/**
 * vault.js — Vault UI: all views (vault, security, sharing, emergency, settings)
 *
 * All sensitive data is decrypted client-side. The server only ever stores
 * encrypted blobs (zero-knowledge architecture).
 */

const Vault = (() => {
  let _items = [];
  let _folders = [];
  let _currentView = 'vault';
  let _activeFilter = null;
  let _sortOrder = 'name-asc';

  const FIELD_LABELS = {
    url: 'Website URL', username: 'Username', password: 'Password', notes: 'Notes',
    note_body: 'Note', cardholder_name: 'Cardholder Name', card_number: 'Card Number',
    expiry_month: 'Expiry Month', expiry_year: 'Expiry Year', cvv: 'CVV',
    bank_name: 'Bank Name', account_type: 'Account Type', routing_number: 'Routing Number',
    account_number: 'Account Number', first_name: 'First Name', last_name: 'Last Name',
    company: 'Company', address_line: 'Street Address', city: 'City', state: 'State',
    zip: 'ZIP', country: 'Country', phone: 'Phone', email: 'Email',
    ssn_number: 'Social Security Number',
  };
  const SENSITIVE_FIELDS = new Set(['password', 'cvv', 'card_number', 'account_number', 'routing_number', 'ssn_number']);

  // ── API helpers ───────────────────────────────────────────────────────────

  async function apiFetch(path, options = {}) {
    let token = sessionStorage.getItem('access_token');
    if (!token) { redirectToLogin(); return null; }

    const defaults = {
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${token}`,
        'X-CSRFToken': csrfToken(),
      },
    };
    const merged = { ...defaults, ...options };
    merged.headers = { ...defaults.headers, ...(options.headers || {}) };

    let res = await fetch(path, merged);

    if (res.status === 401) {
      const refreshed = await tryRefreshToken();
      if (!refreshed) { redirectToLogin(); return null; }
      merged.headers['Authorization'] = `Bearer ${sessionStorage.getItem('access_token')}`;
      res = await fetch(path, merged);
    }

    if (!res.ok && res.status !== 404) {
      const err = await res.json().catch(() => ({}));
      throw new Error(err.error || `HTTP ${res.status}`);
    }
    return res;
  }

  let _refreshPromise = null;
  async function tryRefreshToken() {
    // Singleton: if a refresh is already in flight, reuse it so concurrent 401s
    // don't each fire a separate rotation (which would blacklist each other's tokens).
    if (_refreshPromise) return _refreshPromise;
    _refreshPromise = (async () => {
      const refreshToken = localStorage.getItem('refresh_token');
      if (!refreshToken) return false;
      try {
        const res = await fetch('/api/auth/refresh', {
          method: 'POST',
          headers: { 'Content-Type': 'application/json', 'X-CSRFToken': csrfToken() },
          body: JSON.stringify({ refresh_token: refreshToken }),
        });
        if (!res.ok) return false;
        const data = await res.json();
        sessionStorage.setItem('access_token', data.access_token);
        if (data.refresh_token) localStorage.setItem('refresh_token', data.refresh_token);
        return true;
      } catch { return false; }
    })().finally(() => { _refreshPromise = null; });
    return _refreshPromise;
  }

  function csrfToken() {
    return document.querySelector('meta[name="csrf-token"]')?.content || '';
  }

  function redirectToLogin() {
    VaultSession.clear();
    SharingSession.clear();
    sessionStorage.removeItem('access_token');
    window.dispatchEvent(new CustomEvent('passkeeper:logout'));
    window.location.href = '/login';
  }

  // ── Load ──────────────────────────────────────────────────────────────────

  async function loadVault() {
    const vaultKey = VaultSession.getKey();
    if (!vaultKey) { showUnlockOverlay(); return; }
    showLoadingState(true);
    try {
      const [itemsRes, foldersRes] = await Promise.all([
        apiFetch('/api/vault'), apiFetch('/api/folders'),
      ]);
      if (!itemsRes || !foldersRes) { showUnlockOverlay(); return; }

      const rawItems = await itemsRes.json();
      _folders = await foldersRes.json();

      _items = await Promise.all(rawItems.map(async item => {
        try {
          const plain = await Crypto.decryptItem(vaultKey, item.enc_data, item.iv);
          return { ...item, plain };
        } catch {
          return { ...item, plain: null, decryptError: true };
        }
      }));

      renderFolderList();
      applyCurrentFilter();
    } catch (err) {
      showToast('Failed to load vault: ' + err.message, 'error');
    } finally {
      showLoadingState(false);
    }
  }

  async function loadFolders() {
    try {
      const res = await apiFetch('/api/folders');
      if (!res) return;
      _folders = await res.json();
      renderFolderList();
    } catch (err) {
      showToast('Could not refresh folders: ' + err.message, 'error');
    }
  }

  // ── View switching ────────────────────────────────────────────────────────

  function switchView(view) {
    _currentView = view;
    ['vault', 'security', 'sharing', 'emergency'].forEach(v => {
      document.getElementById(`view-${v}`)?.classList.toggle('hidden', v !== view);
    });
    document.querySelectorAll('.sidebar-item[data-view]').forEach(el => {
      el.classList.toggle('active', el.dataset.view === view);
    });
    if (view !== 'vault') {
      document.querySelectorAll('.sidebar-item[data-type-filter], .sidebar-item[data-folder-id]')
        .forEach(el => el.classList.remove('active'));
    }

    if (view === 'security') renderSecurityDashboard();
    if (view === 'sharing') loadSharingView();
    if (view === 'emergency') loadEmergencyView();
  }

  // ── Vault render ──────────────────────────────────────────────────────────

  function renderFolderList() {
    const ul = document.getElementById('sidebar-folders');
    if (!ul) return;
    ul.innerHTML = '';
    _folders.forEach(folder => {
      const li = document.createElement('li');
      li.className = 'sidebar-item folder-item';
      li.dataset.folderId = folder.id;

      const label = document.createElement('span');
      label.className = 'folder-label';
      label.innerHTML = `<span class="sidebar-icon">📁</span> <span class="sidebar-label">${escHtml(folder.name)}</span>`;
      label.addEventListener('click', () => filterByFolder(folder.id, folder.name));

      const delBtn = document.createElement('button');
      delBtn.className = 'btn-delete-folder';
      delBtn.title = 'Delete folder';
      delBtn.textContent = '🗑';
      delBtn.addEventListener('click', e => { e.stopPropagation(); confirmDeleteFolder(folder); });

      li.appendChild(label);
      li.appendChild(delBtn);
      ul.appendChild(li);
    });
  }

  function getSortedItems(items) {
    const sorted = [...items];
    switch (_sortOrder) {
      case 'name-asc': sorted.sort((a, b) => a.name.localeCompare(b.name)); break;
      case 'name-desc': sorted.sort((a, b) => b.name.localeCompare(a.name)); break;
      case 'date-desc': sorted.sort((a, b) => new Date(b.created_at) - new Date(a.created_at)); break;
      case 'date-asc': sorted.sort((a, b) => new Date(a.created_at) - new Date(b.created_at)); break;
      case 'folder': sorted.sort((a, b) => folderName(a.folder_id).localeCompare(folderName(b.folder_id)) || a.name.localeCompare(b.name)); break;
    }
    return sorted;
  }

  function folderName(id) {
    if (!id) return '(No folder)';
    return _folders.find(f => f.id === id)?.name || 'Unknown';
  }

  function renderItemList(items) {
    const list = document.getElementById('vault-list');
    if (!list) return;
    list.innerHTML = '';
    if (items.length === 0) {
      list.innerHTML = '<li class="vault-empty">No items found. Click + to add one.</li>';
      return;
    }

    const sorted = getSortedItems(items);
    const groups = {};
    sorted.forEach(item => {
      const key = folderName(item.folder_id);
      if (!groups[key]) groups[key] = [];
      groups[key].push(item);
    });

    const keys = _sortOrder === 'folder'
      ? Object.keys(groups).sort()
      : ['(No folder)', ..._folders.map(f => f.name)].filter(k => groups[k]);
    Object.keys(groups).forEach(k => { if (!keys.includes(k)) keys.push(k); });

    keys.forEach(groupName => {
      if (!groups[groupName]) return;
      const header = document.createElement('li');
      header.className = 'vault-group-header';
      header.textContent = groupName;
      list.appendChild(header);
      groups[groupName].forEach(item => list.appendChild(createItemElement(item)));
    });
  }

  function createItemElement(item) {
    const li = document.createElement('li');
    li.className = 'vault-item';
    li.dataset.id = item.id;

    const iconMap = { password: '🔑', note: '📝', card: '💳', bank: '🏦', address: '🏠', ssn: '🪪', passkey: '🔐' };
    const icon = iconMap[item.item_type] || '🔑';

