// State
let models = [];       // the library (not in the trash)
let trashModels = [];  // loaded while the Trash view is open
let projects = [];
let config = { importers: {} };
let stats = { trash: 0, duplicateGroups: 0, fingerprintsPending: 0 };
let selectedScope = 'all'; // 'all' | 'duplicates' | 'trash' | a collection id
let tagFilters = {};       // tag -> 'include' | 'exclude'
let duplicateData = null;  // last /api/duplicates response
let duplicatePoll = null;

// View preferences, remembered per browser.
const prefs = { view: 'grid', tagMatch: 'any', format: '', source: '', license: '', sort: 'newest', group: '' };
const PREFS_KEY = 'printhive.prefs';
const SPECIAL_SCOPES = ['all', 'duplicates', 'trash'];

// DOM
const fileGrid = document.getElementById('fileGrid');
const projectsList = document.getElementById('projectsList');
const tagsList = document.getElementById('tagsList');
const searchInput = document.getElementById('searchInput');
const contentTitle = document.getElementById('contentTitle');
const resultCount = document.getElementById('resultCount');
const emptyTrashBtn = document.getElementById('emptyTrashBtn');
const uploadModal = document.getElementById('uploadModal');
const projectModal = document.getElementById('projectModal');
const importModal = document.getElementById('importModal');
const settingsModal = document.getElementById('settingsModal');
const setupModal = document.getElementById('setupModal');
const editModal = document.getElementById('editModal');
const fileDetailModal = document.getElementById('fileDetailModal');

document.addEventListener('DOMContentLoaded', () => {
  loadPrefs();
  setupAuthListeners();
  bootstrap();
});

function loadPrefs() {
  try { Object.assign(prefs, JSON.parse(localStorage.getItem(PREFS_KEY)) || {}); } catch { /* storage unavailable */ }
}

function savePrefs() {
  try { localStorage.setItem(PREFS_KEY, JSON.stringify(prefs)); } catch { /* storage unavailable */ }
}

// Decide what to show: the app (if signed in), the reset form (if ?reset=...),
// or the sign-in / create-account screen.
async function bootstrap() {
  const resetToken = new URLSearchParams(location.search).get('reset');
  if (resetToken) { showAuth('reset'); return; }
  let status;
  try {
    status = await (await fetch('/api/auth/status')).json();
  } catch {
    status = { authenticated: false, needsSetup: false };
  }
  if (status.authenticated) startApp();
  else showAuth(status.needsSetup ? 'register' : 'login');
}

let appStarted = false;
function startApp() {
  document.getElementById('authScreen').style.display = 'none';
  document.querySelector('.container').style.display = '';
  if (!appStarted) { setupEventListeners(); appStarted = true; }
  loadData();
}

function showAuth(mode) {
  document.querySelector('.container').style.display = 'none';
  document.getElementById('authScreen').style.display = 'flex';
  ['login', 'register', 'forgot', 'reset'].forEach((m) => {
    document.getElementById('auth-' + m).style.display = m === mode ? '' : 'none';
  });
  document.getElementById('authError').textContent = '';
}

function setupAuthListeners() {
  document.getElementById('auth-login').addEventListener('submit', handleLogin);
  document.getElementById('auth-register').addEventListener('submit', handleRegister);
  document.getElementById('auth-forgot').addEventListener('submit', handleForgot);
  document.getElementById('auth-reset').addEventListener('submit', handleReset);
  document.querySelectorAll('.auth-nav').forEach((b) => {
    b.addEventListener('click', () => showAuth(b.dataset.auth));
  });
}

async function authPost(url, body) {
  const res = await fetch(url, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(body) });
  const data = await res.json().catch(() => ({}));
  if (!res.ok) throw new Error(data.error || 'Something went wrong.');
  return data;
}
function authError(msg) { document.getElementById('authError').textContent = msg; }

async function handleLogin(e) {
  e.preventDefault();
  try {
    await authPost('/api/auth/login', {
      email: document.getElementById('loginEmail').value,
      password: document.getElementById('loginPassword').value,
    });
    location.reload();
  } catch (err) { authError(err.message); }
}

async function handleRegister(e) {
  e.preventDefault();
  try {
    await authPost('/api/auth/register', {
      email: document.getElementById('regEmail').value,
      password: document.getElementById('regPassword').value,
    });
    location.reload();
  } catch (err) { authError(err.message); }
}

async function handleForgot(e) {
  e.preventDefault();
  try {
    await authPost('/api/auth/forgot', { email: document.getElementById('forgotEmail').value });
    authError('If that email has an account and email is configured, a reset link is on its way.');
  } catch (err) { authError(err.message); }
}

async function handleReset(e) {
  e.preventDefault();
  const token = new URLSearchParams(location.search).get('reset');
  try {
    await authPost('/api/auth/reset', { token, password: document.getElementById('resetPassword').value });
    window.history.replaceState({}, '', location.pathname); // drop ?reset=
    showAuth('login');
    authError('Password updated — you can sign in now.');
  } catch (err) { authError(err.message); }
}

async function handleLogout() {
  try { await fetch('/api/auth/logout', { method: 'POST' }); } catch { /* ignore */ }
  location.reload();
}

async function loadData() {
  try {
    const [modelsRes, projectsRes, configRes, statsRes] = await Promise.all([
      fetch('/api/models'),
      fetch('/api/projects'),
      fetch('/api/config'),
      fetch('/api/library/stats'),
    ]);
    models = await modelsRes.json();
    projects = await projectsRes.json();
    config = await configRes.json();
    stats = statsRes.ok ? await statsRes.json() : stats;
    if (selectedScope === 'trash') await loadTrash();
    if (!SPECIAL_SCOPES.includes(selectedScope) && !projects.some((p) => String(p.id) === String(selectedScope))) {
      selectedScope = 'all'; // the open collection was deleted
    }

    renderProjects();
    renderTags();
    renderFilterOptions();
    renderModels();
    updateCounts();
    generateMissingThumbnails(); // fire-and-forget; updates cards as they finish
    watchBackgroundWork();

    // First-run onboarding: prompt for import sources once.
    if (config.setupComplete === false && !setupModal.classList.contains('active')) {
      setupModal.classList.add('active');
    }
  } catch (error) {
    console.error('Error loading data:', error);
  }
}

// While the server is still fingerprinting or making thumbnails, check back
// every few seconds and reload once its progress changes, so new thumbnails
// and duplicates show up without a manual refresh.
let backgroundPoll = null;
function watchBackgroundWork() {
  clearTimeout(backgroundPoll);
  const pendingOf = (s) => (s.fingerprintsPending || 0) + (s.thumbnailsPending || 0);
  const pending = pendingOf(stats);
  if (!pending) return;
  backgroundPoll = setTimeout(async () => {
    try {
      const next = await (await fetch('/api/library/stats')).json();
      if (pendingOf(next) !== pending || next.duplicateGroups !== stats.duplicateGroups) {
        await loadData(); // re-arms the watch
        return;
      }
      stats = next;
      watchBackgroundWork();
    } catch { /* offline: try again on the next reload */ }
  }, 5000);
}

async function loadTrash() {
  const res = await fetch('/api/models?view=trash');
  trashModels = res.ok ? await res.json() : [];
}

// The server makes STL/OBJ/3MF thumbnails in the background; the browser
// renders the formats only it can read, then saves them. One at a time, to
// avoid thrashing the GPU / WebGL contexts.
const BROWSER_THUMBNAIL_FORMATS = ['fbx', '3dm', 'step', 'stp'];
const thumbAttempted = new Set();
async function generateMissingThumbnails() {
  if (!window.ModelViewer) return;
  for (const m of models) {
    if (m.thumbnailUrl || thumbAttempted.has(m.id)) continue;
    const file = (m.files || []).find((f) => BROWSER_THUMBNAIL_FORMATS.includes(f.format));
    if (!file) continue;
    thumbAttempted.add(m.id);
    try {
      const src = viewerSourceFor({ kind: 'file', id: file.id, format: file.format });
      const image = await window.ModelViewer.snapshot(src.url, src.format, 512, { resolve: resolverFor(m) });
      if (!image) continue;
      const res = await fetch(`/api/models/${m.id}/thumbnail`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ image }),
      });
      if (!res.ok) continue;
      const updated = await res.json();
      updateCardThumbnail(m.id, updated.thumbnailUrl);
    } catch (err) {
      console.warn('Thumbnail generation failed for model', m.id, err);
    }
  }
}

