// ============================================================
// APP.JS — Core utilities, tabs, model selector, helpers
// ============================================================

// ── Client-side error logging ──────────────────────────────
(function() {
  function sendError(data) {
    try {
      navigator.sendBeacon('/api/logs/client-error', new Blob(
        [JSON.stringify(data)], { type: 'application/json' }
      ));
    } catch(e) {}
  }
  window.onerror = function(msg, src, line, col, err) {
    // Ignore errors from browser extensions
    if (src && src.indexOf('moz-extension') !== -1) return;
    if (src && src.indexOf('chrome-extension') !== -1) return;
    sendError({ type: 'uncaught', message: String(msg), source: src, line: line, col: col, stack: err && err.stack });
  };
  window.addEventListener('unhandledrejection', function(e) {
    var msg = e.reason ? (e.reason.message || String(e.reason)) : 'Unhandled promise rejection';
    sendError({ type: 'unhandledrejection', message: msg, stack: e.reason && e.reason.stack });
  });
})();

document.addEventListener('DOMContentLoaded', function() {

  // --- COMPONENT LOADER (lazy-load tab HTML from /components/) ---
  var _componentCache = {};
  var _componentLoading = {};

  function loadComponent(tabEl) {
    var component = tabEl.getAttribute('data-component');
    if (!component || tabEl.dataset.loaded) return Promise.resolve();
    if (_componentCache[component]) {
      tabEl.innerHTML = _componentCache[component];
      tabEl.dataset.loaded = '1';
      return Promise.resolve();
    }
    if (_componentLoading[component]) return _componentLoading[component];

    _componentLoading[component] = fetch('/components/' + component + '.html')
      .then(function(r) { if (!r.ok) throw new Error(r.status); return r.text(); })
      .then(function(html) {
        _componentCache[component] = html;
        tabEl.innerHTML = html;
        tabEl.dataset.loaded = '1';
        // Re-attach per-tab model selectors
        tabEl.querySelectorAll('.tab-model-select').forEach(function(sel) {
          if (typeof window._buildModelOptions === 'function') window._buildModelOptions(sel);
        });
        delete _componentLoading[component];
      })
      .catch(function(err) {
        console.warn('[Component] Failed to load ' + component + ':', err);
        tabEl.innerHTML = '<div style="padding:40px;text-align:center;color:var(--g400);">Failed to load. Please refresh.</div>';
        delete _componentLoading[component];
      });
    return _componentLoading[component];
  }

  // Preload the first tab immediately
  var firstTab = document.querySelector('.tab-content[data-component]');
  if (firstTab) loadComponent(firstTab);

  // --- TAB NAVIGATION ---
  function activateTab(tabName) {
    var btn = document.querySelector('.tab-btn[data-tab="' + tabName + '"]');
    if (!btn || btn.classList.contains('hidden')) return false;
    document.querySelectorAll('.tab-btn').forEach(function(b) { b.classList.remove('active'); });
    document.querySelectorAll('.tab-content').forEach(function(c) { c.classList.remove('active'); });
    btn.classList.add('active');
    var tabEl = document.getElementById(tabName + '-tab');
    if (tabEl) {
      tabEl.classList.add('active');
      // Lazy-load component HTML, then fire tabChanged after DOM is ready
      loadComponent(tabEl).then(function() {
        document.dispatchEvent(new CustomEvent('tabChanged', { detail: { tab: tabName } }));
      });
    } else {
      document.dispatchEvent(new CustomEvent('tabChanged', { detail: { tab: tabName } }));
    }
    // Persist last tab in localStorage (restored after login in auth.js)
    try { localStorage.setItem('ped_last_tab', tabName); } catch(e) {}
    // Close sidebar on mobile after tab click
    var sidebar = document.getElementById('sidebar');
    if (sidebar && window.innerWidth <= 768) {
      sidebar.classList.remove('open');
    }
    return true;
  }

  // Expose activateTab globally so auth.js can call it after login
  window.activateTab = activateTab;

  document.querySelectorAll('.tab-btn').forEach(function(btn) {
    btn.addEventListener('click', function() {
      activateTab(btn.getAttribute('data-tab'));
      var subtab = btn.getAttribute('data-subtab');
      if (subtab && typeof window.wvSwitchSubtab === 'function') {
        setTimeout(function() { window.wvSwitchSubtab(subtab); }, 0);
      }
    });
  });