    let subText = '';
    if (item.plain) {
      switch (item.item_type) {
        case 'password': subText = item.plain.username || item.plain.url || ''; break;
        case 'note': subText = (item.plain.note_body || '').slice(0, 60); break;
        case 'card': subText = item.plain.card_number ? '•••• ' + String(item.plain.card_number).replace(/\s/g, '').slice(-4) : ''; break;
        case 'bank': subText = item.plain.bank_name || ''; break;
        case 'address': subText = [item.plain.first_name, item.plain.last_name].filter(Boolean).join(' '); break;
        case 'ssn': subText = '•••-••-••••'; break;
      }
    }

    const showCopyUser = item.item_type === 'password';
    const showCopyPass = ['password', 'card', 'bank', 'ssn'].includes(item.item_type);
    const showLaunch = item.item_type === 'password' && item.plain?.url;

    li.innerHTML = `
      <div class="item-icon">${icon}</div>
      <div class="item-info">
        <span class="item-name">${escHtml(item.name)}</span>
        <span class="item-sub">${escHtml(subText)}</span>
      </div>
      <div class="item-actions">
        ${showLaunch ? `<button class="btn-icon" title="Open URL" data-action="launch">🌐</button>` : ''}
        ${showCopyUser ? `<button class="btn-icon" title="Copy username" data-action="copy-user">👤</button>` : ''}
        ${showCopyPass ? `<button class="btn-icon" title="Copy secret" data-action="copy-pass">📋</button>` : ''}
        <button class="btn-icon" title="Edit" data-action="edit">✏️</button>
        <button class="btn-icon" title="Delete" data-action="delete">🗑️</button>
      </div>`;

    if (showLaunch) {
      li.querySelector('[data-action="launch"]').addEventListener('click', e => {
        e.stopPropagation();
        let url = item.plain?.url || '';
        if (url && !/^https?:\/\//i.test(url)) url = 'https://' + url;
        window.open(url, '_blank', 'noopener,noreferrer');
      });
    }
    if (showCopyUser) {
      li.querySelector('[data-action="copy-user"]').addEventListener('click', e => {
        e.stopPropagation(); copyToClipboard(item.plain?.username || '', 'Username copied');
      });
    }
    if (showCopyPass) {
      li.querySelector('[data-action="copy-pass"]').addEventListener('click', e => {
        e.stopPropagation();
        const s = item.item_type === 'password' ? item.plain?.password
          : item.item_type === 'card' ? item.plain?.cvv
            : item.item_type === 'bank' ? item.plain?.account_number
              : item.plain?.ssn_number;
        copyToClipboard(s || '', 'Copied to clipboard');
      });
    }
    li.querySelector('[data-action="edit"]').addEventListener('click', e => { e.stopPropagation(); openModal('edit', item); });
    li.querySelector('[data-action="delete"]').addEventListener('click', e => { e.stopPropagation(); confirmDeleteItem(item); });
    li.addEventListener('click', () => openModal('edit', item));
    return li;
  }

  // ── Security Dashboard ────────────────────────────────────────────────────

  function renderSecurityDashboard() {
    const summaryEl = document.getElementById('security-summary');
    const sectionsEl = document.getElementById('security-sections');
    if (!summaryEl || !sectionsEl) return;

    // If vault hasn't loaded yet, wait for it then re-render
    if (!_items.length && VaultSession.getKey()) {
      summaryEl.innerHTML = '<div class="sec-notice">Loading…</div>';
      sectionsEl.innerHTML = '';
      loadVault().then(() => renderSecurityDashboard());
      return;
    }

    const pwItems = _items.filter(i => i.item_type === 'password' && i.plain?.password);
    if (!pwItems.length) {
      summaryEl.innerHTML = '<div class="sec-notice">No passwords to analyze.</div>';
      sectionsEl.innerHTML = '';
      return;
    }

    const weak = pwItems.filter(i => {
      const p = i.plain.password;
      if (p.length < 10) return true;
      return [/[A-Z]/, /[a-z]/, /[0-9]/, /[^A-Za-z0-9]/].filter(r => r.test(p)).length < 2;
    });

    const passCounts = {};
    pwItems.forEach(i => { const p = i.plain.password; (passCounts[p] = passCounts[p] || []).push(i); });
    const reused = Object.values(passCounts).filter(a => a.length > 1).flat();

    const cutoff = Date.now() - 180 * 86400000;
    const old = pwItems.filter(i => new Date(i.created_at).getTime() < cutoff);

    const total = pwItems.length;
    const score = Math.max(0, Math.round(100 - (weak.length / total) * 40 - (reused.length / total) * 30 - (old.length / total) * 15));
    const cls = score >= 80 ? 'score-good' : score >= 50 ? 'score-fair' : 'score-poor';
    const label = score >= 80 ? 'Good' : score >= 50 ? 'Fair' : 'Needs attention';

    summaryEl.innerHTML = `
      <div class="sec-score-card">
        <div class="sec-score ${cls}">${score}</div>
        <div class="sec-score-label">${label}</div>
        <div class="sec-score-desc">Based on ${total} password${total !== 1 ? 's' : ''}</div>
      </div>
      <div class="sec-stats">
        <div class="sec-stat ${weak.length ? 'sec-stat-warn' : 'sec-stat-ok'}"><span class="sec-stat-num">${weak.length}</span><span class="sec-stat-label">Weak</span></div>
        <div class="sec-stat ${reused.length ? 'sec-stat-warn' : 'sec-stat-ok'}"><span class="sec-stat-num">${reused.length}</span><span class="sec-stat-label">Reused</span></div>
        <div class="sec-stat ${old.length ? 'sec-stat-info' : 'sec-stat-ok'}"><span class="sec-stat-num">${old.length}</span><span class="sec-stat-label">Old (&gt;180d)</span></div>
      </div>`;

    sectionsEl.innerHTML = '';
    const makeSection = (title, icon, items, desc) => {
      if (!items.length) return;
      const sec = document.createElement('div');
      sec.className = 'sec-section';
      sec.innerHTML = `
        <div class="sec-section-header"><span class="sec-section-icon">${icon}</span>
          <div><div class="sec-section-title">${title} (${items.length})</div><div class="sec-section-desc">${desc}</div></div>
        </div>
        <ul class="sec-item-list">
          ${items.map(i => `<li class="sec-item">
            <span class="sec-item-name">${escHtml(i.name)}</span>
            <span class="sec-item-sub">${escHtml(i.plain?.username || '')}</span>
            <button class="btn-secondary btn-sm" data-sec-edit="${i.id}">Edit</button>
          </li>`).join('')}
        </ul>`;
      sec.querySelectorAll('[data-sec-edit]').forEach(btn => {
        btn.addEventListener('click', () => {
          const item = _items.find(it => it.id === parseInt(btn.dataset.secEdit));
          if (item) { switchView('vault'); openModal('edit', item); }
        });
      });
      sectionsEl.appendChild(sec);
    };

    makeSection('Weak Passwords', '⚠️', weak, 'Short or low-complexity passwords.');
    makeSection('Reused Passwords', '♻️', [...new Set(reused.map(i => i.id))].map(id => _items.find(i => i.id === id)).filter(Boolean), 'Same password used on multiple sites.');
    makeSection('Old Passwords', '🕐', old, 'Not changed in over 180 days.');
  }

  // ── Sharing View ──────────────────────────────────────────────────────────

  async function loadSharingView() {
    try {
      const keysRes = await apiFetch('/api/sharing/keys');
      if (!keysRes) return;
      const keysData = await keysRes.json();

      const notice = document.getElementById('sharing-keys-notice');
      if (!keysData.keys_setup) {
        notice.classList.remove('hidden');
      } else {
        notice.classList.add('hidden');
        // Load sharing private key into SharingSession if vault key available
        const vaultKey = VaultSession.getKey();
        if (vaultKey && !SharingSession.isReady()) {
          try {
            const privKey = await SharingCrypto.decryptPrivateKey(
              vaultKey, keysData.private_key_enc, keysData.private_key_iv
            );
            SharingSession.setKey(privKey);
          } catch (err) {
            console.warn('[PassKeeper] Could not load sharing private key:', err);
          }
        }
      }

      await Promise.all([loadSharedOut(), loadSharedIn()]);
    } catch (err) {
      showToast('Could not load sharing data: ' + err.message, 'error');
    }
  }

  async function loadSharedOut() {
    try {
      const res = await apiFetch('/api/sharing');
      if (!res) return;
      const shares = await res.json();
      renderSharedOut(shares);
    } catch (err) {
      console.error('loadSharedOut:', err);
    }
  }