// ---------------------------------------------------------------- lookups
function findModel(id) {
  return models.find((m) => String(m.id) === String(id))
    || trashModels.find((m) => String(m.id) === String(id));
}

function replaceModel(updated) {
  for (const list of [models, trashModels]) {
    const i = list.findIndex((m) => m.id === updated.id);
    if (i !== -1) list[i] = updated;
  }
}

const SOURCE_LABELS = {
  upload: 'Manual upload', thingiverse: 'Thingiverse', printables: 'Printables',
  makerworld: 'MakerWorld', cubee3d: 'Cubee3D', web: 'Web',
};
const sourceKey = (m) => m.source_site || 'upload';
const sourceLabel = (key) => SOURCE_LABELS[key] || key;
const licenseKey = (m) => (m.commercial_use === true ? 'sellable' : m.commercial_use === false ? 'noncommercial' : 'unknown');
const totalSize = (m) => (m.files || []).reduce((s, f) => s + Number(f.size || 0), 0);
const fileCountLabel = (m) => `${m.files.length} file${m.files.length === 1 ? '' : 's'}`;

// Everything a search term can match, lower-cased. Cached per model object
// (objects are replaced whenever data reloads, which invalidates the cache).
const searchCache = new WeakMap();
function searchText(m) {
  if (!searchCache.has(m)) {
    searchCache.set(m, [
      m.name, m.description, m.notes, m.license, sourceLabel(sourceKey(m)),
      m.designer && m.designer.name,
      ...(m.tags || []),
      ...(m.projects || []).map((p) => p.name),
      ...(m.files || []).map((f) => f.originalName),
    ].filter(Boolean).join('\n').toLowerCase());
  }
  return searchCache.get(m);
}

// ---------------------------------------------------------------- rendering
function renderProjects() {
  projectsList.innerHTML = projects.length
    ? projects.map((p) => `
      <div class="project-item" data-scope="${p.id}">
        <span class="project-name">${escapeHtml(p.name)}</span>
        <span class="project-meta">
          <button class="collection-action collection-rename" title="Rename" aria-label="Rename collection">&#9998;</button>
          <button class="collection-action collection-delete" title="Delete" aria-label="Delete collection">&times;</button>
          <span class="count">${p.model_count}</span>
        </span>
      </div>`).join('')
    : '<p class="form-hint">No collections yet.</p>';
}

function renderTags() {
  const all = knownTags();
  for (const t of Object.keys(tagFilters)) if (!all.includes(t)) delete tagFilters[t];
  const titles = {
    include: 'Showing models with this tag — click to exclude it',
    exclude: 'Hiding models with this tag — click to clear',
  };
  tagsList.innerHTML = all.length
    ? all.map((tag) => {
      const state = tagFilters[tag];
      return `<span class="tag${state ? ` ${state}` : ''}" data-tag="${escapeHtml(tag)}"
        title="${titles[state] || 'Click to show only models with this tag'}">${escapeHtml(tag)}</span>`;
    }).join('')
    : '<p class="form-hint">No tags yet.</p>';
  document.getElementById('clearTags').hidden = Object.keys(tagFilters).length === 0;
  document.querySelectorAll('#tagMatch button').forEach((b) => {
    b.classList.toggle('active', b.dataset.match === prefs.tagMatch);
  });
}

// Format/source dropdowns list only what's in the library. A remembered choice
// that no longer matches anything is reset rather than silently hiding everything.
function renderFilterOptions() {
  const formats = [...new Set(models.flatMap((m) => (m.files || []).map((f) => f.format)))].sort();
  const sources = [...new Set(models.map(sourceKey))].sort();
  fillSelect('filterFormat', 'Any format', formats.map((f) => [f, `.${f}`]), 'format');
  fillSelect('filterSource', 'Any source', sources.map((s) => [s, sourceLabel(s)]), 'source');
}

function fillSelect(id, anyLabel, options, prefKey) {
  if (prefs[prefKey] && !options.some(([value]) => value === prefs[prefKey])) {
    prefs[prefKey] = '';
    savePrefs();
  }
  const el = document.getElementById(id);
  el.innerHTML = `<option value="">${anyLabel}</option>`
    + options.map(([value, label]) => `<option value="${escapeHtml(value)}">${escapeHtml(label)}</option>`).join('');
  el.value = prefs[prefKey];
}

function scopeTitle() {
  if (selectedScope === 'all') return 'All Models';
  if (selectedScope === 'duplicates') return 'Duplicates';
  if (selectedScope === 'trash') return 'Trash';
  const p = projects.find((x) => String(x.id) === String(selectedScope));
  return p ? p.name : 'Collection';
}

function updateScopeChrome() {
  contentTitle.textContent = scopeTitle();
  const dupes = selectedScope === 'duplicates';
  document.getElementById('filterBar').hidden = dupes;
  document.querySelector('.view-options').hidden = dupes;
  emptyTrashBtn.hidden = !(selectedScope === 'trash' && trashModels.length);
  document.querySelectorAll('.project-item[data-scope]').forEach((el) => {
    el.classList.toggle('active', el.dataset.scope === String(selectedScope));
  });
  document.querySelectorAll('.view-btn').forEach((b) => b.classList.toggle('active', b.dataset.view === prefs.view));
}

function renderModels() {
  updateScopeChrome();
  if (selectedScope === 'duplicates') { renderDuplicates(); return; }
  clearTimeout(duplicatePoll);

  const list = getFilteredModels();
  resultCount.textContent = `${list.length} model${list.length === 1 ? '' : 's'}`;
  fileGrid.className = prefs.view === 'list' ? 'file-grid list-view' : 'file-grid';

  if (list.length === 0) {
    fileGrid.innerHTML = emptyStateHtml();
    return;
  }
  if (!prefs.group) {
    fileGrid.innerHTML = list.map(cardHtml).join('');
    return;
  }
  const groups = new Map();
  for (const m of list) {
    const key = groupLabel(m);
    if (!groups.has(key)) groups.set(key, []);
    groups.get(key).push(m);
  }
  fileGrid.innerHTML = [...groups.entries()]
    .sort(([a], [b]) => a.localeCompare(b))
    .map(([label, ms]) => `<div class="group-header">${escapeHtml(label)} <span>${ms.length}</span></div>`
      + ms.map(cardHtml).join(''))
    .join('');
}

function groupLabel(m) {
  if (prefs.group === 'source') return sourceLabel(sourceKey(m));
  const formats = [...new Set((m.files || []).map((f) => `.${f.format}`))].sort();
  return formats.length ? formats.join(' + ') : 'No files';
}

function emptyStateHtml() {
  const state = (title, text) => `<div class="empty-state"><h3>${title}</h3><p>${text}</p></div>`;
  if (selectedScope === 'trash' && trashModels.length === 0) {
    return state('Trash is empty', 'Models you delete wait here until you restore them or empty the trash.');
  }
  if (selectedScope === 'all' && models.length === 0) {
    return state('No models yet', 'Upload files or import from a URL to get started');
  }
  return state('No models match', 'Try clearing the search, filters or tag selection.');
}

function thumbHtml(m) {
  return m.thumbnailUrl ? `<img src="${m.thumbnailUrl}" alt="" loading="lazy">` : '<span>📦</span>';
}

function cardHtml(m) {
  const trashed = Boolean(m.deleted_at);
  const when = trashed ? `trashed ${formatDate(m.deleted_at)}` : formatDate(m.date_added);
  return `
    <div class="file-card" data-model-id="${m.id}">
      <div class="file-thumbnail">${thumbHtml(m)}</div>
      <div class="file-info">
        <div class="file-name">${escapeHtml(m.name)}</div>
        ${m.source_site ? `<span class="source-badge">${escapeHtml(m.source_site)}</span>` : ''}
        ${m.commercial_use === true ? '<span class="com-badge ok" title="Commercial use allowed">$ sellable</span>' : m.commercial_use === false ? '<span class="com-badge no" title="Non-commercial only">non-commercial</span>' : ''}
        ${m.description ? `<div class="file-description">${escapeHtml(m.description)}</div>` : ''}
        ${(m.tags && m.tags.length) ? `<div class="file-tags">${m.tags.map((t) => `<span class="file-tag">${escapeHtml(t)}</span>`).join('')}</div>` : ''}
        <div class="file-meta">${fileCountLabel(m)} • ${formatFileSize(totalSize(m))} • ${when}</div>
        ${trashed ? `
        <div class="card-actions">
          <button class="btn btn-secondary btn-sm" data-action="restore">Restore</button>
          <button class="btn btn-danger btn-sm" data-action="purge">Delete forever</button>
        </div>` : ''}
      </div>
    </div>`;
}

