const app = document.querySelector('#app');
let currentUser = null, loginAvailable = false, timer, renderVersion = 0;
let expiryTimer;
const browseState = {q: '', status: 'open', sort: 'newest', page: 1};
const esc = value => String(value).replace(/[&<>"']/g, c => ({'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#39;'}[c]));
const toast = message => { const box = document.querySelector('#toast'); box.textContent = message; box.hidden = false; clearTimeout(timer); timer = setTimeout(() => box.hidden = true, 5000); };
async function api(url, options = {}) {
  let response;
  try { response = await fetch(url, { ...options, headers: {'Content-Type':'application/json', 'X-HuggingPolls':'1', ...options.headers} }); }
  catch { throw new Error('Could not connect. Check your connection and try again.'); }
  let data; try { data = await response.json(); } catch { throw new Error('The server is unavailable. Please try again.'); }
  if (!response.ok) {
    const error = new Error(typeof data.detail === 'string' ? data.detail : 'Please check your question and answer options.');
    error.status = response.status;
    throw error;
  }
  return data;
}
function login() {
  if (!loginAvailable) return toast('HF sign-in is available when this app runs on its Hugging Face Space.');
  // Leave the Space iframe so the OAuth session uses first-party cookies.
  const url = '/auth/login?poll=' + encodeURIComponent(location.hash.slice(1));
  if (window.self !== window.top) window.open(url, '_blank', 'noopener');
  else location.href = url;
}
async function loadAccount() {
  const result = await api('/api/me'); currentUser = result.user; loginAvailable = result.login_available;
  document.querySelector('#account').innerHTML = currentUser ? `<button class="sign-in" id="logout">${esc(currentUser.name)} · Sign out</button>` : '<button class="sign-in" id="login">🤗 Sign in with HF</button>';
  document.querySelector('#login')?.addEventListener('click', login);
  document.querySelector('#logout')?.addEventListener('click', async () => {try {await api('/api/logout', {method:'POST'}); await loadAccount(); route();} catch(e) {toast(e.message);}});
}
function readDraft() {
  return {
    question: document.querySelector('#question').value,
    description: document.querySelector('#description').value,
    options: [...document.querySelectorAll('.option-input')].map(input => input.value),
    duration_hours: Number(document.querySelector('#duration').value),
    listed: document.querySelector('#listed').checked
  };
}
function storedDraft() {
  try {
    const draft = JSON.parse(sessionStorage.getItem('draft'));
    if (draft && typeof draft.question === 'string' && typeof draft.description === 'string'
        && Array.isArray(draft.options) && draft.options.length >= 2 && draft.options.length <= 12
        && draft.options.every(option => typeof option === 'string' && option.length <= 160)
        && draft.question.length <= 240 && draft.description.length <= 2000
        && (draft.duration_hours === undefined || [1, 24, 72, 168, 720].includes(draft.duration_hours))
        && (draft.listed === undefined || typeof draft.listed === 'boolean')) return draft;
  } catch {}
  return null;
}
function saveDraft() {
  const draft = readDraft();
  const hasContent = Boolean(draft.question || draft.description || draft.options.some(Boolean)
    || draft.options.length > 2 || draft.duration_hours !== 168 || !draft.listed);
  document.querySelector('#clear-draft').hidden = !hasContent;
  try {
    if (hasContent) sessionStorage.setItem('draft', JSON.stringify(draft));
    else sessionStorage.removeItem('draft');
    document.querySelector('#draft-status').textContent = hasContent ? 'Draft saved in this tab.' : 'Drafts are saved in this tab as you type.';
  } catch {
    document.querySelector('#draft-status').textContent = 'Draft saving is unavailable in this browser.';
  }
}
function clearValidation() {
  document.querySelectorAll('#create-form input').forEach(input => {
    input.setCustomValidity('');
    input.removeAttribute('aria-invalid');
  });
}
function validateDraft() {
  clearValidation();
  const question = document.querySelector('#question');
  if (!question.value.trim()) question.setCustomValidity('Please enter a question.');
  const seen = new Set();
  document.querySelectorAll('.option-input').forEach(input => {
    const value = input.value.trim().toLowerCase();
    if (!value) input.setCustomValidity('Please enter an answer option.');
    else if (seen.has(value)) input.setCustomValidity('Please use a different answer for each option.');
    seen.add(value);
  });
  document.querySelectorAll('#create-form input').forEach(input => {
    if (!input.validity.valid) input.setAttribute('aria-invalid', 'true');
  });