  async function loadSharedIn() {
    try {
      const res = await apiFetch('/api/sharing/inbox');
      if (!res) return;
      const shares = await res.json();
      renderSharedIn(shares);
    } catch (err) {
      console.error('loadSharedIn:', err);
    }
  }

  function renderSharedOut(shares) {
    const ul = document.getElementById('shared-out-list');
    if (!ul) return;
    if (!shares.length) {
      ul.innerHTML = '<li class="vault-empty">You haven\'t shared any items yet.</li>';
      return;
    }
    ul.innerHTML = shares.map(s => `
      <li class="share-item">
        <div class="share-icon">${itemIcon(s.item_type)}</div>
        <div class="share-info">
          <span class="share-name">${escHtml(s.item_name)}</span>
          <span class="share-meta">Shared with ${escHtml(s.recipient_email)} · ${s.accepted ? '✅ Accepted' : '⏳ Pending'}</span>
        </div>
        <button class="btn-icon" title="Revoke share" data-revoke="${s.id}">🗑️</button>
      </li>`).join('');

    ul.querySelectorAll('[data-revoke]').forEach(btn => {
      btn.addEventListener('click', async () => {
        if (!confirm('Remove this share?')) return;
        try {
          await apiFetch(`/api/sharing/${btn.dataset.revoke}`, { method: 'DELETE' });
          showToast('Share removed');
          loadSharedOut();
        } catch (err) { showToast(err.message, 'error'); }
      });
    });
  }

  function renderSharedIn(shares) {
    const ul = document.getElementById('shared-in-list');
    if (!ul) return;
    if (!shares.length) {
      ul.innerHTML = '<li class="vault-empty">No items have been shared with you.</li>';
      return;
    }
    ul.innerHTML = shares.map(s => `
      <li class="share-item">
        <div class="share-icon">${itemIcon(s.item_type)}</div>
        <div class="share-info">
          <span class="share-name">${escHtml(s.item_name)}</span>
          <span class="share-meta">From ${escHtml(s.owner_email)}</span>
        </div>
        ${!s.accepted
        ? `<button class="btn-primary btn-sm" data-accept="${s.id}">Accept</button>`
        : `<button class="btn-secondary btn-sm" data-view-share="${s.id}" data-owner-key="${escHtml(s.owner_public_key || '')}" data-enc="${escHtml(s.enc_data)}" data-iv="${escHtml(s.iv)}" data-name="${escHtml(s.item_name)}" data-type="${escHtml(s.item_type || '')}">View</button>`
      }
      </li>`).join('');

    ul.querySelectorAll('[data-accept]').forEach(btn => {
      btn.addEventListener('click', async () => {
        try {
          await apiFetch(`/api/sharing/inbox/${btn.dataset.accept}/accept`, { method: 'POST' });
          showToast('Share accepted');
          loadSharedIn();
        } catch (err) { showToast(err.message, 'error'); }
      });
    });

    ul.querySelectorAll('[data-view-share]').forEach(btn => {
      btn.addEventListener('click', async () => {
        if (!SharingSession.isReady()) { showToast('Sharing keys not loaded. Check Settings.', 'error'); return; }
        try {
          const ownerPubKey = await SharingCrypto.importPublicKey(btn.dataset.ownerKey);
          const sharedKey = await SharingCrypto.deriveSharedKey(SharingSession.getKey(), ownerPubKey);
          const plain = await SharingCrypto.decryptShare(sharedKey, btn.dataset.enc, btn.dataset.iv);
          showSharedItemDetails(btn.dataset.name, btn.dataset.type, plain);
        } catch (err) { showToast('Could not decrypt: ' + err.message, 'error'); }
      });
    });
  }

  function showSharedItemDetails(name, itemType, plain) {
    document.getElementById('detail-modal-title').textContent = `${itemIcon(itemType || 'password')} ${name}`;
    renderDetailFields(document.getElementById('detail-modal-body'), plain);
    document.getElementById('detail-modal').classList.add('open');
  }

  function renderDetailFields(container, plain) {
    container.innerHTML = Object.entries(plain)
      .filter(([, v]) => v)
      .map(([k, v]) => {
        const label = FIELD_LABELS[k] || k.replace(/_/g, ' ');
        const val = String(v);
        const sensitive = SENSITIVE_FIELDS.has(k);
        const valHtml = sensitive
          ? `<span class="detail-sensitive">
               <span class="detail-masked">••••••••</span>
               <span class="detail-actual hidden">${escHtml(val)}</span>
             </span>
             <button type="button" class="btn-icon btn-reveal" title="Show/hide">👁</button>`
          : `<span class="detail-val">${escHtml(val)}</span>`;
        return `<div class="detail-field">
          <span class="detail-label">${escHtml(label)}</span>
          <div class="detail-val-row">
            ${valHtml}
            <button type="button" class="btn-icon btn-copy-field" data-copy="${escHtml(val)}" title="Copy">📋</button>
          </div>
        </div>`;
      }).join('') || '<p class="vault-empty">No fields to display.</p>';

    container.querySelectorAll('.btn-reveal').forEach(btn => {
      btn.addEventListener('click', () => {
        const span = btn.previousElementSibling;
        const revealed = span.dataset.revealed === 'true';
        span.dataset.revealed = String(!revealed);
        span.querySelector('.detail-masked').classList.toggle('hidden', !revealed);
        span.querySelector('.detail-actual').classList.toggle('hidden', revealed);
      });
    });
    container.querySelectorAll('.btn-copy-field').forEach(btn => {
      btn.addEventListener('click', () => {
        navigator.clipboard.writeText(btn.dataset.copy).then(() => showToast('Copied!'));
      });
    });
  }

  async function handleShareFormSubmit(e) {
    e.preventDefault();
    const errEl = document.getElementById('share-error');
    errEl.classList.add('hidden');

    if (!SharingSession.isReady()) {
      showToast('Set up sharing keys first (Settings)', 'error');
      return;
    }

    const itemId = parseInt(document.getElementById('share-item-select').value);
    const recipientEmail = document.getElementById('share-recipient-email').value.trim().toLowerCase();

    if (!itemId || !recipientEmail) {
      errEl.textContent = 'Please select an item and enter a recipient email.';
      errEl.classList.remove('hidden');
      return;
    }

    try {
      // Fetch recipient's public key
      const pkRes = await apiFetch(`/api/sharing/public-key?email=${encodeURIComponent(recipientEmail)}`);
      if (!pkRes) return;
      const pkData = await pkRes.json();

      const recipientPubKey = await SharingCrypto.importPublicKey(pkData.public_key);
      const sharedKey = await SharingCrypto.deriveSharedKey(SharingSession.getKey(), recipientPubKey);

      // Find item plaintext
      const item = _items.find(i => i.id === itemId);
      if (!item?.plain) { showToast('Item not found or not decrypted', 'error'); return; }

      const { enc_data, iv } = await SharingCrypto.encryptForShare(sharedKey, item.plain);

      const res = await apiFetch('/api/sharing', {
        method: 'POST',
        body: JSON.stringify({
          item_id: itemId,
          recipient_email: recipientEmail,
          enc_data, iv,
          item_name: item.name,
          item_type: item.item_type,
        }),
      });
      if (!res) return;

      closeModal('share-modal');
      showToast('Item shared successfully');
      loadSharedOut();
    } catch (err) {
      errEl.textContent = err.message;
      errEl.classList.remove('hidden');
    }
  }

  function openShareModal() {
    const sel = document.getElementById('share-item-select');
    sel.innerHTML = _items.map(i =>
      `<option value="${i.id}">${escHtml(i.name)} (${i.item_type})</option>`
    ).join('');
    document.getElementById('share-recipient-email').value = '';
    document.getElementById('share-error').classList.add('hidden');
    document.getElementById('share-modal').classList.add('open');
  }

