex = (searchMatchIndex + 1) % searchMatches.length;
  scrollToSearchMatch(searchMatchIndex);
}

function readerSearchPrev() {
  if (!searchMatches.length) return;
  searchMatchIndex = (searchMatchIndex - 1 + searchMatches.length) % searchMatches.length;
  scrollToSearchMatch(searchMatchIndex);
}

// ---------------------------------------------------------------------------
// Highlights
// ---------------------------------------------------------------------------

async function loadHighlights(bookId) {
  try {
    const res = await fetch(`/books/${bookId}/highlights/`);
    const {ct, iv} = await res.json();
    if (ct) {
      const key = await getOrCreateEncKey();
      const plain = await decryptBytes(key, iv, ct);
      currentHighlights = JSON.parse(new TextDecoder().decode(plain));
    } else {
      currentHighlights = [];
    }
    applyHighlightsToContent();
  } catch (e) {
    currentHighlights = [];
  }
}

async function saveHighlights() {
  if (!currentBookId) return;
  try {
    const key = await getOrCreateEncKey();
    const plain = new TextEncoder().encode(JSON.stringify(currentHighlights));
    const {iv, ciphertext} = await encryptBytes(key, plain);
    const body = JSON.stringify({ct: ciphertext, iv});
    const url = `/books/${currentBookId}/highlights/`;
    _lastHighlightBeacon = {url, body};
    await fetch(url, {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body,
    });
    highlightsDirty = false;
  } catch (e) {}
}

let _highlightSaveDebounce = null;
function debounceSaveHighlights() {
  clearTimeout(_highlightSaveDebounce);
  _highlightSaveDebounce = setTimeout(saveHighlights, 2000);
}

function applyHighlightsToContent() {
  const contentEl = $('reader-content');
  if (!contentEl || currentPdfDoc) return;
  for (const h of currentHighlights) {
    try { renderHighlight(h); } catch (e) {}
  }
}

function renderHighlight(h) {
  const contentEl = $('reader-content');
  if (!contentEl || !h.anchor) return;

  const chapterEl = contentEl.querySelector(`[data-epub-src="${CSS.escape(h.anchor.chapterSrc || '')}"]`)
    || contentEl;

  let range = null;
  try {
    const startNode = xpathToNode(h.anchor.startXpath, chapterEl);
    const endNode   = xpathToNode(h.anchor.endXpath,   chapterEl);
    if (startNode && endNode) {
      range = document.createRange();
      range.setStart(startNode, h.anchor.startOffset);
      range.setEnd(endNode,   h.anchor.endOffset);
    }
  } catch (e) {}

  // Fallback: quote substring search
  if (!range && h.anchor.quote) {
    const walker = document.createTreeWalker(chapterEl, NodeFilter.SHOW_TEXT);
    let node;
    while ((node = walker.nextNode())) {
      const idx = node.textContent.indexOf(h.anchor.quote);
      if (idx !== -1) {
        range = document.createRange();
        range.setStart(node, idx);
        range.setEnd(node, idx + h.anchor.quote.length);
        break;
      }
    }
  }

  if (!range) return;

  try {
    const mark = document.createElement('mark');
    mark.className = 'epub-highlight';
    mark.dataset.highlightId = h.id;
    mark.dataset.color = h.color || 'yellow';
    range.surroundContents(mark);
  } catch (e) {}
}

function xpathToNode(xpath, root) {
  if (!xpath) return null;
  const result = document.evaluate(xpath, root, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
  return result.singleNodeValue;
}

function getXPathForNode(node, root) {
  const parts = [];
  let current = node;
  while (current && current !== root) {
    const parent = current.parentNode;
    if (!parent) break;
    if (current.nodeType === Node.TEXT_NODE) {
      const siblings = Array.from(parent.childNodes).filter(n => n.nodeType === Node.TEXT_NODE);
      const idx = siblings.indexOf(current);
      parts.unshift(`text()[${idx + 1}]`);
    } else {
      const siblings = Array.from(parent.children).filter(n => n.tagName === current.tagName);
      const idx = siblings.indexOf(current);
      parts.unshift(`${current.tagName.toLowerCase()}[${idx + 1}]`);
    }
    current = parent;
  }
  return parts.join('/');
}