  return document.querySelector('#create-form').reportValidity();
}
function optionRow(value = '') {
  const row = document.createElement('div');
  row.className = 'option-row';
  row.innerHTML = `<span class="option-index" aria-hidden="true"></span><input class="option-input" maxlength="160" required value="${esc(value)}"><button type="button" class="remove-option" aria-label="Remove option">×</button>`;
  row.querySelector('button').onclick = () => {
    if (document.querySelectorAll('.option-row').length <= 2) return;
    const neighbor = row.nextElementSibling || row.previousElementSibling;
    row.remove();
    numberOptions();
    clearValidation();
    saveDraft();
    neighbor?.querySelector('input').focus();
  };
  document.querySelector('#options').append(row);
  numberOptions();
  return row;
}
function numberOptions() {
  const rows = document.querySelectorAll('.option-row');
  rows.forEach((row, i) => {
    row.querySelector('.option-index').textContent = String(i + 1);
    row.querySelector('input').placeholder = `Option ${i + 1}`;
    row.querySelector('input').setAttribute('aria-label', `Option ${i + 1}`);
    const remove = row.querySelector('button');
    remove.disabled = rows.length <= 2;
    remove.setAttribute('aria-label', `Remove option ${i + 1}`);
    remove.title = rows.length <= 2 ? 'A poll needs at least two options' : `Remove option ${i + 1}`;
  });
  document.querySelector('#add-option').disabled = rows.length >= 12;
  document.querySelector('#options-count').textContent = `${rows.length} of 12 options`;
}
function home(restore = true) {
  app.replaceChildren(document.querySelector('#home-template').content.cloneNode(true));
  document.title = 'Create a poll · HuggingPolls';
  const draft = restore ? storedDraft() : null;
  document.querySelector('#question').value = draft?.question || '';
  document.querySelector('#description').value = draft?.description || '';
  document.querySelector('#duration').value = String(draft?.duration_hours ?? 168);
  document.querySelector('#listed').checked = draft?.listed ?? true;
  (draft?.options || ['', '']).forEach(optionRow);
  document.querySelector('#question-count').textContent = `${document.querySelector('#question').value.length} / 240`;
  saveDraft();
  if (draft) document.querySelector('#draft-status').textContent = 'Draft restored. Saved in this tab.';
  if (currentUser) document.querySelector('#create-note').innerHTML = `Creating as <b>${esc(currentUser.name)}</b>.`;
  document.querySelector('#add-option').onclick = () => {
    if (document.querySelectorAll('.option-row').length >= 12) return;
    const row = optionRow();
    saveDraft();
    row.querySelector('input').focus();
  };
  document.querySelector('#clear-draft').onclick = () => {
    try { sessionStorage.removeItem('draft'); } catch {}
    home(false);
    document.querySelector('#question').focus();
    toast('Draft cleared.');
  };
  const form = document.querySelector('#create-form');
  form.addEventListener('input', () => {
    clearValidation();
    document.querySelector('#question-count').textContent = `${document.querySelector('#question').value.length} / 240`;
    saveDraft();
  });
  form.onsubmit = async event => {
    event.preventDefault();
    if (!validateDraft()) return;
    saveDraft();
    if (!currentUser) return login();
    const button = document.querySelector('#create-button');
    button.disabled = true;
    button.setAttribute('aria-busy', 'true');
    button.textContent = 'Creating…';
    try {
      const poll = await api('/api/polls', {method: 'POST', body: JSON.stringify(readDraft())});
      try { sessionStorage.removeItem('draft'); } catch {}
      location.hash = poll.id;
      toast('Poll created.');
    } catch (e) {
      toast(e.message);
      button.disabled = false;
      button.removeAttribute('aria-busy');
      button.textContent = 'Create poll';
    }
  };
}
function pollBadge(poll) {
  return `<span class="tag ${poll.closed ? '' : 'tag-open'}">${poll.expired ? 'Expired' : poll.closed ? 'Closed' : 'Open'}</span>`;
}
function deadlineText(poll) {
  if (!poll.expires_at) return poll.closed ? 'Voting closed' : 'No scheduled end';
  const date = new Date(poll.expires_at).toLocaleString(undefined, {
    month: 'short', day: 'numeric', hour: 'numeric', minute: '2-digit'
  });
  return `${poll.expired ? 'Expired' : poll.closed ? 'Scheduled end:' : 'Closes'} ${date}`;
}
function watchExpiry(polls, version, refresh = route) {
  clearTimeout(expiryTimer);
  const delays = polls.filter(poll => poll.expires_at && !poll.expired)
    .map(poll => new Date(poll.expires_at).getTime() - Date.now());
  if (!delays.length) return;
  const delay = Math.min(...delays);
  // Recheck with the server if the browser clock is ahead; avoid a request loop.