  // ── Emergency Access View ─────────────────────────────────────────────────

  async function loadEmergencyView() {
    try {
      const res = await apiFetch('/api/emergency');
      if (!res) return;
      const data = await res.json();
      renderEmergencyGrants(data.grants);
      renderEmergencyAccess(data.access);
    } catch (err) {
      showToast('Could not load emergency access data: ' + err.message, 'error');
    }
  }

  function renderEmergencyGrants(grants) {
    const ul = document.getElementById('em-grants-list');
    if (!ul) return;
    if (!grants.length) {
      ul.innerHTML = '<li class="vault-empty">No trusted contacts set up yet.</li>';
      return;
    }

    ul.innerHTML = grants.map(g => {
      let actions = '';
      if (g.status === 'accepted') {
        actions = `<button class="btn-primary btn-sm" data-provide="${g.id}">Provide Recovery Data</button>`;
      }
      if (g.status === 'pending') {
        const waitInfo = g.wait_elapsed ? 'Wait period elapsed' : 'Access requested';
        actions = `<span class="badge badge-warn">${waitInfo}</span>
          <button class="btn-secondary btn-sm" data-deny="${g.id}">Deny</button>`;
      }
      return `<li class="share-item">
        <div class="share-icon">🚨</div>
        <div class="share-info">
          <span class="share-name">${escHtml(g.grantee_email)}</span>
          <span class="share-meta">Status: ${escHtml(g.status)} · Wait: ${g.wait_days} day(s)</span>
        </div>
        <div class="share-actions">
          ${actions}
          <button class="btn-icon" title="Remove" data-remove-ea="${g.id}">🗑️</button>
        </div>
      </li>`;
    }).join('');

    ul.querySelectorAll('[data-provide]').forEach(btn => {
      btn.addEventListener('click', () => handleProvideEmergencyData(parseInt(btn.dataset.provide)));
    });
    ul.querySelectorAll('[data-deny]').forEach(btn => {
      btn.addEventListener('click', async () => {
        if (!confirm('Deny this access request?')) return;
        try {
          await apiFetch(`/api/emergency/${btn.dataset.deny}/deny`, { method: 'POST' });
          showToast('Access request denied');
          loadEmergencyView();
        } catch (err) { showToast(err.message, 'error'); }
      });
    });
    ul.querySelectorAll('[data-remove-ea]').forEach(btn => {
      btn.addEventListener('click', async () => {
        if (!confirm('Remove this emergency access grant?')) return;
        try {
          await apiFetch(`/api/emergency/${btn.dataset.removeEa}`, { method: 'DELETE' });
          showToast('Emergency access removed');
          loadEmergencyView();
        } catch (err) { showToast(err.message, 'error'); }
      });
    });
  }

  async function handleProvideEmergencyData(eaId) {
    if (!SharingSession.isReady()) {
      showToast('Set up sharing keys first (Settings → Sharing Keys)', 'error');
      return;
    }
    if (!confirm('This will create an encrypted snapshot of all your vault items for your trusted contact. Continue?')) return;

    try {
      // Get grantee's public key from the emergency record
      const listRes = await apiFetch('/api/emergency');
      const listData = await listRes.json();
      const ea = listData.grants.find(g => g.id === eaId);
      if (!ea) { showToast('Emergency access record not found', 'error'); return; }

      // Fetch grantee's public key
      const pkRes = await apiFetch(`/api/sharing/public-key?email=${encodeURIComponent(ea.grantee_email)}`);
      if (!pkRes) return;
      const pkData = await pkRes.json();

      const granteePubKey = await SharingCrypto.importPublicKey(pkData.public_key);
      const sharedKey = await SharingCrypto.deriveSharedKey(SharingSession.getKey(), granteePubKey);

      // Re-encrypt all decrypted vault items
      const encItems = await Promise.all(
        _items.filter(i => i.plain).map(async i => {
          const { enc_data, iv } = await SharingCrypto.encryptForShare(sharedKey, i.plain);
          return { id: i.id, name: i.name, item_type: i.item_type, enc_data, iv };
        })
      );

      await apiFetch(`/api/emergency/${eaId}/provide`, {
        method: 'POST',
        body: JSON.stringify({ enc_vault: JSON.stringify(encItems) }),
      });

      showToast('Recovery data provided');
      loadEmergencyView();
    } catch (err) {
      showToast('Failed to provide recovery data: ' + err.message, 'error');
    }
  }

  function renderEmergencyAccess(access) {
    const ul = document.getElementById('em-access-list');
    if (!ul) return;
    if (!access.length) {
      ul.innerHTML = '<li class="vault-empty">No one has designated you as an emergency contact.</li>';
      return;
    }

    ul.innerHTML = access.map(a => {
      let actions = '';
      if (a.status === 'invited') {
        actions = `<button class="btn-primary btn-sm" data-accept-ea="${a.id}">Accept</button>`;
      } else if (a.status === 'ready') {
        actions = `<button class="btn-primary btn-sm" data-request-ea="${a.id}">Request Access</button>`;
      } else if (a.status === 'pending') {
        let daysLeft = a.wait_days;
        if (a.request_initiated_at) {
          const elapsed = (Date.now() - new Date(a.request_initiated_at).getTime()) / 86400000;
          daysLeft = Math.max(0, Math.ceil(a.wait_days - elapsed));
        }
        actions = a.wait_elapsed
          ? `<button class="btn-primary btn-sm" data-get-vault="${a.id}">View Vault</button>`
          : `<span class="badge badge-info">Waiting (~${daysLeft} day${daysLeft !== 1 ? 's' : ''} left)</span>`;
      }
      return `<li class="share-item">
        <div class="share-icon">🔐</div>
        <div class="share-info">
          <span class="share-name">${escHtml(a.grantor_email || 'Unknown')}</span>
          <span class="share-meta">Status: ${escHtml(a.status)} · Wait: ${a.wait_days} day(s)</span>
        </div>
        <div class="share-actions">${actions}</div>
      </li>`;
    }).join('');

    ul.querySelectorAll('[data-accept-ea]').forEach(btn => {
      btn.addEventListener('click', async () => {
        try {
          await apiFetch(`/api/emergency/${btn.dataset.acceptEa}/accept`, { method: 'POST' });
          showToast('Emergency access accepted');
          loadEmergencyView();
        } catch (err) { showToast(err.message, 'error'); }
      });
    });
    ul.querySelectorAll('[data-request-ea]').forEach(btn => {
      btn.addEventListener('click', async () => {
        if (!confirm('Request emergency access? This will start the waiting period. The vault owner will be notified.')) return;
        try {
          await apiFetch(`/api/emergency/${btn.dataset.requestEa}/request`, { method: 'POST' });
          showToast('Access request sent — wait period has started');
          loadEmergencyView();
        } catch (err) { showToast(err.message, 'error'); }
      });
    });
    ul.querySelectorAll('[data-get-vault]').forEach(btn => {
      btn.addEventListener('click', () => handleGetEmergencyVault(parseInt(btn.dataset.getVault)));
    });
  }

  async function handleGetEmergencyVault(eaId) {
    if (!SharingSession.isReady()) {
      showToast('Set up sharing keys first (Settings → Sharing Keys)', 'error');
      return;
    }
    try {
      const res = await apiFetch(`/api/emergency/${eaId}/vault`);
      if (!res) return;
      const data = await res.json();

      const grantorPubKey = await SharingCrypto.importPublicKey(data.grantor_public_key);
      const sharedKey = await SharingCrypto.deriveSharedKey(SharingSession.getKey(), grantorPubKey);

      const encItems = JSON.parse(data.enc_vault);
      const decItems = await Promise.all(encItems.map(async i => {
        try {
          const plain = await SharingCrypto.decryptShare(sharedKey, i.enc_data, i.iv);
          return { ...i, plain };
        } catch {
          return { ...i, plain: null };
        }
      }));

      renderEmergencyVaultPanel(decItems);
    } catch (err) {
      showToast('Could not retrieve vault: ' + err.message, 'error');
    }
  }

  function renderEmergencyVaultPanel(items) {
    const list = document.getElementById('em-access-list');
    const panel = document.getElementById('em-vault-panel');
    const vaultList = document.getElementById('em-vault-list');
    if (!panel || !vaultList) return;

    list.classList.add('hidden');
    panel.classList.remove('hidden');

    if (!items.length) {
      vaultList.innerHTML = '<li class="vault-empty">No items in emergency vault.</li>';
      return;
    }

    vaultList.innerHTML = items.map((item, idx) => {
      const icon = itemIcon(item.item_type);
      const hasFields = item.plain && Object.values(item.plain).some(v => v);
      return `<li class="em-vault-item">
        <button type="button" class="em-vault-item-header" data-em-idx="${idx}" aria-expanded="false">
          <span class="em-vault-icon">${icon}</span>
          <span class="em-vault-name">${escHtml(item.name)}</span>
          <span class="em-vault-type">${escHtml(item.item_type)}</span>
          <span class="em-vault-chevron">▸</span>
        </button>
        <div class="em-vault-item-body hidden" id="em-vault-body-${idx}">
          ${hasFields
          ? '<div class="detail-body em-detail-body"></div>'
          : '<p class="vault-empty">Could not decrypt this item.</p>'}
        </div>
      </li>`;
    }).join('');