const SORTS = {
  newest: (a, b) => new Date(b.date_added) - new Date(a.date_added),
  oldest: (a, b) => new Date(a.date_added) - new Date(b.date_added),
  name: (a, b) => a.name.localeCompare(b.name, undefined, { numeric: true, sensitivity: 'base' }),
  'name-desc': (a, b) => b.name.localeCompare(a.name, undefined, { numeric: true, sensitivity: 'base' }),
  size: (a, b) => totalSize(b) - totalSize(a),
  modified: (a, b) => new Date(b.date_modified || b.date_added) - new Date(a.date_modified || a.date_added),
};

function getFilteredModels() {
  let result = selectedScope === 'trash' ? trashModels : models;
  if (!SPECIAL_SCOPES.includes(selectedScope)) {
    result = result.filter((m) => (m.projects || []).some((p) => String(p.id) === String(selectedScope)));
  }

  const include = Object.keys(tagFilters).filter((t) => tagFilters[t] === 'include');
  const exclude = Object.keys(tagFilters).filter((t) => tagFilters[t] === 'exclude');
  if (include.length) {
    result = result.filter((m) => {
      const tags = m.tags || [];
      return prefs.tagMatch === 'all' ? include.every((t) => tags.includes(t)) : include.some((t) => tags.includes(t));
    });
  }
  if (exclude.length) result = result.filter((m) => !exclude.some((t) => (m.tags || []).includes(t)));

  if (prefs.format) result = result.filter((m) => (m.files || []).some((f) => f.format === prefs.format));
  if (prefs.source) result = result.filter((m) => sourceKey(m) === prefs.source);
  if (prefs.license) result = result.filter((m) => licenseKey(m) === prefs.license);

  const terms = searchInput.value.toLowerCase().split(/\s+/).filter(Boolean);
  if (terms.length) result = result.filter((m) => terms.every((t) => searchText(m).includes(t)));

  return [...result].sort(SORTS[prefs.sort] || SORTS.newest);
}

function updateCounts() {
  document.getElementById('allFilesCount').textContent = models.length;
  document.getElementById('trashCount').textContent = stats.trash ?? 0;
  document.getElementById('duplicatesCount').textContent = stats.duplicateGroups ?? 0;
}

// ---------------------------------------------------------------- duplicates
async function renderDuplicates() {
  fileGrid.className = 'dup-list';
  resultCount.textContent = '';
  if (!duplicateData) fileGrid.innerHTML = '<div class="empty-state"><p>Looking for duplicates…</p></div>';
  try {
    const res = await fetch('/api/duplicates');
    if (!res.ok) throw new Error((await res.json()).error);
    duplicateData = await res.json();
  } catch (err) {
    fileGrid.innerHTML = `<div class="empty-state"><h3>Couldn't check for duplicates</h3><p>${escapeHtml(err.message)}</p></div>`;
    return;
  }
  if (selectedScope !== 'duplicates') return; // navigated away while loading

  const { groups, pending } = duplicateData;
  stats.duplicateGroups = groups.length;
  updateCounts();
  resultCount.textContent = `${groups.length} group${groups.length === 1 ? '' : 's'}`;
  const pendingNote = pending
    ? `<div class="dup-pending">Fingerprinting ${pending} file${pending === 1 ? '' : 's'}… this list updates automatically.</div>`
    : '';
  fileGrid.innerHTML = pendingNote + (groups.length
    ? groups.map(duplicateGroupHtml).join('')
    : '<div class="empty-state"><h3>No duplicates found</h3><p>Files are compared by content and by shape, so renamed or re-exported copies show up here too.</p></div>');

  clearTimeout(duplicatePoll);
  if (pending) duplicatePoll = setTimeout(() => { if (selectedScope === 'duplicates') renderDuplicates(); }, 4000);
}

function duplicateGroupHtml(g) {
  const title = g.exact ? 'Exact copies' : 'Same shape';
  const hint = g.exact
    ? 'These models share byte-for-byte identical files.'
    : 'Geometry matches but the files differ (re-exported, converted, or possibly mirrored) — compare before trashing.';
  return `
    <section class="dup-group" data-signature="${escapeHtml(g.signature)}">
      <header class="dup-head">
        <div>
          <h3>${title} · ${g.models.length} models</h3>
          <p class="form-hint">${hint}</p>
        </div>
        <button class="btn btn-secondary btn-sm" data-action="dismiss">Not duplicates</button>
      </header>
      <div class="dup-cards">${g.models.map((m) => duplicateCardHtml(g, m)).join('')}</div>
    </section>`;
}

function duplicateCardHtml(g, m) {
  const recommended = m.id === g.recommendedId;
  const unique = m.matchableFiles - m.matchedFiles;
  return `
    <div class="dup-card${recommended ? ' recommended' : ''}" data-model-id="${m.id}">
      <div class="file-thumbnail">${thumbHtml(m)}</div>
      <div class="file-info">
        ${recommended ? '<span class="rec-badge">Recommended keep</span>' : ''}
        <div class="file-name" title="${escapeHtml(m.name)}">${escapeHtml(m.name)}</div>
        <div class="file-meta">${escapeHtml(sourceLabel(sourceKey(m)))} • ${formatDate(m.date_added)}</div>
        <div class="file-meta">${m.matchedFiles} of ${m.matchableFiles} files match${unique ? ` • <span class="warn">${unique} unique</span>` : ''}</div>
        <button class="btn btn-primary btn-sm" data-action="keep">Keep this one</button>
      </div>
    </div>`;
}

async function handleKeepDuplicate(signature, keepId) {
  const group = duplicateData && duplicateData.groups.find((g) => g.signature === signature);
  if (!group) return;
  const keep = group.models.find((m) => m.id === keepId);
  const others = group.models.filter((m) => m.id !== keepId);
  let message = `Keep "${keep.name}" and move ${others.length} other model${others.length === 1 ? '' : 's'} to the trash?\n\n`
    + 'Their tags, collections and notes are merged into the one you keep.';
  const withUnique = others.filter((m) => m.matchableFiles > m.matchedFiles);
  if (withUnique.length) {
    message += `\n\nHeads up: ${withUnique.map((m) => `"${m.name}"`).join(', ')} also contain files that aren't duplicated — they go to the trash too.`;
  }
  if (!confirm(message)) return;
  try {
    const res = await fetch('/api/duplicates/resolve', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ keepId, trashIds: others.map((m) => m.id) }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData();
  } catch (err) {
    alert('Could not resolve duplicates: ' + err.message);
  }
}

async function handleDismissDuplicates(signature) {
  const group = duplicateData && duplicateData.groups.find((g) => g.signature === signature);
  if (!group) return;
  try {
    const res = await fetch('/api/duplicates/dismiss', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ modelIds: group.models.map((m) => m.id) }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData();
  } catch (err) {
    alert('Could not dismiss: ' + err.message);
  }
}

// ---------------------------------------------------------------- trash
async function restoreModel(id) {
  try {
    const res = await fetch(`/api/models/${id}/restore`, { method: 'POST' });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData();
    return true;
  } catch (err) {
    alert('Restore failed: ' + err.message);
    return false;
  }
}

async function purgeModel(id) {
  const model = findModel(id);
  if (!confirm(`Permanently delete "${model ? model.name : 'this model'}" and its files?\n\nThis can't be undone.`)) return false;
  try {
    const res = await fetch(`/api/models/${id}?permanent=true`, { method: 'DELETE' });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData();
    return true;
  } catch (err) {
    alert('Delete failed: ' + err.message);
    return false;
  }
}

async function handleEmptyTrash() {
  const n = trashModels.length;
  if (!n || !confirm(`Permanently delete ${n} model${n === 1 ? '' : 's'} in the trash and all their files?\n\nThis can't be undone.`)) return;
  try {
    const res = await fetch('/api/trash', { method: 'DELETE' });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData();
  } catch (err) {
    alert('Emptying the trash failed: ' + err.message);
  }
}

