/**
 * Calendario slot prenotazione (dashboard admin).
 */
import { Calendar } from '@fullcalendar/core';
import itLocale from '@fullcalendar/core/locales/it';
import dayGridPlugin from '@fullcalendar/daygrid';
import interactionPlugin from '@fullcalendar/interaction';
import listPlugin from '@fullcalendar/list';
import timeGridPlugin from '@fullcalendar/timegrid';

function initSlotCalendar() {
  const calendarEl = document.getElementById('calendarioSlotPrenotazioni');
  if (!calendarEl) {
    return;
  }

  const dataEl = document.getElementById('calendarioSlotPrenotazioniData');
  let events = [];
  try {
    events = JSON.parse(dataEl ? dataEl.textContent : '[]');
  } catch (e) {
    events = [];
  }
  if (!Array.isArray(events)) {
    events = [];
  }

  const now = Date.now();
  const starts = events
    .map(function (event) {
      return event && event.start ? Date.parse(event.start) : NaN;
    })
    .filter(function (ts) {
      return !Number.isNaN(ts);
    })
    .sort(function (a, b) {
      return a - b;
    });
  const nextStart = starts.find(function (ts) {
    return ts >= now;
  });
  const initialDate = nextStart || starts[0];

  const calendar = new Calendar(calendarEl, {
    plugins: [dayGridPlugin, timeGridPlugin, listPlugin, interactionPlugin],
    locale: itLocale,
    firstDay: 1,
    initialView: window.innerWidth < 768 ? 'listWeek' : 'timeGridWeek',
    initialDate: initialDate ? new Date(initialDate) : undefined,
    headerToolbar: {
      left: 'prev,next today',
      center: 'title',
      right: 'dayGridMonth,timeGridWeek,listWeek'
    },
    height: 'auto',
    navLinks: true,
    nowIndicator: true,
    slotMinTime: '06:00:00',
    slotMaxTime: '22:00:00',
    events: events,
    eventClick: function (info) {
      if (info.event.url) {
        info.jsEvent.preventDefault();
        window.location.href = info.event.url;
      }
    }
  });

  calendar.render();
}

if (document.readyState === 'loading') {
  document.addEventListener('DOMContentLoaded', initSlotCalendar);
} else {
  initSlotCalendar();
}