    // Populate detail fields and wire expand/collapse
    items.forEach((item, idx) => {
      const header = vaultList.querySelector(`[data-em-idx="${idx}"]`);
      const body = document.getElementById(`em-vault-body-${idx}`);
      const detailBody = body?.querySelector('.em-detail-body');
      if (detailBody && item.plain) renderDetailFields(detailBody, item.plain);

      header?.addEventListener('click', () => {
        const expanded = header.getAttribute('aria-expanded') === 'true';
        header.setAttribute('aria-expanded', String(!expanded));
        header.querySelector('.em-vault-chevron').textContent = expanded ? '▸' : '▾';
        body?.classList.toggle('hidden', expanded);
      });
    });

    document.getElementById('btn-em-vault-back')?.addEventListener('click', () => {
      panel.classList.add('hidden');
      list.classList.remove('hidden');
    });
  }

  // ── Password Generator ────────────────────────────────────────────────

  const GEN_CHARSETS = {
    upper: 'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
    lower: 'abcdefghijklmnopqrstuvwxyz',
    digits: '0123456789',
    symbols: '!@#$%^&*()-_=+[]{}|;:,.<>?',
  };

  function generatePassword(length = 20, opts = { upper: true, lower: true, digits: true, symbols: true }) {
    let pool = '';
    const required = [];
    if (opts.upper) { pool += GEN_CHARSETS.upper; required.push(GEN_CHARSETS.upper); }
    if (opts.lower) { pool += GEN_CHARSETS.lower; required.push(GEN_CHARSETS.lower); }
    if (opts.digits) { pool += GEN_CHARSETS.digits; required.push(GEN_CHARSETS.digits); }
    if (opts.symbols) { pool += GEN_CHARSETS.symbols; required.push(GEN_CHARSETS.symbols); }
    if (!pool) pool = GEN_CHARSETS.lower;

    const arr = new Uint32Array(length + required.length);
    window.crypto.getRandomValues(arr);

    // Guarantee at least one char from each required charset
    const chars = required.map((cs, i) => cs[arr[i] % cs.length]);
    for (let i = required.length; i < length + required.length; i++) {
      chars.push(pool[arr[i] % pool.length]);
    }
    // Fisher-Yates shuffle using crypto random
    const shuffle = new Uint32Array(chars.length);
    window.crypto.getRandomValues(shuffle);
    for (let i = chars.length - 1; i > 0; i--) {
      const j = shuffle[i] % (i + 1);
      [chars[i], chars[j]] = [chars[j], chars[i]];
    }
    return chars.slice(0, length).join('');
  }

  function scorePassword(pw) {
    if (!pw) return { score: 0, label: '', cls: '' };
    let score = 0;
    if (pw.length >= 8) score++;
    if (pw.length >= 12) score++;
    if (pw.length >= 16) score++;
    if (/[A-Z]/.test(pw)) score++;
    if (/[a-z]/.test(pw)) score++;
    if (/[0-9]/.test(pw)) score++;
    if (/[^A-Za-z0-9]/.test(pw)) score++;
    // clamp to 5 bands
    const band = Math.min(5, Math.ceil(score / 7 * 5));
    const labels = ['', 'Very Weak', 'Weak', 'Fair', 'Strong', 'Very Strong'];
    const clses = ['', 'strength-1', 'strength-2', 'strength-3', 'strength-4', 'strength-5'];
    return { score: band, label: labels[band], cls: clses[band] };
  }

  // Attach strength meter + generate button to the password field in the item modal
  function initPasswordFieldEnhancements() {
    const pwInput = document.getElementById('field-password');
    if (!pwInput) return;

    // Strength bar below the password field
    if (!document.getElementById('field-password-strength')) {
      const bar = document.createElement('div');
      bar.id = 'field-password-strength';
      bar.className = 'password-strength';
      pwInput.closest('.input-with-toggle').insertAdjacentElement('afterend', bar);
    }

    pwInput.addEventListener('input', () => {
      const { label, cls } = scorePassword(pwInput.value);
      const bar = document.getElementById('field-password-strength');
      bar.textContent = pwInput.value ? label : '';
      bar.className = 'password-strength ' + (pwInput.value ? cls : '');
    });

    // Generate button — add only once
    if (!document.getElementById('btn-generate-pass')) {
      const btn = document.createElement('button');
      btn.type = 'button';
      btn.id = 'btn-generate-pass';
      btn.className = 'btn-secondary btn-sm';
      btn.textContent = '⚡ Generate';
      btn.style.marginTop = '6px';
      pwInput.closest('.form-group').appendChild(btn);
    }

    document.getElementById('btn-generate-pass').onclick = () => {
      const pw = generatePassword(20);
      pwInput.value = pw;
      pwInput.type = 'text';   // reveal so user can see what was generated
      pwInput.dispatchEvent(new Event('input')); // trigger strength bar
    };
  }

  function openPasswordGeneratorModal() {
    // Build modal content dynamically — keeps the HTML lean
    let modal = document.getElementById('gen-modal');
    if (!modal) {
      modal = document.createElement('div');
      modal.id = 'gen-modal';
      modal.className = 'modal-overlay';
      modal.setAttribute('role', 'dialog');
      modal.setAttribute('aria-modal', 'true');
      modal.innerHTML = `
        <div class="modal" style="max-width:420px">
          <div class="modal-header">
            <h3>⚡ Password Generator</h3>
            <button class="btn-icon btn-close" id="btn-close-gen-modal" aria-label="Close">✕</button>
          </div>
          <div class="form-group" style="margin-bottom:8px">
            <label>Length: <strong id="gen-length-display">20</strong></label>
            <input type="range" id="gen-length" min="8" max="64" value="20" style="width:100%;margin-top:4px">
          </div>
          <div class="gen-options" style="display:flex;gap:16px;flex-wrap:wrap;margin-bottom:16px">
            <label class="gen-opt"><input type="checkbox" id="gen-upper"   checked> Uppercase</label>
            <label class="gen-opt"><input type="checkbox" id="gen-lower"   checked> Lowercase</label>
            <label class="gen-opt"><input type="checkbox" id="gen-digits"  checked> Numbers</label>
            <label class="gen-opt"><input type="checkbox" id="gen-symbols" checked> Symbols</label>
          </div>
          <div class="form-group">
            <label>Generated Password</label>
            <div class="input-with-toggle" style="margin-bottom:4px">
              <input type="text" id="gen-output" readonly style="font-family:monospace;letter-spacing:.5px;padding-right:40px">
              <button type="button" class="btn-show-pass" id="btn-gen-copy" title="Copy" style="font-size:14px">📋</button>
            </div>
            <div id="gen-strength" class="password-strength"></div>
          </div>
          <div class="modal-actions">
            <button type="button" class="btn-secondary" id="btn-close-gen-modal2">Close</button>
            <button type="button" class="btn-primary"   id="btn-regenerate">↺ Regenerate</button>
          </div>
        </div>`;
      document.body.appendChild(modal);

      const lengthSlider = document.getElementById('gen-length');
      const lengthDisplay = document.getElementById('gen-length-display');
      const output = document.getElementById('gen-output');
      const strengthEl = document.getElementById('gen-strength');

      function refreshGen() {
        const pw = generatePassword(parseInt(lengthSlider.value), {
          upper: document.getElementById('gen-upper').checked,
          lower: document.getElementById('gen-lower').checked,
          digits: document.getElementById('gen-digits').checked,
          symbols: document.getElementById('gen-symbols').checked,
        });
        output.value = pw;
        const { label, cls } = scorePassword(pw);
        strengthEl.textContent = label;
        strengthEl.className = 'password-strength ' + cls;
      }

      lengthSlider.addEventListener('input', () => {
        lengthDisplay.textContent = lengthSlider.value;
        refreshGen();
      });
      ['gen-upper', 'gen-lower', 'gen-digits', 'gen-symbols'].forEach(id => {
        document.getElementById(id).addEventListener('change', refreshGen);
      });
      document.getElementById('btn-regenerate').addEventListener('click', refreshGen);
      document.getElementById('btn-gen-copy').addEventListener('click', () => {
        navigator.clipboard.writeText(output.value).then(() => showToast('Password copied'));
      });
      const closeGen = () => modal.classList.remove('open');
      document.getElementById('btn-close-gen-modal').addEventListener('click', closeGen);
      document.getElementById('btn-close-gen-modal2').addEventListener('click', closeGen);
      modal.addEventListener('click', e => { if (e.target === modal) closeGen(); });

      refreshGen();
    }
    modal.classList.add('open');
    // Regenerate fresh password each time modal opens
    const lengthSlider = document.getElementById('gen-length');
    document.getElementById('gen-length-display').textContent = lengthSlider.value;
    const pw = generatePassword(parseInt(lengthSlider.value), {
      upper: document.getElementById('gen-upper').checked,
      lower: document.getElementById('gen-lower').checked,
      digits: document.getElementById('gen-digits').checked,
      symbols: document.getElementById('gen-symbols').checked,
    });
    document.getElementById('gen-output').value = pw;
    const { label, cls } = scorePassword(pw);
    const strengthEl = document.getElementById('gen-strength');
    strengthEl.textContent = label;
    strengthEl.className = 'password-strength ' + cls;
  }