  // --- SIDEBAR TOGGLE ---
  var sidebar = document.getElementById('sidebar');
  var sidebarOverlay = document.getElementById('sidebar-overlay');
  document.addEventListener('click', function(e) {
    if (e.target.closest('#btn-menu-toggle')) {
      if (sidebar) sidebar.classList.toggle('open');
    }
    if (e.target.closest('#btn-sidebar-close') || e.target.closest('#sidebar-overlay')) {
      if (sidebar) sidebar.classList.remove('open');
    }
  });
  if (sidebarOverlay) {
    sidebarOverlay.addEventListener('click', function() {
      if (sidebar) sidebar.classList.remove('open');
    });
  }

  // --- DESKTOP SIDEBAR COLLAPSE ---
  var sidebarPinBtn = document.getElementById('btn-sidebar-pin');
  var sidebarExpandBtn = document.getElementById('btn-sidebar-expand');
  // Restore collapse state
  try {
    if (localStorage.getItem('ped_sidebar_collapsed') === '1') {
      if (sidebar) sidebar.classList.add('collapsed');
      if (sidebarExpandBtn) sidebarExpandBtn.style.display = 'flex';
      if (sidebarPinBtn) sidebarPinBtn.style.display = 'none';
    }
  } catch(e) {}
  if (sidebarPinBtn) {
    sidebarPinBtn.addEventListener('click', function() {
      if (sidebar) sidebar.classList.add('collapsed');
      if (sidebarExpandBtn) sidebarExpandBtn.style.display = 'flex';
      if (sidebarPinBtn) sidebarPinBtn.style.display = 'none';
      try { localStorage.setItem('ped_sidebar_collapsed', '1'); } catch(e) {}
    });
  }
  if (sidebarExpandBtn) {
    sidebarExpandBtn.addEventListener('click', function() {
      if (sidebar) sidebar.classList.remove('collapsed');
      if (sidebarExpandBtn) sidebarExpandBtn.style.display = 'none';
      if (sidebarPinBtn) sidebarPinBtn.style.display = 'flex';
      try { localStorage.setItem('ped_sidebar_collapsed', '0'); } catch(e) {}
    });
  }

  // Load settings data when settings tab is activated
  document.addEventListener('tabChanged', function(e) {
    if (e.detail && e.detail.tab === 'settings') {
      if (typeof load2FAStatus === 'function') load2FAStatus();
      if (typeof loadNextcloudStatus === 'function') loadNextcloudStatus();
      if (typeof loadMemories === 'function') loadMemories();
      if (typeof loadSavedEncountersList === 'function') loadSavedEncountersList();
      if (typeof renderAudioBackups === 'function') renderAudioBackups();
      if (typeof loadDocuments === 'function') loadDocuments();
    }
  });

  // --- MODEL SELECTOR ---
  var modelSelect = document.getElementById('global-model-select');
  var costBadge = document.getElementById('model-cost-badge');
  window._currentModels = [];
  window._currentProvider = 'openrouter';

  fetch('/api/models')
    .then(function(r) { return r.json(); })
    .then(function(data) {
      window._currentModels = data.models || [];
      window._currentProvider = data.provider || 'openrouter';

      var categories = { free: '🆓 Free', fast: '⚡ Fast & Cheap', smart: '🧠 Smart', premium: '👑 Premium' };

      window._buildModelOptions = function buildModelOptions(selectEl) {
        selectEl.innerHTML = '';
        var grouped = {};
        window._currentModels.forEach(function(m) {
          var cat = m.category || 'smart';
          if (!grouped[cat]) grouped[cat] = [];
          grouped[cat].push(m);
        });
        Object.keys(categories).forEach(function(cat) {
          if (!grouped[cat] || grouped[cat].length === 0) return;
          var optgroup = document.createElement('optgroup');
          optgroup.label = categories[cat];
          grouped[cat].forEach(function(m) {
            var opt = document.createElement('option');
            opt.value = m.id;
            opt.textContent = m.name + ' (' + m.cost + ')';
            optgroup.appendChild(opt);
          });
          selectEl.appendChild(optgroup);
        });
      }

