/* The OC Guy — page behaviour.
   Everything degrades: without JS the page is a plain, readable
   document with working links and a mail form. */
(function () {
  'use strict';

  var doc = document.documentElement;
  doc.classList.add('js');

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  /* ---------- entrance for the blocks of each section ---------- */
  var targets = document.querySelectorAll(
    '.lead-caption, .box, .side-list, .section-head, .card, .feature, .news li, .ask-inner'
  );

  if (!reduce && 'IntersectionObserver' in window) {
    var io = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        if (!entry.isIntersecting) return;
        entry.target.classList.add('rv-in');
        io.unobserve(entry.target);
      });
    }, { rootMargin: '0px 0px -8% 0px', threshold: 0.08 });

    Array.prototype.forEach.call(targets, function (el) {
      el.setAttribute('data-rv', '1');
      io.observe(el);
    });
  } else {
    Array.prototype.forEach.call(targets, function (el) { el.classList.add('rv-in'); });
  }

  /* ---------- the ask form: one question, by mail ---------- */
  var form = document.querySelector('.ask-form');
  var mail = document.getElementById('ask-mail');

  if (form && mail) {
    form.addEventListener('submit', function (event) {
      event.preventDefault();
      var addr = (mail.value || '').trim();
      if (!addr || addr.indexOf('@') === -1) {
        mail.setAttribute('aria-invalid', 'true');
        mail.focus();
        return;
      }
      mail.removeAttribute('aria-invalid');
      var body = 'My question about Odoo Community:\n\n\n— reply to: ' + addr + '\n';
      window.location.href = 'mailto:o.arnold@projektbox.de'
        + '?subject=' + encodeURIComponent('Odoo Community question')
        + '&body=' + encodeURIComponent(body);
    });
  }

  /* ---------- which section the reader is in ---------- */
  var links = Array.prototype.slice.call(document.querySelectorAll('.nav a[href^="#"]'));
  var sections = links
    .map(function (a) { return document.querySelector(a.getAttribute('href')); })
    .filter(Boolean);

  if (sections.length && 'IntersectionObserver' in window) {
    var seen = new IntersectionObserver(function (entries) {
      entries.forEach(function (entry) {
        if (!entry.isIntersecting) return;
        links.forEach(function (a) {
          if (a.getAttribute('href') === '#' + entry.target.id) {
            a.setAttribute('aria-current', 'true');
          } else {
            a.removeAttribute('aria-current');
          }
        });
      });
    }, { rootMargin: '-45% 0px -50% 0px' });
    sections.forEach(function (s) { seen.observe(s); });
  }
})();