  // ── Account Settings ──────────────────────────────────────────────────────

  let _pendingMfaSecret = null;

  async function openSettingsModal() {
    document.getElementById('settings-modal').classList.add('open');
    await Promise.all([loadMfaStatus(), loadSharingKeysStatus()]);
  }

  async function loadMfaStatus() {
    try {
      const res = await apiFetch('/api/auth/mfa/status');
      if (!res) return;
      const data = await res.json();
      renderMfaStatus(data.totp_enabled);
    } catch (err) {
      console.error('loadMfaStatus:', err);
    }
  }

  function renderMfaStatus(enabled) {
    const statusText = document.getElementById('mfa-status-text');
    const actions = document.getElementById('mfa-actions');
    document.getElementById('mfa-setup-area').classList.add('hidden');
    document.getElementById('mfa-disable-area').classList.add('hidden');

    if (enabled) {
      statusText.textContent = '✅ Two-factor authentication is enabled.';
      actions.innerHTML = '<button class="btn-secondary" id="btn-mfa-disable">Disable MFA</button>';
      document.getElementById('btn-mfa-disable')?.addEventListener('click', () => {
        document.getElementById('mfa-disable-area').classList.remove('hidden');
        document.getElementById('mfa-actions').innerHTML = '';
        document.getElementById('mfa-disable-code').focus();
      });
    } else {
      statusText.textContent = 'Two-factor authentication is not enabled.';
      actions.innerHTML = '<button class="btn-primary" id="btn-mfa-setup">Set up MFA</button>';
      document.getElementById('btn-mfa-setup')?.addEventListener('click', handleMfaSetup);
    }
  }

  async function handleMfaSetup() {
    try {
      const res = await apiFetch('/api/auth/mfa/setup');
      if (!res) return;
      const data = await res.json();
      _pendingMfaSecret = data.secret;

      document.getElementById('mfa-qr-img').src = data.qr_code;
      document.getElementById('mfa-secret-display').textContent = data.secret;
      document.getElementById('mfa-setup-area').classList.remove('hidden');
      document.getElementById('mfa-actions').innerHTML = '';
      document.getElementById('mfa-status-text').textContent = 'Scan the QR code below with your authenticator app.';
      document.getElementById('mfa-verify-code').value = '';
      document.getElementById('mfa-verify-code').focus();
    } catch (err) {
      showToast('Could not start MFA setup: ' + err.message, 'error');
    }
  }

  async function handleMfaConfirm() {
    const code = document.getElementById('mfa-verify-code').value.trim();
    if (!code || !_pendingMfaSecret) return;
    try {
      const res = await apiFetch('/api/auth/mfa/enable', {
        method: 'POST',
        body: JSON.stringify({ secret: _pendingMfaSecret, totp_code: code }),
      });
      if (!res) return;
      _pendingMfaSecret = null;
      showToast('MFA enabled successfully');
      renderMfaStatus(true);
    } catch (err) {
      showToast('Failed to enable MFA: ' + err.message, 'error');
    }
  }

  async function handleMfaDisableConfirm() {
    const code = document.getElementById('mfa-disable-code').value.trim();
    if (!code) return;
    try {
      const res = await apiFetch('/api/auth/mfa/disable', {
        method: 'POST',
        body: JSON.stringify({ totp_code: code }),
      });
      if (!res) return;
      showToast('MFA disabled');
      renderMfaStatus(false);
    } catch (err) {
      showToast('Failed to disable MFA: ' + err.message, 'error');
    }
  }

  async function loadSharingKeysStatus() {
    try {
      const res = await apiFetch('/api/sharing/keys');
      if (!res) return;
      const data = await res.json();
      const statusEl = document.getElementById('sharing-keys-status');
      const actionsEl = document.getElementById('sharing-keys-actions');

      if (data.keys_setup) {
        statusEl.textContent = '✅ Sharing keys are set up. You can share items and use emergency access.';
        actionsEl.innerHTML = '<button class="btn-secondary" id="btn-regen-keys">Regenerate keys</button>';
        document.getElementById('btn-regen-keys')?.addEventListener('click', handleGenerateKeys);
      } else {
        statusEl.textContent = 'No sharing keys set up. Generate keys to enable item sharing and emergency access.';
        actionsEl.innerHTML = '<button class="btn-primary" id="btn-gen-keys">Generate sharing keys</button>';
        document.getElementById('btn-gen-keys')?.addEventListener('click', handleGenerateKeys);
      }
    } catch (err) {
      console.error('loadSharingKeysStatus:', err);
    }
  }

  async function handleGenerateKeys() {
    const vaultKey = VaultSession.getKey();
    if (!vaultKey) { showToast('Vault is locked. Unlock first.', 'error'); return; }

    try {
      const keyPair = await SharingCrypto.generateKeyPair();
      const public_key = await SharingCrypto.exportPublicKey(keyPair.publicKey);
      const { private_key_enc, private_key_iv } = await SharingCrypto.encryptPrivateKey(vaultKey, keyPair.privateKey);

      const res = await apiFetch('/api/sharing/keys', {
        method: 'POST',
        body: JSON.stringify({ public_key, private_key_enc, private_key_iv }),
      });
      if (!res) return;

      // Cache private key in session
      SharingSession.setKey(keyPair.privateKey);

      showToast('Sharing keys generated');
      await loadSharingKeysStatus();
    } catch (err) {
      showToast('Key generation failed: ' + err.message, 'error');
    }
  }

  // ── Folder CRUD ───────────────────────────────────────────────────────────

  function showNewFolderRow() {
    document.getElementById('new-folder-row').classList.remove('hidden');
    document.getElementById('new-folder-input').focus();
  }

  function hideNewFolderRow() {
    document.getElementById('new-folder-row').classList.add('hidden');
    document.getElementById('new-folder-input').value = '';
  }

  async function handleNewFolder(e) {
    e.preventDefault();
    const name = document.getElementById('new-folder-input').value.trim();
    if (!name) return;
    try {
      const res = await apiFetch('/api/folders', { method: 'POST', body: JSON.stringify({ name }) });
      if (!res) return;
      hideNewFolderRow();
      await loadFolders();
      showToast('Folder created');
    } catch (err) {
      showToast('Could not create folder: ' + err.message, 'error');
    }
  }

  async function confirmDeleteFolder(folder) {
    if (!confirm(`Delete folder "${folder.name}"?\nItems will be moved to No Folder.`)) return;
    try {
      const res = await apiFetch(`/api/folders/${folder.id}`, { method: 'DELETE' });
      if (!res) return;
      _items = _items.map(i => i.folder_id === folder.id ? { ...i, folder_id: null } : i);
      if (_activeFilter?.type === 'folder' && _activeFilter.value === folder.id) {
        _activeFilter = null;
        updateVaultTitle('All Items');
      }
      await loadFolders();
      applyCurrentFilter();
      showToast('Folder deleted');
    } catch (err) {
      showToast('Could not delete folder: ' + err.message, 'error');
    }
  }

  // ── Filtering / Search ────────────────────────────────────────────────────

  function applyCurrentFilter() {
    if (!_activeFilter) { renderItemList(_items); return; }
    if (_activeFilter.type === 'itemType') renderItemList(_items.filter(i => i.item_type === _activeFilter.value));
    else if (_activeFilter.type === 'folder') renderItemList(_items.filter(i => i.folder_id === _activeFilter.value));
  }

  function filterByFolder(folderId, name) {
    _activeFilter = { type: 'folder', value: folderId };
    switchView('vault');
    document.querySelectorAll('.sidebar-item').forEach(el => el.classList.remove('active'));
    document.querySelector(`[data-folder-id="${folderId}"]`)?.classList.add('active');
    updateVaultTitle(name);
    renderItemList(_items.filter(i => i.folder_id === folderId));
  }

  function handleSearch(e) {
    const q = e.target.value.trim().toLowerCase();
    if (!q) { applyCurrentFilter(); return; }
    const pool = _activeFilter ? (_activeFilter.type === 'itemType' ? _items.filter(i => i.item_type === _activeFilter.value) : _items.filter(i => i.folder_id === _activeFilter.value)) : _items;
    renderItemList(pool.filter(item =>
      item.name.toLowerCase().includes(q) ||
      (item.plain?.username || '').toLowerCase().includes(q) ||
      (item.plain?.url || '').toLowerCase().includes(q) ||
      (item.plain?.note_body || '').toLowerCase().includes(q)
    ));
  }

  function updateVaultTitle(text) {
    const el = document.getElementById('vault-title');
    if (el) el.textContent = text;
  }