// ---------------------------------------------------------------- events
function setupEventListeners() {
  document.getElementById('uploadBtn').addEventListener('click', openUploadModal);
  document.getElementById('newProjectBtn').addEventListener('click', openProjectModal);
  document.getElementById('importBtn').addEventListener('click', openImportModal);
  document.getElementById('settingsBtn').addEventListener('click', openSettingsModal);
  document.getElementById('logoutBtn').addEventListener('click', handleLogout);
  document.getElementById('settingsForm').addEventListener('submit', handleSaveSettings);
  document.getElementById('cancelSettings').addEventListener('click', () => closeModal(settingsModal));
  document.querySelectorAll('.clear-setting').forEach((btn) => {
    btn.addEventListener('click', () => handleClearSetting(btn.dataset.setting));
  });

  document.querySelectorAll('.close-btn').forEach((btn) => {
    btn.addEventListener('click', (e) => closeModal(e.target.closest('.modal')));
  });
  document.querySelectorAll('.modal').forEach((modal) => {
    if (modal.id === 'setupModal') return; // must be finished or skipped, not backdrop-dismissed
    modal.addEventListener('click', (e) => { if (e.target === modal) closeModal(modal); });
  });

  document.getElementById('setupForm').addEventListener('submit', handleFinishSetup);
  document.getElementById('skipSetup').addEventListener('click', handleSkipSetup);

  document.getElementById('uploadForm').addEventListener('submit', handleUpload);
  document.getElementById('cancelUpload').addEventListener('click', () => closeModal(uploadModal));
  document.getElementById('projectForm').addEventListener('submit', handleCreateProject);
  document.getElementById('cancelProject').addEventListener('click', () => closeModal(projectModal));
  document.getElementById('importForm').addEventListener('submit', handleImport);
  document.getElementById('cancelImport').addEventListener('click', () => closeModal(importModal));

  document.getElementById('fileInput').addEventListener('change', (e) => {
    const f = e.target.files[0];
    const nameField = document.getElementById('fileName');
    if (f && !nameField.value) nameField.value = f.name.replace(/\.[^.]+$/, '');
  });

  // Library views (All / Duplicates / Trash) and collections share one scope.
  document.querySelector('.sidebar').addEventListener('click', (e) => {
    const item = e.target.closest('.project-item[data-scope]');
    if (!item) return;
    const scope = item.dataset.scope;
    if (e.target.closest('.collection-rename')) { handleRenameCollection(scope, item.querySelector('.project-name').textContent); return; }
    if (e.target.closest('.collection-delete')) { handleDeleteCollection(scope, item.querySelector('.project-name').textContent); return; }
    selectScope(scope);
  });

  tagsList.addEventListener('click', (e) => {
    const el = e.target.closest('.tag');
    if (!el) return;
    const tag = el.dataset.tag;
    if (!tagFilters[tag]) tagFilters[tag] = 'include';
    else if (tagFilters[tag] === 'include') tagFilters[tag] = 'exclude';
    else delete tagFilters[tag];
    renderTags();
    renderModels();
  });
  document.getElementById('tagMatch').addEventListener('click', (e) => {
    const btn = e.target.closest('button[data-match]');
    if (!btn) return;
    prefs.tagMatch = btn.dataset.match;
    savePrefs();
    renderTags();
    renderModels();
  });
  document.getElementById('clearTags').addEventListener('click', () => {
    tagFilters = {};
    renderTags();
    renderModels();
  });

  searchInput.addEventListener('input', renderModels);
  [['filterFormat', 'format'], ['filterSource', 'source'], ['filterLicense', 'license'], ['sortBy', 'sort'], ['groupBy', 'group']]
    .forEach(([id, key]) => {
      const el = document.getElementById(id);
      el.value = prefs[key];
      el.addEventListener('change', () => { prefs[key] = el.value; savePrefs(); renderModels(); });
    });

  // "/" jumps to search.
  document.addEventListener('keydown', (e) => {
    if (e.key !== '/' || e.metaKey || e.ctrlKey || e.altKey) return;
    if (e.target.closest && e.target.closest('input, textarea, select, [contenteditable]')) return;
    if (document.querySelector('.modal.active') || document.getElementById('filterBar').hidden) return;
    e.preventDefault();
    searchInput.focus();
  });

  document.querySelectorAll('.view-btn').forEach((btn) => {
    btn.addEventListener('click', (e) => {
      prefs.view = e.target.dataset.view;
      savePrefs();
      renderModels();
    });
  });

  fileGrid.addEventListener('click', (e) => {
    const card = e.target.closest('[data-model-id]');
    const actionBtn = e.target.closest('[data-action]');
    if (actionBtn) {
      const group = actionBtn.closest('.dup-group');
      switch (actionBtn.dataset.action) {
        case 'restore': restoreModel(card.dataset.modelId); break;
        case 'purge': purgeModel(card.dataset.modelId); break;
        case 'keep': handleKeepDuplicate(group.dataset.signature, Number(card.dataset.modelId)); break;
        case 'dismiss': handleDismissDuplicates(group.dataset.signature); break;
      }
      return;
    }
    if (card) openModelDetail(card.dataset.modelId);
  });

  emptyTrashBtn.addEventListener('click', handleEmptyTrash);
  document.getElementById('deleteFileBtn').addEventListener('click', handleDeleteModel);
  document.getElementById('restoreModelBtn').addEventListener('click', async () => {
    if (await restoreModel(fileDetailModal.dataset.currentModelId)) closeModal(fileDetailModal);
  });
  document.getElementById('purgeModelBtn').addEventListener('click', async () => {
    if (await purgeModel(fileDetailModal.dataset.currentModelId)) closeModal(fileDetailModal);
  });
  document.getElementById('detailNotes').addEventListener('input', queueNotesSave);
  document.getElementById('detailNotes').addEventListener('blur', flushNotes);
  document.getElementById('detailFileTabs').addEventListener('click', (e) => {
    const tab = e.target.closest('.file-tab');
    const item = tab && detailItems.find((i) => itemKey(i) === tab.dataset.key);
    if (!item) return;
    renderViewerTabs(itemKey(item));
    loadViewer(item);
  });
  document.getElementById('detailPlates').addEventListener('click', (e) => {
    const chip = e.target.closest('.plate-chip');
    const item = chip && detailItems.find((i) => itemKey(i) === activeItemKey);
    if (!item) return;
    item.plate = chip.dataset.plate === 'all' ? null : Number(chip.dataset.plate);
    loadViewer(item);
  });
  document.getElementById('detailFileInfo').addEventListener('click', (e) => {
    const btn = e.target.closest('[data-view-entry]');
    if (!btn) return;
    const archiveId = Number(btn.dataset.archive);
    const entry = (archiveEntryCache.get(archiveId) || []).find((x) => String(x.id) === btn.dataset.viewEntry);
    if (!entry) return;
    openViewerItem({ kind: 'entry', id: entry.id, format: entry.format, name: entry.path.split('/').pop(), archiveId });
    document.getElementById('detailViewer').scrollIntoView({ block: 'nearest', behavior: 'smooth' });
  });

  setupTagAutocomplete(document.getElementById('fileTags'));
  setupTagAutocomplete(document.getElementById('editTags'));
  document.getElementById('regenThumbBtn').addEventListener('click', handleRegenThumbnail);
  document.getElementById('refreshLicenseBtn').addEventListener('click', handleRefreshMetadata);
  document.getElementById('editModelBtn').addEventListener('click', openEditModal);
  document.getElementById('downloadFilesBtn').addEventListener('click', handleDownloadFiles);
  document.getElementById('editForm').addEventListener('submit', handleEditModel);
  document.getElementById('cancelEdit').addEventListener('click', () => closeModal(editModal));
  document.getElementById('addFilesBtn').addEventListener('click', () => document.getElementById('addFilesInput').click());
  document.getElementById('addFilesInput').addEventListener('change', handleAddFiles);
}

async function selectScope(scope) {
  selectedScope = scope;
  if (scope === 'trash') await loadTrash();
  renderModels();
}

// Tracks the file currently shown in the detail viewer (for thumbnail regen).
let currentDetailFile = null;
let currentDetailThumb = null; // model image, used as a viewer fallback

function closeModal(modal) {
  modal.classList.remove('active');
  if (modal === fileDetailModal) {
    flushNotes();
    if (window.ModelViewer) window.ModelViewer.dispose();
  }
}

// ---------------------------------------------------------------- notes
// Notes autosave shortly after typing stops (and on blur / close). The pending
// edit remembers its model, so switching models mid-edit can't misfile it.
let pendingNotes = null;
let notesTimer = null;

function setNotesStatus(text) {
  document.getElementById('notesStatus').textContent = text;
}

function queueNotesSave() {
  pendingNotes = { id: fileDetailModal.dataset.currentModelId, value: document.getElementById('detailNotes').value };
  setNotesStatus('editing…');
  clearTimeout(notesTimer);
  notesTimer = setTimeout(flushNotes, 800);
}

async function flushNotes() {
  clearTimeout(notesTimer);
  const pending = pendingNotes;
  pendingNotes = null;
  if (!pending) return;
  const model = findModel(pending.id);
  if (model && (model.notes || '') === pending.value) { setNotesStatus(''); return; }
  setNotesStatus('saving…');
  try {
    const res = await fetch(`/api/models/${pending.id}`, {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ notes: pending.value }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    replaceModel(await res.json());
    if (fileDetailModal.dataset.currentModelId === String(pending.id)) setNotesStatus('saved');
  } catch (err) {
    setNotesStatus('not saved — ' + err.message);
  }
}