  expiryTimer = setTimeout(() => {
    if (version === renderVersion) refresh();
  }, delay > 0 ? Math.min(delay + 250, 2147483647) : 30000);
}
async function browsePolls(version) {
  document.title = 'See polls \u00b7 HuggingPolls';
  app.replaceChildren(document.querySelector('#browse-template').content.cloneNode(true));
  const form = document.querySelector('#browse-form');
  const search = document.querySelector('#poll-search');
  const status = document.querySelector('#poll-status');
  const sort = document.querySelector('#poll-sort');
  const results = document.querySelector('#browse-results');
  const count = document.querySelector('#browse-count');
  const pager = document.querySelector('#browse-pagination');
  const clear = document.querySelector('#clear-filters');
  search.value = browseState.q;
  status.value = browseState.status;
  sort.value = browseState.sort;
  let requestVersion = 0;

  async function load() {
    const request = ++requestVersion;
    clearTimeout(expiryTimer);
    results.setAttribute('aria-busy', 'true');
    document.querySelector('#previous-page').disabled = true;
    document.querySelector('#next-page').disabled = true;
    count.textContent = 'Finding polls\u2026';
    clear.hidden = !browseState.q && browseState.status === 'open' && browseState.sort === 'newest';
    try {
      const data = await api('/api/browse?' + new URLSearchParams(browseState));
      if (version !== renderVersion || request !== requestVersion) return;
      browseState.page = data.page;
      count.textContent = `${data.total} poll${data.total === 1 ? '' : 's'}${browseState.q ? ` matching \u201c${browseState.q}\u201d` : ''}`;
      results.innerHTML = data.items.length ? `<div class="poll-grid">${data.items.map(poll => `
        <a class="browse-card" href="#${esc(poll.id)}">
          ${pollBadge(poll)}<h2>${esc(poll.question)}</h2>
          ${poll.description ? `<p class="browse-description">${esc(poll.description)}</p>` : ''}
          <div class="card-meta"><p class="subtle">By ${esc(poll.owner)} &middot; ${poll.total} vote${poll.total === 1 ? '' : 's'} &middot; ${poll.option_count} options</p>
          <p class="subtle deadline">${esc(deadlineText(poll))}</p></div>
        </a>`).join('')}</div>` : `<div class="card empty"><h2>${browseState.q ? 'No matching polls' : browseState.status === 'open' ? 'No open polls yet' : 'No polls here yet'}</h2><p class="subtle">${browseState.q ? 'Try another question, topic, or creator, or clear your filters.' : 'Try a different filter or create a poll for the community.'}</p><div class="actions"><a class="primary" href="#">+ Create poll</a></div></div>`;
      const pages = Math.max(1, Math.ceil(data.total / data.page_size));
      pager.hidden = pages <= 1;
      document.querySelector('#browse-page').textContent = `Page ${data.page} of ${pages}`;
      document.querySelector('#previous-page').disabled = data.page <= 1;
      document.querySelector('#next-page').disabled = data.page >= pages;
      watchExpiry(data.items, version, load);
    } catch (error) {
      if (version !== renderVersion || request !== requestVersion) return;
      count.textContent = 'Polls could not be loaded.';
      results.innerHTML = `<div class="card empty"><h2>Unable to browse polls</h2><p class="subtle">${esc(error.message)}</p><button class="secondary" id="retry-browse">Try again</button></div>`;
      pager.hidden = true;
      document.querySelector('#retry-browse').onclick = load;
    } finally {
      if (version === renderVersion && request === requestVersion) results.removeAttribute('aria-busy');
    }
  }
  form.onsubmit = event => {
    event.preventDefault();
    Object.assign(browseState, {q: search.value.trim(), status: status.value, sort: sort.value, page: 1});
    load();
  };
  status.onchange = sort.onchange = () => form.requestSubmit();
  clear.onclick = () => {
    search.value = '';
    status.value = 'open';
    sort.value = 'newest';
    form.requestSubmit();
  };
  document.querySelector('#previous-page').onclick = () => { browseState.page--; load(); };
  document.querySelector('#next-page').onclick = () => { browseState.page++; load(); };
  await load();
}
async function myPolls(version) {
  document.title = 'My polls \u00b7 HuggingPolls';
  if (!currentUser) {
    app.innerHTML = '<div class="empty"><h2>My polls</h2><p class="subtle">Sign in with your HF account to create and manage polls.</p><button id="list-login" class="primary">Sign in with HF</button></div>';
    document.querySelector('#list-login').onclick = login;
    return;
  }
  const polls = await api('/api/polls');
