// State
let models = [];
let projects = [];
let config = { importers: {} };
let selectedProject = 'all';
let selectedTags = [];
let currentView = 'grid';

// DOM
const fileGrid = document.getElementById('fileGrid');
const projectsList = document.getElementById('projectsList');
const tagsList = document.getElementById('tagsList');
const searchInput = document.getElementById('searchInput');
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', () => {
  setupAuthListeners();
  bootstrap();
});

// 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] = await Promise.all([
      fetch('/api/models'),
      fetch('/api/projects'),
      fetch('/api/config'),
    ]);
    models = await modelsRes.json();
    projects = await projectsRes.json();
    config = await configRes.json();

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

    // 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);
  }
}

// Render thumbnails in the browser for models that don't have one yet, then
// persist them. Runs one at a time to avoid thrashing the GPU / WebGL contexts.
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) => window.ModelViewer.RENDERABLE.includes(f.format));
    if (!file) continue;
    thumbAttempted.add(m.id);
    try {
      const src = viewerSourceFor(file.id, file.format);
      const image = await window.ModelViewer.snapshot(src.url, src.format, 512);
      if (!image) continue;
      const res = await fetch(`/api/models/${m.id}/thumbnail`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ image }),
      });
      if (!res.ok) continue;
      const updated = await res.json();
      m.thumbnailUrl = updated.thumbnailUrl;
      const thumb = fileGrid.querySelector(`.file-card[data-model-id="${m.id}"] .file-thumbnail`);
      if (thumb && updated.thumbnailUrl) {
        thumb.innerHTML = `<img src="${updated.thumbnailUrl}" alt="" loading="lazy">`;
      }
    } catch (err) {
      console.warn('Thumbnail generation failed for model', m.id, err);
    }
  }
}

// ---------------------------------------------------------------- rendering
function renderProjects() {
  const items = projects.map((p) => `
    <div class="project-item${String(selectedProject) === String(p.id) ? ' active' : ''}" data-project-id="${p.id}">
      <span class="project-name">${escapeHtml(p.name)}</span>
      <span class="project-meta">
        <button class="collection-action collection-rename" title="Rename" aria-label="Rename collection">&#9998;</button>
        <button class="collection-action collection-delete" title="Delete" aria-label="Delete collection">&times;</button>
        <span class="count" data-project-count="${p.id}">${p.model_count}</span>
      </span>
    </div>`).join('');
  const allItem = projectsList.querySelector('[data-project-id="all"]');
  allItem.classList.toggle('active', selectedProject === 'all');
  projectsList.innerHTML = '';
  projectsList.appendChild(allItem);
  projectsList.insertAdjacentHTML('beforeend', items);
}

function renderTags() {
  const all = new Set();
  models.forEach((m) => (m.tags || []).forEach((t) => all.add(t)));
  tagsList.innerHTML = Array.from(all).sort().map((tag) => `
    <span class="tag${selectedTags.includes(tag) ? ' active' : ''}" data-tag="${escapeHtml(tag)}">${escapeHtml(tag)}</span>`).join('');
}

function renderModels() {
  const filtered = getFilteredModels();
  if (filtered.length === 0) {
    fileGrid.innerHTML = `
      <div class="empty-state">
        <h3>No models found</h3>
        <p>Upload files or import from a URL to get started</p>
      </div>`;
    return;
  }

  fileGrid.className = currentView === 'grid' ? 'file-grid' : 'file-grid list-view';
  fileGrid.innerHTML = filtered.map((m) => {
    const totalSize = (m.files || []).reduce((s, f) => s + Number(f.size || 0), 0);
    const thumb = m.thumbnailUrl
      ? `<img src="${m.thumbnailUrl}" alt="" loading="lazy">`
      : '<span>📦</span>';
    return `
    <div class="file-card" data-model-id="${m.id}">
      <div class="file-thumbnail">${thumb}</div>
      <div class="file-info">
        <div class="file-name">${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">${escapeHtml(t)}</span>`).join('')}</div>` : ''}
        <div class="file-meta">${m.files.length} file${m.files.length === 1 ? '' : 's'} • ${formatFileSize(totalSize)} • ${formatDate(m.date_added)}</div>
      </div>
    </div>`;
  }).join('');
}

function getFilteredModels() {
  let result = models;
  if (selectedProject !== 'all') {
    result = result.filter((m) => (m.projects || []).some((p) => String(p.id) === String(selectedProject)));
  }
  if (selectedTags.length > 0) {
    result = result.filter((m) => selectedTags.some((t) => (m.tags || []).includes(t)));
  }
  const term = searchInput.value.toLowerCase().trim();
  if (term) {
    result = result.filter((m) =>
      m.name.toLowerCase().includes(term) ||
      (m.description && m.description.toLowerCase().includes(term)));
  }
  return result;
}

function updateCounts() {
  document.getElementById('allFilesCount').textContent = models.length;
}

