/* ── App bootstrap & routing ── */

const PAGES = {
  tracker:    { container: 'page-tracker',    init: (el) => TrackerPage.init(el) },
  bills:      { container: 'page-bills',      init: (el) => BillsPage.init(el) },
  categories: { container: 'page-categories', init: (el) => CategoriesPage.init(el) },
  settings:   { container: 'page-settings',   init: (el) => SettingsPage.init(el) },
  status:     { container: 'page-status',     init: (el) => StatusPage.init(el) },
};

let activePage  = null;
let currentUser = null;

// ── Auth gate ──────────────────────────────────────────────────────────────

async function boot() {
  let res;
  try { res = await fetch('/api/auth/me'); }
  catch { location.href = '/login.html'; return; }

  if (!res.ok) { location.href = '/login.html'; return; }

  const data = await res.json();
  currentUser = data.user;

  if (currentUser.role === 'admin') { location.href = '/admin.html'; return; }

  document.getElementById('sidebar-username').textContent = currentUser.username;

  if (data.single_user_mode) {
    document.getElementById('sidebar-logout').style.display = 'none';
    startApp();
    return;
  }

  if (currentUser.must_change_password) { showChangePasswordOverlay(); return; }
  if (currentUser.first_login)          { showPrivacyNotice();         return; }

  startApp();
}

// ── Password change overlay ────────────────────────────────────────────────

function showChangePasswordOverlay() {
  document.getElementById('change-password-overlay').classList.remove('hidden');

  document.getElementById('change-password-form').onsubmit = async (e) => {
    e.preventDefault();
    const np  = document.getElementById('cp-new').value;
    const cnf = document.getElementById('cp-confirm').value;
    const err = document.getElementById('cp-error');

    if (np !== cnf)    { err.textContent = 'Passwords do not match.'; return; }
    if (np.length < 8) { err.textContent = 'Password must be at least 8 characters.'; return; }
    err.textContent = '';

    try {
      const res = await fetch('/api/auth/change-password', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ new_password: np }),
      });
      const body = await res.json();
      if (!res.ok) throw new Error(body.error);
      document.getElementById('change-password-overlay').classList.add('hidden');
      currentUser.must_change_password = false;
      currentUser.first_login ? showPrivacyNotice() : startApp();
    } catch (ex) {
      document.getElementById('cp-error').textContent = 'Error: ' + ex.message;
    }
  };
}

// ── Privacy notice overlay ─────────────────────────────────────────────────

function showPrivacyNotice() {
  document.getElementById('privacy-overlay').classList.remove('hidden');
  document.getElementById('privacy-ack-btn').onclick = async () => {
    await fetch('/api/auth/acknowledge-privacy', { method: 'POST' });
    document.getElementById('privacy-overlay').classList.add('hidden');
    currentUser.first_login = false;
    startApp();
  };
}

// ── Main app ───────────────────────────────────────────────────────────────

function startApp() {
  document.getElementById('app').style.visibility = 'visible';
  setupLogout();
  setupNavLinks();
  handleHash();
}

function setupLogout() {
  document.getElementById('sidebar-logout').addEventListener('click', async (e) => {
    e.preventDefault();
    await fetch('/api/auth/logout', { method: 'POST' });
    location.href = '/login.html';
  });
}

function setupNavLinks() {
  document.querySelectorAll('.nav-link[data-page]').forEach(link => {
    link.addEventListener('click', () => { activePage = null; navigate(link.dataset.page); });
  });
  window.addEventListener('hashchange', () => { activePage = null; handleHash(); });
}

function handleHash() {
  navigate(location.hash.replace('#', '') || 'tracker');
}

function navigate(page) {
  if (!PAGES[page]) page = 'tracker';

  document.querySelectorAll('.nav-link[data-page]').forEach(a => {
    a.classList.toggle('active', a.dataset.page === page);
  });
  document.querySelectorAll('.page').forEach(el => el.classList.remove('active'));
  document.getElementById(PAGES[page].container).classList.add('active');

  if (activePage !== page) {
    activePage = page;
    PAGES[page].init(document.getElementById(PAGES[page].container));
  }
}

// ── Toast system ───────────────────────────────────────────────────────────

const TOAST_ICONS = {
  success: '✓',
  error:   '✕',
  warning: '⚠',
  info:    'ℹ',
};

let toastContainer = null;

function getToastContainer() {
  if (!toastContainer) {
    toastContainer = document.createElement('div');
    toastContainer.id = 'toast-container';
    document.body.appendChild(toastContainer);
  }
  return toastContainer;
}

function showToast(msg, type = 'info', duration = 3500) {
  const container = getToastContainer();
  const toast     = document.createElement('div');
  const icon      = TOAST_ICONS[type] || TOAST_ICONS.info;

  toast.className = `toast toast-${type}`;
  toast.innerHTML = `
    <span class="toast-icon">${icon}</span>
    <span class="toast-msg">${msg}</span>
    <button class="toast-close" aria-label="Dismiss">&times;</button>
    <div class="toast-bar"></div>
  `;

  container.appendChild(toast);
  // Trigger animation
  requestAnimationFrame(() => toast.classList.add('toast-show'));

  const dismiss = () => {
    toast.classList.remove('toast-show');
    toast.classList.add('toast-hide');
    toast.addEventListener('transitionend', () => toast.remove(), { once: true });
  };

  const timer = setTimeout(dismiss, duration);
  toast.querySelector('.toast-close').onclick = () => { clearTimeout(timer); dismiss(); };
}

// Hide app shell until auth check completes (prevents flash)
document.getElementById('app').style.visibility = 'hidden';

boot();