  if (version !== renderVersion) return;
  app.innerHTML = `<div class="page-title"><h1>My polls</h1><p class="subtle">View results and manage your polls.</p></div><section class="card">${polls.length ? polls.map(poll => `
    <a class="list-poll" href="#${esc(poll.id)}"><div><strong>${esc(poll.question)}</strong>
    <span class="subtle">${poll.total} vote${poll.total === 1 ? '' : 's'} &middot; ${poll.listed ? 'Listed' : 'Unlisted'} &middot; ${new Date(poll.created_at).toLocaleDateString()}</span>
    <p class="subtle deadline">${esc(deadlineText(poll))}</p></div>${pollBadge(poll)}</a>`).join('') : '<div class="empty"><h2>No polls yet</h2><p class="subtle">Create a poll to get started.</p></div>'}
    <div class="actions"><a class="primary" href="#">+ Create poll</a></div></section>`;
  watchExpiry(polls, version);
}
async function pollPage(id, version) {
  const p = await api('/api/polls/' + encodeURIComponent(id));
  if (version !== renderVersion) return;
  document.title = `${p.question} \u00b7 HuggingPolls`;
  const total = p.results?.reduce((a, b) => a + b, 0) || 0;
  const results = p.results ? `
    <div class="section-heading"><h2>${p.closed ? 'Final results' : 'Results'}</h2><span class="small-pill">${total} vote${total === 1 ? '' : 's'}</span></div>
    ${p.options.map((label, i) => `<div class="result"><div class="result-label"><span>${esc(label)}${p.choice === i ? ' &middot; Your vote' : ''}</span><b>${p.results[i]} &middot; ${total ? Math.round(p.results[i] / total * 100) : 0}%</b></div><div class="bar" aria-hidden="true"><span style="width:${total ? p.results[i] / total * 100 : 0}%"></span></div></div>`).join('')}
    <div class="actions"><button class="secondary" id="refresh-results">Refresh</button>${p.is_owner ? `
      <a class="secondary" href="/api/polls/${p.id}/export">Export CSV</a>
      ${!p.expired ? `<button class="secondary" id="toggle-status">${p.closed ? 'Reopen voting' : 'Close voting'}</button>` : ''}
      <button class="secondary" id="toggle-listing">${p.listed ? 'Unlist poll' : 'List publicly'}</button>
      <button class="quiet danger" id="delete-poll">Delete poll</button>` : ''}</div>` : '';
  app.innerHTML = `<a class="back" href="#${p.is_owner ? 'my-polls' : 'see-polls'}">&larr; ${p.is_owner ? 'My polls' : 'See polls'}</a>
    <section class="card poll-card"><div class="poll-meta">${pollBadge(p)}${!p.listed ? '<span class="tag">Unlisted</span>' : ''}</div>
    <h1>${esc(p.question)}</h1><p class="subtle">Asked by ${esc(p.owner)} &middot; ${new Date(p.created_at).toLocaleDateString()}</p>
    <p class="subtle deadline">${esc(deadlineText(p))}</p>
    ${p.description ? `<p class="description">${esc(p.description)}</p>` : ''}
    ${p.is_owner ? `<div class="share"><label for="share-url">Share link</label><div class="share-line"><input id="share-url" readonly value="${esc(p.url)}"><button class="primary" id="copy-link">Copy link</button></div><p class="subtle">${p.listed ? 'Listed on See polls. Anyone can discover this poll.' : 'Unlisted. Share this link with anyone you want to invite.'}</p></div>` : ''}
    ${p.voted ? `<p class="notice">Vote recorded: <b>${esc(p.options[p.choice])}</b>.</p>` : ''}
    ${p.closed ? `<p class="notice" id="poll-closed-notice">${p.expired ? 'This poll has expired. Voting has ended.' : 'This poll is closed.'} Final results are available below.</p>` : ''}
    ${results}
    ${!p.voted && !p.closed ? `${p.is_owner ? '<hr class="vote-divider"><h2>Vote</h2>' : ''}
      <form id="vote-form">${p.options.map((label, i) => `<label class="vote-option"><input type="radio" name="choice" value="${i}" required><span>${esc(label)}</span></label>`).join('')}
      <div class="actions"><button type="submit" class="primary" id="vote-button">Submit vote</button></div>
      <p class="subtle">${currentUser ? 'Voting while signed in.' : 'No account needed to vote.'} Results appear after voting or once the poll closes.</p></form>` : ''}</section>`;
  document.querySelector('#copy-link')?.addEventListener('click', async () => {
    try { await navigator.clipboard.writeText(p.url); toast('Poll link copied.'); }
    catch { document.querySelector('#share-url').select(); toast('Select and copy the poll link above.'); }
  });
  document.querySelector('#refresh-results')?.addEventListener('click', () => route());
  for (const [selector, change, message] of [
    ['#toggle-status', {closed: !p.closed}, p.closed ? 'Voting reopened.' : 'Voting closed.'],
    ['#toggle-listing', {listed: !p.listed}, p.listed ? 'Poll unlisted.' : 'Poll is now listed on See polls.']
