/* ─── Theme System ────────────────────────────────────────────────────────── */
(function () {
  const saved = localStorage.getItem('learnix-theme') || 'dark';
  document.documentElement.setAttribute('data-theme', saved);
})();

let page = 1;

/* ─── Theme Management ────────────────────────────────────────────────────── */
function initTheme() {
  const saved = localStorage.getItem('learnix-theme') || 'dark';
  applyTheme(saved);
}

function applyTheme(theme) {
  document.documentElement.setAttribute('data-theme', theme);
  localStorage.setItem('learnix-theme', theme);
  updateSettingsUI(theme);
}

function updateSettingsUI(theme) {
  // Update base toggle
  document.querySelectorAll('.theme-base-btn').forEach(btn => {
    btn.classList.toggle('active', btn.dataset.base === (isDarkVariant(theme) ? 'dark' : 'light'));
  });
  // Update swatches
  document.querySelectorAll('.swatch').forEach(s => {
    s.classList.toggle('active', s.dataset.theme === theme);
  });
}

function isDarkVariant(theme) {
  return ['dark', 'emerald', 'rose', 'amber'].includes(theme);
}

/* ─── Settings Popup ──────────────────────────────────────────────────────── */
function openSettings() {
  document.getElementById('settingsOverlay').classList.add('open');
  document.getElementById('settingsPopup').classList.add('open');
}

function closeSettings() {
  document.getElementById('settingsOverlay').classList.remove('open');
  document.getElementById('settingsPopup').classList.remove('open');
}

/* ─── Toast Notification ──────────────────────────────────────────────────── */
function showToast(msg, icon = '✓') {
  let toast = document.getElementById('toast');
  toast.innerHTML = `<span>${icon}</span><span>${msg}</span>`;
  toast.classList.remove('hide');
  toast.classList.add('show');
  clearTimeout(toast._timeout);
  toast._timeout = setTimeout(() => {
    toast.classList.remove('show');
    toast.classList.add('hide');
  }, 2800);
}

/* ─── Chat ────────────────────────────────────────────────────────────────── */
function getTime() {
  return new Date().toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
}

function appendMsg(content, role) {
  const chatBox = document.getElementById('chatBox');

  // Remove empty state
  const empty = chatBox.querySelector('.empty-chat');
  if (empty) empty.remove();

  const isUser = role === 'user';
  const row = document.createElement('div');
  row.className = `msg-row ${isUser ? 'user-row user' : 'bot'}`;
  row.innerHTML = `
    <div class="msg-avatar ${isUser ? 'user-av' : 'bot-av'}">${isUser ? 'U' : 'AI'}</div>
    <div class="msg-meta">
      <div class="msg-bubble">${content}</div>
      <span class="msg-time">${getTime()}</span>
    </div>
  `;
  chatBox.appendChild(row);
  chatBox.scrollTo({ top: chatBox.scrollHeight, behavior: 'smooth' });
  return row;
}

function showTyping() {
  const chatBox = document.getElementById('chatBox');
  const row = document.createElement('div');
  row.className = 'typing-row';
  row.id = 'typingIndicator';
  row.innerHTML = `
    <div class="msg-avatar bot-av">AI</div>
    <div class="typing-bubble">
      <div class="typing-dot"></div>
      <div class="typing-dot"></div>
      <div class="typing-dot"></div>
    </div>
  `;
  chatBox.appendChild(row);
  chatBox.scrollTo({ top: chatBox.scrollHeight, behavior: 'smooth' });
}

function removeTyping() {
  const el = document.getElementById('typingIndicator');
  if (el) el.remove();
}

async function sendMessage() {
  const input = document.getElementById('messageInput');
  const msg = input.value.trim();
  if (!msg) return;

  input.value = '';
  input.disabled = true;

  const sendBtn = document.getElementById('sendBtn');
  sendBtn.classList.add('sending');
  setTimeout(() => sendBtn.classList.remove('sending'), 500);

  appendMsg(msg, 'user');
  showTyping();

  try {
    const res = await fetch('/chat', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ message: msg })
    });
    const data = await res.json();
    removeTyping();
    appendMsg(data.answer, 'bot');
  } catch (err) {
    removeTyping();
    appendMsg('⚠ Could not reach the server.', 'bot');
  } finally {
    input.disabled = false;
    input.focus();
  }
}