// ---------------------------------------------------------------- modals
function openUploadModal() {
  document.getElementById('fileProjects').innerHTML =
    projects.map((p) => `<option value="${p.id}">${escapeHtml(p.name)}</option>`).join('');
  uploadModal.classList.add('active');
}

function openProjectModal() {
  document.getElementById('projectForm').reset();
  projectModal.classList.add('active');
}

async function markSetupComplete() {
  try {
    await fetch('/api/setup/complete', { method: 'POST' });
    config.setupComplete = true;
  } catch { /* non-fatal */ }
}

async function handleFinishSetup(e) {
  e.preventDefault();
  const status = document.getElementById('setupStatus');
  const payload = {};
  document.querySelectorAll('#setupForm [data-setting]').forEach((input) => {
    if (input.value.trim()) payload[input.dataset.setting] = input.value.trim();
  });
  try {
    if (Object.keys(payload).length) {
      const res = await fetch('/api/settings', {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(payload),
      });
      if (!res.ok) throw new Error((await res.json()).error);
    }
    await markSetupComplete();
    closeModal(setupModal);
    await loadData();
  } catch (err) {
    status.textContent = 'Could not save: ' + err.message;
  }
}

async function handleSkipSetup() {
  await markSetupComplete();
  closeModal(setupModal);
}

async function openSettingsModal() {
  document.getElementById('settingsForm').reset();
  document.getElementById('settingsStatus').textContent = '';
  try {
    const settings = await (await fetch('/api/settings')).json();
    document.querySelectorAll('.setting-status').forEach((el) => {
      const s = settings[el.dataset.status];
      if (!s) { el.textContent = '—'; return; }
      el.textContent = s.set
        ? `set ${s.hint || ''}${s.source === 'env' ? ' (from .env — edit here to override)' : ''}`
        : 'not set';
      el.className = `setting-status ${s.set ? 'is-set' : 'is-unset'}`;
    });
    // Prefill non-secret fields (e.g. the FlareSolverr URL) with their current value.
    document.querySelectorAll('#settingsForm [data-setting]').forEach((input) => {
      const s = settings[input.dataset.setting];
      if (s && !s.secret && s.value) input.value = s.value;
    });
    await renderLicenseRules();
  } catch (err) {
    document.getElementById('settingsStatus').textContent = 'Could not load settings: ' + err.message;
  }
  settingsModal.classList.add('active');
}

function openImportModal() {
  document.getElementById('importForm').reset();
  document.getElementById('importStatus').textContent = '';
  const tvEnabled = config.importers && config.importers.thingiverse;
  const flareEnabled = config.importers && config.importers.flaresolverr;
  const mw = flareEnabled ? 'MakerWorld' : 'MakerWorld (needs FlareSolverr in Settings)';
  document.getElementById('importHint').innerHTML = tvEnabled
    ? `Thingiverse imports files automatically. Printables, ${mw} &amp; other sites import the title, description &amp; preview image — then add the files you downloaded.`
    : `Printables, ${mw} &amp; other sites import the title, description &amp; preview image — then add the files you downloaded. Add a Thingiverse token in Settings for automatic file downloads.`;
  document.getElementById('importSubmit').disabled = false;
  importModal.classList.add('active');
}

function openModelDetail(modelId) {
  const model = findModel(modelId);
  if (!model) return;
  flushNotes(); // save any edit still pending for the previously open model
  fileDetailModal.dataset.currentModelId = modelId;
  currentDetailThumb = model.thumbnailUrl || null;

  document.getElementById('detailFileName').textContent = model.name;
  document.getElementById('detailDescription').textContent = model.description || 'No description';
  document.getElementById('detailNotes').value = model.notes || '';
  setNotesStatus('');

  const trashed = Boolean(model.deleted_at);
  document.getElementById('detailActions').hidden = trashed;
  document.getElementById('trashActions').hidden = !trashed;

  // Source
  const src = document.getElementById('detailSource');
  if (model.source_url) {
    const designer = model.designer ? ` by ${escapeHtml(model.designer.name)}` : '';
    src.innerHTML = `<a href="${escapeHtml(model.source_url)}" target="_blank" rel="noopener">${escapeHtml(model.source_site || 'link')}${designer}</a>`;
  } else {
    src.textContent = 'Manual upload';
  }

  renderDetailLicense(model);
  document.getElementById('refreshLicenseBtn').style.display = model.source_url ? '' : 'none';

  // "Download files from source" — only for sites we can auto-download from.
  const autoDownloadSites = ['thingiverse', 'printables', 'makerworld'];
  const dlBtn = document.getElementById('downloadFilesBtn');
  if (model.source_url && autoDownloadSites.includes(model.source_site)) {
    dlBtn.style.display = '';
    dlBtn.textContent = model.files.length === 0 ? 'Download files from source' : 'Re-check source for files';
  } else {
    dlBtn.style.display = 'none';
  }

  // Tags / projects / print settings
  document.getElementById('detailTags').innerHTML = (model.tags && model.tags.length)
    ? model.tags.map((t) => `<span class="tag">${escapeHtml(t)}</span>`).join('') : 'No tags';
  const ps = model.projects || [];
  document.getElementById('detailProjects').innerHTML = ps.length
    ? ps.map((p) => `<div>${escapeHtml(p.name)}</div>`).join('') : 'Not in any collection';
  const settings = model.print_settings || {};
  const settingRows = Object.entries(settings).filter(([, v]) => v);
  document.getElementById('detailPrintSettings').innerHTML = settingRows.length
    ? settingRows.map(([k, v]) => `<div><strong>${escapeHtml(k)}:</strong> ${escapeHtml(String(v))}</div>`).join('')
    : 'No print settings';

  // File list (+ a "download all as zip" action when there's more than one file)
  const fileInfoEl = document.getElementById('detailFileInfo');
  if (model.files.length === 0) {
    const autoSite = ['thingiverse', 'printables', 'makerworld'].includes(model.source_site);
    const hint = !model.source_url
      ? 'No files yet — use “Add files” below.'
      : autoSite
        ? 'No files yet — use “Download files from source” below.'
        : 'Manual source — download the files from the source page, then use “Add files” below.';
    fileInfoEl.innerHTML = `<div class="lic-note">${hint}</div>`;
  } else {
    const downloadAll = model.files.length > 1
      ? `<a class="btn btn-secondary btn-sm download-all" href="/api/models/${model.id}/download">Download all ${model.files.length} files (.zip)</a>`
      : '';
    fileInfoEl.innerHTML = downloadAll + model.files.map((f) => `
      <div class="file-row">
        <span>${escapeHtml(f.originalName)} <em>(${formatFileSize(f.size)}${f.volume ? `, ${Number(f.volume).toFixed(2)} cm³` : ''})</em></span>
        <a href="/api/files/${f.id}/raw" download>download</a>
      </div>
      ${ARCHIVE_FORMATS.includes(f.format) ? `<div class="entry-list" data-entries-for="${f.id}"><div class="entry-head">Reading archive…</div></div>` : ''}`).join('');
    model.files.filter((f) => ARCHIVE_FORMATS.includes(f.format)).forEach((f) => loadArchiveEntries(model.id, f.id));
  }

  renderProjectPanels(null);

  // Viewer tabs: 3D files first, then pictures/PDFs/text (entries inside
  // archives get a tab when opened from the file list).
  const { RENDERABLE, DOCUMENT_FORMATS } = window.ModelViewer;
  detailItems = [
    ...model.files.filter((f) => RENDERABLE.includes(f.format)),
    ...model.files.filter((f) => DOCUMENT_FORMATS.includes(f.format) && f.format !== 'mtl'),
  ].map((f) => ({ kind: 'file', id: f.id, format: f.format, name: f.originalName }));
  renderViewerTabs(detailItems.length ? itemKey(detailItems[0]) : null);

  fileDetailModal.classList.add('active');
  currentDetailFile = null;
  if (detailItems.length) {
    loadViewer(detailItems[0]);
  } else {
    // A model that's only archives previews a file from inside once they're listed.
    const hasArchive = model.files.some((f) => ARCHIVE_FORMATS.includes(f.format));
    document.getElementById('regenThumbBtn').style.display = 'none';
    window.ModelViewer.render(document.getElementById('detailViewer'), '', 'none', {
      fallbackImage: currentDetailThumb,
      message: hasArchive ? 'Opening a file from the archive…' : 'Nothing here can be previewed yet — add files below.',
    });
  }
}

