// App bootstrap: auth check, top nav, and a tiny hash router.
// Routes: #/login, #/trips, #/trip/:id
import { api } from './api.js';
import { el, clear, mount, toast, loading } from './dom.js';
import { renderAuth } from './views/auth.js';
import { renderTrips } from './views/trips.js';
import { renderTripDetail } from './views/tripDetail.js';

const state = { user: null };

function root() {
  return document.getElementById('app');
}

function navigate(hash) {
  if (location.hash === hash) route();
  else location.hash = hash;
}

// Parse "#/trip/5" -> { name: 'trip', params: { id: '5' } }
function parseHash() {
  const raw = (location.hash || '').replace(/^#/, '');
  const parts = raw.split('/').filter(Boolean);
  if (parts.length === 0) return { name: 'trips', params: {} };
  if (parts[0] === 'login') return { name: 'login', params: {} };
  if (parts[0] === 'trips') return { name: 'trips', params: {} };
  if (parts[0] === 'trip' && parts[1]) return { name: 'trip', params: { id: parts[1] } };
  return { name: 'trips', params: {} };
}

function renderNav() {
  const nav = el(
    'header',
    { class: 'topnav' },
    el(
      'a',
      { class: 'brand', href: '#/trips' },
      el('span', { class: 'brand-mark' }, '🧭'),
      el('span', { class: 'brand-name' }, 'Trip Plan'),
    ),
    el(
      'div',
      { class: 'nav-right' },
      state.user ? renderUserArea() : null,
      state.user ? el('button', { class: 'btn btn-ghost', onClick: onLogout }, 'Log out') : null,
    ),
  );
  return nav;
}

// Current user's display name with an inline pencil-edit (PATCH /api/auth/me).
function renderUserArea() {
  const area = el('span', { class: 'nav-user' });

  function initial() {
    return (state.user.display_name || '?').charAt(0).toUpperCase();
  }

  function showDisplay() {
    mount(
      area,
      el('span', { class: 'nav-avatar' }, initial()),
      el('span', { class: 'nav-name' }, state.user.display_name || 'me'),
      el('button', { class: 'nav-edit', title: 'Edit name', type: 'button', onClick: showEdit }, '✎'),
    );
  }

  function showEdit() {
    const input = el('input', {
      class: 'input input-sm nav-name-input',
      type: 'text',
      maxlength: '40',
      value: state.user.display_name || '',
      'aria-label': 'Display name',
    });
    async function save() {
      const dn = input.value.trim();
      if (!dn) return showDisplay();
      try {
        const data = await api.auth.updateMe({ display_name: dn });
        state.user = data.user;
        showDisplay();
      } catch (err) {
        toast(err.message);
      }
    }
    input.addEventListener('keydown', (e) => {
      if (e.key === 'Enter') { e.preventDefault(); save(); }
      else if (e.key === 'Escape') showDisplay();
    });
    mount(
      area,
      input,
      el('button', { class: 'btn btn-sm btn-primary', type: 'button', onClick: save }, 'Save'),
      el('button', { class: 'btn btn-sm btn-ghost', type: 'button', onClick: showDisplay }, 'Cancel'),
    );
    input.focus();
    input.select();
  }

  showDisplay();
  return area;
}

async function onLogout() {
  try {
    await api.auth.logout();
  } catch (e) {
    // Even if the request fails, drop local state.
  }
  state.user = null;
  navigate('#/login');
}

function render() {
  const view = parseHash();

  // Defensively remove any body-level overlay (e.g. an open day editor) so it
  // can never orphan on top of a freshly rendered view.
  document.querySelectorAll('.overlay').forEach((n) => n.remove());
  document.body.classList.remove('no-scroll');

  // Auth guards.
  if (!state.user && view.name !== 'login') {
    navigate('#/login');
    return;
  }
  if (state.user && view.name === 'login') {
    navigate('#/trips');
    return;
  }

  const container = root();
  clear(container);
  if (state.user) container.appendChild(renderNav());

  const viewEl = el('main', { class: 'view', id: 'view' });
  container.appendChild(viewEl);

  const ctx = { state, navigate, refresh: render };

  if (view.name === 'login') renderAuth(viewEl, ctx);
  else if (view.name === 'trips') renderTrips(viewEl, ctx);
  else if (view.name === 'trip') renderTripDetail(viewEl, ctx, view.params.id);
}

// Exposed so views can update the current user after login/register.
function route() {
  render();
}

async function bootstrap() {
  const container = root();
  clear(container);
  container.appendChild(loading('Starting Trip Plan…'));

  try {
    const data = await api.auth.me();
    state.user = data && data.user ? data.user : null;
  } catch (e) {
    state.user = null; // 401 is expected when logged out.
  }

  window.addEventListener('hashchange', route);

  // render()'s guards redirect a signed-out visitor to #/login and a
  // signed-in one away from it, so a single render() is enough here.
  render();
}

bootstrap();