  // ── Item Modal ────────────────────────────────────────────────────────────

  const TYPE_LABELS = { password: '🔑 Password', note: '📝 Secure Note', card: '💳 Payment Card', bank: '🏦 Bank Account', address: '🏠 Address', ssn: '🪪 Identity (SSN)' };

  function switchModalType(type) {
    document.querySelectorAll('.type-fields').forEach(el => {
      el.classList.toggle('hidden', !el.dataset.forTypes.split(' ').includes(type));
    });
  }

  function openModal(mode, item = null) {
    const form = document.getElementById('item-form');
    form.reset();
    form.dataset.mode = mode;
    form.dataset.itemId = item ? item.id : '';

    const folderSel = document.getElementById('field-folder');
    folderSel.innerHTML = '<option value="">— No folder —</option>';
    _folders.forEach(f => {
      const opt = document.createElement('option');
      opt.value = f.id;
      opt.textContent = f.name;
      folderSel.appendChild(opt);
    });

    if (mode === 'add') {
      document.getElementById('type-selector-group').classList.remove('hidden');
      document.getElementById('modal-title').textContent = 'Add Item';
      switchModalType(document.getElementById('field-type').value || 'password');
    } else {
      document.getElementById('type-selector-group').classList.add('hidden');
      const t = item.item_type || 'password';
      document.getElementById('modal-title').textContent = `Edit ${TYPE_LABELS[t] || 'Item'}`;
      switchModalType(t);
      form.dataset.itemType = t;
      setVal('field-name', item.name);
      setVal('field-folder', item.folder_id || '');
      if (item.plain) {
        const p = item.plain;
        switch (t) {
          case 'password': setVal('field-url', p.url); setVal('field-username', p.username); setVal('field-password', p.password); setVal('field-notes', p.notes); break;
          case 'note': setVal('field-note-body', p.note_body); break;
          case 'card': setVal('field-cardholder', p.cardholder_name); setVal('field-card-number', p.card_number); setVal('field-expiry-month', p.expiry_month); setVal('field-expiry-year', p.expiry_year); setVal('field-cvv', p.cvv); setVal('field-notes', p.notes); break;
          case 'bank': setVal('field-bank-name', p.bank_name); setVal('field-account-type', p.account_type); setVal('field-routing', p.routing_number); setVal('field-account-number', p.account_number); setVal('field-notes', p.notes); break;
          case 'address': ['first_name', 'last_name', 'company', 'address_line', 'city', 'state', 'zip', 'country', 'phone', 'email'].forEach(k => setVal('field-' + k.replace(/_/g, '-'), p[k])); setVal('field-notes', p.notes); break;
          case 'ssn': setVal('field-ssn-number', p.ssn_number); setVal('field-notes', p.notes); break;
        }
      }
    }
    document.getElementById('item-modal').classList.add('open');
    document.getElementById('field-name').focus();
    if ((mode === 'add' && (document.getElementById('field-type').value || 'password') === 'password') ||
      (mode === 'edit' && (item?.item_type || 'password') === 'password')) {
      initPasswordFieldEnhancements();
    }
  }

  function setVal(id, val) { const el = document.getElementById(id); if (el) el.value = val || ''; }
  function getVal(id) { const el = document.getElementById(id); return el ? el.value : ''; }

  function closeModal(id = 'item-modal') {
    document.getElementById(id)?.classList.remove('open');
  }

  function buildPlainData(t) {
    switch (t) {
      case 'password': return { url: getVal('field-url').trim(), username: getVal('field-username').trim(), password: getVal('field-password'), notes: getVal('field-notes').trim() };
      case 'note': return { note_body: getVal('field-note-body') };
      case 'card': return { cardholder_name: getVal('field-cardholder').trim(), card_number: getVal('field-card-number').trim(), expiry_month: getVal('field-expiry-month'), expiry_year: getVal('field-expiry-year').trim(), cvv: getVal('field-cvv').trim(), notes: getVal('field-notes').trim() };
      case 'bank': return { bank_name: getVal('field-bank-name').trim(), account_type: getVal('field-account-type'), routing_number: getVal('field-routing').trim(), account_number: getVal('field-account-number').trim(), notes: getVal('field-notes').trim() };
      case 'address': return { first_name: getVal('field-first-name').trim(), last_name: getVal('field-last-name').trim(), company: getVal('field-company').trim(), address_line: getVal('field-address-line').trim(), city: getVal('field-city').trim(), state: getVal('field-state').trim(), zip: getVal('field-zip').trim(), country: getVal('field-country').trim(), phone: getVal('field-phone').trim(), email: getVal('field-email').trim(), notes: getVal('field-notes').trim() };
      case 'ssn': return { ssn_number: getVal('field-ssn-number'), notes: getVal('field-notes').trim() };
      default: return {};
    }
  }

  async function handleFormSubmit(e) {
    e.preventDefault();
    try {
      const vaultKey = VaultSession.getKey();
      if (!vaultKey) { closeModal(); showUnlockOverlay(); return; }
      const form = e.target;
      const mode = form.dataset.mode;
      const itemId = form.dataset.itemId;
      const name = getVal('field-name').trim();
      if (!name) { showToast('Name is required', 'error'); return; }

      const itemType = mode === 'add' ? getVal('field-type') : (form.dataset.itemType || 'password');
      const { enc_data, iv } = await Crypto.encryptItem(vaultKey, buildPlainData(itemType));
      const folderVal = getVal('field-folder');
      const payload = { name, item_type: itemType, folder_id: folderVal ? parseInt(folderVal) : null, enc_data, iv };

      if (mode === 'add') {
        const res = await apiFetch('/api/vault', { method: 'POST', body: JSON.stringify(payload) });
        if (!res) return;
        showToast('Item added');
      } else {
        const res = await apiFetch(`/api/vault/${itemId}`, { method: 'PUT', body: JSON.stringify(payload) });
        if (!res) return;
        showToast('Item updated');
      }
      closeModal();
      await loadVault();
    } catch (err) {
      showToast('Save failed: ' + err.message, 'error');
    }
  }

  async function confirmDeleteItem(item) {
    if (!confirm(`Delete "${item.name}"? This cannot be undone.`)) return;
    try {
      const res = await apiFetch(`/api/vault/${item.id}`, { method: 'DELETE' });
      if (!res) return;
      showToast('Item deleted');
      await loadVault();
    } catch (err) {
      showToast('Delete failed: ' + err.message, 'error');
    }
  }

  // ── Logout ────────────────────────────────────────────────────────────────

  async function handleLogout() {
    const refreshToken = localStorage.getItem('refresh_token');
    await fetch('/api/auth/logout', {
      method: 'POST',
      headers: { 'Authorization': `Bearer ${sessionStorage.getItem('access_token') || ''}`, 'Content-Type': 'application/json', 'X-CSRFToken': csrfToken() },
      body: JSON.stringify({ refresh_token: refreshToken }),
    }).catch(() => { });
    VaultSession.clear();
    SharingSession.clear();
    sessionStorage.removeItem('access_token');
    localStorage.removeItem('refresh_token');
    window.dispatchEvent(new CustomEvent('passkeeper:logout'));
    window.location.href = '/login';
  }

  // ── Utilities ─────────────────────────────────────────────────────────────

  function copyToClipboard(text, msg = 'Copied') {
    navigator.clipboard.writeText(text).then(() => showToast(msg)).catch(() => { });
  }

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

  function itemIcon(type) {
    return { password: '🔑', note: '📝', card: '💳', bank: '🏦', address: '🏠', ssn: '🪪' }[type] || '🔑';
  }

  function showToast(message, type = 'success') {
    const toast = document.getElementById('toast');
    if (!toast) return;
    toast.textContent = message;
    toast.className = `toast toast-${type} show`;
    clearTimeout(toast._timer);
    toast._timer = setTimeout(() => toast.classList.remove('show'), 2500);
  }

  function showLoadingState(loading) {
    document.getElementById('vault-spinner')?.classList.toggle('hidden', !loading);
  }

  // ── Unlock overlay ────────────────────────────────────────────────────────

  function showUnlockOverlay() {
    document.getElementById('unlock-overlay').classList.add('open');
    document.getElementById('unlock-password').focus();
  }

  async function handleUnlock(e) {
    e.preventDefault();
    const password = document.getElementById('unlock-password').value;
    const enc_key_salt = sessionStorage.getItem('enc_key_salt');
    const btn = e.target.querySelector('[type="submit"]');
    const errEl = document.getElementById('unlock-error');
    if (!enc_key_salt) { redirectToLogin(); return; }

    btn.disabled = true; btn.textContent = 'Unlocking…'; errEl.classList.add('hidden');
    try {
      const vaultKey = await Crypto.deriveVaultKey(password, enc_key_salt);
      VaultSession.setKey(vaultKey);
      document.getElementById('unlock-overlay').classList.remove('open');
      await loadFolders();
      await loadVault();
    } catch {
      errEl.classList.remove('hidden');
    } finally {
      btn.disabled = false; btn.textContent = 'Unlock';
      document.getElementById('unlock-password').value = '';
    }
  }