// ---------------------------------------------------------------- viewer items
// An item is something the viewer can show: { kind: 'file' | 'entry', id, format, name, archiveId? }.
const ARCHIVE_FORMATS = ['zip', '7z', 'rar', 'tar', 'tgz'];
let detailItems = [];
let activeItemKey = null;
const archiveEntryCache = new Map(); // archive file id -> entries
const itemKey = (item) => `${item.kind}:${item.id}`;

function renderViewerTabs(activeKey) {
  activeItemKey = activeKey;
  document.getElementById('detailFileTabs').innerHTML = detailItems.map((item) => `
    <button class="file-tab${itemKey(item) === activeKey ? ' active' : ''}" data-key="${itemKey(item)}">${escapeHtml(item.name)}</button>`).join('');
}

function openViewerItem(item) {
  if (!detailItems.some((i) => itemKey(i) === itemKey(item))) detailItems.push(item);
  renderViewerTabs(itemKey(item));
  loadViewer(item);
}

// What the viewer should load: 3MF goes through the server's GLB conversion,
// documents are served inline, everything else raw.
function viewerSourceFor(item) {
  const base = `/api/${item.kind === 'entry' ? 'entries' : 'files'}/${item.id}`;
  if (item.format === '3mf') return { url: `${base}/glb${item.plate ? `?plate=${item.plate}` : ''}`, format: 'glb' };
  if (window.ModelViewer.DOCUMENT_FORMATS.includes(item.format)) return { url: `${base}/raw?inline=1`, format: item.format };
  return { url: `${base}/raw`, format: item.format };
}

// Finds files shipped alongside a model by name — OBJ materials, FBX/MTL
// textures. Entries of the same archive win, then the model's own files.
function resolverFor(model, archiveEntries = null) {
  const byName = new Map();
  const key = (name) => String(name).split(/[\\/]/).pop().toLowerCase();
  const add = (name, url) => { if (!byName.has(key(name))) byName.set(key(name), url); };
  (archiveEntries || []).forEach((e) => add(e.path, `/api/entries/${e.id}/raw`));
  ((model && model.files) || []).forEach((f) => add(f.originalName, `/api/files/${f.id}/raw`));
  return (name) => byName.get(key(name)) || null;
}

// For a model with nothing to preview directly: open the most useful file
// inside its archive — a slicer project, then other 3D files, then pictures/PDFs.
const ENTRY_PREVIEW_ORDER = ['3mf', 'stl', 'obj', 'step', 'stp', 'fbx', '3dm', 'jpg', 'jpeg', 'png', 'webp', 'gif', 'pdf'];
function previewFirstEntry(archiveId, entries) {
  const rank = (e) => (ENTRY_PREVIEW_ORDER.includes(e.format) ? ENTRY_PREVIEW_ORDER.indexOf(e.format) : Infinity);
  const best = [...entries].sort((a, b) => rank(a) - rank(b))[0];
  if (!best || rank(best) === Infinity) {
    window.ModelViewer.render(document.getElementById('detailViewer'), '', 'none',
      { fallbackImage: currentDetailThumb, message: 'Nothing inside this archive can be previewed.' });
    return;
  }
  openViewerItem({ kind: 'entry', id: best.id, format: best.format, name: best.path.split('/').pop(), archiveId });
}

async function loadArchiveEntries(modelId, fileId) {
  const container = () => (fileDetailModal.dataset.currentModelId === String(modelId)
    ? document.querySelector(`[data-entries-for="${fileId}"]`) : null);
  try {
    const res = await fetch(`/api/files/${fileId}/entries`);
    const data = await res.json();
    if (!res.ok) throw new Error(data.error);
    if (!container()) return;
    if (data.status === 'pending') {
      setTimeout(() => { if (container()) loadArchiveEntries(modelId, fileId); }, 2000);
      return;
    }
    if (data.status === 'error') {
      container().innerHTML = `<div class="entry-head">Couldn't read this archive: ${escapeHtml(data.error || 'unknown error')}</div>`;
      return;
    }
    archiveEntryCache.set(fileId, data.entries);
    const { PREVIEWABLE } = window.ModelViewer;
    container().innerHTML = `<div class="entry-head">${data.entries.length} file${data.entries.length === 1 ? '' : 's'} inside</div>`
      + data.entries.map((e) => {
        const name = e.path.split('/').pop();
        const folder = e.path.replace(/^\.\//, '').slice(0, -name.length);
        return `
      <div class="entry-row">
        <span title="${escapeHtml(e.path)}">${escapeHtml(name)}${folder ? `<span class="entry-folder">${escapeHtml(folder)}</span>` : ''} <em>${formatFileSize(e.size)}</em></span>
        <span class="row-actions">
          ${PREVIEWABLE.includes(e.format) && e.format !== 'mtl' ? `<button type="button" class="link-btn" data-view-entry="${e.id}" data-archive="${fileId}">view</button>` : ''}
          <a href="/api/entries/${e.id}/raw" download>download</a>
        </span>
      </div>`;
      }).join('');
    if (!detailItems.length) previewFirstEntry(fileId, data.entries);
  } catch (err) {
    if (container()) container().innerHTML = `<div class="entry-head">Couldn't list this archive: ${escapeHtml(err.message)}</div>`;
  }
}

function renderDetailLicense(model) {
  const com = model.commercial_use; // true / false / null
  const badge = com === true
    ? '<span class="lic-badge ok">Commercial use allowed</span>'
    : com === false
      ? '<span class="lic-badge no">Non-commercial only</span>'
      : '<span class="lic-badge unknown">Commercial use unclear</span>';
  document.getElementById('detailLicense').innerHTML =
    `<div>${model.license ? escapeHtml(model.license) : 'Not specified'} ${badge}</div>` +
    '<div class="lic-note">A guess from the license name — always confirm on the source page before selling.</div>';
}

function openEditModal() {
  const id = fileDetailModal.dataset.currentModelId;
  const model = findModel(id);
  if (!model) return;
  editModal.dataset.editId = id;

  document.getElementById('editName').value = model.name || '';
  document.getElementById('editDescription').value = model.description || '';
  document.getElementById('editTags').value = (model.tags || []).join(', ');
  document.getElementById('editLicense').value = model.license || '';

  const ps = model.print_settings || {};
  document.getElementById('editMaterial').value = ps.material || '';
  document.getElementById('editLayerHeight').value = ps.layerHeight || '';
  document.getElementById('editInfill').value = ps.infill || '';
  document.getElementById('editSupports').value = ps.supports || '';

  const current = new Set((model.projects || []).map((p) => String(p.id)));
  document.getElementById('editProjects').innerHTML = projects
    .map((p) => `<option value="${p.id}"${current.has(String(p.id)) ? ' selected' : ''}>${escapeHtml(p.name)}</option>`)
    .join('');

  editModal.classList.add('active');
}

async function handleEditModel(e) {
  e.preventDefault();
  const id = editModal.dataset.editId;
  const body = {
    name: document.getElementById('editName').value,
    description: document.getElementById('editDescription').value,
    license: document.getElementById('editLicense').value || null,
    tags: splitTags(document.getElementById('editTags').value),
    projects: Array.from(document.getElementById('editProjects').selectedOptions).map((o) => Number(o.value)),
    print_settings: {
      material: document.getElementById('editMaterial').value,
      layerHeight: document.getElementById('editLayerHeight').value,
      infill: document.getElementById('editInfill').value,
      supports: document.getElementById('editSupports').value,
    },
  };
  try {
    const res = await fetch(`/api/models/${id}`, {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    closeModal(editModal);
    await loadData();
    openModelDetail(id); // refresh the (still-open) detail view
  } catch (err) {
    alert('Failed to save changes: ' + err.message);
  }
}

async function handleDownloadFiles() {
  const id = fileDetailModal.dataset.currentModelId;
  const btn = document.getElementById('downloadFilesBtn');
  btn.disabled = true;
  btn.textContent = 'Downloading… (this can take a moment)';
  try {
    const res = await fetch(`/api/models/${id}/download-files`, { method: 'POST' });
    const data = await res.json();
    if (!res.ok) throw new Error(data.error);
    await loadData();
    openModelDetail(id);
    if (data.added === 0) alert('No new files were found (the source returned nothing new).');
  } catch (err) {
    alert('Download failed: ' + err.message);
    btn.disabled = false;
  }
}

