// Summary panel built from the /route response's `summary` block:
// days, nights, flights, hotels, travel legs, activities, total km, and the
// list of locations in visit order.
import { el } from '../dom.js';

export function renderSummary(tctx) {
  const route = tctx.route || {};
  const s = route.summary || {
    days: 0, nights: 0, flights: 0, flightSegments: 0, hotels: 0, travelLegs: 0, activities: 0, locations: [],
  };
  const totalKm = route.totalKm || 0;
  // Show the leg count under the Flights tile only when a flight has segments.
  const flightSub = s.flightSegments > 0
    ? `${s.flightSegments} ${s.flightSegments === 1 ? 'leg' : 'legs'}`
    : '';

  const section = el('section', { class: 'card summary-section' });
  section.appendChild(
    el(
      'div',
      { class: 'section-head' },
      el('h2', {}, 'Summary'),
      el('p', { class: 'muted' }, 'Trip at a glance.'),
    ),
  );

  const tiles = el(
    'div',
    { class: 'stat-grid' },
    tile('🗓️', s.days, s.days === 1 ? 'Day' : 'Days'),
    tile('🌙', s.nights, s.nights === 1 ? 'Night' : 'Nights'),
    tile('✈️', s.flights, 'Flights', flightSub),
    tile('🏨', s.hotels, 'Hotels'),
    tile('🚗', s.travelLegs, 'Travel legs'),
    tile('📍', s.activities, 'Activities'),
    s.rentals > 0 ? tile('🚙', s.rentals, s.rentals === 1 ? 'Rental' : 'Rentals') : null,
    s.stays > 0 ? tile('🏙️', s.stays, s.stays === 1 ? 'Stay' : 'Stays') : null,
  );
  section.appendChild(tiles);

  const kmDriven = s.kmDriven || 0;
  const kmAir = s.kmAir || 0;
  const includedKm = s.includedKm != null ? s.includedKm : null;
  const kmBlock = el(
    'div',
    { class: 'km-block' },
    el(
      'div',
      { class: 'total-km' },
      el('span', { class: 'total-km-value' }, fmtKm(totalKm)),
      el('span', { class: 'total-km-label' }, 'km total (great-circle)'),
    ),
  );
  const breakdown = el('div', { class: 'km-breakdown' });
  if (kmDriven > 0) {
    // Rental allowance (includedKm) is paired with the rough driven figure;
    // flag red when the rough estimate already exceeds the included allowance.
    const over = includedKm != null && kmDriven > includedKm;
    const drivenText = includedKm != null
      ? `≈ ${fmtKm(kmDriven)} km / ${fmtKm(includedKm)} incl.`
      : `≈ ${fmtKm(kmDriven)} km`;
    breakdown.appendChild(kmRow('🚗', drivenText, 'driven',
      over
        ? 'Rough great-circle estimate already exceeds the included allowance — real road km will be higher'
        : 'Rough great-circle estimate — not routed driving distance',
      over ? 'km-over' : ''));
  }
  if (kmAir > 0) {
    breakdown.appendChild(kmRow('✈️', `${fmtKm(kmAir)} km`, 'flown',
      'Great-circle distance between airports'));
  }
  if (breakdown.childElementCount) kmBlock.appendChild(breakdown);
  section.appendChild(kmBlock);

  const areas = s.areas || [];
  if (areas.length) {
    const areaBlock = el('div', { class: 'loc-block' }, el('h3', {}, 'Areas'));
    const ul = el('ul', { class: 'area-list' });
    for (const a of areas) {
      ul.appendChild(el('li', {}, `🏙️ ${a.name} — ${a.days} ${a.days === 1 ? 'day' : 'days'}`));
    }
    areaBlock.appendChild(ul);
    section.appendChild(areaBlock);
  }

  const locations = s.locations || [];
  const locBlock = el('div', { class: 'loc-block' }, el('h3', {}, 'Locations in order'));
  if (!locations.length) {
    locBlock.appendChild(el('p', { class: 'muted' }, 'No located stops yet.'));
  } else {
    const ol = el('ol', { class: 'loc-order' });
    for (const name of locations) ol.appendChild(el('li', {}, name));
    locBlock.appendChild(ol);
  }
  section.appendChild(locBlock);

  return section;
}

function kmRow(icon, valueText, label, title, cls = '') {
  return el(
    'div',
    { class: `km-row${cls ? ` ${cls}` : ''}`, title },
    el('span', { class: 'km-row-icon' }, icon),
    el('span', { class: 'km-row-value' }, valueText),
    el('span', { class: 'km-row-label muted' }, label),
  );
}

function tile(icon, value, label, sub) {
  return el(
    'div',
    { class: 'stat-tile' },
    el('span', { class: 'stat-icon' }, icon),
    el('span', { class: 'stat-value' }, String(value ?? 0)),
    el('span', { class: 'stat-label' }, label),
    sub ? el('span', { class: 'stat-sub' }, sub) : null,
  );
}

function fmtKm(n) {
  return (Math.round((Number(n) || 0) * 10) / 10).toLocaleString();
}