/* ─── Records ─────────────────────────────────────────────────────────────── */
function makeRow(rowData, i, prepend = false) {
  const tr = document.createElement('tr');
  tr.style.animationDelay = prepend ? '0s' : `${i * 0.04}s`;
  if (prepend) tr.classList.add('row-new');
  tr.innerHTML = `
    <td contenteditable="true">${rowData.question}</td>
    <td contenteditable="true">${rowData.answer}</td>
    <td><button class="save-btn" onclick="saveEdit(this)">Save</button></td>
  `;
  return tr;
}

async function loadRecords(reset = false) {
  if (reset) {
    page = 1;
    document.querySelector('#recordsTable tbody').innerHTML = '';
    const vm = document.getElementById('viewMore');
    vm.style.display = '';
  }

  const btn = document.getElementById('viewMore');
  btn.classList.add('loading');
  btn.querySelector('span').innerHTML = `<svg class="load-icon" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21 12a9 9 0 11-6.219-8.56"/></svg> Loading...`;

  const res = await fetch(`/records?page=${page}`);
  const data = await res.json();
  const tbody = document.querySelector('#recordsTable tbody');

  data.records.forEach((row, i) => {
    tbody.appendChild(makeRow(row, i));
  });

  btn.classList.remove('loading');
  btn.querySelector('span').innerHTML = `
    <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><polyline points="6 9 12 15 18 9"/></svg>
    View More
  `;

  if (data.records.length < 30) {
    document.getElementById('viewMore').style.display = 'none';
  }
}

async function refreshRecords() {
  const refreshBtn = document.getElementById('refreshBtn');
  refreshBtn.classList.add('spinning');
  await loadRecords(true);
  setTimeout(() => refreshBtn.classList.remove('spinning'), 600);
  showToast('Knowledge base refreshed', '↺');
}

async function saveEdit(btn) {
  const row = btn.parentNode.parentNode;
  const q = row.children[0].innerText;
  const a = row.children[1].innerText;

  btn.textContent = '...';
  btn.disabled = true;

  await fetch('/update', {
    method: 'PUT',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ old_question: q, question: q, answer: a })
  });

  btn.textContent = 'Save';
  btn.disabled = false;
  showToast('Record updated', '✓');
}

async function addRecord() {
  const qEl = document.getElementById('newQ');
  const aEl = document.getElementById('newA');
  const q = qEl.value.trim();
  const a = aEl.value.trim();
  if (!q || !a) { showToast('Fill in both fields', '⚠'); return; }

  await fetch('/add', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ question: q, answer: a })
  });

  // Prepend new row to top of table without reloading page
  const tbody = document.querySelector('#recordsTable tbody');
  const tr = makeRow({ question: q, answer: a }, 0, true);
  tbody.insertBefore(tr, tbody.firstChild);

  qEl.value = '';
  aEl.value = '';
  showToast('Record added', '✓');
}

function viewMore() {
  page++;
  loadRecords();
}

/* ─── Init ────────────────────────────────────────────────────────────────── */
document.addEventListener('DOMContentLoaded', () => {
  initTheme();
  loadRecords();

  // Enter key to send
  document.getElementById('messageInput').addEventListener('keydown', (e) => {
    if (e.key === 'Enter' && !e.shiftKey) {
      e.preventDefault();
      sendMessage();
    }
  });

  // Close settings on overlay click
  document.getElementById('settingsOverlay').addEventListener('click', closeSettings);

  // Theme base buttons
  document.querySelectorAll('.theme-base-btn').forEach(btn => {
    btn.addEventListener('click', () => {
      const base = btn.dataset.base;
      const current = localStorage.getItem('learnix-theme') || 'dark';
      // Switch base while keeping color if applicable
      if (base === 'light') applyTheme('light');
      else applyTheme('dark');
    });
  });

  // Swatch clicks
  document.querySelectorAll('.swatch').forEach(swatch => {
    swatch.addEventListener('click', () => {
      applyTheme(swatch.dataset.theme);
    });
  });
});