      // Determine default model (admin override or first model)
      var defaultModelId = data.defaultModel || (window._currentModels.length > 0 ? window._currentModels[0].id : '');

      if (modelSelect && window._currentModels.length > 0) {
        window._buildModelOptions(modelSelect);
        // Select the admin-configured default
        if (defaultModelId) modelSelect.value = defaultModelId;
        var defaultM = window._currentModels.find(function(x) { return x.id === modelSelect.value; });
        if (costBadge) costBadge.textContent = window._currentProvider.toUpperCase() + ' | ' + (defaultM ? defaultM.cost : '');
      }

      // Populate all per-tab model selectors already in DOM
      document.querySelectorAll('.tab-model-select').forEach(function(sel) {
        window._buildModelOptions(sel);
        if (defaultModelId) sel.value = defaultModelId;
      });
    })
    .catch(function(err) { console.warn('Models load failed:', err); });

  if (modelSelect) {
    modelSelect.addEventListener('change', function() {
      var m = window._currentModels.find(function(x) { return x.id === modelSelect.value; });
      if (m && costBadge) costBadge.textContent = window._currentProvider.toUpperCase() + ' | ' + m.cost;
      showToast('Model: ' + modelSelect.value.split('/').pop(), 'info');
    });
  }

  console.log('✅ App.js DOM ready');

}); // end DOMContentLoaded

// ============================================================
// GLOBAL FUNCTIONS (must be outside DOMContentLoaded)
// ============================================================

// ── Set formatted text on output/contenteditable elements ──
// Converts \n to <br> so line breaks survive in contenteditable divs
// and are preserved when copying with innerText
function setOutputText(el, text) {
  if (!el) return;
  if (typeof el === 'string') el = document.getElementById(el);
  if (!el) return;
  // Escape HTML, then convert newlines to <br>
  var safe = String(text || '').replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
  el.innerHTML = safe.replace(/\n/g, '<br>');
}

// ── Data-action event delegation (replaces inline onclick handlers) ──
// Handles data-action="copy|speak|nc-export" on any element,
// allowing removal of 'unsafe-inline' from the Content Security Policy.
document.addEventListener('click', function(e) {
  var btn = e.target.closest('[data-action]');
  if (!btn) return;
  var action = btn.getAttribute('data-action');
  var targetId = btn.getAttribute('data-target');
  if (!action) return;

  if (action === 'copy' && targetId) {
    if (typeof copyText === 'function') copyText(targetId);
    return;
  }
  if (action === 'speak' && targetId) {
    if (typeof speakText === 'function') speakText(targetId);
    return;
  }
  if (action === 'nc-export' && targetId) {
    var label = btn.getAttribute('data-label') || 'export';
    if (typeof exportToNextcloud === 'function') exportToNextcloud(targetId, label);
    return;
  }
});

// ── Announcement banner ────────────────────────────────────
function loadAnnouncement() {
  fetch('/api/admin/config/announcement', { headers: getAuthHeaders() })
    .then(function(r) { if (!r.ok) throw new Error('not ok'); return r.json(); })
    .then(function(data) {
      if (!data.success) return;
      var banner = document.getElementById('announcement-banner');
      var text   = document.getElementById('announcement-text');
      var icon   = document.getElementById('announcement-icon');
      if (!banner || !text) return;
      if (data.enabled && data.text && data.text.trim()) {
        text.textContent = data.text;
        // type → icon + class
        var icons = { info: 'fa-info-circle', warning: 'fa-triangle-exclamation', error: 'fa-circle-xmark', success: 'fa-circle-check' };
        var type = data.type || 'info';
        if (icon) { icon.className = 'fas ' + (icons[type] || icons.info); }
        banner.className = 'announcement-banner ann-' + type;
      } else {
        banner.className = 'announcement-banner hidden';
      }
    })
    .catch(function() {}); // silently ignore if endpoint not yet available
}

function getSelectedModel() {
  // Prefer the active tab's own model selector if present
  var activeTab = document.querySelector('.tab-content.active');
  if (activeTab) {
    var tabSel = activeTab.querySelector('.tab-model-select');
    if (tabSel && tabSel.value) return tabSel.value;
  }
  var sel = document.getElementById('global-model-select');
  return sel ? sel.value : 'google/gemini-2.5-flash';
}

function showLoading(text) {
  var overlay = document.getElementById('loading-overlay');
  var textEl = document.getElementById('loading-text');
  if (textEl) textEl.textContent = text || 'Processing...';
  if (overlay) { overlay.style.display = 'flex'; overlay.className = overlay.className.replace('hidden', '').trim(); }
}