async function handleRefreshMetadata() {
  const modelId = fileDetailModal.dataset.currentModelId;
  const btn = document.getElementById('refreshLicenseBtn');
  btn.disabled = true;
  btn.textContent = 'Refreshing…';
  try {
    const res = await fetch(`/api/models/${modelId}/refresh-metadata`, { method: 'POST' });
    if (!res.ok) throw new Error((await res.json()).error);
    const updated = await res.json();
    // update in-memory state, the license panel, and the card badge
    replaceModel(updated);
    renderDetailLicense(updated);
    renderModels();
    btn.textContent = 'Updated ✓';
    setTimeout(() => { btn.textContent = 'Refresh from source'; }, 1500);
  } catch (err) {
    btn.textContent = 'Refresh failed';
    console.warn('Refresh metadata failed:', err.message);
    setTimeout(() => { btn.textContent = 'Refresh from source'; }, 1800);
  } finally {
    btn.disabled = false;
  }
}

async function loadViewer(item) {
  if (item.format === '3mf') {
    await loadProjectInfo(item);
    if (activeItemKey !== itemKey(item)) return; // another tab was opened meanwhile
  }
  renderProjectPanels(item);
  const src = viewerSourceFor(item);
  const model = findModel(fileDetailModal.dataset.currentModelId);
  const resolve = resolverFor(model, item.kind === 'entry' ? archiveEntryCache.get(item.archiveId) : null);
  const is3d = window.ModelViewer.MODEL_FORMATS.includes(src.format);
  currentDetailFile = is3d ? { viewerUrl: src.url, viewerFormat: src.format, resolve } : null;
  document.getElementById('regenThumbBtn').style.display = is3d ? '' : 'none';
  window.ModelViewer.render(document.getElementById('detailViewer'), src.url, src.format,
    { fallbackImage: currentDetailThumb, resolve });
}

// Plates and filaments of a 3MF slicer project, fetched once per viewer item.
// Projects with several plates open on their first plate, like the slicer.
function loadProjectInfo(item) {
  if (!item.projectPromise) {
    item.projectPromise = fetch(`/api/${item.kind === 'entry' ? 'entries' : 'files'}/${item.id}/project`)
      .then((res) => (res.ok ? res.json() : null))
      .catch(() => null)
      .then((project) => {
        item.project = project || { plates: [], filaments: [] };
        if (item.plate === undefined && item.project.plates.length > 1) item.plate = item.project.plates[0].index;
      });
  }
  return item.projectPromise;
}

const HEX_COLOUR = /^#[0-9a-f]{6}([0-9a-f]{2})?$/i;

function renderProjectPanels(item) {
  const project = item && item.format === '3mf' ? item.project : null;
  const platesEl = document.getElementById('detailPlates');
  if (!project || project.plates.length < 2) {
    platesEl.hidden = true;
    platesEl.innerHTML = '';
  } else {
    platesEl.hidden = false;
    platesEl.innerHTML = project.plates.map((p) => `
      <button type="button" class="plate-chip${item.plate === p.index ? ' active' : ''}" data-plate="${p.index}"
              title="${escapeHtml(p.name || `Plate ${p.index}`)} · ${p.objectCount} object${p.objectCount === 1 ? '' : 's'}">
        ${p.thumbnailUrl ? `<img src="${escapeHtml(p.thumbnailUrl)}" alt="">` : ''}
        <span>${p.index}${p.name ? ` · ${escapeHtml(p.name)}` : ''}</span>
      </button>`).join('')
      + `<button type="button" class="plate-chip${item.plate ? '' : ' active'}" data-plate="all"><span>All plates</span></button>`;
  }

  const filaments = ((project && project.filaments) || [])
    .map((f, i) => ({ ...f, slot: i + 1 }))
    .filter((f) => HEX_COLOUR.test(f.colour || ''));
  document.getElementById('detailFilamentsSection').hidden = filaments.length === 0;
  document.getElementById('detailFilaments').innerHTML = filaments.map((f) => `
    <div class="filament">
      <span class="swatch" style="background:${f.colour.slice(0, 7)}"></span>
      <span>Slot ${f.slot}${f.type ? ` · ${escapeHtml(f.type)}` : ''}</span>
      <em>${f.colour.slice(0, 7).toUpperCase()}</em>
    </div>`).join('');
}

function updateCardThumbnail(modelId, thumbnailUrl) {
  const m = findModel(modelId);
  if (m) m.thumbnailUrl = thumbnailUrl;
  const thumb = fileGrid.querySelector(`[data-model-id="${modelId}"] .file-thumbnail`);
  if (thumb && thumbnailUrl) thumb.innerHTML = `<img src="${thumbnailUrl}" alt="" loading="lazy">`;
}

async function handleRegenThumbnail() {
  const modelId = fileDetailModal.dataset.currentModelId;
  if (!currentDetailFile) { alert('No previewable file to render.'); return; }
  const btn = document.getElementById('regenThumbBtn');
  btn.disabled = true;
  btn.textContent = 'Rendering…';
  try {
    const image = await window.ModelViewer.snapshot(currentDetailFile.viewerUrl, currentDetailFile.viewerFormat, 512,
      { resolve: currentDetailFile.resolve });
    const res = await fetch(`/api/models/${modelId}/thumbnail`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ image }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    const updated = await res.json();
    updateCardThumbnail(modelId, updated.thumbnailUrl);
    thumbAttempted.add(Number(modelId));
    btn.textContent = 'Done ✓';
    setTimeout(() => { btn.textContent = 'Regenerate thumbnail'; }, 1500);
  } catch (err) {
    console.warn('Thumbnail regen failed:', err.message);
    btn.textContent = "Can't render this file";
    setTimeout(() => { btn.textContent = 'Regenerate thumbnail'; }, 1800);
  } finally {
    btn.disabled = false;
  }
}

async function handleAddFiles(e) {
  const input = e.target;
  if (!input.files.length) return;
  const modelId = fileDetailModal.dataset.currentModelId;
  const formData = new FormData();
  Array.from(input.files).forEach((f) => formData.append('files', f));
  try {
    const res = await fetch(`/api/models/${modelId}/files`, { method: 'POST', body: formData });
    if (!res.ok) throw new Error((await res.json()).error);
    input.value = '';
    await loadData();
    openModelDetail(modelId); // reopen with the new files
  } catch (err) {
    alert('Failed to add files: ' + err.message);
  }
}

// ---------------------------------------------------------------- handlers
async function handleUpload(e) {
  e.preventDefault();
  const formData = new FormData();
  const input = document.getElementById('fileInput');
  Array.from(input.files).forEach((f) => formData.append('files', f));
  formData.append('name', document.getElementById('fileName').value);
  formData.append('description', document.getElementById('fileDescription').value);
  formData.append('tags', JSON.stringify(splitTags(document.getElementById('fileTags').value)));
  formData.append('projects', JSON.stringify(
    Array.from(document.getElementById('fileProjects').selectedOptions).map((o) => Number(o.value))));
  formData.append('printSettings', JSON.stringify({
    material: document.getElementById('printMaterial').value,
    layerHeight: document.getElementById('printLayerHeight').value,
    infill: document.getElementById('printInfill').value,
    supports: document.getElementById('printSupports').value,
  }));

  try {
    const res = await fetch('/api/models', { method: 'POST', body: formData });
    if (res.ok) {
      closeModal(uploadModal);
      document.getElementById('uploadForm').reset();
      await loadData();
    } else {
      alert('Upload failed: ' + (await res.json()).error);
    }
  } catch (err) {
    alert('Upload failed: ' + err.message);
  }
}

async function handleImport(e) {
  e.preventDefault();
  const status = document.getElementById('importStatus');
  const submit = document.getElementById('importSubmit');
  status.textContent = 'Importing… fetching metadata and downloading files.';
  submit.disabled = true;
  try {
    const res = await fetch('/api/import', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ url: document.getElementById('importUrl').value }),
    });
    const data = await res.json();
    if (res.ok) {
      await loadData();
      if (data.metadataOnly) {
        status.textContent = data.metadataFetched
          ? `Imported "${data.name}". Opening it so you can add the downloaded files…`
          : `Couldn't read that page (the site blocks automated access), so I created a stub named "${data.name}". Opening it so you can add files…`;
        setTimeout(() => { closeModal(importModal); openModelDetail(data.id); }, 1200);
      } else {
        status.textContent = `Imported "${data.name}" with ${data.files.length} file(s).`;
        setTimeout(() => closeModal(importModal), 900);
      }
    } else if (res.status === 409) {
      status.textContent = 'That model is already in your library.';
    } else {
      status.textContent = 'Import failed: ' + data.error;
    }
  } catch (err) {
    status.textContent = 'Import failed: ' + err.message;
  } finally {
    submit.disabled = false;
  }
}