function buildEpubAnchor(range) {
  const contentEl = $('reader-content');
  const chapterEl = range.commonAncestorContainer.nodeType === Node.ELEMENT_NODE
    ? range.commonAncestorContainer.closest('[data-epub-src]')
    : range.commonAncestorContainer.parentElement?.closest('[data-epub-src]');
  const root = chapterEl || contentEl;

  return {
    type: 'epub',
    chapterSrc: chapterEl?.getAttribute('data-epub-src') || '',
    startXpath: getXPathForNode(range.startContainer, root),
    startOffset: range.startOffset,
    endXpath: getXPathForNode(range.endContainer, root),
    endOffset: range.endOffset,
    quote: range.toString().slice(0, 200),
  };
}

function handleReaderSelection(e) {
  // If clicking an existing highlight, show tooltip
  const hlMark = e.target.closest('.epub-highlight');
  if (hlMark) {
    dismissHighlightPopover();
    const id = hlMark.dataset.highlightId;
    const h = currentHighlights.find(x => x.id === id);
    showHighlightTooltip(hlMark, h);
    return;
  }

  dismissHighlightPopover();
  const sel = window.getSelection();
  if (!sel || sel.isCollapsed || !sel.rangeCount) return;
  const range = sel.getRangeAt(0);
  const contentEl = $('reader-content');
  if (!contentEl || !contentEl.contains(range.commonAncestorContainer)) return;
  if (range.toString().trim().length === 0) return;

  showHighlightPopover(range);
}

function showHighlightPopover(range) {
  const rect = range.getBoundingClientRect();
  const popover = document.createElement('div');
  popover.id = 'highlight-popover';
  popover.className = 'highlight-popover';
  popover.innerHTML = `
    <button class="hl-color-btn" data-hl-color="yellow" style="background:#f1c40f" title="Yellow">A</button>
    <button class="hl-color-btn" data-hl-color="green"  style="background:#2ecc71" title="Green">A</button>
    <button class="hl-color-btn" data-hl-color="blue"   style="background:#3498db" title="Blue">A</button>
    <button class="hl-color-btn" data-hl-color="red"    style="background:#e63946" title="Red">A</button>
    <button class="hl-note-btn" title="Add note">✎</button>
  `;
  popover.style.top  = (rect.top  + window.scrollY - 44) + 'px';
  popover.style.left = (rect.left + window.scrollX + rect.width / 2 - 70) + 'px';
  document.body.appendChild(popover);
  currentHighlightPopover = popover;

  // Store range info before selection is cleared
  const savedRange = range.cloneRange();

  popover.addEventListener('click', e => {
    const colorBtn = e.target.closest('.hl-color-btn');
    const noteBtn  = e.target.closest('.hl-note-btn');
    if (colorBtn) {
      createHighlight(colorBtn.dataset.hlColor, savedRange);
    } else if (noteBtn) {
      createHighlightWithNote(savedRange);
    }
  });
}

function showHighlightTooltip(markEl, h) {
  const rect = markEl.getBoundingClientRect();
  const popover = document.createElement('div');
  popover.id = 'highlight-popover';
  popover.className = 'highlight-popover';
  popover.style.flexDirection = 'column';
  popover.style.maxWidth = '220px';
  const noteText = h?.note ? escapeHtml(h.note) : '<span class="muted">No note</span>';
  popover.innerHTML = `
    <div style="font-size:12px;padding-bottom:4px;">${noteText}</div>
    <div style="display:flex;gap:6px;">
      <button class="btn btn-sm" data-hl-edit-note="${escapeHtml(h?.id || '')}">Edit note</button>
      <button class="btn btn-sm btn-danger" data-hl-delete="${escapeHtml(h?.id || '')}">Delete</button>
    </div>
  `;
  popover.style.top  = (rect.bottom + window.scrollY + 4) + 'px';
  popover.style.left = (rect.left + window.scrollX) + 'px';
  document.body.appendChild(popover);
  currentHighlightPopover = popover;

  popover.addEventListener('click', ev => {
    const editBtn = ev.target.closest('[data-hl-edit-note]');
    const delBtn  = ev.target.closest('[data-hl-delete]');
    if (editBtn && h) {
      dismissHighlightPopover();
      openNoteEditor(h);
    }
    if (delBtn && h) {
      dismissHighlightPopover();
      deleteHighlight(h.id);
    }
  });