function hideLoading() {
  var overlay = document.getElementById('loading-overlay');
  if (overlay) overlay.style.display = 'none';
}

function showToast(message, type) {
  var container = document.getElementById('toast-container');
  if (!container) { console.log('Toast:', type, message); return; }
  var toast = document.createElement('div');
  toast.className = 'toast toast-' + (type || 'success');
  var icon = type === 'error' ? 'exclamation-circle' : type === 'info' ? 'info-circle' : 'check-circle';
  toast.innerHTML = '<i class="fas fa-' + icon + '"></i> ' + message;
  container.appendChild(toast);
  setTimeout(function() { toast.remove(); }, 3500);
}

function copyText(elementId) {
  var el = document.getElementById(elementId);
  if (!el) return;
  var text = el.innerText || el.textContent || '';
  if (!text.trim()) { showToast('Nothing to copy', 'error'); return; }

  // Try modern clipboard API (requires HTTPS or localhost)
  if (navigator.clipboard && navigator.clipboard.writeText) {
    navigator.clipboard.writeText(text).then(function() {
      showToast('Copied!', 'success');
    }).catch(function(err) {
      // Fallback: select + execCommand
      try {
        var range = document.createRange();
        range.selectNodeContents(el);
        window.getSelection().removeAllRanges();
        window.getSelection().addRange(range);
        var ok = document.execCommand('copy');
        window.getSelection().removeAllRanges();
        showToast(ok ? 'Copied!' : 'Copy failed — please select text manually', ok ? 'success' : 'error');
      } catch (e) {
        showToast('Copy not supported in this browser', 'error');
      }
    });
  } else {
    // No clipboard API — use execCommand directly
    try {
      var range = document.createRange();
      range.selectNodeContents(el);
      window.getSelection().removeAllRanges();
      window.getSelection().addRange(range);
      var ok = document.execCommand('copy');
      window.getSelection().removeAllRanges();
      showToast(ok ? 'Copied!' : 'Copy failed — please select text manually', ok ? 'success' : 'error');
    } catch (e) {
      showToast('Copy not supported in this browser', 'error');
    }
  }
}

// Speak / Stop
var currentlyReadingId = null;
var currentAudio = null;

function speakText(elementId) {
  if (currentlyReadingId === elementId) { stopReading(); return; }
  stopReading();
  var el = document.getElementById(elementId);
  if (!el) return;
  var text = (el.innerText || el.textContent).trim();
  if (!text) { showToast('Nothing to read', 'error'); return; }

  currentlyReadingId = elementId;
  var btn = findReadButton(elementId);
  if (btn) { btn.classList.add('btn-reading'); btn.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Loading...'; }

  fetch('/api/text-to-speech', {
    method: 'POST',
    headers: window.getAuthHeaders ? window.getAuthHeaders() : { 'Content-Type': 'application/json' },
    body: JSON.stringify({ text: text })
  })
  .then(function(r) {
    if (!r.ok) throw new Error('TTS request failed (' + r.status + ')');
    return r.blob();
  })
  .then(function(blob) {
    var url = URL.createObjectURL(blob);
    currentAudio = new Audio(url);
    currentAudio.onended = function() { URL.revokeObjectURL(url); stopReading(); };
    currentAudio.onerror = function() { URL.revokeObjectURL(url); stopReading(); showToast('Audio playback error', 'error'); };
    currentAudio.play();
    if (btn) { btn.classList.add('btn-reading'); btn.innerHTML = '<i class="fas fa-stop"></i> Stop'; }
    showToast('Reading aloud (Adam/ElevenLabs)', 'info');
  })
  .catch(function(err) {
    stopReading();
    // Fallback to browser TTS if ElevenLabs fails
    if ('speechSynthesis' in window) {
      var utter = new SpeechSynthesisUtterance(text);
      utter.rate = 0.9;
      utter.onend = function() { stopReading(); };
      currentlyReadingId = elementId;
      if (btn) { btn.classList.add('btn-reading'); btn.innerHTML = '<i class="fas fa-stop"></i> Stop'; }
      window.speechSynthesis.speak(utter);
      showToast('TTS unavailable — using browser voice', 'info');
    } else {
      showToast('Read aloud failed: ' + err.message, 'error');
    }
  });
}