  ]) {
    document.querySelector(selector)?.addEventListener('click', async event => {
      const button = event.currentTarget;
      button.disabled = true;
      try { await api('/api/polls/' + p.id, {method: 'PATCH', body: JSON.stringify(change)}); await route(); toast(message); }
      catch (error) { toast(error.message); button.disabled = false; if (error.status === 409) route(); }
    });
  }
  document.querySelector('#delete-poll')?.addEventListener('click', async () => {
    if (!confirm('Delete this poll and all its votes? This cannot be undone.')) return;
    try { await api('/api/polls/' + p.id, {method: 'DELETE'}); location.hash = 'my-polls'; toast('Poll deleted.'); }
    catch (error) { toast(error.message); }
  });
  document.querySelector('#vote-form')?.addEventListener('submit', async event => {
    event.preventDefault();
    const button = document.querySelector('#vote-button');
    button.disabled = true;
    button.setAttribute('aria-busy', 'true');
    button.textContent = 'Sending your vote\u2026';
    try {
      await api('/api/polls/' + p.id + '/vote', {method: 'POST', body: JSON.stringify({choice: Number(new FormData(event.target).get('choice'))})});
      await route();
    } catch (error) {
      toast(error.message);
      button.disabled = false;
      button.removeAttribute('aria-busy');
      button.textContent = 'Submit vote';
      if (error.status === 409) route();
    }
  });
  watchExpiry([p], version);
}
async function route() {
  const version = ++renderVersion;
  clearTimeout(expiryTimer);
  const id = location.hash.slice(1);
  for (const [selector, active] of [['#new-poll', !id], ['#see-polls', id === 'see-polls'], ['#my-polls', id === 'my-polls']]) {
    const tab = document.querySelector(selector);
    tab.classList.toggle('active', active);
    if (active) tab.setAttribute('aria-current', 'page');
    else tab.removeAttribute('aria-current');
  }
  app.setAttribute('aria-busy', 'true');
  try {
    if (!id) home();
    else {
      document.title = 'Loading · HuggingPolls';
      app.innerHTML = '<p class="empty subtle">Loading…</p>';
      if (id === 'see-polls') await browsePolls(version);
      else if (id === 'my-polls') await myPolls(version);
      else await pollPage(id, version);
    }
  } catch (e) {
    if (version === renderVersion) {
      document.title = 'Unable to load · HuggingPolls';
      app.innerHTML = `<div class="empty"><h2>Unable to load ${id === 'my-polls' ? 'your polls' : 'poll'}</h2><p class="subtle">${esc(e.message)}</p><div class="actions"><button class="secondary" id="retry-page">Try again</button><a class="primary" href="#">Create a poll</a></div></div>`;
      document.querySelector('#retry-page').onclick = () => route();
    }
  } finally {
    if (version === renderVersion) app.removeAttribute('aria-busy');
  }
}
document.querySelector('#my-polls').onclick=()=>location.hash='my-polls';
document.querySelector('.skip-link').onclick = event => { event.preventDefault(); app.focus(); };
window.addEventListener('hashchange', async () => { await route(); app.focus({preventScroll: true}); });
window.addEventListener('pageshow',event=>{if(event.persisted)loadAccount().then(route).catch(e=>toast(e.message));});
loadAccount().catch(e => toast(e.message)).then(route);