  // Close on outside click
  setTimeout(() => {
    document.addEventListener('click', dismissHighlightPopover, {once: true});
  }, 0);
}

function createHighlight(color, range) {
  const anchor = buildEpubAnchor(range);
  const h = {
    id: crypto.randomUUID(),
    anchor,
    color,
    note: '',
    createdAt: new Date().toISOString(),
  };
  currentHighlights.push(h);
  highlightsDirty = true;
  window.getSelection()?.removeAllRanges();
  dismissHighlightPopover();
  renderHighlight(h);
  debounceSaveHighlights();
}

function createHighlightWithNote(range) {
  const anchor = buildEpubAnchor(range);
  const h = {
    id: crypto.randomUUID(),
    anchor,
    color: 'yellow',
    note: '',
    createdAt: new Date().toISOString(),
  };
  currentHighlights.push(h);
  highlightsDirty = true;
  window.getSelection()?.removeAllRanges();
  dismissHighlightPopover();
  renderHighlight(h);
  openNoteEditor(h);
}

function openNoteEditor(h) {
  openSidebar('Edit note', `
    <textarea id="hl-note-input" class="search-input" rows="5" style="width:100%;resize:vertical;">${escapeHtml(h.note || '')}</textarea>
    <button class="btn" style="margin-top:8px;" data-save-note="${escapeHtml(h.id)}">Save note</button>
  `);
  const body = $('sidebar-body');
  body.addEventListener('click', function _noteClick(e) {
    const btn = e.target.closest('[data-save-note]');
    if (!btn) return;
    body.removeEventListener('click', _noteClick);
    const text = (body.querySelector('#hl-note-input')?.value || '').trim();
    h.note = text;
    highlightsDirty = true;
    debounceSaveHighlights();
    closeSidebar();
  });
}

function deleteHighlight(id) {
  currentHighlights = currentHighlights.filter(h => h.id !== id);
  highlightsDirty = true;
  // Re-apply all highlights after removing the deleted one
  const contentEl = $('reader-content');
  if (contentEl && !currentPdfDoc) {
    // Snapshot restore not available mid-session, so remove the mark manually
    const mark = contentEl.querySelector(`mark[data-highlight-id="${id}"]`);
    if (mark) {
      const parent = mark.parentNode;
      while (mark.firstChild) parent.insertBefore(mark.firstChild, mark);
      parent.removeChild(mark);
    }
  }
  debounceSaveHighlights();
}

function dismissHighlightPopover() {
  if (currentHighlightPopover) {
    currentHighlightPopover.remove();
    currentHighlightPopover = null;
  }
}

// ---------------------------------------------------------------------------
// Focus station sidebar
// ---------------------------------------------------------------------------

const FOCUS_STATION_PRESETS = [
  {name: 'None (no station)', url: ''},
  {name: 'SomaFM Groove Salad', url: 'https://ice5.somafm.com/groovesalad-128-aac'},
  {name: 'SomaFM Deep Space One', url: 'https://ice5.somafm.com/deepspaceone-128-aac'},
  {name: 'SomaFM Drone Zone', url: 'https://ice5.somafm.com/dronezone-128-aac'},
  {name: 'SomaFM Space Station', url: 'https://ice5.somafm.com/spacestation-128-aac'},
  {name: 'Linn Jazz', url: 'http://radio.linnrecords.com/linnjazz.pls'},
];

function openFocusStationSidebar() {
  // null = never saved (default active); {url:''} = disabled; {url:'...'} = custom
  const effectiveUrl = USER_FOCUS_STATION === null ? DEFAULT_FOCUS_STATION.url : (USER_FOCUS_STATION.url || '');
  const currentName = USER_FOCUS_STATION === null ? DEFAULT_FOCUS_STATION.name
    : (USER_FOCUS_STATION.name || 'None (no station)');

  let presetsHtml = FOCUS_STATION_PRESETS.map((p, i) => {
    const active = p.url === effectiveUrl ? ' class="focus-preset-active"' : '';
    return `<li${active}><button class="btn btn-sm" data-focus-preset="${i}">${escapeHtml(p.name)}</button></li>`;
  }).join('');

  const html = `
    <p class="muted">Station played when opening a book.</p>
    <p><strong>Current:</strong> ${escapeHtml(currentName)}</p>
    <ul class="focus-preset-list">${presetsHtml}</ul>
    <div class="focus-custom-input">
      <input type="text" id="focus-custom-name" class="search-input" placeholder="Station name" value="${escapeHtml(effectiveUrl ? currentName : '')}">
      <input type="text" id="focus-custom-url" class="search-input" placeholder="Stream URL" value="${escapeHtml(effectiveUrl)}">
      <button class="btn" data-focus-save="1">Save</button>
      <button class="btn btn-sm" data-focus-play="1">Play Now</button>
    </div>
  `;