function stopReading() {
  if ('speechSynthesis' in window) window.speechSynthesis.cancel();
  if (currentAudio) { currentAudio.pause(); currentAudio = null; }
  if (currentlyReadingId) {
    var btn = findReadButton(currentlyReadingId);
    if (btn) { btn.classList.remove('btn-reading'); btn.innerHTML = '<i class="fas fa-volume-high"></i> Read'; }
    currentlyReadingId = null;
  }
}

function findReadButton(elementId) {
  var el = document.getElementById(elementId);
  if (!el) return null;
  var card = el.closest('.output-card') || el.closest('.card');
  if (!card) return null;
  var buttons = card.querySelectorAll('button');
  for (var i = 0; i < buttons.length; i++) {
    var oc = buttons[i].getAttribute('onclick') || '';
    if (oc.indexOf('speakText') !== -1 && oc.indexOf(elementId) !== -1) return buttons[i];
  }
  return null;
}

// Timer
function createTimer(el) {
  var s = 0, iv = null;
  return {
    start: function() { s = 0; this.update(); var self = this; iv = setInterval(function() { s++; self.update(); }, 1000); },
    stop: function() { if (iv) { clearInterval(iv); iv = null; } return s; },
    update: function() { el.textContent = String(Math.floor(s / 60)).padStart(2, '0') + ':' + String(s % 60).padStart(2, '0'); }
  };
}

// Audio Recorder
function AudioRecorder() { this.mediaRecorder = null; this.chunks = []; this.stream = null; }
AudioRecorder.prototype.start = function() {
  var self = this; self.chunks = [];
  return navigator.mediaDevices.getUserMedia({ audio: { channelCount: 1, sampleRate: 16000, echoCancellation: true, noiseSuppression: true } })
  .then(function(stream) {
    self.stream = stream;
    var mime = MediaRecorder.isTypeSupported('audio/webm;codecs=opus') ? 'audio/webm;codecs=opus' : 'audio/webm';
    // 32kbps Opus is excellent for speech — small files, fast upload, great quality
    self.mediaRecorder = new MediaRecorder(stream, { mimeType: mime, audioBitsPerSecond: 32000 });
    self.mediaRecorder.ondataavailable = function(e) { if (e.data.size > 0) self.chunks.push(e.data); };
    self.mediaRecorder.start(1000);
  });
};
AudioRecorder.prototype.stop = function() {
  var self = this;
  return new Promise(function(resolve) {
    if (!self.mediaRecorder || self.mediaRecorder.state === 'inactive') { resolve(null); return; }
    self.mediaRecorder.onstop = function() {
      var blob = new Blob(self.chunks, { type: self.mediaRecorder.mimeType });
      if (self.stream) self.stream.getTracks().forEach(function(t) { t.stop(); });
      // Auto-save to IndexedDB backup before transcription
      if (blob.size > 0 && typeof saveAudioBackup === 'function') {
        var module = self._module || 'unknown';
        saveAudioBackup(blob, module).catch(function() {});
      }
      resolve(blob);
    };
    self.mediaRecorder.stop();
  });
};

// Check if server-side transcription (Whisper/AWS) is available
window._transcribeAvailable = null; // null = not checked yet, true/false after check
function checkTranscribeStatus() {
  var token = window.AUTH_TOKEN || localStorage.getItem('ped_scribe_token') || '';
  if (!token) return;
  fetch('/api/transcribe/status', {
    headers: { 'Authorization': 'Bearer ' + token, 'Content-Type': 'application/json' }
  })
  .then(function(r) { return r.json(); })
  .then(function(data) {
    window._transcribeAvailable = !!data.available;
    window._transcribeProvider = data.provider || 'none';
    if (!data.available) {
      console.log('[Transcribe] No server transcription configured — using browser speech recognition only');
    }
  })
  .catch(function() { window._transcribeAvailable = false; });
}

function transcribeAudio(blob) {
  // If no server transcription is configured, skip upload entirely
  if (window._transcribeAvailable === false) {
    return Promise.resolve({ success: false, noProvider: true, error: 'No transcription API configured — using live transcript' });
  }