// ---------------------------------------------------------------- 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(/\.[^.]+$/, '');
  });

  projectsList.addEventListener('click', (e) => {
    const item = e.target.closest('.project-item');
    if (!item) return;
    const id = item.dataset.projectId;
    const name = item.querySelector('.project-name') ? item.querySelector('.project-name').textContent : 'All Models';

    if (e.target.closest('.collection-rename')) { handleRenameCollection(id, name); return; }
    if (e.target.closest('.collection-delete')) { handleDeleteCollection(id, name); return; }

    document.querySelectorAll('.project-item').forEach((i) => i.classList.remove('active'));
    item.classList.add('active');
    selectedProject = id;
    document.getElementById('contentTitle').textContent = id === 'all' ? 'All Models' : name;
    renderModels();
  });

  tagsList.addEventListener('click', (e) => {
    if (!e.target.classList.contains('tag')) return;
    const tag = e.target.dataset.tag;
    e.target.classList.toggle('active');
    if (selectedTags.includes(tag)) selectedTags = selectedTags.filter((t) => t !== tag);
    else selectedTags.push(tag);
    renderModels();
  });

  searchInput.addEventListener('input', renderModels);

  document.querySelectorAll('.view-btn').forEach((btn) => {
    btn.addEventListener('click', (e) => {
      document.querySelectorAll('.view-btn').forEach((b) => b.classList.remove('active'));
      e.target.classList.add('active');
      currentView = e.target.dataset.view;
      renderModels();
    });
  });

  fileGrid.addEventListener('click', (e) => {
    const card = e.target.closest('.file-card');
    if (card) openModelDetail(card.dataset.modelId);
  });

  document.getElementById('deleteFileBtn').addEventListener('click', handleDeleteModel);
  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);
}

// 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 && window.ModelViewer) window.ModelViewer.dispose();
}

// ---------------------------------------------------------------- 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 = models.find((m) => String(m.id) === String(modelId));
  if (!model) return;
  fileDetailModal.dataset.currentModelId = modelId;
  currentDetailThumb = model.thumbnailUrl || null;

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

  // 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>`).join('');
  }

  // Viewer tabs
  const renderable = model.files.filter((f) => window.ModelViewer.RENDERABLE.includes(f.format));
  const tabs = document.getElementById('detailFileTabs');
  tabs.innerHTML = renderable.map((f, i) => `
    <button class="file-tab${i === 0 ? ' active' : ''}" data-file-id="${f.id}" data-format="${f.format}">${escapeHtml(f.originalName)}</button>`).join('');
  tabs.querySelectorAll('.file-tab').forEach((tab) => {
    tab.addEventListener('click', () => {
      tabs.querySelectorAll('.file-tab').forEach((t) => t.classList.remove('active'));
      tab.classList.add('active');
      loadViewer(tab.dataset.fileId, tab.dataset.format);
    });
  });

  fileDetailModal.classList.add('active');
  currentDetailFile = null;
  if (renderable.length) {
    loadViewer(renderable[0].id, renderable[0].format);
  } else {
    document.getElementById('regenThumbBtn').style.display = 'none';
    window.ModelViewer.render(document.getElementById('detailViewer'), '', 'none', { fallbackImage: currentDetailThumb });
  }
}

// Maps a file to what the viewer should load: 3MF goes through the server's
// GLB conversion; everything else is served raw.
function viewerSourceFor(fileId, format) {
  return format === '3mf'
    ? { url: `/api/files/${fileId}/glb`, format: 'glb' }
    : { url: `/api/files/${fileId}/raw`, format };
}

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 = models.find((m) => String(m.id) === String(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
    const idx = models.findIndex((m) => String(m.id) === String(modelId));
    if (idx !== -1) models[idx] = 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;
  }
}

function loadViewer(fileId, format) {
  const src = viewerSourceFor(fileId, format);
  currentDetailFile = { id: fileId, viewerUrl: src.url, viewerFormat: src.format };
  document.getElementById('regenThumbBtn').style.display = '';
  window.ModelViewer.render(document.getElementById('detailViewer'), src.url, src.format, { fallbackImage: currentDetailThumb });
}

function updateCardThumbnail(modelId, thumbnailUrl) {
  const m = models.find((x) => String(x.id) === String(modelId));
  if (m) m.thumbnailUrl = thumbnailUrl;
  const thumb = fileGrid.querySelector(`.file-card[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);
    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);
    if (String(selectedProject) === String(id)) {
      document.getElementById('contentTitle').textContent = trimmed;
    }
    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(selectedProject) === String(id)) {
      selectedProject = 'all';
      document.getElementById('contentTitle').textContent = 'All Models';
    }
    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('Delete this model and all its files?')) return;
  try {
    const res = await fetch(`/api/models/${id}`, { method: 'DELETE' });
    if (res.ok) {
      closeModal(fileDetailModal);
      await loadData();
    } else {
      alert('Failed to delete: ' + (await res.json()).error);
    }
  } catch (err) {
    alert('Failed to delete: ' + 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' });
}