  openSidebar('Focus Station', html);

  const body = $('sidebar-body');
  body.addEventListener('click', function _focusClick(e) {
    const presetBtn = e.target.closest('[data-focus-preset]');
    const saveBtn = e.target.closest('[data-focus-save]');
    const playBtn = e.target.closest('[data-focus-play]');
    if (presetBtn) {
      const preset = FOCUS_STATION_PRESETS[parseInt(presetBtn.dataset.focusPreset, 10)];
      if (preset) saveFocusStation(preset.url, preset.name);
      body.removeEventListener('click', _focusClick);
    } else if (saveBtn) {
      const url = (body.querySelector('#focus-custom-url')?.value || '').trim();
      const name = (body.querySelector('#focus-custom-name')?.value || '').trim();
      saveFocusStation(url, name);
      body.removeEventListener('click', _focusClick);
    } else if (playBtn) {
      const url = (body.querySelector('#focus-custom-url')?.value || '').trim();
      const name = (body.querySelector('#focus-custom-name')?.value || '').trim();
      if (url) playStation(url, name, null);
    }
  });
}


async function saveFocusStation(url, name) {
  url = (url || '').trim();
  name = (name || '').trim();
  if (!IS_AUTHENTICATED) {
    USER_FOCUS_STATION = {url, name};
    closeSidebar();
    return;
  }
  try {
    const res = await fetch('/accounts/focus-station/', {
      method: 'POST',
      headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
      body: JSON.stringify({url, name}),
    });
    const data = await res.json();
    if (data.ok) {
      USER_FOCUS_STATION = {url, name};
      closeSidebar();
    }
  } catch (e) {}
}

// ---------------------------------------------------------------------------
// Init
// ---------------------------------------------------------------------------

(function init() {
  // Migrate PBKDF2-derived key stored by login/register form
  if (window.USER_ID) {
    const pending = localStorage.getItem('diora_pending_enc_key');
    if (pending) {
      localStorage.setItem(`diora_enc_key_${window.USER_ID}`, pending);
      localStorage.removeItem('diora_pending_enc_key');
    }
  }

  // Populate saved stations from server-side context if available
  if (typeof INITIAL_SAVED !== 'undefined' && Array.isArray(INITIAL_SAVED)) {
    // The server already renders saved stations in the template; nothing extra needed.
    // But if JS-rendered saved tab were needed we'd call addSavedRow here.
  }

  // Seed podcast feeds from server context
  if (typeof INITIAL_PODCAST_FEEDS !== 'undefined' && Array.isArray(INITIAL_PODCAST_FEEDS)) {
    podcastFeeds = INITIAL_PODCAST_FEEDS;
  }

  // Wire seek slider
  const seekSlider = $('seek-slider');
  if (seekSlider) {
    seekSlider.addEventListener('input', function () {
      if (podcastMode) audio.currentTime = parseInt(this.value, 10);
    });
  }

  // Restore persisted volume, fall back to slider default
  const volSlider = $('volume');
  if (volSlider) {
    const saved = localStorage.getItem('diora_volume');
    const vol = saved !== null ? parseInt(saved, 10) : parseInt(volSlider.value, 10);
    setVolume(vol);
  }

  // Load recommendations on page load
  loadRecommendations();

  // Initialise focus timer display
  renderTimer();

  // Initialise mood/genre chips
  initMoodChips();

  // Initialise curated station lists
  initCuratedLists();

  // Show curated lists again when search input is cleared
  const searchInput = document.getElementById('search-input');
  if (searchInput) {
    searchInput.addEventListener('input', function () {
      if (this.value === '') {
        const curated = document.getElementById('curated-lists');
        if (curated) curated.style.display = '';
      }
    });
  }

  // Load focus session stats
  loadFocusStats();

  // Apply encrypted wallpaper (if set)
  applyEncryptedBackground();

  // Init book drop zone
  initBookDropZone();

  // Restore last active tab
  const savedTab = localStorage.getItem('diora_active_tab') || 'radio';
  const savedRadioTab = localStorage.getItem('diora_active_radio_tab') || 'saved';
  showTab(savedTab);
  showRadioTab(savedRadioTab);
})();