  var startTime = Date.now();
  var formData = new FormData();
  formData.append('audio', blob, 'audio.webm');
  return fetch('/api/transcribe', {
    method: 'POST',
    headers: { 'Authorization': 'Bearer ' + (window.AUTH_TOKEN || localStorage.getItem('ped_scribe_token') || '') },
    body: formData
  }).then(function(r) { return r.json(); }).then(function(data) {
    var elapsed = ((Date.now() - startTime) / 1000).toFixed(1);
    if (data.success && data.provider) {
      showToast('Transcribed via ' + data.provider + ' (' + elapsed + 's)', 'info');
    }
    // Delete audio backup on successful transcription
    if (data.success && window._lastAudioBackupId) {
      if (typeof deleteAudioBackup === 'function') deleteAudioBackup(window._lastAudioBackupId);
      window._lastAudioBackupId = null;
    }
    return data;
  });
}

function refineDocument(outputElementId, inputElementId) {
  var doc = document.getElementById(outputElementId);
  var input = document.getElementById(inputElementId);
  if (!doc || !input) return;
  var docText = doc.innerText.trim();
  var instructions = input.value.trim();
  if (!docText) { showToast('No document', 'error'); return; }
  if (!instructions) { showToast('Enter instructions', 'error'); return; }
  showLoading('Refining...');
  fetch('/api/refine', {
    method: 'POST', headers: getAuthHeaders(),
    body: JSON.stringify({ currentDocument: docText, instructions: instructions, model: getSelectedModel() })
  })
  .then(function(r) { return r.json(); })
  .then(function(data) {
    hideLoading();
    if (data.success) { setOutputText(doc, data.refined); input.value = ''; showToast('Refined!', 'success'); }
    else showToast(data.error || 'Failed', 'error');
  })
  .catch(function(err) { hideLoading(); showToast(err.message, 'error'); });
}

function shortenDocument(outputElementId) {
  var doc = document.getElementById(outputElementId);
  if (!doc) return;
  var text = doc.innerText.trim();
  if (!text) { showToast('No document', 'error'); return; }
  showLoading('Shortening...');
  fetch('/api/shorten', {
    method: 'POST', headers: getAuthHeaders(),
    body: JSON.stringify({ document: text, model: getSelectedModel() })
  })
  .then(function(r) { return r.json(); })
  .then(function(data) {
    hideLoading();
    if (data.success) { setOutputText(doc, data.shortened); showToast('Shortened!', 'success'); }
    else showToast(data.error || 'Failed', 'error');
  })
  .catch(function(err) { hideLoading(); showToast(err.message, 'error'); });
}

function exportToNextcloud(elementId, docType) {
  var el = document.getElementById(elementId);
  if (!el) return;
  var text = el.innerText.trim();
  if (!text) { showToast('Nothing to export', 'error'); return; }
  fetch('/api/nextcloud/export', {
    method: 'POST', headers: getAuthHeaders(),
    body: JSON.stringify({ content: text, filename: docType + '-' + Date.now(), type: docType })
  })
  .then(function(r) { return r.json(); })
  .then(function(data) {
    if (data.success) showToast(data.message, 'success');
    else showToast(data.error || 'Export failed', 'error');
  })
  .catch(function() { showToast('Nextcloud not connected', 'error'); });
}

function createSpeechRecognition() {
  if (!(window.SpeechRecognition || window.webkitSpeechRecognition)) return null;
  var SR = window.SpeechRecognition || window.webkitSpeechRecognition;
  var rec = new SR();
  rec.continuous = true;
  rec.interimResults = true;
  rec.lang = 'en-US';
  rec.maxAlternatives = 1;
  return rec;
}

// Deduplicate speech recognition finals — Chrome can repeat text across restarts
function deduplicateFinal(newText, existingText) {
  if (!newText || !existingText) return newText;
  var trimmed = newText.trim();
  if (!trimmed) return '';
  // Check if the new text is already at the end of existing text
  if (existingText.trimEnd().endsWith(trimmed)) return '';
  // Check for partial overlap (last sentence repeated)
  var words = trimmed.split(/\s+/);
  if (words.length >= 3) {
    var tail = existingText.trimEnd().split(/\s+/).slice(-words.length).join(' ');
    if (tail === trimmed) return '';
    // Check if first half of new text overlaps with end of existing
    var half = Math.ceil(words.length / 2);
    var firstHalf = words.slice(0, half).join(' ');
    if (existingText.trimEnd().endsWith(firstHalf)) {
      return words.slice(half).join(' ') + ' ';
    }
  }
  return newText;
}

// PWA Service Worker
if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw.js').catch(function() {});
}

console.log('✅ App.js loaded');