let state = {
  people: [],
  slots: [],
  personIds: [],
};

async function loadPeople() {
  state.people = await api.get('/api/calendar/people');
  state.personIds = state.people.map((p) => p.id);
}

async function loadSlots() {
  state.slots = await api.get('/api/calendar/slots?weeks=3');
  renderCalendar();
}

async function loadLastChecked() {
  const { last_checked } = await api.get('/api/calendar/last-checked');
  const el = document.getElementById('last-checked');
  el.textContent = last_checked
    ? 'Dernière mise à jour : ' + formatDatetime(last_checked)
    : 'Aucune donnée pour le moment — cliquez sur Actualiser';
}

function isoDate(d) {
  return d.getFullYear() + '-' + String(d.getMonth() + 1).padStart(2, '0') + '-' + String(d.getDate()).padStart(2, '0');
}

function shortMonth(d) {
  return d.toLocaleDateString('fr-FR', { month: 'short' });
}

function formatTime(iso) {
  return new Date(iso).toLocaleTimeString('fr-FR', { hour: '2-digit', minute: '2-digit', timeZone: 'Europe/Paris' });
}

function formatDatetime(iso) {
  return new Date(iso).toLocaleString('fr-FR', {
    day: '2-digit', month: '2-digit', year: 'numeric', hour: '2-digit', minute: '2-digit',
  });
}

function renderCalendar() {
  const grid = document.getElementById('calendar-grid');
  grid.innerHTML = '';

  const today = new Date();
  today.setHours(0, 0, 0, 0);

  const selectedSet = new Set(state.personIds);

  const slotMap = new Map();
  for (const slot of state.slots) slotMap.set(slot.slot_date, slot);

  // Grid starts on the Monday of the current week so columns align Mon->Sun.
  const start = new Date(today);
  const dow = start.getDay();
  start.setDate(start.getDate() + (dow === 0 ? -6 : 1 - dow));

  const daysBeforeToday = Math.round((today - start) / 86400000);
  const totalDays = Math.ceil((daysBeforeToday + 21) / 7) * 7;

  for (let i = 0; i < totalDays; i++) {
    const date = new Date(start);
    date.setDate(start.getDate() + i);

    const isPastDay = date < today;
    const isBeyond21 = i >= daysBeforeToday + 21;
    const isToday = date.getTime() === today.getTime();
    const slot = slotMap.get(isoDate(date));

    const cell = document.createElement('div');
    cell.className = 'cal-cell' + (isToday ? ' today' : '');

    if (isBeyond21) {
      cell.classList.add('empty');
      grid.appendChild(cell);
      continue;
    }

    const dateLabel = document.createElement('div');
    dateLabel.className = 'cell-date';
    dateLabel.innerHTML = `<span class="day-num">${date.getDate()}</span>${shortMonth(date)}`;
    cell.appendChild(dateLabel);

    if (isPastDay) {
      cell.classList.add('empty');
      const lbl = document.createElement('div');
      lbl.className = 'no-slot-label';
      lbl.textContent = 'passé';
      cell.appendChild(lbl);
    } else if (slot) {
      const visible = slot.people.filter((p) => selectedSet.has(p.id));
      const avail = visible.filter((p) => p.is_available);

      cell.classList.add('has-slot');
      if (visible.length > 0) {
        if (avail.length === visible.length) {
          cell.classList.add('all-available');
        } else {
          const unavailRatio = (visible.length - avail.length) / visible.length;
          if (unavailRatio <= 0.2) cell.classList.add('heat-1');
          else if (unavailRatio <= 0.4) cell.classList.add('heat-2');
          else if (unavailRatio <= 0.6) cell.classList.add('heat-3');
          else if (unavailRatio <= 0.8) cell.classList.add('heat-4');
          else cell.classList.add('heat-5');
        }
      }

      const timeEl = document.createElement('div');
      timeEl.className = 'cell-time';
      timeEl.textContent = formatTime(slot.lower) + '–' + formatTime(slot.upper);
      cell.appendChild(timeEl);

      const dotsEl = document.createElement('div');
      dotsEl.className = 'cell-dots';
      for (const person of visible) {
        const dot = document.createElement('div');
        dot.className = 'cell-dot' + (person.is_available ? '' : ' busy');
        dot.style.backgroundColor = person.color;
        dot.title = person.name + (person.is_available ? ' ✓' : ' ✗');
        dotsEl.appendChild(dot);
      }
      cell.appendChild(dotsEl);

      cell.addEventListener('click', () => openModal(date, slot, visible));

      const countEl = document.createElement('div');
      countEl.className = 'cell-count';
      countEl.textContent = avail.length + '/' + visible.length;
      cell.appendChild(countEl);
    } else {
      cell.classList.add('empty');
      const lbl = document.createElement('div');
      lbl.className = 'no-slot-label';
      lbl.textContent = 'aucune donnée';
      cell.appendChild(lbl);
    }

    grid.appendChild(cell);
  }
}

function buildFilters() {
  const listEl = document.getElementById('people-list');
  for (const person of state.people) {
    const row = document.createElement('label');
    row.className = 'person-toggle';
    row.dataset.id = person.id;

    const dot = document.createElement('span');
    dot.className = 'person-dot';
    dot.style.backgroundColor = person.color;

    row.appendChild(dot);
    row.appendChild(document.createTextNode(person.name));