async function renderLicenseRules() {
  const wrap = document.getElementById('licenseRules');
  let rules;
  try { rules = await (await fetch('/api/licenses')).json(); }
  catch { wrap.textContent = 'Could not load licenses.'; return; }
  if (!rules.length) { wrap.innerHTML = '<p class="form-hint">No licenses yet — import some models.</p>'; return; }
  const opt = (v, sel) => `<option value="${v}"${sel ? ' selected' : ''}>`;
  wrap.innerHTML = rules.map((r) => {
    const cur = r.commercial === true ? 'true' : r.commercial === false ? 'false' : '';
    return `<div class="license-row">
      <span class="license-name" title="${escapeHtml(r.name)}">${escapeHtml(r.name)} <em>(${r.model_count})</em></span>
      <select class="license-select" data-license="${escapeHtml(r.name)}">
        ${opt('true', cur === 'true')}Sellable</option>
        ${opt('false', cur === 'false')}Non-commercial</option>
        ${opt('', cur === '')}Unknown</option>
      </select>
    </div>`;
  }).join('');
  wrap.querySelectorAll('.license-select').forEach((sel) => {
    sel.addEventListener('change', () => handleLicenseChange(sel.dataset.license, sel.value));
  });
}

async function handleLicenseChange(name, value) {
  const commercial = value === 'true' ? true : value === 'false' ? false : null;
  try {
    const res = await fetch('/api/licenses', {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ name, commercial }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData(); // model badges reflect the new policy
  } catch (err) {
    alert('Could not update license: ' + err.message);
  }
}

async function handleSaveSettings(e) {
  e.preventDefault();
  const status = document.getElementById('settingsStatus');
  // Only send fields the user actually typed into (blank = leave unchanged).
  const payload = {};
  document.querySelectorAll('#settingsForm [data-setting]').forEach((input) => {
    if (input.value.trim()) payload[input.dataset.setting] = input.value.trim();
  });
  if (Object.keys(payload).length === 0) {
    status.textContent = 'Nothing to save.';
    return;
  }
  try {
    const res = await fetch('/api/settings', {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    status.textContent = 'Saved.';
    await loadData(); // refresh config so import button reflects new token
    setTimeout(() => closeModal(settingsModal), 600);
  } catch (err) {
    status.textContent = 'Save failed: ' + err.message;
  }
}

async function handleClearSetting(key) {
  if (!confirm('Clear this value?')) return;
  const status = document.getElementById('settingsStatus');
  try {
    const res = await fetch('/api/settings', {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ [key]: null }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    status.textContent = 'Cleared.';
    await loadData();
    await openSettingsModal();
  } catch (err) {
    status.textContent = 'Clear failed: ' + err.message;
  }
}

async function handleRenameCollection(id, currentName) {
  const name = prompt('Rename collection:', currentName);
  if (name === null) return;
  const trimmed = name.trim();
  if (!trimmed || trimmed === currentName) return;
  try {
    const res = await fetch(`/api/projects/${id}`, {
      method: 'PUT',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ name: trimmed }),
    });
    if (!res.ok) throw new Error((await res.json()).error);
    await loadData();
  } catch (err) {
    alert('Failed to rename collection: ' + err.message);
  }
}

async function handleDeleteCollection(id, name) {
  if (!confirm(`Delete the collection "${name}"?\n\nThe models in it are kept — only the collection is removed.`)) return;
  try {
    const res = await fetch(`/api/projects/${id}`, { method: 'DELETE' });
    if (!res.ok) throw new Error((await res.json()).error);
    if (String(selectedScope) === String(id)) selectedScope = 'all';
    await loadData();
  } catch (err) {
    alert('Failed to delete collection: ' + err.message);
  }
}

async function handleCreateProject(e) {
  e.preventDefault();
  try {
    const res = await fetch('/api/projects', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        name: document.getElementById('projectName').value,
        description: document.getElementById('projectDescription').value,
      }),
    });
    if (res.ok) {
      closeModal(projectModal);
      document.getElementById('projectForm').reset();
      await loadData();
    } else {
      alert('Failed to create collection:' + (await res.json()).error);
    }
  } catch (err) {
    alert('Failed to create collection:' + err.message);
  }
}

async function handleDeleteModel() {
  const id = fileDetailModal.dataset.currentModelId;
  if (!id || !confirm('Move this model to the trash?\n\nYou can restore it from Trash until the trash is emptied.')) return;
  try {
    const res = await fetch(`/api/models/${id}`, { method: 'DELETE' });
    if (res.ok) {
      closeModal(fileDetailModal);
      await loadData();
    } else {
      alert('Failed to move to trash: ' + (await res.json()).error);
    }
  } catch (err) {
    alert('Failed to move to trash: ' + err.message);
  }
}

// ---------------------------------------------------------------- utils
// All distinct tags currently in the library, sorted.
function knownTags() {
  const set = new Set();
  models.forEach((m) => (m.tags || []).forEach((t) => set.add(t)));
  return [...set].sort((a, b) => a.localeCompare(b));
}

// Autocomplete for a comma-separated tag input: suggests existing tags that
// match the token currently being typed (after the last comma).
function setupTagAutocomplete(input) {
  if (!input) return;
  const box = document.createElement('div');
  box.className = 'tag-suggest';
  box.style.display = 'none';
  input.parentNode.style.position = 'relative';
  input.parentNode.appendChild(box);
  let active = -1;

  const parts = () => input.value.split(',');
  const currentToken = () => parts().pop().trim().toLowerCase();
  const hide = () => { box.style.display = 'none'; active = -1; };

  function choose(tag) {
    const p = parts().map((x) => x.trim());
    p[p.length - 1] = tag;
    input.value = p.join(', ') + ', ';
    hide();
    input.focus();
  }

  function render() {
    const tok = currentToken();
    if (!tok) return hide();
    const taken = new Set(parts().map((x) => x.trim().toLowerCase()));
    const matches = knownTags().filter((t) => t.toLowerCase().includes(tok) && !taken.has(t.toLowerCase())).slice(0, 8);
    if (!matches.length) return hide();
    active = -1;
    box.innerHTML = matches.map((t) => `<div class="tag-suggest-item" data-tag="${escapeHtml(t)}">${escapeHtml(t)}</div>`).join('');
    box.style.top = `${input.offsetTop + input.offsetHeight + 2}px`;
    box.style.left = `${input.offsetLeft}px`;
    box.style.width = `${input.offsetWidth}px`;
    box.style.display = '';
  }

  input.addEventListener('input', render);
  input.addEventListener('focus', render);
  input.addEventListener('blur', () => setTimeout(hide, 150));
  input.addEventListener('keydown', (e) => {
    const items = [...box.querySelectorAll('.tag-suggest-item')];
    if (box.style.display === 'none' || !items.length) return;
    if (e.key === 'ArrowDown') { e.preventDefault(); active = (active + 1) % items.length; }
    else if (e.key === 'ArrowUp') { e.preventDefault(); active = (active - 1 + items.length) % items.length; }
    else if (e.key === 'Enter' && active >= 0) { e.preventDefault(); choose(items[active].dataset.tag); return; }
    else if (e.key === 'Escape') { hide(); return; }
    else return;
    items.forEach((it, i) => it.classList.toggle('active', i === active));
  });
  box.addEventListener('mousedown', (e) => {
    const it = e.target.closest('.tag-suggest-item');
    if (it) { e.preventDefault(); choose(it.dataset.tag); }
  });
}

function splitTags(value) {
  return value.split(',').map((t) => t.trim()).filter(Boolean);
}

function escapeHtml(text) {
  const div = document.createElement('div');
  div.textContent = text == null ? '' : text;
  return div.innerHTML;
}

function formatFileSize(bytes) {
  bytes = Number(bytes) || 0;
  if (bytes === 0) return '0 Bytes';
  const k = 1024;
  const sizes = ['Bytes', 'KB', 'MB', 'GB'];
  const i = Math.floor(Math.log(bytes) / Math.log(k));
  return Math.round((bytes / Math.pow(k, i)) * 100) / 100 + ' ' + sizes[i];
}

function formatDate(dateString) {
  return new Date(dateString).toLocaleDateString('en-US', { year: 'numeric', month: 'short', day: 'numeric' });
}