  // ── Tabs ──────────────────────────────────────────────────────────────────

  function initTabs(container) {
    const tabs = container.querySelectorAll('.tab-btn');
    tabs.forEach(btn => {
      btn.addEventListener('click', () => {
        tabs.forEach(t => t.classList.remove('active'));
        btn.classList.add('active');
        const target = btn.dataset.tab;
        container.querySelectorAll('.tab-pane').forEach(pane => {
          pane.classList.toggle('hidden', !pane.id.endsWith(target));
        });
      });
    });
  }

  // ── Init ──────────────────────────────────────────────────────────────────

  async function init() {
    if (!sessionStorage.getItem('access_token')) {
      // Give the extension bridge up to 800 ms to inject a session before redirecting
      await new Promise(resolve => {
        const timer = setTimeout(resolve, 800);
        window.addEventListener('passkeeper:ext-login', () => { clearTimeout(timer); resolve(); }, { once: true });
      });
      if (!sessionStorage.getItem('access_token')) { window.location.href = '/login'; return; }
    }

    // Vault
    document.getElementById('unlock-form')?.addEventListener('submit', handleUnlock);
    document.getElementById('btn-new-folder')?.addEventListener('click', showNewFolderRow);
    document.getElementById('btn-cancel-folder')?.addEventListener('click', hideNewFolderRow);
    document.getElementById('new-folder-form')?.addEventListener('submit', handleNewFolder);
    document.getElementById('search-input')?.addEventListener('input', handleSearch);
    document.getElementById('btn-add-item')?.addEventListener('click', () => openModal('add'));
    document.getElementById('btn-close-modal')?.addEventListener('click', () => closeModal());
    document.getElementById('btn-cancel-modal')?.addEventListener('click', () => closeModal());
    document.getElementById('item-form')?.addEventListener('submit', handleFormSubmit);
    document.getElementById('btn-logout')?.addEventListener('click', handleLogout);

    document.getElementById('sort-select')?.addEventListener('change', e => { _sortOrder = e.target.value; applyCurrentFilter(); });
    document.getElementById('field-type')?.addEventListener('change', e => {
      switchModalType(e.target.value);
      if (e.target.value === 'password') initPasswordFieldEnhancements();
    });
    document.getElementById('btn-toggle-pass')?.addEventListener('click', () => { const el = document.getElementById('field-password'); el.type = el.type === 'password' ? 'text' : 'password'; });
    document.getElementById('btn-toggle-ssn')?.addEventListener('click', () => { const el = document.getElementById('field-ssn-number'); el.type = el.type === 'password' ? 'text' : 'password'; });

    // Sidebar navigation
    document.getElementById('sidebar-all')?.addEventListener('click', () => {
      _activeFilter = null; switchView('vault');
      document.querySelectorAll('.sidebar-item').forEach(el => el.classList.remove('active'));
      document.getElementById('sidebar-all').classList.add('active');
      updateVaultTitle('All Items'); renderItemList(_items);
    });
    document.getElementById('sidebar-security')?.addEventListener('click', () => switchView('security'));
    document.getElementById('sidebar-sharing')?.addEventListener('click', () => switchView('sharing'));
    document.getElementById('sidebar-emergency')?.addEventListener('click', () => switchView('emergency'));
    document.getElementById('sidebar-generator')?.addEventListener('click', () => openPasswordGeneratorModal());

    document.querySelectorAll('[data-type-filter]').forEach(el => {
      el.addEventListener('click', () => {
        const type = el.dataset.typeFilter;
        const labels = { password: 'Passwords', note: 'Secure Notes', card: 'Payment Cards', bank: 'Bank Accounts', address: 'Addresses', ssn: 'Identities' };
        _activeFilter = { type: 'itemType', value: type };
        switchView('vault');
        document.querySelectorAll('.sidebar-item').forEach(s => s.classList.remove('active'));
        el.classList.add('active');
        updateVaultTitle(labels[type] || type);
        renderItemList(_items.filter(i => i.item_type === type));
      });
    });

    document.getElementById('item-modal')?.addEventListener('click', e => { /* backdrop click intentionally disabled — modal closes only via Cancel or Save */ });
    document.addEventListener('keydown', e => { if (e.key === 'Escape') { closeModal('share-modal'); closeModal('emergency-modal'); closeModal('settings-modal'); closeModal('detail-modal'); closeModal('gen-modal'); } });

    // Detail modal (shared item view)
    const closeDetailModal = () => closeModal('detail-modal');
    document.getElementById('btn-close-detail-modal')?.addEventListener('click', closeDetailModal);
    document.getElementById('btn-detail-done')?.addEventListener('click', closeDetailModal);
    document.getElementById('detail-modal')?.addEventListener('click', e => { if (e.target.id === 'detail-modal') closeDetailModal(); });

    document.getElementById('field-card-number')?.addEventListener('input', e => {
      let v = e.target.value.replace(/\D/g, '').slice(0, 16);
      e.target.value = v.replace(/(.{4})/g, '$1 ').trim();
    });

    // Settings modal
    document.getElementById('btn-settings')?.addEventListener('click', openSettingsModal);
    document.getElementById('btn-close-settings')?.addEventListener('click', () => closeModal('settings-modal'));
    document.getElementById('settings-modal')?.addEventListener('click', e => { if (e.target.id === 'settings-modal') closeModal('settings-modal'); });
    document.getElementById('btn-mfa-confirm')?.addEventListener('click', handleMfaConfirm);
    document.getElementById('btn-mfa-cancel-setup')?.addEventListener('click', () => { document.getElementById('mfa-setup-area').classList.add('hidden'); loadMfaStatus(); });
    document.getElementById('btn-mfa-disable-confirm')?.addEventListener('click', handleMfaDisableConfirm);
    document.getElementById('btn-mfa-disable-cancel')?.addEventListener('click', () => { document.getElementById('mfa-disable-area').classList.add('hidden'); loadMfaStatus(); });

    // Share modal
    document.getElementById('btn-share-item')?.addEventListener('click', openShareModal);
    document.getElementById('btn-close-share-modal')?.addEventListener('click', () => closeModal('share-modal'));
    document.getElementById('btn-cancel-share')?.addEventListener('click', () => closeModal('share-modal'));
    document.getElementById('share-modal')?.addEventListener('click', e => { if (e.target.id === 'share-modal') closeModal('share-modal'); });
    document.getElementById('share-form')?.addEventListener('submit', handleShareFormSubmit);
    document.getElementById('btn-setup-keys-from-sharing')?.addEventListener('click', () => { closeModal('share-modal'); openSettingsModal(); });

    // Emergency modal
    document.getElementById('btn-add-emergency')?.addEventListener('click', () => {
      document.getElementById('emergency-error').classList.add('hidden');
      document.getElementById('emergency-modal').classList.add('open');
    });
    document.getElementById('btn-close-emergency-modal')?.addEventListener('click', () => closeModal('emergency-modal'));
    document.getElementById('btn-cancel-emergency')?.addEventListener('click', () => closeModal('emergency-modal'));
    document.getElementById('emergency-modal')?.addEventListener('click', e => { if (e.target.id === 'emergency-modal') closeModal('emergency-modal'); });
    document.getElementById('emergency-form')?.addEventListener('submit', handleEmergencyFormSubmit);

    // Tabs
    document.querySelectorAll('.panel-tabs').forEach(c => initTabs(c));

    if (!VaultSession.getKey()) { showUnlockOverlay(); } else { loadVault(); }
  }

  async function handleEmergencyFormSubmit(e) {
    e.preventDefault();
    const errEl = document.getElementById('emergency-error');
    errEl.classList.add('hidden');
    const email = document.getElementById('emergency-email').value.trim().toLowerCase();
    const waitDays = document.getElementById('emergency-wait-days').value;
    if (!email) { errEl.textContent = 'Email is required.'; errEl.classList.remove('hidden'); return; }
    try {
      const res = await apiFetch('/api/emergency', {
        method: 'POST',
        body: JSON.stringify({ grantee_email: email, wait_days: parseInt(waitDays) }),
      });
      if (!res) return;
      closeModal('emergency-modal');
      showToast('Invitation sent');
      loadEmergencyView();
    } catch (err) {
      errEl.textContent = err.message;
      errEl.classList.remove('hidden');
    }
  }

  return { init };
})();

document.addEventListener('DOMContentLoaded', Vault.init);