    row.addEventListener('click', () => {
      const id = person.id;
      if (state.personIds.includes(id)) {
        if (state.personIds.length === 1) return;
        state.personIds = state.personIds.filter((x) => x !== id);
        row.classList.add('excluded');
      } else {
        state.personIds.push(id);
        row.classList.remove('excluded');
      }
      renderCalendar();
    });

    listEl.appendChild(row);
  }

  buildLegend();

  document.getElementById('btn-refresh').addEventListener('click', async () => {
    const btn = document.getElementById('btn-refresh');
    btn.disabled = true;
    btn.textContent = 'Actualisation…';
    showToast('Déclenchement du workflow n8n…');
    try {
      await api.post('/api/calendar/refresh', {});
      showToast('Workflow en cours — en attente des résultats…');
      pollWorkflowStatus(btn);
    } catch (err) {
      const message = err.message === 'n8n_not_configured'
        ? "L'actualisation automatique n'est pas configurée (n8n)."
        : err.message;
      showToast(message, true);
      resetRefreshButton(btn);
    }
  });
}

function resetRefreshButton(btn) {
  btn.disabled = false;
  btn.textContent = 'Actualiser les disponibilités';
}

function pollWorkflowStatus(btn, maxMs = 180000, intervalMs = 4000) {
  const started = Date.now();
  const timer = setInterval(async () => {
    if (Date.now() - started > maxMs) {
      clearInterval(timer);
      showToast('La synchronisation a expiré — aucun résultat après 3 minutes', true);
      resetRefreshButton(btn);
      return;
    }
    try {
      const data = await api.get('/api/calendar/workflow-status');
      if (data.status === 'success') {
        clearInterval(timer);
        showToast('Calendrier mis à jour !' + (data.message ? ' ' + data.message : ''), false, 10000);
        resetRefreshButton(btn);
        await loadSlots();
        await loadLastChecked();
      } else if (data.status === 'error') {
        clearInterval(timer);
        showToast('Erreur lors de la synchronisation : ' + (data.message || 'inconnue'), true);
        resetRefreshButton(btn);
      }
    } catch (err) {
      /* transient, keep polling */
    }
  }, intervalMs);
}

function openModal(date, slot, visible) {
  const avail = visible.filter((p) => p.is_available);
  const busy = visible.filter((p) => !p.is_available);

  document.getElementById('modal-date').textContent = date.toLocaleDateString('fr-FR', {
    weekday: 'long', day: 'numeric', month: 'long', year: 'numeric', timeZone: 'Europe/Paris',
  });
  document.getElementById('modal-time').textContent = formatTime(slot.lower) + ' – ' + formatTime(slot.upper);

  const renderPeople = (list, containerId) => {
    const el = document.getElementById(containerId);
    el.innerHTML = '';
    if (!list.length) {
      const em = document.createElement('div');
      em.className = 'modal-empty empty';
      em.textContent = 'Aucune';
      el.appendChild(em);
      return;
    }
    for (const person of list) {
      const row = document.createElement('div');
      row.className = 'modal-person';
      const dot = document.createElement('span');
      dot.className = 'person-dot';
      dot.style.backgroundColor = person.color;
      row.appendChild(dot);
      row.appendChild(document.createTextNode(person.name));
      el.appendChild(row);
    }
  };

  renderPeople(avail, 'modal-available');
  renderPeople(busy, 'modal-busy');

  document.getElementById('modal-overlay').classList.remove('hidden');
}

function closeModal() {
  document.getElementById('modal-overlay').classList.add('hidden');
}

function openFilters() {
  document.getElementById('filters-panel').classList.add('open');
  document.getElementById('filters-backdrop').classList.add('open');
}

function closeFilters() {
  document.getElementById('filters-panel').classList.remove('open');
  document.getElementById('filters-backdrop').classList.remove('open');
}

function buildLegend() {
  const el = document.getElementById('legend');
  for (const person of state.people) {
    const item = document.createElement('div');
    item.className = 'legend-item';
    const dot = document.createElement('span');
    dot.className = 'legend-dot';
    dot.style.backgroundColor = person.color;
    item.appendChild(dot);
    item.appendChild(document.createTextNode(person.name));
    el.appendChild(item);
  }
  const allItem = document.createElement('div');
  allItem.className = 'legend-item';
  allItem.innerHTML = '<span class="legend-dot legend-dot-all"></span> Tout le monde libre';
  el.appendChild(allItem);
}

function showToast(msg, isError = false, duration = 5000) {
  const el = document.getElementById('toast');
  el.textContent = msg;
  el.classList.remove('hidden', 'error');
  if (isError) el.classList.add('error');
  clearTimeout(el._timer);
  el._timer = setTimeout(() => el.classList.add('hidden'), duration);
}

function showError(message) {
  document.getElementById('error').innerHTML = `<div class="error-banner">${escapeHtml(message)}</div>`;
}

(async function init() {
  await initNav('calendar');

  document.getElementById('modal-close').addEventListener('click', closeModal);
  document.getElementById('modal-overlay').addEventListener('click', (e) => {
    if (e.target === e.currentTarget) closeModal();
  });
  document.addEventListener('keydown', (e) => {
    if (e.key === 'Escape') {
      closeModal();
      closeFilters();
    }
  });

  document.getElementById('btn-filters-toggle').addEventListener('click', openFilters);
  document.getElementById('btn-filters-close').addEventListener('click', closeFilters);
  document.getElementById('filters-backdrop').addEventListener('click', closeFilters);

  try {
    await loadPeople();
    buildFilters();
    await loadSlots();
    await loadLastChecked();
  } catch (err) {
    showError(err.message);
  }
})();